CN219455791U - Four-point bending testing device - Google Patents

Abstract

The disclosure provides a four-point bending test device, which comprises a base, wherein the base comprises a first mounting seat, a first sliding seat, a first driving mechanism and a lower supporting plate; the first mounting seat is internally provided with a cavity, the side wall of the first mounting seat is provided with a sliding groove, the sliding groove is communicated with the cavity, the first driving mechanism is arranged in the cavity, the lower supporting plate is arranged on a corresponding first sliding seat, and the first sliding seat is connected with the first driving mechanism; the distance between the two lower support plates is adjusted via the first drive mechanism. According to the testing device, the first driving mechanism is arranged in the cavity of the first mounting seat, so that the first driving mechanism can be protected; the spout sets up in the both sides wall and the cavity intercommunication of first mount pad, and a smooth plane is kept at the top of first mount pad, and the residue of the test article that forms in the bending test process drops on smooth plane be convenient for clear up.

Description

Four-point bending testing device

Technical Field

The utility model relates to the technical field of four-point bending test, in particular to a four-point bending test device.

Background

When the four-point bending test is carried out, the tested object is easy to drop and residue; the existing four-point bending test machine adopts clamps, wherein the supporting plate is adjusted at the top of the base, a sliding groove is formed in the top of the base, and the supporting plate is slidably mounted in the sliding groove and fixed through bolts. When the residue that the measured object dropped gets into the spout, hardly clear up, consequently can lead to anchor clamps unable use, must change, causes material resources financial loss.

Disclosure of Invention

Therefore, the utility model aims to provide a four-point bending test device so as to solve the problem that the conventional four-point bending test machine is inconvenient to clean.

Based on the above purpose, the utility model provides a four-point bending test device, which comprises a base, a bracket, a base arranged on the base, and an upper pressure head arranged on the bracket, wherein the base comprises a first mounting seat, a first sliding seat, a first driving mechanism and a lower supporting plate;

the first mounting seat is internally provided with a cavity, the side wall of the first mounting seat is provided with a sliding groove, the sliding groove is communicated with the cavity, the first driving mechanism is arranged in the cavity, the first sliding seats comprise two groups, each first sliding seat is provided with a lower supporting plate, and the first sliding seat penetrates through the sliding groove and is connected with the first driving mechanism; the distance between the two lower support plates is adjusted via the first drive mechanism.

Further, the first actuating mechanism includes first regulation pole, first gag lever post, first regulation pole with first gag lever post rotate set up in the cavity, first sliding seat runs through behind the spout stretch into part in the cavity is connected with first slider, second slider, first slider with first regulation pole sliding fit, the second slider with first gag lever post sliding fit, first regulation pole one end runs through behind the lateral wall of first mount pad be connected with first regulation portion.

Further, the first sliding seat is of a rectangular frame structure, a notch is formed in the portion, located in the cavity, of the first sliding seat, and the first sliding block and the second sliding block are respectively arranged on two side walls of the notch.

Further, the first sliding seat comprises a top plate and a third connecting rod, the third connecting rod is arranged on the side wall of the top plate and penetrates through the sliding groove, and the third connecting rod penetrates through the sliding groove and then is connected with the first sliding block and the second sliding block.

Further, a first mounting groove is formed in the top of the first sliding seat, and the lower supporting plate is arranged in the first mounting groove and is fixed through a locking piece.

Further, the end part of the lower supporting plate is rotatably provided with a lower supporting roller.

Further, the side wall of the lower support plate is slidably provided with a limiting part, a long-strip hole is formed in the limiting part, a positioning part is arranged on the lower support plate and penetrates through the long-strip hole, and the limiting part can move relative to the positioning part in the range of the long-strip hole.

Further, the upper pressing head comprises a second installation seat, a second driving mechanism, a second sliding seat and an upper pressing plate, the second driving mechanism is rotationally arranged on the second installation seat, the second sliding seat is provided with two groups, the number of the upper pressing plate corresponds to the number of the second sliding seats, the upper pressing plate is arranged on the corresponding second sliding seat, the two second sliding seats are arranged on the second driving mechanism, and the two second sliding seats are relatively close to or far away from each other on the second driving mechanism.

Further, the second driving mechanism comprises a second adjusting rod and two second limiting rods, the two second limiting rods are symmetrically arranged, the second adjusting rod is positioned between the two second limiting rods, the second adjusting rod is rotatably arranged on the second mounting seat, and the two second limiting rods are fixedly arranged on the second mounting seat;

the second sliding seat is provided with a first through hole corresponding to the two second limiting rods, the two second limiting rods penetrate through the first through holes, a second through hole is formed between the two first through holes, a ball nut matched with the second adjusting rod is arranged in the second through hole, and the second adjusting rod penetrates through the ball nut.

Further, a second mounting groove is formed in the top of the second sliding seat, and the upper pressing plate is arranged in the second mounting groove and is fixed through a locking piece;

the end part of the upper pressing plate is rotatably provided with an upper supporting roller.

From the above, it can be seen that the four-point bending test device provided by the utility model has the advantages that the first driving mechanism is arranged in the cavity of the first mounting seat, so that the first driving mechanism can be protected; the spout sets up in the both sides wall and the cavity intercommunication of first mount pad, and first sliding seat runs through behind the spout and is connected with first actuating mechanism, guarantees that first actuating mechanism keeps a smooth plane at the top of drive sliding seat under the condition of operation, when the bending test, and the residue of the test article that forms in the test process drops and is convenient for clear up on smooth plane, consequently, has solved the problem of four-point bending test testing machine inconvenient clearance.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a four-point bending test device according to an embodiment of the present utility model;

FIG. 2 is an enlarged schematic view of portion A of FIG. 1 according to an embodiment of the present utility model;

FIG. 3 is a schematic view of a base structure according to an embodiment of the present utility model;

FIG. 4 is a schematic cross-sectional view of a base structure according to one embodiment of the present utility model;

FIG. 5 is a schematic cross-sectional view of a base structure according to another embodiment of the present utility model;

fig. 6 is a schematic diagram of the structure of the ram according to the embodiment of the utility model.

Reference numerals illustrate:

1. a base; 11. a lower connecting part; 2. a bracket; 21. a lifting plate; 211. an upper connection part; 22. an opening/closing door; 23. a baffle; 3. an upper pressure head; 30. a second connecting shaft; 31. a second mounting base; 32. a second driving mechanism; 321. a second limit rod; 322. a second adjusting lever; 323. a second adjusting part; 33. a second sliding seat; 331. a second mounting groove; 332. a finger; 333. a ball nut; 34. an upper press plate; 35. an upper roller; 36. a second mounting plate; 4. a base; 41. a first mount; 411. a cavity; 412. a chute; 42. a first driving mechanism; 421. a first adjusting lever; 422. a first stop lever; 423. a first adjusting part; 43. a first sliding seat; 430. a first mounting groove; 431. a top plate; 432. a first connecting rod; 433. a second connecting rod; 434. a first slider; 435. a second slider; 436. a third connecting rod; 44. a first connecting shaft; 45. a lower support plate; 451. a lower support roller; 452. a positioning piece; 453. a first mounting plate; 5. a limiting piece; 51. and (5) a strip hole.

Detailed Description

The present utility model will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present utility model more apparent.

It should be noted that unless otherwise defined, technical or scientific terms used in the embodiments of the present utility model should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure pertains. The terms "first," "second," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

As shown in fig. 1 to 4, a four-point bending test device comprises a base 1, a bracket 2, a base 4 arranged on the base 1, and an upper pressure head 3 arranged on the bracket 2, wherein the base 4 comprises a first mounting seat 41, a first sliding seat 43, a first driving mechanism 42 and a lower supporting plate 45;

the first mounting seat 41 is internally provided with a cavity 411, the side wall of the first mounting seat 41 is provided with a chute 412, the chute 412 is communicated with the cavity 411, the first driving mechanism 42 is arranged in the cavity 411, the first sliding seats 43 comprise two groups, each first sliding seat 43 is provided with a lower supporting plate 45, and the first sliding seats 43 penetrate through the chute 412 and are connected with the first driving mechanism 42; the distance between the two lower support plates 45 is adjusted via the first drive mechanism 42.

Specifically, as shown in fig. 3 and 4, the first driving mechanism 42 is disposed in the cavity 411 of the first mounting seat 41, so as to protect the first driving mechanism 42 and provide a dust-proof effect. The chute 412 is arranged at two side walls of the first mounting seat 41 and is communicated with the cavity 411, the first sliding seat 43 penetrates through the chute 412 and is connected with the first driving mechanism 42, so that the first driving mechanism 42 can keep a smooth plane at the top of the first mounting seat 41 under the condition of driving the sliding seat to work, and residues of test objects formed in the bending test process fall on the smooth plane to be convenient to clean.

In some embodiments, as shown in fig. 4, the first driving mechanism 42 includes a first adjusting rod 421 and a first limiting rod 422, the first adjusting rod 421 and the first limiting rod 422 are rotatably disposed in the cavity 411, one end of the first sliding seat 43 extending into the cavity 411 after penetrating through the sliding groove 412 is connected with a first sliding block 434 and a second sliding block 435, the first sliding block 434 is in sliding fit with the first adjusting rod 421, the second sliding block 435 is in sliding fit with the first limiting rod 422, and one end of the first adjusting rod 421 penetrates through the side wall of the first mounting seat 41 and is connected with a first adjusting part 423.

Specifically, as shown in fig. 4, the first adjusting rod 421 is a bidirectional screw rod, the first slider 434 of one of the first sliding seats 43 moves along one of the screw rod threads, the first slider 434 of the other first sliding seat 43 moves along the other screw thread of the screw rod, and the first adjusting rod 421 can be adjusted to rotate by the first adjusting part 423, so that the two sliding seats can be adjusted to move in opposite directions, and the distance between the two sliding seats can be adjusted. The first limiting rod 422 is adjacent to and parallel to the first adjusting rod 421, and when the sliding seat moves, the first limiting rod 422 can assist the sliding seat to move stably.

In some embodiments, as shown in fig. 4, the first sliding seat 43 is a rectangular frame structure, a portion of the first sliding seat 43 located in the cavity 411 is provided with a notch, and the first sliding block 434 and the second sliding block 435 are respectively disposed on two sidewalls of the notch.

Specifically, as shown in fig. 4, the rectangular frame structure includes a top plate 431, and a first connecting rod 432 and a second connecting rod 433 that are located at two sides of the top plate 431 and sequentially connected, two sliding grooves 412 are provided, two sliding grooves 412 are symmetrically disposed on a side wall of the first mounting seat 41, the first connecting rod 432 and the second connecting rod 433 are symmetrically disposed on a side wall of the top plate 431, the first connecting rod 432 penetrates through one sliding groove 412 and then is connected with the first sliding block 434, and the second connecting rod 433 penetrates through the other sliding groove 412 and then is connected with the second sliding block 435.

Further, as shown in fig. 4, the first connecting rod 432 and the second connecting rod 433 are both L-shaped, the short connecting portion of the first connecting rod 432 and the short connecting portion of the second connecting rod 433 are symmetrically arranged and are integrally formed with the top plate 431, the long connecting portion of the first connecting rod 432 penetrates one of the sliding grooves 412 and then is connected with the first sliding block 434, the long connecting portion of the second connecting rod 433 penetrates the other sliding groove 412 and then is connected with the second sliding block 435, and the two connecting rods are matched with the two sliding blocks, so that the first sliding seat 43 can be ensured to slide stably under the driving of the first driving mechanism 42.

In some embodiments, as shown in fig. 5, the first sliding seat 43 includes a top plate 431 and a third connecting rod 436, where the third connecting rod 436 is disposed on a side wall of the top plate 431 and penetrates through the sliding groove 412, and the third connecting rod 436 penetrates through the sliding groove 412 and is connected to the first sliding block 434 and the second sliding block 435.

Specifically, as shown in fig. 5, the third connecting rod 436 is L-shaped, one end of the third connecting rod is integrally formed with the top plate 431, and the other end of the third connecting rod penetrates the chute 412 and is connected with the first slider 434 and the second slider 435, where the first slider 434 and the second slider 435 are disposed in parallel and move through the first driving mechanism 42, so as to ensure that the first sliding seat 43 slides stably.

In some embodiments, as shown in fig. 3 to 5, a first mounting groove 430 is formed at the top of the first sliding seat 43, and the lower support plate 45 is disposed in the first mounting groove 430 and is fixed by a locking member.

Specifically, as shown in fig. 3 to 5, the locking member may be a bolt, the thickness of the lower support plate 45 corresponds to the width of the first mounting groove 430, the bottom of the lower support plate 45 is inserted into the first mounting groove 430 and fixed by the bolt, and the lower support plate 45 is detachably connected with the first sliding seat 43, so that the lower support plate 45 with different sizes can be replaced according to actual testing requirements, so as to adapt to tested objects with different widths.

In some embodiments, as shown in fig. 3 to 5, the end of the lower support plate 45 is rotatably provided with a lower support roller 451.

Specifically, as shown in fig. 3 to 5, the first mounting plates 453 are rotatably disposed at two ends of the lower support roller 451, the first mounting plates 453 are fixed on the side wall of the lower support plate 45 by bolts, the lower support roller 451 is rotatably disposed at the top of the lower support plate 45, when a bending test is performed, a tested article is bent under the pressure of the upper press head 3, the lower support roller 451 rotates along with the bending, friction with the tested article can be reduced, and the obtained test result is more accurate.

In some embodiments, as shown in fig. 3 to 5, a limiting member 5 is slidably disposed on a side wall of the lower support plate 45, a long hole 51 is disposed on the limiting member 5, a positioning member 452 is disposed on a side wall of the lower support plate 45, the positioning member 452 is disposed through the long hole 51, and the limiting member 5 can move relative to the positioning member 452 within a range of the long hole 51.

Specifically, as shown in fig. 3 to 5, two limiting pieces 5 are symmetrically arranged, the two limiting pieces 5 are used for placing the tested object, the two limiting pieces 5 can limit the tested object, the distance between the two limiting pieces 5 is adjustable, and the device can adapt to different types of tested objects.

The positioning members 452 may be hexagon socket bolts, the side wall of the lower support plate 45 is provided with bolt holes for installing the positioning members 452, the long strip holes 51 of the positioning members are formed in the side wall of the positioning members 5 and correspond to the bolt holes, the positioning members 5 are positioned through the positioning members 452, when the distance between the two positioning members 5 needs to be adjusted, the positioning members 452 can be unscrewed, the positioning members 5 can be moved, and after the positioning members 452 are moved to a proper position, the positioning members 452 can be screwed.

In some embodiments, as shown in fig. 3 to 5, the side wall of the first mounting seat 41 is provided with graduations, and the graduations are located above the chute 412.

Specifically, as shown in fig. 3 to 5, the scale is located above the chute 412, and when the first sliding seat 43 slides, the second connecting rod 433 of the first sliding seat 435 can be marked by the scale, so that the sliding position of the first sliding seat 43 can be accurately adjusted.

In some embodiments, as shown in fig. 6, the upper pressing head 3 includes a second mounting seat 31, a second driving mechanism 32, a second sliding seat 33, and an upper pressing plate 34, where the second driving mechanism 32 is rotatably disposed on the second mounting seat 31, the second sliding seats 33 are provided with two groups, the number of the upper pressing plates 34 corresponds to the number of the second sliding seats 33, the upper pressing plates 34 are disposed on the corresponding second sliding seats 33, the two second sliding seats 33 are disposed on the second driving mechanism 32, and the two second sliding seats 33 are relatively close to or far away from each other on the second driving mechanism 32.

Specifically, as shown in fig. 6, when the second driving mechanism 32 rotates, the two second sliding seats 33 are driven to move in opposite directions, so as to adjust the distance between the two second sliding seats 33, so as to adapt to the measured objects with different lengths.

In some embodiments, as shown in fig. 6, the second driving mechanism 32 includes a second adjusting rod 322 and two second limiting rods 321, the two second limiting rods 321 are symmetrically disposed, the second adjusting rod 322 is located between the two second limiting rods 321, the second adjusting rod 322 is rotatably disposed on the second mounting seat 31, and the two second limiting rods 321 are both fixedly disposed on the second mounting seat 31;

the second sliding seat 33 is provided with a first through hole corresponding to the two second limiting rods 321, the two second limiting rods 321 penetrate through the first through holes, a second through hole is arranged between the two first through holes, a ball nut 333 matched with the second adjusting rod 322 is arranged in the second through hole, and the second adjusting rod 322 penetrates through the ball nut 333.

Specifically, as shown in fig. 6, when the second adjusting rod 322 rotates, the ball nut 333 on the second sliding seat 33 slides on the second adjusting rod 322, so as to drive the second sliding seat 33 to move on the two second limiting rods 321, the second adjusting rod 322 is located between the two second limiting rods 321, and when the second adjusting rod 322 rotates to drive the second sliding seat 33 to move, the two second limiting rods 321 can ensure that the second sliding seat 33 moves stably.

As shown in fig. 6, one end of the second adjusting rod 322 penetrates the second mounting seat 31 and is connected with a second adjusting portion 323.

Specifically, as shown in fig. 6, the second adjusting rod 322 is a bidirectional screw rod, and the second adjusting rod 322 can be adjusted to rotate by the second adjusting portion 323, so that the bidirectional screw rod can drive the two second sliding seats 33 to slide on the two second limiting rods 321, and the distance between the two second sliding seats 33 is adjusted to adapt to the measured objects with different widths.

In some embodiments, as shown in fig. 6, a second mounting groove 331 is formed at the top of the second sliding seat 33, and the upper pressing plate 34 is disposed in the second mounting groove 331 and is fixed by a locking member.

Specifically, as shown in fig. 6, the locking member may be a bolt, the thickness of the upper pressing plate 34 corresponds to the width of the second mounting groove 331, the bottom of the upper pressing plate 34 is inserted into the second mounting groove 331 and fixed by the bolt, and the upper pressing plate 34 is detachably connected with the second sliding seat 33, so that the upper pressing plate 34 with different sizes can be replaced according to actual testing requirements, so as to adapt to the tested objects with different widths.

In some embodiments, as shown in fig. 6, the upper platen 34 is provided with an upper roller 35 at an end thereof.

Specifically, as shown in fig. 6, the two ends of the upper support roller 35 are rotatably provided with second mounting plates 36, the second mounting plates 36 are fixed on the side walls of the upper pressing plate 34 through bolts, the upper support roller 35 is rotatably provided at the top of the upper pressing plate 34, when a bending test is performed, the tested object is bent under the pressure of the upper pressing plate 34, and the upper support roller 35 rotates along with the bending, so that friction with the tested object can be reduced, and the obtained test result is more accurate.

In some embodiments, as shown in fig. 6, a scale is provided on a side wall of the second mounting seat 31, and a finger 332 is provided on the second sliding seat 33, where the finger 332 points to the scale.

Specifically, as shown in fig. 6, the finger 332 is disposed on a side wall of the second sliding seat 33 and points to the scale, so as to precisely adjust the position of the second sliding seat 33.

In the above embodiment, as shown in fig. 1 and 2, a first connecting shaft 44 is provided at the bottom of the first mounting seat 41, and the first connecting shaft 44 is connected to the lower connecting portion 11 on the base 1;

the second mounting seat 31 is provided with a second connecting shaft 30 on a side wall far away from the upper pressing plate 34, and the second connecting shaft 30 is connected with an upper connecting portion 211 on the bracket 2.

The upper connecting portion 211 is provided on the lifting plate 21 of the stand 2.

The four-point bending test device adopts any one of a toughened glass four-point bending test machine, a concrete beam four-point bending test machine, a steel pipe four-point bending test machine and the like, the utility model improves a clamp formed by the upper pressure head 3 and the base 4, other devices adopt the prior art, and the connection between the connecting shaft and the connecting part adopts the installation mode of the traditional four-point bending test machine, which is not described in detail here.

The side wall of the bracket 2 is provided with a baffle plate 23, the opposite sides of the baffle plate 23 are provided with an opening and closing door 22, the opening and closing door 22 is provided with an observation window, and transparent glass is arranged at the observation window.

Specifically, as shown in fig. 1, when the glass bending test is performed, the glass splashes during the test, so that the personal safety of the tester can be ensured by the blocking of the baffle plate 23 and the opening and closing door 22, and the tested object is not easy to splash to the ground, so that the cleaning is convenient.

The four-point bending test device is used as follows:

in this embodiment, when a toughened film test is needed, an appropriate upper pressing plate 34 and a lower pressing plate 45 are selected according to the width and the size of the toughened film, the selected appropriate upper pressing plate 34 and lower pressing plate are mounted on the corresponding first sliding seat 43 and second sliding seat 33, after the mounting is completed, the base 4 and the upper pressing plate 3 are mounted on the base 1 and the bracket 2, after the mounting is completed, the first adjusting part 423 is rotated first, the distance between the two lower pressing plates 45 is adjusted to be suitable for the width of the toughened film, the lifting plate 21 is controlled to descend by the control system, the distance between the upper pressing plate 3 and the base 4 is made to be greater than the thickness of the toughened film (the upper pressing plate is convenient to adjust according to the size of the toughened film), then the second adjusting rod 322 is rotated to enable the two second sliding seats 33 to slide, so that the distance between the two upper pressing plates 34 is adjusted, after the mounting is completed, the opening and closing door 22 is closed, and the control system controls the lifting plate 21 to move downwards until the toughened film blasting is completed.

After the test is completed, the control system controls the lifting plate 21 to lift, and then the residues on the base 1 and the base 4 are cleaned, and the cleaning is convenient because the top of the first mounting seat 41 of the base 4 is smooth.

Those of ordinary skill in the art will appreciate that: the discussion of any of the embodiments above is merely exemplary and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the utility model, the steps may be implemented in any order and there are many other variations of the different aspects of the utility model as described above, which are not provided in detail for the sake of brevity.

The embodiments of the utility model are intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Therefore, any omission, modification, equivalent replacement, improvement, etc. of the present utility model should be included in the scope of the present utility model.

Claims (10)

1. The four-point bending testing device comprises a base (1), a support (2), a base (4) arranged on the base (1) and an upper pressure head (3) arranged on the support (2), and is characterized in that the base (4) comprises a first mounting seat (41), a first sliding seat (43), a first driving mechanism (42) and a lower supporting plate (45);

the novel sliding seat comprises a first installation seat (41), wherein a cavity (411) is formed in the first installation seat, a sliding groove (412) is formed in the side wall of the first installation seat (41), the sliding groove (412) is communicated with the cavity (411), a first driving mechanism (42) is arranged in the cavity (411), each first sliding seat (43) comprises two groups, a lower supporting plate (45) is arranged on each first sliding seat (43), and the first sliding seats (43) penetrate through the sliding groove (412) and are connected with the first driving mechanism (42); the distance between the two lower support plates (45) is adjusted via the first drive mechanism (42).

2. The four-point bending test device according to claim 1, wherein the first driving mechanism (42) comprises a first adjusting rod (421) and a first limiting rod (422), the first adjusting rod (421) and the first limiting rod (422) are rotatably arranged in the cavity (411), a first sliding seat (43) penetrates through the sliding groove (412) and then stretches into the cavity (411), a first sliding block (434) and a second sliding block (435) are connected to the first sliding block (434) and are in sliding fit with the first adjusting rod (421), and the second sliding block (435) is in sliding fit with the first limiting rod (422), and a first adjusting part (423) is connected to one end of the first adjusting rod (421) after penetrating through the side wall of the first mounting seat (41).

3. The four-point bending test device according to claim 2, wherein the first sliding seat (43) has a rectangular frame structure, a notch is formed in a portion of the first sliding seat (43) located in the cavity (411), and the first sliding block (434) and the second sliding block (435) are respectively disposed on two side walls of the notch.

4. The four-point bending test device according to claim 2, wherein the first sliding seat (43) comprises a top plate (431) and a third connecting rod (436), the third connecting rod (436) is arranged on the side wall of the top plate (431) and penetrates through the sliding groove (412), and the third connecting rod (436) penetrates through the sliding groove (412) and then is connected with the first sliding block (434) and the second sliding block (435).

5. The four-point bending test device according to claim 1, wherein a first mounting groove (430) is formed in the top of the first sliding seat (43), and the lower support plate (45) is disposed in the first mounting groove (430) and is fixed by a locking member.

6. A four-point bending test device according to claim 1, wherein the lower support plate (45) is provided with a lower support roller (451) at its end in rotation.

7. The four-point bending test device according to claim 1, wherein a limiting member (5) is slidably arranged on the side wall of the lower support plate (45), a long hole (51) is formed in the limiting member (5), a positioning member (452) is arranged on the lower support plate (45), the positioning member (452) penetrates through the long hole (51), and the limiting member (5) can move relative to the positioning member (452) within the range of the long hole (51).

8. The four-point bending test device according to claim 1, wherein the upper pressure head (3) comprises a second mounting seat (31), a second driving mechanism (32), a second sliding seat (33) and an upper pressure plate (34), the second driving mechanism (32) is rotatably arranged on the second mounting seat (31), the second sliding seats (33) are provided with two groups, the number of the upper pressure plate (34) corresponds to the number of the second sliding seats (33), the upper pressure plate (34) is arranged on the corresponding second sliding seats (33), the two second sliding seats (33) are arranged on the second driving mechanism (32), and the two second sliding seats (33) are relatively close to or far away from each other on the second driving mechanism (32).

9. The four-point bending test device according to claim 8, wherein the second driving mechanism (32) comprises a second adjusting rod (322) and two second limiting rods (321), the two second limiting rods (321) are symmetrically arranged, the second adjusting rod (322) is located between the two second limiting rods (321), the second adjusting rod (322) is rotatably arranged on the second mounting seat (31), and the two second limiting rods (321) are fixedly arranged on the second mounting seat (31);

the second sliding seat (33) is provided with first through holes corresponding to the two second limiting rods (321), the two second limiting rods (321) penetrate through the first through holes, second through holes are formed between the two first through holes, ball nuts (333) matched with the second adjusting rods (322) are arranged in the second through holes, and the second adjusting rods (322) penetrate through the ball nuts (333).

10. The four-point bending test device according to claim 8, wherein a second mounting groove (331) is formed in the top of the second sliding seat (33), and the upper pressing plate (34) is disposed in the second mounting groove (331) and is fixed by a locking member;

an upper supporting roller (35) is rotatably arranged at the end part of the upper pressing plate (34).