Auxiliary positioning device with COD gauge protection function for CTOD test and use method of auxiliary positioning device

Abstract

The invention relates to the technical field of CTOD tests, in particular to an auxiliary positioning device with a COD gauge protection function for a CTOD test and a use method of the auxiliary positioning device. The auxiliary positioning device comprises a base, sliding adjusting rulers and a COD gauge protective sleeve, the base is fixed on the sample carrying table, sliding adjusting structures are arranged on the two sides of the base respectively, and each sliding adjusting structure is composed of two sliding adjusting rulers which are symmetrically arranged and a sliding locking bolt; a COD gauge protection sleeve is arranged at the center of the base and can contain a COD gauge. The auxiliary positioning device not only can quickly and accurately position the span of the supporting roller, but also can effectively protect the COD gauge from being damaged in the test process, and the test precision, efficiency and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of CTOD test, and particularly relates to an auxiliary positioning device for CTOD test with COD gauge protection function and its using method. Background Art

[0002] CTOD (Crack Tip Opening Displacement) test is a test for evaluating the fracture resistance ability of the crack tip of metal materials, and is one of the core methods for evaluating the fracture toughness of materials, which has important application value in the fields of ocean engineering, pressure vessels, etc. The commonly used specimen types include compact tension specimens and three-point bending specimens.

[0003] When using a three-point bending specimen for testing, it is necessary to support the specimen through two supporting rollers below, and then press the specimen tightly through the upper indenter above. During the test, it is required that the two supporting rollers forming the specimen fixture are parallel to each other and perpendicular to the axial direction of the specimen stage. The distance between the two supporting rollers is called the span. According to the different sizes of the specimens, the span needs to be adjusted according to the standard requirements. Although there are slide rails between the two supporting rollers and the specimen stage, the gap of the slide rails is large and cannot meet the test requirements. The conventional method for adjusting the span is to measure with a vernier caliper and then manually adjust. However, due to the lack of a positioning device between the vernier caliper and the supporting rollers, it can only rely on the operator's visual observation, resulting in inaccurate span measurement and unable to ensure the position accuracy and parallelism of the supporting rollers, thus affecting the accuracy of the test.

[0004] COD gauge (clip-on extensometer) is used to measure the crack mouth opening displacement (CMOD), and synchronously records the load-displacement curve in combination with a load sensor, and is one of the indispensable important measuring instruments for CTOD test. However, during the low-temperature CTOD test, the specimen may have brittle fracture, and the COD gauge is located directly below the specimen, and the specimen after brittle fracture may damage the COD gauge. At present, the main measure for protecting the COD gauge is to suspend the test during the test process and remove the COD gauge, which directly affects the test efficiency.

[0005] In view of this, the present invention provides a device to solve the above problems, which is convenient for adjusting the span when replacing specimens of different sizes, can not only ensure that the two supporting rollers are parallel to each other and perpendicular to the specimen stage, but also effectively protect the COD gauge from being damaged by the brittle fracture specimen. The present invention can improve the accuracy of the test, greatly save the time cost of sample replacement and COD gauge removal, and improve the test efficiency. Summary of the Invention

[0006] The present invention provides an auxiliary positioning device for CTOD test with COD gauge protection function and its using method. The auxiliary positioning device can not only quickly and accurately position the span of the supporting rollers, but also effectively protect the COD gauge from being damaged during the test, improving the accuracy, efficiency and safety of the test.

[0007] To achieve the above object, the present invention is implemented by the following technical solutions:

[0008] An auxiliary positioning device for CTOD test with COD gauge protection function. On the loading table of the CTOD testing machine, 2 supporting roller seats are movably arranged. Supporting rollers are arranged on the supporting roller seats. The auxiliary positioning device is installed on the loading table between the 2 supporting roller seats; the auxiliary positioning device includes a base, a sliding adjustment scale and a COD gauge protection sleeve. The base is fixed on the loading table. Sliding adjustment structures are respectively arranged on both sides of the base. The sliding adjustment structure is composed of 2 symmetrically arranged sliding adjustment scales and sliding locking bolts. The sliding adjustment scale can horizontally slide along the sliding groove opened on the base and is locked and fixed by the sliding locking bolt; the inner positioning surface of the supporting roller seat abuts against the positioning plate at the outer end of the corresponding side sliding adjustment scale; a COD gauge protection sleeve is arranged at the center of the base, and the COD gauge protection sleeve can accommodate the COD gauge.

[0009] A slide rail is arranged at the top of the loading table of the CTOD testing machine. Rail grooves are arranged at the bottoms of the 2 supporting roller seats and are slidably connected with the slide rail in a matching manner.

[0010] The base is an inverted U-shaped structure composed of a flat plate and 2 side plates. The flat plate is placed on the top of the loading table, and the side plates are attached to the corresponding side surfaces of the loading table; sliding grooves are arranged at both ends of the side plates, and fixing bolt holes are arranged in the middle. Fixing locking bolts are installed in the fixing bolt holes.

[0011] The sliding adjustment scale is a T-shaped structure composed of a sliding plate and a positioning plate. The sliding plate is arranged in the sliding groove, and the outer end of the sliding plate is connected with the positioning plate; bolt mounting seats are arranged on the side plates in the middle of the sliding groove for installing the sliding locking bolts.

[0012] A scale is arranged on the outer side of the sliding groove of the side plate.

[0013] The COD gauge protection sleeve is a cylindrical structure, with a diameter larger than the maximum radial dimension of the COD gauge and a height larger than the height of the COD gauge; a lead wire groove is arranged on one side of the COD gauge protection sleeve.

[0014] A positioning groove is arranged at the center of the base, and the COD gauge protection sleeve is embedded in the positioning groove.

[0015] The using method of the auxiliary positioning device for CTOD test with COD gauge protection function includes the following steps:

[0016] 1) Insert 4 sliding adjustment scales into the corresponding sliding grooves on the base, adjust the extended length according to the scale, and then lock and fix with the sliding locking bolts;

[0017] 2) Embed the COD gauge protection sleeve into the positioning groove at the top of the base, and make the lead wire groove on the COD gauge protection sleeve face the direction of the operator.

[0018] 3) Place the assembled auxiliary positioning device on the specimen stage of the CTOD testing machine. Align the center scribed line pre-marked outside the fixed bolt holes with the center scribed lines pre-marked on both sides of the specimen stage to ensure that the longitudinal central axis of the auxiliary positioning device coincides with the transverse central axis of the specimen stage. Then tighten the fixed locking bolts.

[0019] 4) Slide the two support roller seats along the slide rails on the specimen stage until the inner positioning surfaces of the two support roller seats are tightly pressed against the positioning plates of the corresponding sliding adjusting rulers. Then lock the fixed bolts of the support roller seats. At this time, the span between the two support rollers is adjusted, and the two support rollers are parallel to the upper pressure head, and the axial directions of the two support rollers are perpendicular to the longitudinal direction of the specimen stage.

[0020] 5) Place the specimen on top of the two support rollers and press it tightly with the upper pressure head. Install the COD gauge at the bottom of the specimen, place the lower end of the COD gauge in the COD gauge protective sleeve, and lead out the cable of the COD gauge from the lead wire groove to connect with external equipment.

[0021] 6) Start the CTOD test. During the test, if the specimen undergoes brittle fracture, the COD gauge will fall into the COD gauge protective sleeve, which can avoid damaging the COD gauge due to direct collision of the specimen.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1) By using the described auxiliary positioning device, when the size of the specimen changes, the span of the two support rollers can be quickly and accurately adjusted and positioned, and the adjustment is convenient, effectively improving the test efficiency.

[0024] 2) By using the described auxiliary positioning device, the parallelism between the two support rollers and the upper pressure head during the CTOD test, as well as the perpendicularity between the two support rollers and the specimen stage of the CTOD testing machine, can be ensured, which is beneficial to improving the test accuracy.

[0025] 3) The described auxiliary positioning has a COD gauge protection function, which can effectively protect the COD gauge from being damaged when the specimen undergoes brittle fracture, improving the safety of the test and avoiding economic losses.

[0026] 4) The device has a simple structure, is convenient to manufacture and use, has a low manufacturing cost, and has a good use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic three-dimensional structure diagram of the auxiliary positioning device of the present invention.

[0028] Figure 2 is a front view of the auxiliary positioning device of the present invention.

[0029] Figure 3 It is a schematic diagram of the usage state of the auxiliary positioning device described in the present invention.

[0030] In the figure: 1. Auxiliary positioning device; 1-1. Base; 1-2. Slide groove; 1-3. Slide adjusting ruler; 1-4. Slide locking bolt; 1-5. Fixed locking bolt; 1-6. COD gauge protective cover; 1-7. Lead wire groove; 2. Specimen loading table; 3. Support roller; 4. Support roller seat; 5. Upper pressure head; 6. COD gauge; 7. Specimen Specific embodiments

[0031] The following further describes the specific embodiments of the present invention with reference to the accompanying drawings:

[0032] As Figures 1 - 3 shown, for the auxiliary positioning device for CTOD test with COD gauge protection function described in the present invention, two support roller seats 4 are movably arranged on the specimen loading table 2 of the CTOD testing machine. A support roller 3 is arranged on the support roller seat 4. The auxiliary positioning device 1 is installed on the specimen loading table 2 between the two support roller seats 4. The auxiliary positioning device 1 includes a base 1-1, a slide adjusting ruler 1-3 and a COD gauge protective cover 1-6. The base 1-1 is fixed on the specimen loading table 2. Slide adjusting structures are respectively arranged on both sides of the base 1-1. The slide adjusting structure is composed of two symmetrically arranged slide adjusting rulers 1-3 and a slide locking bolt 1-4. The slide adjusting ruler 1-3 can horizontally slide along the slide groove 1-2 opened on the base 1-1 and is locked and fixed by the slide locking bolt 1-4. The inner positioning surface of the support roller seat 4 abuts against the positioning plate at the outer end of the corresponding side slide adjusting ruler 1-3. A COD gauge protective cover 1-6 is arranged at the center of the base 1-1. The COD gauge protective cover 1-6 can accommodate the COD gauge 6.

[0033] A slide rail is arranged at the top of the specimen loading table 2 of the CTOD testing machine. Rail grooves are arranged at the bottoms of the two support roller seats 4 and are slidably connected with the slide rail in a matching manner.

[0034] The base 1-1 is an inverted U-shaped structure composed of a flat plate and two side plates. The flat plate is placed on the top of the specimen loading table 2, and the side plates are attached to the corresponding sides of the specimen loading table 2. Slide grooves 1-3 are arranged at both ends of the side plates, and fixed bolt holes are arranged in the middle. The fixed locking bolt 1-5 is installed in the fixed bolt holes.

[0035] The slide adjusting ruler 1-3 is a T-shaped structure composed of a slide plate and a positioning plate. The slide plate is arranged in the slide groove 1-2, and the outer end of the slide plate is connected with the positioning plate. A bolt mounting seat is arranged on the side plate in the middle of the slide groove 1-2 for installing the slide locking bolt 1-4.

[0036] A scale is arranged on the outer side of the side plate of the slide groove 1-2.

[0037] The COD gauge protective sleeve 1-6 is in a cylindrical structure, with a diameter larger than the maximum radial dimension of the COD gauge 6 and a height larger than the height of the COD gauge 6; a lead wire groove 1-7 is provided on one side of the COD gauge protective sleeve 1-6.

[0038] A positioning groove is provided at the center of the base 1-1, and the COD gauge protective sleeve 1-6 is fitted into the positioning groove.

[0039] The usage method of the auxiliary positioning device for CTOD test with COD gauge protection function according to the present invention includes the following steps:

[0040] 1) Insert 4 sliding adjustment rulers 1-3 into the corresponding sliding grooves 1-2 on the base 1-1, adjust the extended length according to the scale, and then lock and fix with the sliding locking bolt 1-4;

[0041] 2) Insert the COD gauge protective sleeve 1-6 into the positioning groove at the top of the base 1-1, and make the lead wire groove 1-7 on the COD gauge protective sleeve 1-6 face the direction of the operator;

[0042] 3) Place the assembled auxiliary positioning device 1 on the sample stage 2 of the CTOD testing machine, align the center marking pre-marked outside the fixing bolt hole with the center markings pre-marked on both sides of the sample stage 2, ensure that the longitudinal central axis of the auxiliary positioning device 1 coincides with the transverse central axis of the sample stage 2, and then tighten the fixing locking bolt 1-5;

[0043] 4) Slide the 2 supporting roller seats 4 along the slide rails on the sample stage 2 until the inner positioning surfaces of the 2 supporting roller seats 4 are tightly pressed against the positioning plates of the corresponding side sliding adjustment rulers 1-3, and then lock the fixing bolts of the supporting roller seats 4. At this time, the span between the 2 supporting rollers 3 is adjusted, and the 2 supporting rollers 3 are parallel to the upper pressure head 5, and the axial direction of the 2 supporting rollers 3 is perpendicular to the longitudinal direction of the sample stage 2;

[0044] 5) Place the specimen 7 on the tops of the 2 supporting rollers 3 and press it tightly with the upper pressure head 5; install the COD gauge 6 at the bottom of the specimen 7, place the lower end of the COD gauge 6 into the COD gauge protective sleeve 1-6, and lead out the cable of the COD gauge 6 from the lead wire groove 1-7 to connect with external equipment;

[0045] 6) Start the CTOD test; during the test, if the specimen 7 undergoes brittle fracture, the COD gauge 6 will fall into the COD gauge protective sleeve 1-6, which can avoid damaging the COD gauge 6 due to the direct collision of the specimen 7.

[0046] For the auxiliary positioning device for CTOD test with COD gauge protection function according to the present invention, the functions of each part are as follows:

[0047] 1. To ensure the precise adjustment of the distance (span) between the two support rollers, sliding positioning rulers are respectively arranged at the four corners of the auxiliary positioning device, which can not only measure and position the distance between the two support rollers, but also ensure the parallelism between the two support rollers. The sliding positioning rulers slide along the sliding grooves, facilitating the adjustment of the extended length.

[0048] 2. After the sliding positioning rulers slide along the sliding grooves and are adjusted in place, they can be locked and fixed by the sliding locking bolts.

[0049] 3. To ensure that the central axis of the auxiliary positioning device is perpendicular to the central axis of the sample stage, the base adopts a U-shaped structure, and the two side plates are closely attached to the sides of the sample stage. By aligning the central scribing pre-marked outside the fixed bolt holes with the central scribing pre-marked on both sides of the sample stage, and then locking and fixing with the fixed locking bolts.

[0050] 4. The COD gauge protective sleeve and the positioning groove on the base adopt a transition fit, which is convenient for installation and ensures that it will not loosen easily. The COD gauge protective sleeve is arranged directly below the COD gauge, which can effectively protect the COD gauge; a wire leading groove is opened on the COD gauge protective sleeve to facilitate the leading out of the cable of the COD gauge.

[0051] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent replacements or changes, and should be covered by the protection scope of the present invention.

Claims

1. An auxiliary positioning device for CTOD test with COD gauge protection function. Two support roller seats are movably arranged on the sample loading table of the CTOD testing machine. Support rollers are arranged on the support roller seats. The auxiliary positioning device is installed on the sample loading table between the two support roller seats. It is characterized in that The auxiliary positioning device includes a base, a sliding adjustment scale and a COD gauge protective sleeve. The base is fixed on the specimen stage. Sliding adjustment structures are respectively arranged on both sides of the base. The sliding adjustment structure consists of two symmetrically arranged sliding adjustment scales and a sliding locking bolt. The sliding adjustment scale can horizontally slide along the chute opened on the base and is locked and fixed by the sliding locking bolt. The inner positioning surface of the support roller seat abuts against the positioning plate at the outer end of the corresponding side sliding adjustment scale. A COD gauge protective sleeve is arranged at the center of the base, and the COD gauge protective sleeve can accommodate the COD gauge.

2. The auxiliary positioning device for CTOD test with COD gauge protection function according to claim 1, characterized in that, A slide rail is arranged at the top of the specimen stage of the CTOD testing machine. Rail grooves are arranged at the bottoms of the two support roller seats and are slidably connected with the slide rail in a matching manner.

3. The auxiliary positioning device for CTOD test with COD gauge protection function according to claim 1, characterized in that, The base is an inverted U-shaped structure composed of a flat plate and two side plates. The flat plate is placed on the top of the specimen stage, and the side plates are attached to the corresponding side surfaces of the specimen stage. Chutes are arranged at both ends of the side plates, and fixing bolt holes are arranged in the middle. The fixing locking bolt is installed in the fixing bolt hole.

4. The auxiliary positioning device for CTOD test with COD gauge protection function according to claim 1, characterized in that, The sliding adjustment scale is a T-shaped structure composed of a sliding plate and a positioning plate. The sliding plate is arranged in the chute, and the outer end of the sliding plate is connected with the positioning plate. A bolt mounting seat is arranged on the side plate in the middle of the chute for installing the sliding locking bolt.

5. The auxiliary positioning device for CTOD test with COD gauge protection function according to claim 4, characterized in that, A scale is arranged on the outer side of the chute of the side plate.

6. The auxiliary positioning device for CTOD test with COD gauge protection function according to claim 1, characterized in that, The COD gauge protective sleeve is a cylindrical structure, with a diameter larger than the maximum radial dimension of the COD gauge and a height larger than the height of the COD gauge. A lead wire groove is arranged on one side of the COD gauge protective sleeve.

7. The auxiliary positioning device for CTOD test with COD gauge protection function according to claim 1, characterized in that, A positioning groove is arranged at the center of the base, and the COD gauge protective sleeve is embedded in the positioning groove.

8. The method of using the auxiliary positioning device for CTOD test with COD gauge protection function according to any one of claims 1 to 7, characterized in that, It includes the following steps: 1) Insert the four sliding adjustment scales into the corresponding chutes on the base, adjust the extended length according to the scale, and then lock and fix them with the sliding locking bolts. 2) Embed the COD gauge protective sleeve into the positioning groove at the top of the base, and make the lead wire groove on the COD gauge protective sleeve face the direction of the operator. 3) Place the assembled auxiliary positioning device on the specimen stage of the CTOD testing machine, align the center marking pre-marked outside the fixing bolt hole with the center markings pre-marked on both sides of the specimen stage to ensure that the longitudinal central axis of the auxiliary positioning device coincides with the transverse central axis of the specimen stage, and then tighten the fixing locking bolt. 4) Slide the two support roller seats along the slide rail on the specimen stage until the inner positioning surfaces of the two support roller seats abut against the positioning plates of the corresponding side sliding adjustment scales, and then lock the fixing bolts of the support roller seats. At this time, the span between the two support rollers is adjusted, and the two support rollers are parallel to the upper pressure head, and the axes of the two support rollers are perpendicular to the longitudinal direction of the specimen stage. 5) Place the specimen on the tops of the two support rollers and press it tightly with the upper pressure head; install the COD gauge at the bottom of the specimen, place the lower end of the COD gauge in the COD gauge protective sleeve, and lead out the cable of the COD gauge from the lead wire groove to connect with external equipment. 6) Start the CTOD test; during the test, if the specimen undergoes brittle fracture, the COD gauge will fall into the COD gauge protective sleeve, which can avoid damaging the COD gauge due to direct collision of the specimen.

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