Apparatus and method for determining material properties of a material

Abstract

A device is provided for determining material properties of a material, preferably a wood or a wooden material, having a pin arrangement having at least two pins, a drive unit for at least partially driving the pins into the material using a defined force, and a measuring unit for measuring both the penetration depth of at least one of the at least two pins and also an electrical resistance between two of the pins.

Claims

1. A device configured to determine material properties of a material, the device comprising: a housing; a pin arrangement having at least two pins supported by the housing; a drive device supported by the housing and configured to at least partially drive the at least two pins into the material using a defined force, a position measurement device supported by the housing, the position measuring device configured to measure a penetration depth of the at least two pins; and an electrical measurement device, the electrical measurement device configured to measure an electrical resistance between each of the at least two pins.

2. The device as claimed in claim 1, wherein the device further comprises a temperature measurement device configured to measure a temperature of at least one of the at least two pins.

3. The device as claimed in claim 1, wherein the at least two pins includes two pins that are each electrically insulated in a region of a shaft facing away from or toward a tip, or that are each divided along the shaft into electrically isolated segments.

4. The device as claimed in claim 3, wherein the pin arrangement further includes two pins that are not electrically insulated along a shaft and not divided into segments.

5. The device as claimed in claim 1, wherein the at least two pins further comprise four pins that are arranged such that the electrical resistance is measurable simultaneously or in succession in two different directions along the material.

6. The device as claimed in claim 5, wherein the four pins are arranged in a square or rectangle in relation to one another.

7. The device as claimed in claim 1, wherein the drive device has a spring mechanism that is chargeable via turnstile impellers.

8. The device as claimed in claim 1, further comprising: a support block configured to removably surround the pins to thereby safely secure the pins when the device for determining material properties of a material is not in use; and a locking mechanism configured to prevent an undesired activation of the drive device by securing the support block within the housing.

9. The device as claimed in claim 1, wherein the device further comprises a generator that includes a piezo element configured to generate energy from a movement or acceleration of the at least two pins, the generated energy being provided to the device for operation of the device.

10. The device as claimed in claim 1, wherein the electrical measurement device is supported by the housing.

11. The device as claimed in claim 10, wherein the housing includes regions formed from a transparent material that includes plastic or glass.

12. The device as claimed in claim 1, wherein the device is associated with a camera for detecting or storing a position of at least one of the at least two pins or the pin arrangement, or for detecting or storing measurement results, and wherein the camera is installed in or integrated into a housing.

Description

(1) There are now various options for designing and refining the teaching of the present disclosure in an advantageous manner. For this purpose, reference is made, on the one hand, to the following claims and, on the other hand, to the following explanation of a preferred exemplary embodiment of the device according to the disclosure and the method according to the disclosure on the basis of the drawing. Generally preferred designs and refinements of the teaching are also explained in conjunction with the explanation of the preferred exemplary embodiments. In the figures of the drawing

(2) FIG. 1 shows a schematic side view in section of an exemplary embodiment of the device according to the disclosure,

(3) FIG. 2 shows the exemplary embodiment according to FIG. 1 in different operating states in schematic side views, and

(4) FIG. 3 shows a schematic bottom view of a further exemplary embodiment having four pins.

(5) An exemplary embodiment of the device according to the disclosure is shown in schematic side views in each of FIGS. 1 and 2, wherein FIG. 1 shows the device in the idle state and FIG. 2 shows the device in the idle state and in different operating states.

(6) In many areas of application it is not only desired and preferred by the user, but rather also advantageous, due to the sometimes difficult boundary conditions in remote regions of application, for example, in the frost, on wooden bridges, etc., if the device is essentially mechanically driven and also functions without a separate power supply.

(7) For this purpose, a lever, turnstile, and spring structure located completely in the interior of the device can be used, which is designed so that measuring pins 7 only come out of the device when they are placed on a material and the drive spring or springs 9 is tensioned via pressure on a housing 2 or the device. The risk of injury is thus minimized.

(8) In the idle and starting states, the support block 1 is located completely in the surrounding, preferably cup-shaped housing 2. To start a measuring procedure, firstly the support block 1 is drawn downward out of the housing 2. Engagement holes 3 in the support block 1 help in this case, for example. Lateral guide grooves 4 prevent the support block 1 from falling out downward out of the cup housing or housing 2. The idle position of the support block 1 could optionally also be ensured using a locking pin (not shown here), which preferably not only secures or clamps the support block 1 in the housing 2, but rather also the pins 7.

(9) When the support block 1 is drawn downward out of the housing 2, the rockers 5 fastened in the interior on the housing 2 fold in to pass upward by vane arms 6 of a turnstile. Above this, they fold out again. The support block 1 can then be placed in the correct position on the material to be examined. LED lasers (not shown) seated adjacent to the measuring pins 7 can mark the location of measuring points on the surface to be checked, wherein positioning with millimeter accuracy is usually not important—particularly because the dimensions of the entire device are relatively small in any case in consideration of the typical spacings of the measuring pins 7 from one another of a few, preferably approximately 2 to 3 cm. Therefore, the position of the measuring points can already be detected on the basis of the position of the support block 1 on the material and selected accordingly.

(10) After the positioning of the support block 1 on the point to be measured of the material to be examined, the housing cup or the housing 2 is thus pressed downward. Two turnstile brackets 8 each preferably having four vane arms 6 beveled at the tip on one side are preferably seated on the respective turnstile on the support block 1.

(11) In the idle position of the spring 9 tensioned between support block 1 and pin block 10, it holds the pin block 10 at a moderate height. When the outer housing cup or the housing 2 is pressed downward, the rockers 5, which are only tiltable downward, press on the vane arms 6 of the respective turnstile pointing upward toward the outer housing 2, whereby the opposing, lower inner arm raises the pin block 10 upward and thus tensions the spring 9 by an elongation of the spring 9.

(12) As soon the inner lifting turnstile arm or vane arm 6 releases the pin block 10, it is drawn downward by the spring 9 from defined height, so that the measuring pins 7 are pressed with defined force into the material located below the support block 1. The achieved penetration depth of the pins 7 can be read directly on the basis, for example, of the position of the pin block 10 through the preferably transparent housing 2 having, for example, printed scale. Therefore, a separate display does not have to be placed on the outside, as is the case in the devices heretofore found on the market and which makes them more complex and costly.

(13) The length of the measuring pins 7 is preferably selected so that they are not raised upward out of guide holes 11 of the support block 1 even with maximum raising of the pin block 10. Pin length and spring 9 are in turn preferably embodied so that the pins 7 do not protrude downward out of the device in the idle state, i.e., in the idle position of the spring 9, so that there is no risk of injury.

(14) Measurement and Documentation:

(15) When the pins 7 are stuck in the material, the measurements are performed. The penetration depth is readable directly. The measurement of the conductivity between the pins 7 and the temperature of the measuring pins 7 generally only requires fractions of a second. The energy required for this purpose can be taken from a battery or an accumulator.

(16) In the moisture content measuring devices conventional up to this point, the 9 V block batteries typical therein are usually sufficient for several years to execute thousands of measurements and display the respective value. The power consumption for the measurement is thus minimal. The current for these short measurements can therefore also alternatively be generated by a piezo ceramic on the pin block, for example, because the accelerations generated during the hammering in are sufficient for this purpose.

(17) A display for the measured values, for example, conductivity and/or temperature, can be attached on the top of the pin block 10 and read through the housing 2, which is transparent in this exemplary embodiment.

(18) The documentation of the measurement results has heretofore typically been performed in the previously typical single methods in that the values are noted. The position of the measurement is usually additionally documented using a photo.

(19) In the exemplary embodiment described here, in particular the transparent embodiment of the housing 2 enables for the first time the local measuring position and also the measuring results to be documented as a whole and at the same time on one photo, because the measurement results, in particular penetration depth, temperature, and conductivity, are visible at the same time from the outside.

(20) Optionally, an ultrasmall camera, which has become available in miniaturized form in the meantime, and which is attached in the cup housing or housing 2, could even detect and document measurement results and position.

(21) To detach the pins 7 from the material again after the measurement, the housing 2 is firstly drawn upward until the lateral rockers 5 are located above the upper outer turnstile arms or vane arms 6. The cup housing or housing 2 can then again be pressed downward to move the turnstile and thus draw the pin block 10 upward by the two turnstile arms or wing arms 6 pointing inward engaging in a correspondingly formed opening or recess 12 in the pin block 10 and raising it until the pins 7 are detached from the material to be studied. The pin block 10 is then moved by the spring 9 back into the middle starting and idle position and held there.

(22) Sequence of the Work Steps according to FIG. 2:

(23) The device has the smallest dimensions in the idle position A. After the housing 2 is raised according to B, so that the lateral rockers 5 are located above the turnstile vane arms 6, the housing 2 can subsequently be pressed downward according to C in order to raise the pin block 10. The spring 9 is stretched apart at the same time. As soon as the lever arms or vane arms 6 release the pin block 10, it is drawn downward by the spring 9 according to D and penetrates into the material to be studied in consideration of defined force as deeply as the density of the material permits. It was already shown in the nineteen sixties by HILTI AG that the penetration depth of such pins 7—often simple steel nails are used—correlates with the density of the material at defined hammering force, and this was later one of the starting points of diverse diagnostic techniques for woods, inter alia, the needle drilling resistance measurement. To be able to draw the pins 7 stuck in the material to be studied back out of the material, the housing 2 is raised again according to E, wherein the lateral rockers 5 fold in to pass by the turnstile vane arms 6. The pin block 10 can then be raised again according to F by again pressing down the upper cup housing or housing 2, because the turnstile vane arms 6 engage laterally in the pin block 10 and can move it upward.

(24) FIG. 3 shows a further exemplary embodiment of the device according to the disclosure, wherein FIG. 3 is a bottom view which shows that the device of this exemplary embodiment has four pins 7 in a square arrangement.

(25) Advantages of this Procedure and this Device Over the Heretofore Typical Single Methods:

(26) Combination of penetration depth, conductivity, and temperature measurement higher accuracy of the measurement results many times faster measurement of the material properties two, three, four, or more pins 7 for simultaneous measurements higher accuracy and significance of the measurement results mixture of pins 7 insulated on the shaft and fully-conductive pins higher accuracy of the measurement results The determination of the penetration depth of the non-insulated pins 7 enables the calibration of the measured conductivity value to the active length (=penetration depth). closed housing 2 and measurement procedure without risk of injury measurement can occur, and therefore the pins 7 can protrude from the housing 2, only when the device is placed, the cup housing or housing 2 is unlocked and actively pressed down transparent housing 2 saves feeding measured items of information outward and corresponding separate displays enables the simultaneous documentation of measuring position and all measurement results using one photo enables the visual check of the measuring procedure and the recognition of possible technical problems

(27) In one exemplary embodiment of the device according to the disclosure, it can be a penetration pin combination measuring device and a method for mutually corrected and temperature-compensated determination of various material properties, such as density and moisture content in particular, preferably on wood and wooden materials, wherein two or more pins 7 are pressed using defined force into the material to be studied and penetration depth, conductivity, and temperature can be measured at the same time, so that they can be mutually corrected and/or compensated.

(28) By combination of, for example, two pins electrically insulated on the shaft of the pin 7 and two pins 7 not insulated on the shaft, both mean moisture values and also those in deeper layers can be detected at the same time.

(29) By combination of, for example, four identical pins 7 in a square arrangement, conductivities can be detected at the same time parallel and perpendicular to the wood fibers or other directions, which are preferably orthogonal to one another.

(30) The pins 7 can be pressed into the material by an internal spring mechanism charged via turnstile impellers.

(31) For example, for safety reasons, the spring raising mechanism can only function when a locking pin is removed, the device is placed on a material after pulling out the support block 1, the housing 2 is firstly drawn upward and then pressed downward to tension the spring 9 until the pins 7 are released after release by the turnstile impellers and can be drawn downward by the spring 9 to penetrate into the material located in front of the support block 1.

(32) The housing 2 can be embodied from transparent material to read and photographically document all relevant measurement results at the same time and also be able to check the functionality of the device.

(33) The current for the measurement can be generated by a piezo element from the acceleration during the raising and lowering of the pins 7.

(34) An installed camera can document and also store the position and measurement results.

(35) Reference is made to the general part of the description and to the appended claims with respect to further advantageous embodiments of the device according to the disclosure and the method according to the disclosure to avoid repetitions.

(36) Finally, it is to be expressly noted that the above-described exemplary embodiments are only used to explain the claimed teaching, but do not restrict it to the exemplary embodiment.

LIST OF REFERENCE NUMERALS

(37) 1 support block 2 housing 3 engagement hole 4 guide groove 5 rocker 6 vane arm 7 measuring pin, pin 8 turnstile bracket 9 spring 10 pin block 11 guide hole 12 recess