High-low temperature loading tensile clamp for a stretcher

Abstract

The application discloses a high-low temperature loading stretching clamp for a stretching machine and belongs to the technical field of stretching machine clamp design. The clamp comprises an upper stretching rod and a lower stretching rod, opposite ends of the upper stretching rod and the lower stretching rod are both connected with stretching clamp connectors, one end of the stretching clamp connector, which is far away from the upper stretching rod or the lower stretching rod, is connected with a stretching clamp through a thermal expansion screw rod, a sliding groove is formed in the inside of the stretching clamp, a sample clamp baffle is slidingly connected with the sliding groove, a spherical groove is arranged in the sample clamp baffle, a sample clamp for clamping a sample is arranged in the spherical groove, and the sample clamp is connected with the sample clamp baffle through surface contact. The stretching clamp is completely suitable for the high-low temperature oven of the stretching machine in the aspects of spatial size and service performance, can match common sample shapes and sizes, guarantees the uniaxiality in the stretching process and the accuracy of strain measurement, and has the advantages of low processing cost, simple operation and installation and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a high-low temperature loading tensile clamp for a tensile testing machine, and belongs to the technical field of tensile testing machine clamp design. BACKGROUND

[0002] With the continuous development of independent research and innovation in China, the demand for high-tech materials serving under extreme conditions is increasing, and the importance of high-low temperature material tensile testing is self-evident. With the advancement of the national deep space and deep sea exploration strategy, higher demands are placed on the mechanical properties of materials at extremely high and low temperatures. The testing and research of mechanical properties in a wide temperature range have become an important research direction in the field of metals.

[0003] In view of the limited operating space of the tensile testing machine high-low temperature oven and the complex situation of the clamp mechanism bearing temperature and stress cycles, while ensuring the unidirectionality of the sample force and the accuracy of the strain measurement, a high-low temperature loading tensile clamp that can match common sample shapes and sizes is needed. SUMMARY

[0004] In order to solve the above-mentioned problems existing at present, the present application provides a high-low temperature loading tensile clamp for a tensile testing machine.

[0005] The present application is realized by the following technical solutions:

[0006] A high-low temperature loading tensile clamp for a tensile testing machine, comprising an upper tensile rod and a lower tensile rod, the opposite ends of the upper tensile rod and the lower tensile rod are connected with a tensile chuck coupling head, the end of the tensile chuck coupling head away from the upper tensile rod or the lower tensile rod is connected with a tensile chuck through a thermal expansion screw rod, a sliding groove is formed in the inside of the tensile chuck, a sample chuck baffle is slidingly connected in the sliding groove, a spherical groove is arranged in the sample chuck baffle, a sample chuck for clamping a sample is arranged in the spherical groove, and the sample chuck is connected with the sample chuck baffle through surface contact.

[0007] In an embodiment of the present application, the end of the upper tensile rod and the lower tensile rod is provided with a through hole, a fastening bolt is arranged in the through hole, the end of the upper tensile rod and the lower tensile rod is connected with the tensile testing machine respectively through the fastening bolt, and a fastening nut is used for fixation.

[0008] In an embodiment of the present application, the opposite ends of the upper tensile rod and the lower tensile rod are connected with the tensile chuck coupling head through the fastening bolt and the fastening nut.

[0009] In an embodiment of the present application, a threaded hole is formed in the end of the tensile chuck coupling head away from the upper tensile rod or the lower tensile rod, the thermal expansion screw rod passes through the threaded hole of the tensile chuck coupling head and the tensile chuck to fix the tensile chuck coupling head and the tensile chuck.

[0010] In one embodiment of the present application, the side of the sample chuck stopper is provided with a slit, and the sample passes through the slit and is arranged in the sample chuck.

[0011] In one embodiment of the present application, the sample includes a sheet sample or a rod sample, the sample chuck includes a sheet sample chuck or a rod sample chuck, the sheet sample is fastened by sample chuck teeth arranged in the sheet sample chuck, and the outer side of the sample chuck teeth is matched with an inclined surface arranged in the sheet sample chuck; the rod sample is provided with threads at both ends, and the threads are connected with the rod sample chuck.

[0012] In one embodiment of the present application, the outer surface of the sample chuck is matched with a spherical groove in the sample chuck stopper.

[0013] In one embodiment of the present application, the width of the slit is 1-5 mm.

[0014] In one embodiment of the present application, the stretch chuck connector and the stretch chuck are detachable.

[0015] In one embodiment of the present application, the number of fastening bolts and fastening nuts is four; and the number of stretch chuck connectors, heat expansion threaded rods, stretch chucks and sample chuck stoppers is two.

[0016] Advantages

[0017] Compared with the prior art, the present application has the following advantages: first, the stretch clamp of the present application is completely suitable for the high-low temperature oven of the stretching machine in terms of spatial size and service performance, and can match common sample shapes and sizes. Second, the stretch clamp of the present application adopts fastening bolts and fastening nuts for connection, according to the principle of thermal expansion and cold contraction, the use of fastening bolts can ensure the stable connection of the stretch clamp at high temperature, and the use of fastening nuts can ensure the stable connection at room temperature and low temperature; and the outer surface of the sample chuck is matched with the spherical groove in the sample chuck stopper, so that the sample chuck is connected with the chuck stopper through surface contact, which can maximize the uniaxiality in the stretching process. At the same time, the stretch chuck designed in the present application is detachable, which can be replaced by a compression or three-point bending clamp. The above ensures the universality of the stretch clamp, the uniaxiality in the stretching process, the flexibility of clamp switching and the accuracy of strain measurement. Finally, the high-low temperature loading stretch clamp for the stretching machine has the advantages of low processing cost and simple operation and installation. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the stretch clamp of the present application.

[0019] Figure 2 is a cross-sectional view of the tensile grips of the present invention.

[0020] Figure 3 is a side view of the tensile grips of the present invention.

[0021] Figure 4 is a schematic view of a sheet sample for the tensile grips of the present invention.

[0022] Figure 5 is a schematic view of a sheet sample collet and sample collet teeth engagement for the tensile grips of the present invention.

[0023] Figure 6 is a schematic view of a rod sample for the tensile grips of the present invention.

[0024] Figure: 1, fastening bolt; 2, fastening nut; 3, upper tensile rod; 4, tensile collet coupling; 5, thermal expansion screw; 6, tensile collet; 7, sample collet stop; 8, sheet sample; 9, sheet sample collet; 10, lower tensile rod; 11, sample collet teeth; 12, rod sample; 13, rod sample collet. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0026] In the description of the present application, unless explicitly defined and limited, the terms "connected", "connected", "fixed" should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or integrated; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Example 1 - Sheet sample tensile test

[0028] As Figures 1-3As shown, this embodiment provides a high and low temperature loading tensile fixture for a tensile testing machine and a tensile testing method for sheet samples. The tensile fixture includes an upper tensile rod 3 and a lower tensile rod 10. Each of the upper tensile rod 3 and the lower tensile rod 10 is connected to a tensile clamp connector 4 at one end. The end of the tensile clamp connector 4 away from the upper tensile rod 3 or the lower tensile rod 10 is connected to a tensile clamp 6 via a thermal expansion screw 5. The tensile clamp 6 has a sliding groove inside, and a sample clamp baffle 7 is slidably connected to the sliding groove. The sample clamp baffle 7 has a spherical groove inside, and a sheet sample clamp 9 for clamping a sheet sample 8 is disposed in the spherical groove. The sheet sample clamp 9 is connected to the sample clamp baffle 7 through surface contact.

[0029] Furthermore, the ends of the upper tension rod 3 and the lower tension rod 10 are provided with through holes, and fastening pins 1 are installed in the through holes. The upper tension rod 3 and the lower tension rod 10 are connected to the tensioning machine by the fastening pins 1 and fixed with fastening nuts 2. During the high and low temperature tensioning process, due to the cooperation of the fastening pins 1 and the fastening nuts 2, the upper tension rod 3 and the lower tension rod 10 will not wobble.

[0030] Furthermore, the opposite ends of the upper tension rod 3 and the lower tension rod 10 are both connected to the tension clamp connector 4 via fastening pins 1 and fastening nuts 2.

[0031] Furthermore, the end of the tension clamp connector 4 away from the upper tension rod 3 or the lower tension rod 10 is provided with a threaded hole. The thermal expansion screw 5 passes through the threaded hole of the tension clamp connector 4 and the tension clamp 6 to fix the tension clamp connector 4 and the tension clamp 6. The tension clamp 6 has a sliding groove inside, through which the sample clamp baffle 7 can be installed, which facilitates the disassembly of the sample clamp baffle 7 and allows it to be replaced after it fails.

[0032] Furthermore, the sample clamp baffle 7 has a slit on its side, through which the sheet sample 8 passes into the sheet sample clamp 9, and is secured by the sample clamp teeth 11 provided in the sheet sample clamp 9.

[0033] Furthermore, such as Figures 4-5 As shown, the two ends of the sheet-like sample 8 are respectively clamped in a pair of sample clamp teeth 11. The inner surface of the sample clamp teeth 11 is patterned, providing good friction with the sheet-like sample 8 and preventing slippage during the stretching process. At the same time, the outer surface of the sample clamp teeth 11 cooperates with the inclined surface of the sheet-like sample clamp 9, becoming increasingly tighter as it is stretched.

[0034] Further, the outer surface of the sheet sample chuck 9 is matched with the spherical groove in the sample chuck baffle 7, so that the sheet sample chuck 9 is connected with the chuck baffle 7 through surface contact, which can maximize the uniaxiality in the stretching process.

[0035] Optionally, the width of the slit is 1-5 mm, preferably 3 mm.

[0036] Optionally, the stretching chuck connector 4 and the stretching chuck 6 are detachable, and other clamps such as compression clamps and three-point bending clamps can be replaced.

[0037] Optionally, the number of fastening pins 1 and fastening nuts 2 is four, and the number of stretching chuck connectors 4, heat expansion threaded rods 5, stretching chucks 6 and sample chuck baffles 7 is two.

[0038] The working principle of the present application is as follows: Figure 2 After the upper and lower parts of the stretching clamp are installed, the upper stretching rod 3 and the lower stretching rod 10 are pre-installed on the stretching machine through the through holes in the head and the fastening pins 1, then all the fastening nuts 2 are tightened to fix them, and they are placed in a high-low temperature oven. Adjust the position of the upper stretching rod 3 to reduce the distance between the upper and lower sample chuck baffles 7 so that the sheet sample 8 can enter. Figure 4 After the prepared sheet sample 8 passes through the slit of the sample chuck baffle 7, the upper and lower sheet sample chucks 9 are respectively in surface contact with the spherical groove in the upper and lower sample chuck baffles 7, the upper stretching rod 3 is adjusted, and a few N of pre-tightening force is applied, and thus the stretching clamp and the sheet sample 8 are installed. The stretching machine and the high-low temperature oven are used to load different temperature fields and stress fields on the sheet material to obtain the mechanical property parameters of the sheet material.

[0039] Example 2 - rod sample stretching experiment

[0040] As shown in Figure 1 , 2 , 3, the present embodiment provides a rod sample stretching experiment method for a high-low temperature loading stretching clamp of a stretching machine. Referring to Example 1, after the upper and lower parts of the stretching clamp are installed, the upper stretching rod 3 and the lower stretching rod 10 are pre-installed on the stretching machine through the through holes in the head and the fastening pins 1, then all the fastening nuts 2 are tightened to fix them, and they are placed in a high-low temperature oven. As shown in Figure 6As shown, the rod-shaped sample 12 is screwed at both ends with the rod-shaped sample chuck 13. After the installation of the rod-shaped sample is completed, the position of the upper stretching rod 3 is adjusted to reduce the distance between the upper and lower sample chuck stoppers 7 so that the rod-shaped sample 12 can enter. After the rod-shaped sample 12 passes through the slit of the sample chuck stopper 7, the upper and lower rod-shaped sample chucks 13 are respectively in contact with the spherical recessed surfaces in the upper and lower sample chuck stoppers 7, the upper stretching rod 3 is adjusted, and a few N of pre-tightening force is applied. At this point, the stretching clamp is installed with the rod-shaped sample 13. The rod-shaped material is subjected to different temperature field and stress field loading by the stretching machine and the high-low temperature oven, and the mechanical property parameters of the rod-shaped material are obtained.

[0041] Although the present application has been described in detail with reference to the foregoing embodiments, technical solutions recorded in the foregoing embodiments can be modified or some technical features can be replaced by equivalent features by those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high and low temperature loading tension fixture for a tensioning machine, characterized in that, The device includes an upper tension rod and a lower tension rod. Each of the upper and lower tension rods has a tension clamp connector at one opposite end. The end of the tension clamp connector away from the upper or lower tension rod is connected to a tension clamp via a thermal expansion screw. The tension clamp has an internal sliding groove, and a sample clamp baffle is slidably connected to the sliding groove. The sample clamp baffle has a spherical groove, and a sample clamp for holding the sample is disposed within the spherical groove. The sample clamp is connected to the sample clamp baffle via surface contact. The ends of the upper and lower tension rods are provided with through holes, and fastening pins are provided in the through holes. The ends of the upper and lower tension rods are connected to the tensioning machine by the fastening pins and fixed with fastening nuts. The opposite ends of the upper and lower tension rods are connected to the tension clamp connector via fastening pins and fastening nuts. The end of the tension clamp connector away from the upper tension rod or the lower tension rod has a threaded hole. The thermal expansion screw passes through the threaded hole of the tension clamp connector and the tension clamp to fix the tension clamp connector to the tension clamp. The sample clamp baffle has a slit on its side, through which the sample is inserted into the sample clamp. The sample includes a sheet sample or a rod sample, and the sample chuck includes a sheet sample chuck or a rod sample chuck. The sheet sample is fastened by the sample chuck teeth set in the sheet sample chuck, and the outer side of the sample chuck teeth cooperates with the inclined surface set in the sheet sample chuck. The rod sample has threads machined at both ends and is threadedly connected to the rod sample chuck. The outer surface of the sample clamp fits into the spherical groove inside the sample clamp baffle.

2. The high and low temperature loading tensile fixture for a tensile machine according to claim 1, characterized in that, The width of the slit is 1-5 mm.

3. The high and low temperature loading tensile fixture for a tensile machine according to claim 1, characterized in that, Both the tension clamp connector and the tension clamp are detachable.

4. The high and low temperature loading tensile fixture for a tensile machine according to claim 1, characterized in that, The number of fastening pins and fastening nuts is four; the number of tension chuck connectors, thermal expansion threaded rods, tension chucks and sample chuck baffles is two.

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