CN214277705U

CN214277705U - Testing device for detecting crack resistance of cover plate step plate

Info

Publication number: CN214277705U
Application number: CN202120001257.4U
Authority: CN
Inventors: 刘桂森; 张平萍; 李鹏举; 黄帅; 崔鹏飞
Original assignee: Sinosteel Nanjing New Material Research Institute Co Ltd; Sinosteel Zhengzhou Research Institute of Steel Wire Products Co Ltd
Current assignee: Sinosteel Nanjing New Material Research Institute Co Ltd; Sinosteel Zhengzhou Research Institute of Steel Wire Products Co Ltd
Priority date: 2021-01-03
Filing date: 2021-01-03
Publication date: 2021-09-24
Anticipated expiration: 2031-01-03

Abstract

The utility model discloses a test device for detecting apron step crack resistance ability, anti technical field who splits the performance test device. The testing device comprises a bottom frame with supporting legs at the bottom, a reverse bearing frame erected right above the bottom frame through four guide studs, two bearing supports transversely buckled at the middle part of the reverse bearing frame, two horizontal guide rails transversely paved on the top surface of the bottom frame and extending towards the right side, a trolley striding on the two horizontal guide rails and used for transporting a sample to be tested, a jack loading assembly installed at the center of the bottom frame, and a height adjusting assembly installed on a cross beam and the guide studs. The utility model discloses a reverse bearing frame provides the support counter-force, carries out reverse loading through jack loading subassembly to the bottom surface of the sample under test and can accurately detect the anti crack performance of different specification apron step fast, has detection efficiency height, the result is accurate, be convenient for observe, convenient operation, application scope are wide, the advantage that the commonality is strong.

Description

Testing device for detecting crack resistance of cover plate step plate

Technical Field

The utility model relates to a technical field of anti crack performance test device, more specifically say a test device for detecting apron step crack resistance ability, be applicable to the apron or the step that detect multiple materials such as concrete material, RPC material.

Background

Decking and decking are widely used in road and railway engineering construction. The cover plate usually comprises a cable trough cover plate and a ditch cover plate, is a part of a tunnel drainage facility and a pipeline facility, not only plays a role in preventing sundries from falling into a ditch to block a drainage system or damage a pipeline, but also bears crowd load and wheel load. The sidewalk footplate is an important accessory facility of the bridge, is a main channel for daily maintenance and repair of the bridge, and mainly bears crowd load and ballast stacking load on a sidewalk during maintenance and repair. The existing standard of China strictly stipulates the test method and the qualified index of the crack resistance and the bearing capacity of the cover plate, also provides specific requirements for the detection method of the crack resistance and the bearing capacity of the cover plate, but does not particularly stipulate a test device required for detecting the crack resistance. Moreover, a mature and proper detection device for scientifically detecting the anti-cracking performance of the cable trough cover plate and the sidewalk step plate does not exist in the current market, so that the anti-cracking performance of the cable trough cover plate and the sidewalk step plate is difficult to control, and the construction progress and the engineering quality are seriously influenced.

Disclosure of Invention

The utility model aims at exactly being directed at the weak point one kind that exists among the above-mentioned prior art and being used for detecting the test device of apron step crack resistance ability. Utilize the utility model discloses can detect the anti crack performance of different specification apron step fast accurately, have detection efficiency height, the result is accurate, be convenient for observe, convenient operation, application scope wide, the strong advantage of commonality.

The purpose of the utility model can be realized by the following technical measures:

the utility model discloses a test device for detecting apron step crack resistance ability includes the chassis of landing leg (be the utility model discloses a support chassis), erect the anti-bearing frame directly over the chassis (for being surveyed the sample and provide counter-force support) through four direction double-screw bolts, transversely detain two bearing support (the reverse holding power of transmitting anti-bearing frame to being surveyed the sample) of hanging in anti-bearing frame middle part, transversely lay the top surface of chassis, and two horizontal guide rails of epitaxial to the right side, ride on two horizontal guide rails and be used for transporting the dolly of being surveyed the sample, install the jack loading subassembly (for being surveyed the sample and provide the loading force) in the chassis center, install the height adjustment subassembly (being used for adjusting the height interval between anti-bearing frame and the chassis) on crossbeam and direction double-screw bolt; the height adjusting component comprises a crank, a speed reducer, a driving chain wheel, a chain, a tension chain wheel, a driven chain wheel (the rotation crank drives the speed reducer and the driving chain wheel which are connected in sequence to rotate, the rotation of the driving chain wheel is transmitted to the driven chain wheel through the chain, the chain can be tensioned through the tension chain wheel, the rotating crank at the position can be replaced by a motor), a screw nut (the driven chain wheel drives the screw nut to rotate synchronously when rotating) which is combined with the driven chain wheel in a key mode, a thrust bearing seat (the thrust bearing seat drives the thrust bearing seat to rotate synchronously when the screw nut rotates) which is combined with the screw nut in a thread mode, a thrust bearing (the thrust bearing seat generates thrust to the thrust bearing, the thrust bearing transmits the thrust to the reverse bearing frame, and the reverse bearing frame is driven to move horizontally along the vertical direction, and further the height distance between the counter bearing frame and the underframe).

The jack loading component in the utility model consists of a support, a jack, a tray, a force measuring sensor and a force application block which are arranged from bottom to top in sequence; the bottom surface of the jack is placed on the support, and the support is connected to the bottom surface of the underframe through bolts (the underframe provides an installation foundation and a force application foundation for the jack through the support); the tray is of a stepped column structure, the diameter of the small-diameter section of the tray is equal to that of the piston rod of the jack, and the small-diameter section of the tray and the piston rod of the jack are combined through a matched boss and groove structure (the tray and the piston rod of the jack are connected together to move synchronously and transfer loading force); the force sensor is arranged on the upper end surface of the large-diameter section of the tray (the tray is simultaneously used as an installation platform of the force sensor), and a positioning hole for embedding the force application block is processed in the center of the force sensor (the lower part of the force application block is embedded in the force sensor to synchronously move and transmit loading force); the force application block is of a stepped columnar structure, and the diameter of the small-diameter section of the force application block is matched with the inner diameter of the positioning hole (the force application block and the force measurement sensor are conveniently and quickly embedded together).

In the utility model, the underframe is composed of a rectangular frame and a Chinese character 'mi' -shaped inner support, a jack positioning sleeve (for mounting a jack) is arranged at the center of the Chinese character 'mi' -shaped inner support, and guide stud positioning sleeves (an upper cavity is inserted and embedded with a guide stud, and a lower cavity is inserted and embedded with a support leg) are arranged at four corners of the rectangular frame; the center of the jack positioning sleeve is provided with a mounting hole for mounting the jack in a penetrating way, and the center of the guide stud positioning sleeve is provided with an inserting hole for inserting and embedding the upper cavity into the guide stud and inserting and embedding the lower cavity into the supporting leg.

The utility model discloses in anti-force bearing frame is indulged by rectangle frame, one and props, a plurality of stull constitutes, is provided with the position sleeve that is used for installing screw nut in four corners of rectangle frame, is located the stull intersection of indulging at rectangle frame center and is fixed with the speed reducer connecting plate, and processing has the tensioning sprocket mounting hole on non-central crossbeam.

The utility model discloses in the load support links together the disjunctor frame that forms two straight turning bottom through a horizontal board by two perpendicular cardboards, the top of erecting the cardboard forms a last hook right angle draw-in groove that is used for the anti-load frame of inlay card through bending twice, offers the bolt hole that is used for connecting the lumber skid on horizontal board, offers the bolt hole of connecting the anti-load frame on erecting the cardboard.

The utility model discloses in guide stud is echelonment post structure, and guide stud's big footpath section is smooth cylinder (insert and inlay in the cartridge hole of the guide stud position sleeve of chassis), and guide stud's path section is the screw section of surface machining screw thread (with screw nut and driven sprocket assembly back, can convert screw nut and driven sprocket's rotation into the linear motion of the vertical direction of anti-load frame).

In the utility model, the inner holes of the screw nut and the driven sprocket are all provided with inner threads for installing the guide stud (after being assembled with the stud section of the guide stud, the rotation of the screw nut and the driven sprocket can be converted into the linear movement in the vertical direction of the reverse bearing frame); the bottom end of the screw nut is provided with an external thread for installing a thrust bearing seat (the thrust bearing seat and the screw nut which are connected together through the thread can realize synchronous rotation).

The utility model discloses in circular loading operation hole (jack piston rod drives tray, force cell sensor, the synchronous upward translation of application of force piece, and the transmission loading power has been seted up at the center of dolly (after above-mentioned spare part runs through circular loading operation hole, the top surface of application of force piece contacts the bottom surface center of being surveyed the sample, load being surveyed the sample to the size of loading power can show through force cell sensor in real time, until being surveyed the sample and destroyed, observe the loading power that corresponds when the destruction condition, the record destroys, experimental the end the upper surface of dolly is carved with the location contour line of cross central line and being surveyed the sample (be convenient for by the quick location of surveying the sample).

The utility model discloses the bottom surface of well horizontal guide outside extension end is provided with the erector (keeping horizontal guide to be in the horizontality, avoiding horizontal guide outside extension end cantilever).

The design principle of the utility model is as follows:

the utility model discloses a reverse bearing frame provides the anti-cracking performance that supports the counter-force, carries out reverse loading through jack loading subassembly to the bottom surface of being surveyed the sample and detects the apron step: firstly, adjusting the height distance between a reverse bearing frame and a bottom frame to be equal to the sum of the heights of a trolley and a tested sample by using a height adjusting assembly, so that two paddings connected with the bottoms of two bearing supports are in contact and pressed on the upper surface of the tested sample, and a supporting reverse force is provided for the tested sample; and then starting the jack, moving a piston rod of the jack upwards to drive the tray, the force transducer and the force application block to synchronously move upwards and transfer the loading force, loading the sample to be measured when the top surface of the force application block contacts the center of the bottom surface of the sample to be measured, and displaying the size of the loading force in real time through the force transducer until the sample to be measured can be visually observed to be damaged, observing the damage condition and recording the corresponding loading force during the damage. Therefore the utility model discloses have the anti crack performance that can accurately detect the apron step fast, have detection efficiency height, the result is accurate, be convenient for observe, convenient operation's advantage. Simultaneously, owing to can adjust the high interval of anti-bearing frame and chassis in a flexible way with the help of the height adjustment subassembly, the area is great in addition predetermineeing to the dolly, so can test the crack resistance of the apron step of multiple different thickness specification, different shape specification, different dimensions, so the utility model has the advantages of application scope is wide, the commonality is strong.

The utility model has the advantages of:

utilize the utility model discloses can detect the anti crack performance of different specification apron step fast accurately, have detection efficiency height, the result is accurate, be convenient for observe, convenient operation, application scope wide, the strong advantage of commonality.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a top view of fig. 1.

Fig. 3 is a partial enlarged view of the point i in fig. 1.

Fig. 4 is a partial enlarged view of fig. 1 at ii.

Fig. 5 is a schematic structural diagram of the middle chassis according to the present invention.

Fig. 6 is a schematic structural view of the middle counter force bearing frame and the force bearing support of the present invention.

The sequence numbers in the figures illustrate: 1. a support leg; 2. 2-1 of an underframe, 2-1 of a rectangular frame, 2-2 of a cross-shaped inner support, 2-3 of a jack positioning sleeve, 2-3-1 of a mounting hole, 2-4 of a guide stud positioning sleeve, 2-4-1 of a plug-in hole; 3. 3-1 parts of guide studs, 3-1 parts of smooth cylinders, 3-2 parts of stud sections; 4. 4-1 of a reverse bearing frame, 4-2 of a rectangular outer frame, 4-3 of a longitudinal support, 4-4 of a transverse support, 4-5 of a positioning sleeve, 4-6 of a speed reducer connecting plate and a tensioning chain wheel mounting hole; 5. 5-1 parts of a force bearing support, 5-1 parts of a vertical clamping plate, 5-1 parts of an upper hook right-angle clamping groove, 5-2 parts of a transverse connecting plate; 6. horizontal guide rail, 6-1, vertical support; 7. a trolley 7-1 and a circular loading operation hole; 8. a sample to be tested; 9. 9-1 parts of a jack loading assembly, 9-2 parts of a support, 9-2 parts of a jack, 9-2-1 parts of a jack piston rod, 9-3 parts of a tray, 9-4 parts of a force measuring sensor, 9-4-1 parts of a positioning hole, 9-5 parts of a force application block; 10. the device comprises a height adjusting assembly, a crank, a speed reducer, a driving chain wheel, a chain, a tensioning chain wheel, a driven chain wheel, a screw nut, a thrust bearing and a driving chain wheel, wherein the height adjusting assembly comprises 10-1 parts of a crank, 10-2 parts of a speed reducer, 10-3 parts of a driving chain wheel, 10-4 parts of a chain, 10-5 parts of a tensioning chain wheel, 10-6 parts of a driven chain wheel, 10-7 parts of a screw nut, 10-8 parts of a thrust bearing seat, 10-9 parts of a thrust bearing; 11. and (5) wood cushion.

Detailed Description

The utility model is further described with the following figures:

as shown in figures 1-6, the testing device for detecting the crack resistance of the cover plate step plate of the utility model comprises a bottom frame 2 (which is the supporting framework of the utility model) with legs 1 at the bottom, a reverse bearing frame 4 erected right above the underframe through four guide studs 3 provides counter-force support for a measured sample 8), two bearing supports 5 transversely buckled at the middle part of the reverse bearing frame (transmit the reverse supporting force of the reverse bearing frame 4 to the measured sample 8), two horizontal guide rails 6 transversely paved on the top surface of the underframe and extending outwards towards the right side, a trolley 7 striding on the two horizontal guide rails and used for transporting the measured sample 8, a jack loading assembly 9 arranged at the center of the underframe (provides loading force for the measured sample 8), and a height adjusting assembly 10 arranged on a cross beam and the guide studs (used for adjusting the height distance between the reverse bearing frame 4 and the underframe 2); the height adjusting assembly 10 comprises a crank handle 10-1, a speed reducer 10-2, a driving chain wheel 10-3, a chain 10-4, a tension chain wheel 10-5 and a driven chain wheel 10-6 which are connected in sequence to form a chain transmission (the rotation crank handle 10-1 drives the speed reducer 10-2 and the driving chain wheel 10-3 which are connected in sequence to rotate, the rotation of the driving chain wheel 10-3 is transmitted to the driven chain wheel 10-6 through the chain 10-4, the chain 10-4 can be tensioned through the tension chain wheel 10-5, the rotation crank handle 10-1 can be replaced by a motor), a screw nut 10-7 which is combined with the driven chain wheel in a key mode (the driven chain wheel 10-6 drives the screw nut 10-7 to rotate synchronously when rotating), and a thrust bearing seat 10-8 which is combined with the screw nut in a thread mode (the screw nut 10-7 drives the screw nut to rotate Thrust bearing blocks 10-8 synchronously rotate), and thrust bearings 10-9 embedded between the inner end surfaces of the thrust bearings and the lower end surfaces of the reverse bearing frames (the thrust bearing blocks 10-8 generate thrust for the thrust bearings 10-9, and the thrust bearings 10-9 transmit the thrust to the reverse bearing frames 4 to drive the reverse bearing frames 4 to translate along the vertical direction, so as to adjust the height distance between the reverse bearing frames 4 and the underframe 2).

The jack loading component 9 in the utility model consists of a support 9-1, a jack 9-2, a tray 9-3, a force measuring sensor 9-4 and a force application block 9-5 which are arranged from bottom to top in sequence; wherein the bottom surface of the jack 9-2 is seated on the support 9-1, and the support 9-1 is connected with the bottom surface of the underframe 2 through a bolt (the underframe 2 provides an installation foundation and a force application foundation for the jack 9-2 through the support 9-1); the tray 9-3 is of a stepped column structure, the diameter of the small-diameter section of the tray 9-3 is equal to that of the jack piston rod 9-2-1, and the small-diameter section and the jack piston rod 9-2-1 are combined through matched boss and groove structures (the tray 9-3 and the jack piston rod 9-2-1 are connected together to move synchronously and transfer loading force); the force sensor 9-4 is placed on the upper end face of the large-diameter section of the tray 9-3 (the tray 9-3 is simultaneously used as an installation platform of the force sensor 9-4), and a positioning hole 9-4-1 embedded with a force application block is processed in the center of the force sensor 9-4 (the lower part of the force application block 9-5 is embedded in the force sensor 9-4 and moves synchronously together and transmits loading force); the force application block 9-5 is of a stepped columnar structure, and the diameter of the small-diameter section of the force application block 9-5 is matched with the inner diameter of the positioning hole 9-4-1 (the force application block 9-5 and the force measurement sensor 9-4 are conveniently and quickly embedded together).

In the utility model, the underframe 2 is composed of a rectangular frame 2-1 and a cross-shaped inner support 2-2, a jack positioning sleeve 2-3 (for mounting a jack 9-2) is arranged at the center of the cross-shaped inner support 2-2, and guide stud positioning sleeves 2-4 (an upper cavity is inserted and embedded with a guide stud, a lower cavity is inserted and embedded with a support leg) are arranged at four corners of the rectangular frame 2-1; the center of the jack positioning sleeve 2-3 is provided with a mounting hole 2-3-1 for mounting the jack in a penetrating way, and the center of the guide stud positioning sleeve 2-4 is provided with an inserting hole 2-4-1 for inserting and embedding the guide stud in the upper cavity and inserting and embedding the supporting leg in the lower cavity.

The utility model discloses in anti-force bearing frame 4 is by rectangle frame 4-1, one indulge and props 4-2, a plurality of stull 4-3 and constitute, is provided with the position sleeve 4-4 that is used for installing screw nut in four corners of rectangle frame, is located the stull intersection of indulging at rectangle frame center and is fixed with speed reducer connecting plate 4-5, processes on non-central crossbeam and has tensioning sprocket mounting hole 4-6.

The utility model discloses in force bearing support 5 is by two perpendicular cardboards 5-1 link together the bottom through a horizontal link board 5-2 and form the disjunctor frame at two straight turning, the top of erecting cardboard 5-1 forms one through twice bending and is used for the reverse bearing frame 4 of inlay card's upward hook right angle draw-in groove 5-1-1, offers the bolt hole that is used for connecting lumber skid 11 on horizontal link board 5-2, offers the bolt hole of connecting reverse bearing frame 4 on erecting cardboard 5-1.

The utility model discloses in guide stud 3 is echelonment post structure, and guide stud 3's major diameter section is smooth cylinder 3-1 (insert and inlay in the cartridge hole 2-4-1 of guide stud position sleeve 2-4 of chassis 2), and guide stud 3's minor diameter section is the double-screw bolt section 3-2 of surface finish screw thread (join in marriage with screw nut 10-7 and passive sprocket 10-6 and join in marriage the dress back, can convert screw nut 10-7 and passive sprocket 10-6 rotation into the straight-line motion of the 4 vertical directions of anti-load frame).

In the utility model, internal threads for installing the guide stud 3 are processed in the inner holes of the lead screw nut 10-7 and the driven chain wheel 10-6 (after being assembled with the stud section 3-2 of the guide stud 3, the rotation of the lead screw nut 10-7 and the driven chain wheel 10-6 can be converted into the linear movement of the anti-bearing frame 4 in the vertical direction); the bottom end of the lead screw nut 10-7 is provided with an external thread for installing a thrust bearing seat 10-8 (the thrust bearing seat 10-8 and the lead screw nut 10-7 which are connected together through threads can realize synchronous rotation).

The utility model discloses in circular loading operation hole 7-1 has been seted up at the center of dolly 7 (jack piston rod 9-2-1 drives tray 9-3, force cell 9-4, application of force piece 9-5 and upwards translates in step, and transmits the loading power, and after above-mentioned spare part runs through circular loading operation hole 7-1, the top surface of application of force piece 9-5 contacted the bottom surface center of surveyed sample 8, carries out the loading to surveyed sample 8, and the size of loading power can show through force cell 9-4 in real time, until surveyed sample 8 is destroyed, observe the damage condition, the corresponding loading power when the record destroys, the experiment finishes, the upper surface of dolly 7 is carved with the location contour line of cross central line and surveyed sample (the quick location of being convenient for surveyed sample 8).

The utility model discloses the bottom surface of the outside extension end of well horizontal guide 6 is provided with erector 6-1 (keep horizontal guide 6 to be in the horizontality, avoid horizontal guide 6 outside extension end cantilever).

The utility model discloses a concrete in service behavior as follows:

first, the present invention is assembled according to the above structural description. Then, a positioning contour line is drawn according to the cross center line of the upper surface of the trolley 7 and the shape specification of the tested sample 8. Then, the sample 8 to be measured is placed on the upper surface of the trolley 7, so that the outer contour of the sample 8 to be measured is pressed on the positioning contour line for quick positioning. Then, two skids 11 are respectively connected to the bottoms of the vertical clamping plates 5-1 of the two force-bearing supports 5 by bolts. And then, when the height distance between the counter bearing frame 4 and the base frame 2 is ensured to be larger than the sum of the heights of the trolley 7 and the tested sample 8, the trolley 7 is pushed leftwards to the test space between the base frame 2 and the counter bearing frame 4. Then, the height adjusting component 10 is operated to adjust the counter bearing frame 4 to move vertically downwards along the guide stud 3 until the height distance between the counter bearing frame 4 and the base frame 2 is equal to the sum of the heights of the trolley 7 and the tested sample 8, namely, two skid blocks 11 are in contact and pressed on the upper surface of the tested sample 8, and the specific operation process is as follows: the rotation crank 10-1 (the rotation crank 10-1 can be replaced by a motor) drives a speed reducer 10-2 and a driving chain wheel 10-3 which are connected in sequence to rotate, the rotation of the driving chain wheel 10-3 is transmitted to a driven chain wheel 10-6 through a chain 10-4, the chain 10-4 can be tensioned through a tensioning chain wheel 10-5, the driven chain wheel 10-6 drives a screw nut 10-7 to rotate synchronously when rotating, the screw nut 10-7 drives a thrust bearing seat 10-8 to rotate synchronously when rotating, the thrust bearing seat 10-8 generates thrust to a thrust bearing 10-9, the thrust bearing 10-9 transmits the thrust to a reverse bearing frame 4, the reverse bearing frame 4 is driven to translate along the vertical direction, and the height distance between the reverse bearing frame 4 and an underframe 2 is adjusted. And then, starting the jack loading assembly 9 to load the bottom surface of the sample 8 to be tested, wherein the specific operation process comprises the following steps: the jack piston rod 9-2-1 drives the tray 9-3, the force measuring sensor 9-4 and the force application block 9-5 to synchronously move upwards and transmit loading force, when the parts penetrate through the circular loading operation hole 7-1, the top surface of the force application block 9-5 contacts the center of the bottom surface of the sample 8 to be measured, the sample 8 to be measured is loaded, the magnitude of the loading force can be displayed in real time through the force measuring sensor 9-4 until the sample 8 to be measured is damaged, the damage condition is observed, the corresponding loading force during the damage is recorded, and the test is finished.

Claims

1. The utility model provides a test device for detecting apron step crack resistance ability which characterized in that: the testing device comprises a bottom frame (2) with a supporting leg (1) at the bottom, a reverse bearing frame (4) erected right above the bottom frame through four guide studs (3), two bearing supports (5) transversely buckled and hung in the middle of the reverse bearing frame, two horizontal guide rails (6) transversely laid on the top surface of the bottom frame and extending towards the right side, a trolley (7) straddling the two horizontal guide rails and used for transporting a sample to be tested (8), a jack loading assembly (9) installed in the center of the bottom frame, and a height adjusting assembly (10) installed on a cross beam and the guide studs; the height adjusting assembly (10) comprises a crank (10-1), a speed reducer (10-2), a driving chain wheel (10-3), a chain (10-4), a tensioning chain wheel (10-5), a driven chain wheel (10-6), a screw nut (10-7) combined with the driven chain wheel in a key mode, a thrust bearing seat (10-8) combined with the screw nut in a thread mode, and a thrust bearing (10-9) embedded between the inner end face of the thrust bearing and the lower end face of the reverse bearing frame.

2. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: the jack loading assembly (9) consists of a support (9-1), a jack (9-2), a tray (9-3), a force measuring sensor (9-4) and a force application block (9-5) which are sequentially arranged from bottom to top; wherein the bottom surface of the jack (9-2) is seated on the support (9-1), and the support (9-1) is connected with the bottom surface of the underframe (2) through a bolt; the tray (9-3) is of a stepped column structure, the diameter of the small-diameter section of the tray (9-3) is equal to that of the jack piston rod (9-2-1), and the small-diameter section and the jack piston rod are combined through matched boss and groove structures; the force measuring sensor (9-4) is arranged on the upper end face of the large-diameter section of the tray (9-3), and a positioning hole (9-4-1) for embedding the force application block is machined in the center of the force measuring sensor (9-4); the force application block (9-5) is of a stepped columnar structure, and the diameter of the small-diameter section of the force application block (9-5) is matched with the inner diameter of the positioning hole (9-4-1).

3. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: the chassis (2) is composed of a rectangular frame (2-1) and a cross-shaped inner support (2-2), a jack positioning sleeve (2-3) is arranged at the center of the cross-shaped inner support (2-2), and guide stud positioning sleeves (2-4) are arranged at four corners of the rectangular frame (2-1); the center of the jack positioning sleeve (2-3) is provided with a mounting hole (2-3-1) for mounting the jack in a penetrating way, and the center of the guide stud positioning sleeve (2-4) is provided with an inserting hole (2-4-1) for inserting and embedding the guide stud at the upper part and inserting and embedding the supporting leg at the lower part.

4. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: the anti-bearing frame (4) is composed of a rectangular outer frame (4-1), a longitudinal support (4-2) and a plurality of transverse supports (4-3), positioning sleeves (4-4) for mounting screw nuts are arranged at four corners of the rectangular outer frame, a speed reducer connecting plate (4-5) is fixed at the intersection of the longitudinal support and the transverse support at the center of the rectangular outer frame, and tensioning chain wheel mounting holes (4-6) are machined in non-central cross beams.

5. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: the bearing support (5) is a connected frame with two vertical clamping plates (5-1) and two straight corners formed by connecting the bottoms of the two vertical clamping plates together through a transverse connecting plate (5-2), the top of each vertical clamping plate (5-1) is bent twice to form an upper hook right-angle clamping groove (5-1-1) used for clamping and embedding the reverse bearing frame (4), bolt holes used for connecting the skid (11) are formed in the transverse connecting plate (5-2), and bolt holes used for connecting the reverse bearing frame (4) are formed in the vertical clamping plates (5-1).

6. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: the guide stud (3) is of a step-shaped column structure, the large-diameter section of the guide stud (3) is a smooth cylinder (3-1), and the small-diameter section of the guide stud (3) is a stud section (3-2) with threads machined on the surface.

7. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: internal threads for mounting the guide stud (3) are machined in inner holes of the screw nut (10-7) and the driven chain wheel (10-6); the bottom end of the screw rod nut (10-7) is provided with an external thread for installing a thrust bearing seat (10-8).

8. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: a circular loading operation hole (7-1) is formed in the center of the trolley (7), and a cross center line and a positioning contour line of a tested sample are marked on the upper surface of the trolley (7).

9. The testing device for testing the crack resistance of the cover plate step plate according to claim 1, wherein: a vertical support (6-1) is arranged on the bottom surface of the external extending end of the horizontal guide rail (6).