CN201387426Y - Fixing device for displacement probe of early-age concrete shrinkage performance tester - Google Patents

Abstract

The displacement probe fixing device of the early-age concrete shrinkage performance tester provided by the utility model has a gate-shaped bracket that spans the top of the test mold [18], and a probe mounting seat [13] is arranged on the gate-shaped bracket. 9] is a channel-shaped member with a gate-shaped cross-section, including a platform and downwardly extending side walls, the width between the inner sides of the two side walls of the gate-shaped bracket is greater than the width between the outer sides of the two side walls of the test mold, and the gate-shaped bracket The height of the two sidewalls is less than the height of the test mold, and screw holes are respectively arranged on the two sidewalls of the door-shaped support, and the inward bracket fixing screws [8] with heads on the screw holes are arranged, and the said probe mounting seat is on the support platform. Compared with the prior art, the utility model enables the displacement probe to be fixed on the test mold conveniently and accurately, without moving the heavy test mold to the test bench and determining the distance between the probe and the target through complicated movements and adjustments. relative position. Moreover, the relative position between the probe and the target is fixed by the screws on both sides of the bracket.

Description

Fixing device for displacement probe of early-age concrete shrinkage performance tester

technical field

The utility model relates to a displacement probe fixing device for an early-age concrete shrinkage performance tester. The early-age concrete shrinkage tester is a test device for measuring the early-age shrinkage performance of concrete under unconstrained conditions, which belongs to the field of physics. The technical field of distance measurement with non-contact sensors. The displacement is the deformation displacement of the measured point relative to the concrete member rather than the displacement of the measured object relative to the ground.

Background technique

Concrete will shrink and deform with the process of solidification and aging after casting. The shrinkage performance of concrete, especially the shrinkage performance at the early age within 3 days, is an important technical index for evaluating the crack resistance of concrete. The detection of this performance has practical significance for concrete engineering to prevent cracks in concrete components. Since the early-age concrete has not completely solidified within 3 days and its shrinkage deformation is very small, if the shrinkage displacement is directly measured by mechanical contact, the force generated by the mechanical contact may cause displacement of the measured object and affect the measurement results. . In order to accurately measure the early-age shrinkage performance of concrete, "Study on the Eddy Current Method of Concrete Early-age Shrinkage Test" ("Journal of Building Materials", Volume 9, No. 6, 2006) proposed a method to measure the early-age shrinkage of concrete under unconstrained conditions. The performance method, that is, the eddy current non-contact method for testing the early age shrinkage performance of concrete. On this basis, an electric eddy current tester for early-age shrinkage performance of concrete is produced. The displacement sensor of the tester is composed of a probe, its driving device and a target.

When using the eddy current method tester for early-age shrinkage performance of concrete, apply lubricating oil in the concrete test mold of 10cm×10cm×51.5cm, and then lay two layers of plastic films in the test mold, and apply it evenly on each layer of film A layer of lubricating oil is used to ensure the free deformation of the concrete in the test mold. Two metal targets are embedded in the two ends of the concrete specimen and vibrated on the vibration machine. After the test piece is formed, it is moved to the test bench together with the test mold, and the displacement probe of the early-age concrete shrinkage performance tester is installed in place with a fixing device. The so-called probe fixing device has two door-shaped brackets that span the top of the test mold and are placed on the test bench. On the beam of the door-shaped bracket, a suspension column extends downwards to serve as the probe mounting seat. A probe of an eddy current non-contact displacement sensor is fixed on each of the two probe mounting bases. The probe must be adjusted and aligned with the target at the same end to expose the reflection target area of the concrete specimen to form a micro-displacement sensor that meets the requirements. The device structure of the early-age concrete shrinkage performance eddy current method tester is as shown in Figure 1: the test piece 5 is formed in the test mold 6 and placed on the test platform 7, and there is a target 4 at both ends of the test mold. There is a gate-shaped support 1 straddling the top of the test mold, and a cantilever-type probe mounting seat 2 extending downward is arranged on the gate-shaped support beam, and a probe 3 is installed on the mounting seat to align with the target.

The structure of the above-mentioned probe fixing device has the disadvantages that it is inconvenient to place the test mold in application and may lead to inaccurate positions between the probe and the target:

Since the door-shaped bracket is placed on the bottom plane supported by the columns on both sides, if the bottom plane it is placed on is not flat enough, its installation status will be affected. After forming, the trial mold should be placed under the gate-shaped bracket of the displacement probe of the probe fixing device, and the displacement probe should be aimed at the measurement surface of the measured reflection target (target). Due to the limitation of the structure of the door-shaped bracket, there are roughly two placement situations as follows:

One is that the probe bracket has been fixed on the test platform, and the test mold needs to be moved longitudinally to an appropriate position to avoid the collision between the suspension column and the target, and then moved laterally to align the displacement probe with the reflective target to be tested. In this method, due to the heavy weight of the formed concrete specimen, it is extremely inconvenient to move and place the operation. It is difficult for the displacement probe to align with the measured reflection target, and it is easy to cause the reflection target to be touched by the measured reflection target, which will cause the displacement of the reflection target and affect the measurement. .

The second is to put the test mold first, then place the probe bracket at a suitable position above the test mold, and then fix the probe bracket on the test bench. This method is relatively easier to operate than the previous method, but since the probe bracket must be fixed on the test platform after the position is placed, the installation structure is not simple and the operation time is long.

It can be seen that the probe fixing device in the prior art makes it difficult to determine the relative position between the probe and the target, thereby affecting the accuracy of the measurement results.

Contents of the invention

In view of the above-mentioned defects, the utility model is to provide a displacement probe fixing device for the early-age concrete shrinkage performance measuring instrument which solves the inconvenience of placing the test mold.

The displacement probe fixing device of the early-age concrete shrinkage performance tester provided by the utility model has a gate-shaped bracket that spans the top of the test mold. There is a probe mounting seat on it. The gate-shaped bracket is a channel-shaped member with a gate-shaped cross-section, including a platform and two side walls extending downward. The width between the outer sides, the height of the two side walls of the door-shaped bracket is less than the height of the test mold, there are screw holes on the two side walls of the door-shaped bracket, and there are screws with heads facing inward on the screw holes, and the probe mounting seat is on the bracket. on the platform.

The operating process of the displacement probe fixing device of the concrete early-age shrinkage performance tester provided by the utility model is: after the test piece is obtained by the same method as the prior art, the gate-shaped bracket in the utility model is placed across At the proper position of the test mold, tighten the fastening screws on both sides of the bracket outside the two sides of the test mold to realize the fixation between the door-shaped bracket and the concrete test mold. The appropriateness of the door-shaped bracket on the test mold The position means that the displacement probe installed on the probe mounting base is aligned with the measured reflection target and maintains an appropriate measurement distance.

The displacement probe fixing device of the early-age concrete shrinkage performance tester provided by the utility model can be easily carried to the scene through the trough structure of the door-shaped bracket and placed on the test mold; through the screw structure on the two side walls of the bracket, the The bracket is firmly connected to the trial mold. Compared with the prior art, the utility model enables the displacement probe to be fixed on the test mold conveniently and accurately, without moving the heavy test mold to the test bench and determining the distance between the probe and the target through complicated movements and adjustments. relative position. Moreover, the relative position between the probe and the target is fixed by the screws on both sides of the bracket, which overcomes the problem that the door-shaped displacement probe fixing device in the prior art maintains the relative position with the test mold by being fixed on the test platform. In fact, the relative position between the probe and the target is not fixed, and because the measured displacement value is in the order of microns, it is very easy to be affected by environmental vibrations and cause measurement errors. That is, the utility model provides a displacement probe fixing device for a concrete early-age shrinkage performance tester which makes the probe installation convenient and accurate.

There are protrusions on the position where the lower plane of the support platform contacts the two side walls of the test mold, and its function is to make the lower plane of the platform higher than the upper plane of the concrete test mold and have an appropriate distance, so that the platform will not be in contact with the test mold. Contact with the concrete specimens in the test will eventually lead to condensation, which may affect the test results.

Marks such as gaps or rulers are arranged on the front and rear sides of the support platform, and these marks are aligned with the inner edges of the two sides above the concrete test form, and are used as positioning references for the direction and position of the support during installation.

There are more than 2 screw holes on the two walls of the support, in order to obtain a firmer and more accurate connection between the door-shaped support and the test mold.

The utility model provides the displacement probe fixing device for the early-age concrete shrinkage performance measuring instrument. The displacement probe mounting seat is installed on the door-shaped support platform with a guide rail mechanism parallel to the two side walls, and the mounting seat and the support There are adjustments to move the mount along the rails.

The measurement range of the probe of the eddy current non-contact displacement sensor selected by the concrete early shrinkage performance tester is very small, 1mm to 2mm. Therefore, before the test starts, the probe of the displacement sensor must be placed in a suitable initial position within the range to ensure that the entire test process is within the effective range of the sensor. The deviation range of this initial position is preferably within 0.2mm. In the prior art, the displacement probe is fastened on the probe bracket through a screw and nut structure, and it is also very difficult to adjust the distance between the displacement probe and the measured reflection target through the fastening nuts on both sides to achieve a suitable position. The utility model can conveniently adjust the distance between the probe and the target through the adjustment structure composed of the guide rail and the adjustment device between the door-shaped bracket and the probe mounting seat, thereby adjusting the distance between the displacement probe and the measured reflection target to the range best initial position.

The adjustment device between the probe mounting base and the door-shaped bracket that moves the base along the guide rail is a threaded mechanism that acts on the probe mounting base and the door-shaped bracket, such as the screw holes on the mounting base and the screw holes. Screw, a threaded mechanism consisting of a screw mounting bracket and a knob (hand wheel) fixed on the screw to limit the axial position between the screw and the bracket; The screw mechanism formed by the mounting bracket at the axial position between the brackets. The eddy current displacement probe is installed on the probe mounting base through its upper screw or flange.

The adjustment device also includes a spring, the elastic force of which acts between the probe mounting seat and the door-shaped bracket and is parallel to the guide rail, so that the adjustment knob can be adjusted smoothly when it is operated. This spring can be extension spring form also can be compression spring form.

The utility model provides a displacement probe fixing device for the early-age concrete shrinkage performance measuring instrument. There is a locking device between the probe mounting seat and the door-shaped bracket. This locking device is usually realized by a fastening screw, which is used to lock and adjust The position between the probe mounting seat and the door-shaped bracket, so that the position of the probe relative to the bracket is fixed during work.

Description of drawings

Fig. 1 is a displacement probe fixing device in the prior art and a diagram of the device in application. In the figure: 1-door bracket, 2-suspended column probe mounting seat, 3-probe, 4-target, 5-test pieces, 6-mold test, 7-test platform;

Fig. 2 is a structural diagram of an embodiment of the utility model and a device configuration diagram during application, in the figure: 8-bracket fixing screw, 9-door-shaped bracket, 10-support pad, 11-displacement probe adjustment knob, 12-adjustment Screw, 13-displacement probe mounting seat, 14-guide rail, 15-displacement probe mounting screw hole, 16-mounting seat locking bolt, 17-concrete specimen, 18-test mold;

Figure 3 is the top view of Figure 2, in the figure: 8-bracket fixing screw, 9-door bracket, 11-displacement probe adjustment knob, 12-adjustment screw, 13-displacement probe mounting seat, 14-guide rail, 16-mounting seat Locking bolt, 19-adjusting screw mounting frame, 20-notch mark on the door-shaped bracket platform, 21-spring;

Figure 4 is the right view of Figure 2, in the figure: 8-bracket fixing screw, 9-door bracket, 11-displacement probe adjustment knob, 12-adjustment screw, 13-displacement probe mounting seat, 14-guide rail, 16-installation Seat locking bolt, 19-adjusting screw mount, 21-spring.

Detailed ways

As shown in Figures 2, 3, and 4, the displacement probe fixing device of the early-age concrete shrinkage performance tester of the present embodiment has a gate-shaped support 9 made of steel materials through welding or washing and cutting, so that it has enough The thickness guarantees its rigidity and resistance to deformation. There are two screw holes on the walls extending downward on both sides of the door-shaped bracket. Four bracket fixing screws 8 (the tails of the screws are knobs) are screwed on the four screw holes. By tightening the screws, the bracket can be fixed on the concrete test mold. The bracket will not move, and the bracket can be detached from the concrete test form by loosening the screws. There is a T-shaped guide rail 14 parallel to the two side walls on the upper plane of the door-shaped support platform, and a displacement probe mounting seat 13 is assembled on the support with a T-shaped groove. Displacement probe mounting screw holes 15 are arranged on the front side of the probe mount, so that the probe is assembled on it with the screw rod. There is adjusting screw rod 12 to be made of the polished rod of front section and the threaded rod of rear section, and adjusting screw rod is parallel with guide rail. The front section of the adjusting screw is fixed on the probe mount from the rear. A displacement probe adjustment knob 11 is fitted on the rear section of the adjustment screw with internal thread, and an adjustment screw mount 19 is respectively arranged at the two ends of the knob to install the adjustment screw on the door-shaped support and make the adjustment knob can not move back and forth. A spring 21 is set between the probe mounting seat at the front section of the adjusting screw and the adjusting screw mounting frame, so that the probe mounting seat always obtains a forward thrust and keeps it adjusted smoothly and accurately. There is a locking bolt 16 perpendicular to the platform of the gantry support on the probe mounting base, and the positions of the mounting base and the gantry support are tightly fixed after the mounting base is adjusted in place. There are respectively downward support pads 10 on both sides of the lower plane of the door-shaped support platform, so that the support rests on the two side walls of the trial mold with this support pads. Respectively have a width equal to the gap of trial mold width on the front and rear ends of door-shaped support, namely the breach mark 20 on the door-shaped support platform, as the location mark when being installed on the trial mold.

After the concrete specimen 17 in the test mold 18 is molded, the probe of the concrete early age shrinkage performance tester is installed on the test mold as shown in Figure 2 with the above-mentioned probe fixing device. When installing, the notch of the door-shaped bracket of the fixing device is downward, the front of the probe mounting seat points to the target on the test piece, and it is buckled on the test mold across the test mold. on the side wall. Then align the gaps at both ends of the gate-shaped bracket platform with the two sides of the test, and make the distance between the probe and the target fall within the adjustable range, and then tighten the fixing screws of the bracket. Afterwards, adjust the adjusting knob on the displacement adjusting screw to make the distance between the probe and the target meet the measurement requirements and lock the position of the displacement probe through the locking screw. After the installation is completed, the measurement test of the early-age shrinkage performance of the concrete begins.

This example does not include all the solutions that the utility model can implement. According to the prior art and the disclosed content of the utility model, various implementation solutions can be obtained, especially for the adjustment mechanism of the guide rail structure and the probe mounting seat And tightening mechanism, can adopt numerous technical schemes with the same effect in the existing mechanical technology field.

Claims (8)

1, a kind of concrete shrinkage analyzer displacement probe stationary installation in length of time morning, the portal trestle that the die trial of striding across top is arranged, portal trestle is the support of its cross section for the shape of the few following horizontal stroke of mouthful word, one probe mount pad is arranged on the portal trestle, it is characterized in that said portal trestle is the grooved member with shape xsect, comprise platform and the two side of extending downwards, width between the inboard, portal trestle two side is greater than the width between the outside, die trial two side, the height of portal trestle two side is less than the height of die trial, screw is respectively arranged on the portal trestle two side, the inside screw of head is arranged on the screw, and said probe mount pad is on rack platform.

2, concrete as claimed in claim 1 early the length of time shrinkage analyzer displacement probe stationary installation, it is characterized in that on the lower plane of said rack platform and the die trial two side position contacting projection being arranged.

3, concrete shrinkage analyzer displacement probe stationary installation in length of time morning as claimed in claim 1 is characterized in that both sides, said rack platform front and back are furnished with the mark that aligns with edge in the both sides, concrete die trial top.

4, concrete shrinkage analyzer displacement probe stationary installation in length of time morning as claimed in claim 1 is characterized in that on the said support two side there being more than 2 screw.

5, concrete shrinkage analyzer displacement probe stationary installation in length of time morning as claimed in claim 1, it is characterized in that said displacement probe mount pad is to be installed on the portal trestle platform with the guide rail mechanism parallel with the two side, and between displacement probe mount pad and the support regulating device that mount pad is moved along guide rail is arranged.

6, concrete shrinkage analyzer displacement probe stationary installation in length of time morning as claimed in claim 5, it is characterized in that making between said probe mount pad and the portal trestle seat along the regulating device that guide rail moves, is the thread mechanism that acts between probe mount pad and the portal trestle.

7, concrete shrinkage analyzer displacement probe stationary installation in length of time morning as claimed in claim 5 is characterized in that said regulating device also comprises a spring, and the elastic force of this spring acts between probe mount pad and the portal trestle and is parallel to guide rail.

8, concrete shrinkage analyzer displacement probe stationary installation in length of time morning as claimed in claim 5, it is characterized in that popping one's head in also has a locking device between mount pad and the portal trestle.

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