CN115753443B - Tool for thermal extension test and thermal extension test device - Google Patents

Abstract

The invention relates to the technical field of thermal extension test devices, in particular to a tool for thermal extension test and a thermal extension test device, wherein the tool comprises a tool frame, a weight assembly and a release mechanism, the tool frame comprises a cross beam, the release mechanism is arranged on the cross beam and is used for releasably clamping the upper end of a dumbbell sample, the weight assembly comprises a main body part and two hanging rods respectively connected to two sides of the main body part, and the gravity center of the weight assembly is positioned above the hanging rods; the weight assembly comprises a weight assembly, wherein the weight assembly is arranged on the weight assembly, brackets are arranged on two sides of the weight assembly at intervals, the brackets on two sides of the weight assembly are arranged at intervals relatively to form a space for the main body part to freely fall, the brackets comprise mounting surfaces for mounting the hanging rod after the weight assembly falls, and the hanging rod can rotate relative to the mounting surfaces. The tool provided by the invention is applied to a thermal extension test, can automatically release the weight assembly on the premise of not opening the oven, and can avoid the phenomenon that the dumbbell sample is adhered to influence the test process.

Description

Tool for thermal extension test and thermal extension test device

Technical Field

The invention relates to the technical field of thermal extension test devices, in particular to a tool for thermal extension test and a thermal extension test device.

Background

In the thermal extension test of the cable, the main process is to firstly manufacture a dumbbell sample for replacing the cable product, then clamp the dumbbell sample by using a tool, specifically fix the upper end of the dumbbell sample, hang weights at the lower end to serve as loads, and put the whole into an oven for thermal extension test at a set temperature, when the set time period expires, remove the weights, and obtain a detection result by measuring the distance change between two gauge lines on the dumbbell sample.

In the process, the traditional operation of detaching the weight is that the dumbbell sample is sheared by utilizing a tool such as scissors to be close to the position of the lower end, so that the weight falls off from the dumbbell sample, however, the shearing requirement of the scissors opens the oven to operate, so that the weight is easy to scald and is not safe enough, the temperature in the oven can be influenced, and the distance between two gauge lines of the dumbbell sample can be influenced.

Therefore, in the related art, in order to enable the dumbbell to be dismounted without opening the oven, a release mechanism capable of being automatically released is generally arranged on the weight to clamp the lower end of the dumbbell, so that when the weight needs to be dismounted, the release mechanism releases the dumbbell and the weight falls along with the release mechanism, for example, the invention patent application with publication number of CN115219345A discloses a cable insulation thermal extension test device and a test method, in the application, a normally closed pneumatic clamp (namely the release mechanism) is arranged, and a high-pressure air flow is filled into the normally closed pneumatic clamp through a control air source of the electromagnetic valve to enable the normally closed pneumatic clamp to be separated from the lower end of a dumbbell sample, so that the normally closed pneumatic clamp falls along with a load weight, and the purpose of dismounting the weight is achieved; however, in this way, the weight of the load at the lower end of the dumbbell is equivalent to the sum of the weights and the weight of the pneumatic clamp, and an automatic release mechanism similar to the pneumatic clamp exists, which has a pipe and/or wire connection (for example, the pneumatic clamp described above is necessarily provided with a gas pipe connected with the pneumatic clamp), which is associated with the pneumatic clamp, so that the existence of the pipe and the wire makes it difficult to accurately calculate the total weight of the load at the lower end of the dumbbell, and the accuracy of the total weight of the load cannot be guaranteed, thereby affecting the accuracy of the test.

Disclosure of Invention

In order to solve at least one technical problem mentioned in the background art, the invention aims to provide a tool for a thermal extension test and a thermal extension test device.

In order to achieve the above purpose, the present invention provides the following technical solutions:

the tool for the thermal extension test comprises a tool frame, a weight assembly and a release mechanism, wherein the tool frame comprises a cross beam, the weight assembly is used for being hung at the lower end of a dumbbell sample, the release mechanism is arranged on the cross beam and used for releasably clamping the upper end of the dumbbell sample, the weight assembly comprises a main body part and two hanging rods which are respectively connected to two sides of the main body part and transversely extend, and the gravity center of the weight assembly is positioned above the hanging rods; brackets are arranged on two sides of the weight assembly, are positioned at the bottom of the cross beam and are kept in position relative to the cross beam; the brackets on two sides of the weight assembly are arranged at opposite intervals to form a space for the main body part to freely fall, and each bracket comprises a mounting surface for mounting the hanging rod after the weight assembly falls, wherein the hanging rod can rotate relative to the mounting surface.

Compared with the prior art, the scheme has the advantages that:

firstly, through the upper end at the dumbbell sample through release mechanism centre gripping in this scheme, so when using, only need control release mechanism release dumbbell sample, dumbbell sample and weight subassembly alright free fall together, realize the dismantlement of weight, compare the lower extreme mode of locating the dumbbell sample with release mechanism with the relevant technique in this scheme, release mechanism does not regard as the load of dumbbell sample lower extreme in this scheme, therefore its structure can not influence the load weight that the dumbbell sample lower extreme hung, basically do not influence to the experiment, the load of dumbbell sample lower extreme is basically constituted by the weight subassembly, and the weight of weight subassembly is clear, therefore can guarantee the accuracy of experiment. In the manner of clamping the weight at the lower end of the dumbbell through the release mechanism, the weight and the release mechanism are used as a load, so that the total weight of the load is affected by a part of the structure (such as a pipeline or a wire) of the release mechanism, and the weight of the load is not clear, thereby affecting the accuracy of the test.

Secondly, the release mechanism is arranged at the upper end of the dumbbell sample, when the dumbbell sample is released by the release mechanism, the dumbbell sample can fall along with the weight component, and the dumbbell sample is generally made of rubber and other materials, and can be melted to a certain extent at high temperature, so that when the dumbbell sample falls, the dumbbell sample can be adhered to the bottom of the tool rack if falling to the bottom of the tool rack, and further the subsequent test is affected; in addition, the dumbbell-shaped part of the dumbbell-shaped part is likely to be folded in the falling process, so that the folded parts are mutually adhered, and the subsequent test is affected.

Based on the above-mentioned process, in this scheme, through set up the peg in the both sides of weight subassembly, the bottom setting at the crossbeam is located weight subassembly both sides bracket, so dumbbell sample is being released the back, weight subassembly and dumbbell sample drop down, in the in-process that drops, the peg of weight subassembly both sides can finally hang on the mount face of both sides bracket and be hung, the weight subassembly just is unsettled to hang at this moment and can't continue to fall, and the focus of weight subassembly is located the upper portion of peg in this scheme, and the peg can be for mount face pivoted, so when the peg is hung on the mount face, weight subassembly can overturn 180 along with the peg down under the dead weight, the dumbbell sample that the weight subassembly was in-process of upset can drive centre of gravity is overturned together, thereby get rid of dumbbell sample to the downside of weight subassembly, at this moment just can be hung by the downside of hanging at the weight subassembly, avoid with the bottom adhesion of frock frame, in addition, the dumbbell sample is with the upset of the mode of turning over 180 place of weight subassembly, can guarantee that the follow-up test of the area of can be folded normally each other.

Preferably, a slot opening which extends vertically to enable the hanging rod to move vertically is formed in one side of the bracket, facing the hanging rod, and the mounting surface is formed at the bottom of the slot opening.

Preferably, the hanging rod is of a round rod structure, and the bottom of the notch is of an arc surface.

Preferably, the upper end of the notch is provided with an opening, and the notch is gradually narrowed from top to bottom.

Preferably, the release mechanism comprises two movable chucks movably arranged along the length direction of the cross beam and a linkage assembly for driving the two movable chucks to be close to or far away from each other along the length direction of the cross beam, first steps are arranged at the bottoms of the side walls of the opposite sides of the two movable chucks, and first baffle plates are arranged on the outer sides of the first steps.

Preferably, the linkage assembly comprises a sliding block and a linkage block, wherein the sliding block and the linkage block are arranged on the back side of the movable chuck and are arranged in a sliding manner along the length direction of the cross beam, the linkage block is positioned between the sliding blocks on the two movable chucks and can vertically move, a first inclined guide surface is formed on the side wall of each of the two sliding blocks facing the two sliding blocks, a second inclined guide surface is formed on one side of each of the two sliding blocks facing the first inclined guide surface, and when the linkage block is vertically pushed downwards, the first inclined guide surface acts on the second inclined guide surface to enable the two sliding blocks to slide in a direction away from each other; a tension spring for driving the two sliding blocks to be close to each other is further arranged between the two sliding blocks.

Preferably, a linkage shaft is arranged at the top of the linkage block, the linkage shaft extends vertically, and the upper end of the linkage shaft movably penetrates out of the top of the cross beam.

Preferably, the main body part comprises a weight box, a cavity for accommodating weights is formed in the weight box, the cavity comprises a cavity opening, and a cover plate which is used for sealing the cavity opening and can be opened is arranged at the position of the cavity opening of the weight box.

The invention further provides a thermal extension test device, which comprises an oven and a tool, wherein the oven is provided with a detection mechanism for detecting the distance between gauge lines on a dumbbell sample, and the tool adopts the tool for thermal extension test; the test device further comprises a pushing mechanism for vertically pushing the linkage shaft downwards.

Preferably, the pushing mechanism comprises a motor, a screw rod and a guide rod, the guide rod vertically movably penetrates through the top of the oven, a pushing head which is positioned in the oven and used for pushing the linkage shaft downwards is arranged at the bottom of the guide rod, a connecting rod in threaded connection with the screw rod is arranged at the upper end of the guide rod, and the screw rod vertically extends and is driven to rotate by the motor.

Additional advantages and effects of the invention are set forth in the detailed description and drawings.

Drawings

Fig. 1 is a schematic structural view (in an initial state) of embodiment 1;

fig. 2 is a schematic structural view (in a towed state) of embodiment 1;

fig. 3 is a front view (in a towed state) of embodiment 1;

FIG. 4 is a schematic structural view of the bracket;

FIG. 5 is a schematic view of the structure of the release mechanism;

FIG. 6 is an exploded view of the release mechanism;

FIG. 7 is a schematic view of a movable chuck;

FIG. 8 is a schematic structural view of a weight assembly;

FIG. 9 is a schematic view of the bottom structure of the weight assembly;

fig. 10 is a schematic structural view of embodiment 2;

fig. 11 is a schematic view of the internal structure of embodiment 2;

fig. 12 is a schematic structural view of the pushing mechanism.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Referring to fig. 1-9, the present embodiment provides a tool for thermal extension test, which includes a tool frame 1, a weight assembly 2 and a release mechanism, and the tool provided in the present embodiment is mainly used for clamping a dumbbell sample during thermal extension test, as shown in fig. 1 and 2, and in fig. 8, the dumbbell sample is shown at a portion a. The two end mechanisms of the dumbbell sample in the dumbbell sample embodiment are basically the same, and have no substantial distinguishing significance, but for convenience of explanation, one end of the dumbbell sample connected with the weight assembly 2 is denoted as the lower end of the dumbbell sample in this embodiment, and the corresponding other end is denoted as the upper end of the dumbbell sample.

As shown in fig. 1, the tool rack 1 mainly comprises a base 12 and a cross beam 11, wherein the cross beam 11 is horizontally arranged above the base 12 through a stand column 13, and the release mechanism is arranged on the cross beam 11 and used for releasably clamping the upper end of a dumbbell sample.

The weight assembly 2 is used as a load and is used for being hung at the lower end of a dumbbell sample, and can be shown by referring to fig. 1; the weight assembly 2 comprises a main body part and two hanging rods 21 which are respectively connected to two sides of the main body part and transversely extend, and the two hanging rods 21 are symmetrically arranged on two sides of the main body part; the transverse direction is also understood here as the longitudinal direction of the transverse beam 11 or the extension direction of the transverse beam 11.

In an initial state, namely a state shown in fig. 1, the upper end of the dumbbell is clamped by the release mechanism, and the weight assembly 2 is naturally hung at the lower end of the dumbbell; the gravity center of the weight component 2 is located above the hanging rod 21, so that the weight component 2 can turn over under the dead weight when the hanging rod 21 is hung.

As shown in fig. 1-3, brackets 3 are arranged on two sides of the weight assembly 2, and the brackets 3 are fixedly arranged at the bottom of the cross beam 11 so as to keep positioning relative to the cross beam 11; the brackets 3 on two sides of the weight assembly 2 are arranged at intervals relatively to form a space for the main body part to freely fall, in an initial state, as shown in fig. 1, the weight assembly 2 is hung at the interval space position between the two brackets 3, and when the dumbbell sample is released by the release mechanism, the weight assembly 2 freely falls at the interval space position.

The brackets 3 each comprise a mounting surface 311 for mounting the mounting bar 21 after the weight assembly 2 is dropped, wherein the mounting bar 21 can rotate relative to the mounting surface 311, or the mounting bar 21 can rotate based on the mounting surface 311.

When the dumbbell is used, the dumbbell and the weight assembly 2 can fall freely together by controlling the release mechanism, so that the weight can be removed, and compared with the mode that the release mechanism is arranged at the lower end of the dumbbell in the related art, the release mechanism in the embodiment is not used as the load of the lower end of the dumbbell, so that the structure of the release mechanism does not influence the weight of the load hung at the lower end of the dumbbell, the test is basically not influenced, the load at the lower end of the dumbbell is basically formed by the weight assembly 2, and the weight of the weight assembly 2 is definite, so that the test accuracy can be ensured.

In the manner of clamping the weight at the lower end of the dumbbell through the release mechanism, the weight and the release mechanism are used as a load, so that the total weight of the load is affected by a part of the structure (such as a pipeline or a wire) of the release mechanism, and the weight of the load is not clear, thereby affecting the accuracy of test data.

In addition, the release mechanism is arranged at the upper end of the dumbbell sample, so that the unloading operation of weights can be realized, but when the dumbbell sample is released by the release mechanism, the dumbbell sample can fall along with the weight component 2, and the dumbbell sample is generally made of materials such as rubber and the like, and can be melted to a certain extent at high temperature, so that when the dumbbell sample falls, the dumbbell sample can be adhered to the bottom of the tool rack 1 if falling to the bottom of the tool rack 1, and further the subsequent test is influenced; in addition, the dumbbell sample is likely to fold in a part area in the falling process, so that the folding parts are mutually adhered, the follow-up test can be influenced, in particular, the dumbbell sample has certain retraction performance after the weight is removed, if the dumbbell sample is adhered, the retraction performance can be reduced or even can not be retracted, and the retraction rate of the dumbbell sample can not be checked.

Based on the above process, in this embodiment, the hanging rods 21 are disposed on two sides of the weight assembly 2, the brackets 3 disposed on two sides of the weight assembly 2 are disposed at the bottom of the cross beam 11, so that after the dumbbell is released, the weight assembly 2 and the dumbbell drop down, during the drop process, the hanging rods 21 on two sides of the weight assembly 2 are finally hung on the mounting surfaces 311 of the brackets 3 on two sides to be hung, at this time, the weight assembly 2 is suspended and cannot fall down continuously, in this case, the center of gravity of the weight assembly 2 is located at the upper part of the hanging rods 21, and the hanging rods 21 can rotate relative to the mounting surfaces 311, when the hanging rods 21 are hung on the mounting surfaces 311, the weight assembly 2 can be turned down by 180 ° together with the hanging rods 21 under the dead weight, the weight assembly 2 can drive the dumbbell clamped on the hanging rods to turn down together, so that the dumbbell is thrown to the lower side of the weight assembly 2, at this time, the dumbbell is towed on the lower side of the weight assembly 2, and enters the suspended and suspended state, namely, the state shown in fig. 2 and 3;

in the towing state, as shown in fig. 2 and 3, the weight assembly 2 is turned 180 ° and is mounted on the mounting surface 311 of the carrier through the hanging rod 21, at this time, the lower end of the dumbbell is located above the upper end of the dumbbell, the dumbbell is naturally towed in whole, and the lower end of the dumbbell is suspended above the base 12. In practical design, a certain vertical interval is required to be ensured between the supporting surface of the bracket 3 and the base 12, so that the upper end of the dumbbell sample is prevented from contacting with the base 12 in a towing state, and the dumbbell sample is prevented from being adhered to the base 12 of the tool frame 1.

In addition, the dumbbell is turned over to the lower position of the weight assembly 2 along with the weight assembly 2 in a way of turning over 180 degrees, and the dumbbell is not directly and vertically dropped down to the lower side of the weight assembly 2, so that the phenomenon that the partial areas of the dumbbell are mutually folded and adhered can be prevented, and the follow-up test can be normally performed. Moreover, the weight removing mode can also meet the weight removing requirement specified in GB 2951.21.

In addition, in other alternative embodiments, in order to realize multiple dumbbell-like tests at one time, as shown in fig. 1-3, a plurality of release mechanisms, weight assemblies 2 and brackets 3 may be provided, wherein the plurality of release mechanisms are sequentially arranged along the length direction of the cross beam 11, and each release mechanism corresponds to one weight assembly 2; the brackets 3 are sequentially distributed at intervals along the length direction of the cross beam 11, spaces for forming free falling spaces of the weight assemblies 2 are formed between two adjacent brackets 3 at intervals, and the weight assemblies 2 are located between two adjacent brackets 3 during use.

The specific structure of the bracket 3 is as follows: as shown in fig. 1 and fig. 4, a side of the bracket 3 facing the hanging rod 21 is provided with a notch 31 extending vertically for the hanging rod 21 to move vertically, specifically, in this embodiment, the bracket 3 is in a cylindrical structure with an open upper end, two lateral side walls of the bracket 3 are provided with the notch 31, so that the notches 31 on the opposite lateral side walls of two adjacent brackets 3 are respectively used for mounting two hanging rods 21 on the weight assembly 2; in addition, reinforcing ribs 312 are provided inside the bracket 3 in order to reinforce the strength of the bracket 3.

The mounting surface 311 is formed at the bottom of the slot 31, the hanging rod 21 falls vertically along the slot 31, and finally is hung at the bottom of the slot 31 and supported by the bottom of the slot, in addition, in order to ensure that the hanging rod 21 can rotate smoothly at the bottom of the slot, in this embodiment, the hanging rod 21 is in a round rod structure, as shown in fig. 4, and the bottom of the slot 31 is in an arc surface. The hanger bar 21 having such a round bar structure can be rotated on the mounting surface 311 formed by the arc-shaped groove bottom.

In order to facilitate the hanging rod 21 to be placed in the notch 31, in this embodiment, an opening is formed at the upper end of the notch 31; in addition, the notch 31 is gradually narrowed from top to bottom, for example, a V-shaped notch 31 is used. In addition, it should be noted that the tendency of the notch 31 to gradually narrow from top to bottom includes the situation that, as shown in fig. 4, the upper portion of the notch 31 has a straight groove structure, and gradually narrows from top to bottom from the lower end of the straight groove. This arrangement allows the upper end of the slot 31 to be open to a large extent to facilitate the insertion of the hanger bar 21.

In this embodiment, all the release mechanisms have substantially the same structure, so in this embodiment, one of the release mechanisms is taken as an example for explanation:

as shown in fig. 5 and 6, the release mechanism includes a fixed block 40 having a receiving cavity therein, and two movable chucks 41 movably disposed along the length direction of the cross beam 11, specifically, the two movable chucks 41 are plate-shaped and are slidably disposed on the front side wall of the fixed block 40, as shown in fig. 1 and 2.

Referring to fig. 6 and fig. 7, the two movable chucks 41 are symmetrically arranged, the bottoms of the side walls on opposite sides of the two movable chucks 41 are respectively provided with a first step 411, the first steps 411 are adapted to the inclined walls of the dumbbell-shaped end parts, the outer sides of the first steps 411 are provided with first baffle plates 412, and the embodiment further comprises a linkage assembly for driving the two movable chucks 41 to be close to or far away from each other along the length direction of the cross beam 11.

The two movable chucks 41 jointly clamp the upper end of the dumbbell sample, in the clamped state, as shown in fig. 1, the inclined walls on two sides of the upper end of the dumbbell sample are respectively clamped on the two first steps 411 of the two movable chucks 41 to prevent the dumbbell sample from falling down, the dumbbell sample is backed against the front end wall of the fixed block 40, and the first baffle 412 is located on the front side of the upper end of the dumbbell sample to form side limit for the dumbbell sample, so that the dumbbell sample is prevented from falling out from the front side of the fixed block 40.

The linkage assembly includes a sliding block 42 and a linkage block 43, which are disposed on the back side of the movable chuck 41 and slidably disposed along the length direction of the beam 11, specifically, two guide shafts 401 extending transversely (the transverse direction can be understood as the length direction of the beam 11) are disposed in the accommodating cavity of the fixed block 40, and the two sliding blocks 42 are slidably disposed on the two guide shafts 401, so as to realize transverse movement; a tension spring 44 is arranged between the two sliding blocks 42, wherein two ends of the tension spring 44 are respectively fixed with the two sliding blocks 42 to drive the two sliding blocks 42 to be close to each other.

The linkage block 43 is located in the accommodating cavity of the fixed block 40 and between the two sliding blocks 42, and the linkage block 43 can vertically move in the accommodating cavity; as shown in fig. 6, the two side walls of the linkage block 43 facing the two sliding blocks 42 respectively form first inclined guiding surfaces 431, and the two first inclined guiding surfaces 431 are gradually closed from top to bottom.

The two sliding blocks 42 form a second inclined guide surface 421 towards one side of the first inclined guide surface 431, and the two second inclined guide surfaces 421 are gradually closed from top to bottom, so that when the linkage block 43 is forced to push the linkage block 43 to move vertically downwards, the first inclined guide surface 431 pushes the second inclined guide surface 421, and the two sliding blocks 42 slide towards the direction away from each other against the pulling force of the tension spring 44, so that the two movable chucks 41 are driven to move away from each other, and at the moment, the two movable chucks 41 release the clamping of the upper ends of the dumbbell samples, and the dumbbell samples are released; when the force applied to the linkage block 43 is released, the two sliding blocks are pulled to be close to each other under the tension of the tension spring 44, so that the two movable chucks 41 are closed to clamp the upper end of the dumbbell, and when the two sliding blocks are closed, the second inclined guide surface 421 pushes the first inclined guide surface 431 to further enable the linkage block 43 to rise vertically and return to the initial position.

It should be noted that, by providing the linkage block 43, the first inclined guide surface 431 and the second inclined guide surface 421 cooperate with each other, the linkage block 43 can simultaneously drive the two sliding blocks 42 to move away from each other synchronously when moving down, and when the linkage block 43 is released, the two sliding blocks 42 can keep close to each other synchronously under the pulling of the tension spring 44.

In order to apply force to the linkage block 43, in this embodiment, a linkage shaft 432 is disposed at the top of the linkage block 43, the linkage shaft 432 extends vertically, and the upper end of the linkage shaft 432 penetrates through the top of the fixed block 40 to finally penetrate through the top of the beam 11. Thus, the downward movement of the link block 43 can be achieved by pressing the link shaft 432.

In order to change the weight of the weight assembly 2, in this embodiment, as shown in fig. 8 and 9, the main body portion includes a weight box 22, a cavity 221 for accommodating weights is provided in the weight box 22, the cavity 221 includes a cavity opening, the cavity opening is located at the bottom of the weight box 22, and a cover plate 222 for closing the cavity opening and capable of being opened is provided at the cavity opening position of the weight box 22, when in use, only the cover plate 222 is opened, weights with a predetermined number or weight are plugged into the cavity 221 through the cavity opening, and then the cover plate 222 is closed.

As shown in fig. 9, the cover plate 222 is specifically configured such that the cover plate 222 is horizontally rotatably disposed on the bottom wall of the weight box 22, and a spring bead 223 is disposed on the bottom wall of the weight box 22, and a clamping hole (not shown in view angle reason diagram) into which the spring bead 223 is clamped is correspondingly disposed on the side wall of the cover plate facing the side of the weight box 22 corresponding to the position of the spring bead 223, and when the cover plate 222 is rotated to rotate the clamping hole to the position of the spring bead 223, the spring bead 223 can be sprung into the clamping hole to fix the cover plate 222. When the cover plate 222 needs to be opened, the spring beads 223 can be contracted inwards to finally be separated from the clamping holes only by forcedly rotating the cover plate 222, and the cover plate 222 can be opened.

In addition, as shown in fig. 8, in this embodiment, in order to enable the weight assembly 2 to be mounted at the lower end of the dumbbell sample, the main body portion further includes a carrier plate 23 disposed at the top of the weight box 22, a clamping groove 231 for placing the lower end of the dumbbell sample is formed on the side wall of the carrier plate 23, the groove walls on two sides of the top of the clamping groove 231 are inclined towards the middle to form a second step 232, two second baffle plates 233 are respectively and fixedly disposed on the outer sides of the two second steps 232, when in use, the lower end of the dumbbell sample is placed in the clamping groove 231, and the inclined walls on two sides of the lower end of the dumbbell sample can be finally clamped at the positions of the two second steps 232, so that the whole weight assembly 2 cannot fall off the dumbbell sample directly, and the second baffle plates 233 can limit the side of the dumbbell sample, so as to avoid the dumbbell sample from falling out of the carrier plate 23 from the side.

Example 2

Referring to fig. 1-12, the present embodiment provides a thermal extension test apparatus based on embodiment 1, as shown in fig. 10, including an oven 5 and a tooling, wherein the tooling is used for the thermal extension test described in embodiment 1; the oven 5 is provided with a detection mechanism for detecting the distance between the gauge lines on the dumbbell sample, specifically, in this embodiment, taking the dumbbell sample with two gauge lines as an example, the detection mechanism is used for detecting the distance between the two gauge lines in the oven 5.

The detection mechanism may adopt a visual detection system, as shown in fig. 11, and includes a camera 51 and a processing module, where the camera 51 is installed on the back side of the oven 5 and is used for shooting and tracking the gauge length lines on the dumbbell sample in real time, and feeding back the shot result to the processing module, and processing and calculating the distance between the two gauge length lines through the processing module.

Of course, other detecting mechanisms capable of detecting the gauge line spacing in the oven 5 are also possible, and are not particularly limited herein.

In order to cooperate with the linkage shaft 432 in the release mechanism so that the release mechanism can release the dumbbell without opening the oven 5, the test apparatus further comprises in this embodiment a pushing mechanism 6 for pushing the linkage shaft 432 vertically downwards. Specifically:

referring to fig. 12, the pushing mechanism 6 includes a motor 61, a screw 62 and a guide rod 63, the motor 61 is fixedly installed on the top of the oven 5, the main shaft thereof is vertically downward, the screw 62 is vertically fixedly installed on the main shaft of the motor 61, and is driven by the motor 61 to rotate; the guide rods 63 are arranged, vertically and movably penetrate through the top of the oven 5, the upper ends of the two guide rods 63 are connected through a connecting rod 64, and the connecting rod 64 is in threaded connection with the lead screw 62.

The bottom of guide arm 63 is equipped with the push head 65 that is arranged in oven 5 and is used for pushing down universal driving shaft 432, in order to drive all universal driving shafts 432 action simultaneously, push head 65 is rectangular form structure in this embodiment, horizontal fixed mounting is in the lower extreme of two guide arms 63, so when using, the motor drives lead screw 62 rotation, lead screw 62 drives connecting rod 64 and moves down, and then drive guide arm 63 moves down, and then guide arm 63 drives push head 65 and moves down, push head 65 moves down the in-process downwardly extrusion universal driving shaft 432, realize the move down of universal driving shaft 432, and then accomplish the release action.

Before the test, clamping the dumbbell sample outside the oven 5 onto the tool, then putting the whole tool into the oven 5 at 200 ℃, tracking a gauge length line through the camera 51, keeping the oven 5 for 10min, pressing down through the pushing mechanism, and driving the release mechanism to release the dumbbell sample; and finally, taking out the whole tool and cooling for a period of time, and manually detecting the gauge length line spacing on the dumbbell sample again to finish the test action.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (10)

1. The tool for the thermal extension test comprises a tool frame, a weight assembly and a release mechanism, wherein the tool frame comprises a cross beam, the weight assembly is used for being hung at the lower end of a dumbbell sample, and the tool is characterized in that the release mechanism is arranged on the cross beam and used for releasably clamping the upper end of the dumbbell sample, the weight assembly comprises a main body part and two hanging rods which are respectively connected to two sides of the main body part and transversely extend, and the gravity center of the weight assembly is positioned above the hanging rods; brackets are arranged on two sides of the weight assembly, are positioned at the bottom of the cross beam and are kept in position relative to the cross beam; the brackets on two sides of the weight assembly are arranged at opposite intervals to form a space for the main body part to freely fall, and each bracket comprises a mounting surface for mounting the hanging rod after the weight assembly falls, wherein the hanging rod can rotate relative to the mounting surface.

2. A tool for thermal extension testing according to claim 1, wherein the side of the bracket facing the hanger bar is provided with a notch extending vertically for the hanger bar to move vertically, wherein the bottom of the notch forms the mounting surface.

3. The tool for thermal extension test according to claim 2, wherein the hanging rod is of a round rod structure, and the groove bottom of the notch is of an arc surface.

4. The tool for thermal extension test according to claim 2, wherein the notch is provided with an opening at an upper end and is gradually narrowed from top to bottom.

5. The tool for thermal extension test according to claim 1, wherein the release mechanism comprises two movable chucks movably arranged along the length direction of the cross beam and a linkage assembly for driving the two movable chucks to be close to or far away from each other along the length direction of the cross beam, first steps are arranged at bottoms of side walls of opposite sides of the two movable chucks, and first baffle plates are arranged on outer sides of the first steps.

6. The tool for thermal extension test according to claim 5, wherein the linkage assembly comprises a sliding block and a linkage block, the sliding block is arranged on the back side of the movable clamping head and is slidably arranged along the length direction of the cross beam, the linkage block is arranged between the sliding blocks on the two movable clamping heads and can vertically move, the two side walls of the linkage block, which face the two sliding blocks, respectively form a first inclined guide surface, the two sliding blocks, which face one side of the first inclined guide surface, form a second inclined guide surface, and when the linkage block is vertically pushed downwards, the first inclined guide surface acts on the second inclined guide surface to enable the two sliding blocks to slide in a direction away from each other; a tension spring for driving the two sliding blocks to be close to each other is further arranged between the two sliding blocks.

7. The tool for thermal extension test according to claim 6, wherein the linkage block is provided with a linkage shaft at the top, the linkage shaft extends vertically and the upper end of the linkage shaft is movably penetrated out of the top of the cross beam.

8. The tool for thermal extension test according to claim 1, wherein the main body portion comprises a weight box, a cavity for accommodating weights is formed in the weight box, the cavity comprises a cavity opening, and a cover plate which is used for sealing the cavity opening and can be opened is arranged at the position of the cavity opening of the weight box.

9. The thermal extension test device comprises an oven and a tool, wherein a detection mechanism for detecting the distance between gauge lines on a dumbbell sample is arranged on the oven; the test device further comprises a pushing mechanism for vertically pushing the linkage shaft downwards.

10. The thermal extension test device according to claim 9, wherein the pushing mechanism comprises a motor, a screw rod and a guide rod, the guide rod vertically movably penetrates through the top of the oven, a pushing head which is positioned in the oven and used for pushing the linkage shaft downwards is arranged at the bottom of the guide rod, a connecting rod in threaded connection with the screw rod is arranged at the upper end of the guide rod, and the screw rod vertically extends and is driven to rotate by the motor.