CN201189727Y - Fixed cylindrical pin thermotropic pressure device - Google Patents

Abstract

The utility model provides a cylindrical pin fixed type heat-induced pressure device, which comprises a test sample, fixed pins and an external mould. The heat-induced pressure device is characterized in that the external mould and the test sample are both cylindrical and coaxial, and the test sample is arranged at the center of the external mould through the interference fit and through a mounting hole on the axle center on the upper part of the external mould; the external mould is provided with through holes vertically penetrating the axle center on the parts corresponding to the upper end and the lower end of the test sample, and the two through holes are vertical to each other; in each through hole, a fixed pin is arranged through interference fit, both ends of the test sample closely contact the fixed pins on the upper end and the lower end of the test sample, and the coefficient of thermal expansion of the test sample is more than the coefficients of thermal expansion of the fixed pins and the external mould. The heat-induced pressure device has the advantages of simple design, small volume, low-priced materials, easy machine processing of all parts, easy assembly of the complete set of the device and low manufacturing cost, so that the heat-induced pressure device is more suitable for a laboratory to research the influence of the high-pressure environment processing on tissue and performance of materials.

Description

Cylindrical pin fixed thermal pressure device

technical field

The utility model provides a cylindrical pin fixed heat-induced pressure device, which belongs to the technical field of designing and manufacturing high-pressure and ultra-high-pressure equipment.

Background technique

Existing devices for generating high pressure mainly include six-sided roof and double-sided roof equipment used in engineering and anvils (anvil) for laboratory research. The basic principle of these devices is to use external force to create a high-pressure environment inside the cavity. The advantage of the six-sided roof and double-sided roof equipment is that the cavity is larger, which can meet the requirements of the cavity size of Φ30-50mm, and is suitable for Industrial production, but the equipment is bulky, with a self-weight of tens of tons, and the pressure generated is relatively small, generally only ~10GPa; the pressure anvil can generate pressure greater than 100GPa, and the device is small, but its disadvantage is that the cavity is extremely small, Only 10 ^-4 mm ³ orders of magnitude. The principle of high pressure generation of existing equipment determines that both cavity volume and high pressure cannot be balanced. Therefore, it is impossible to achieve a high pressure environment of cm ³ order of magnitude and above 10GPa with the current high pressure equipment.

In order to overcome the shortcomings of the above-mentioned high-pressure generating device, the invention patent application with the application number "200610166214" proposed the idea of designing a pressure generating device based on the principle of thermal expansion and contraction, which does not rely on external forces to directly perform work, and utilizes the difference in thermal expansion coefficient of different materials. , under high temperature conditions, pressure is generated due to the inability of the volume to expand freely, and a high-pressure environment of more than 10GPa can be generated in the cavity volume of the order of cm ³ , but the inventive device is suitable for samples that are long in the axial direction and short in the radial direction.

Utility model content

The purpose of the utility model is to provide a cylindrical pin fixed thermal pressure device, which can overcome the defects of the prior art and is suitable for processing samples with long axial dimensions and relatively large radial dimensions. Its technical solution is:

It includes a sample, a fixed pin and an outer mold, and is characterized in that: both the outer mold and the sample are cylindrical, and the sample is coaxially installed in the center of the outer mold through the installation hole located at the axis center above the outer mold with interference fit , the outer mold is provided with through holes vertically passing through the axis at the corresponding positions of the upper and lower ends of the sample, and the two through holes are perpendicular to each other, and a fixed pin is installed in each through hole for interference fit. The end is in close contact with the fixed pins that separate the upper and lower ends, and the thermal expansion coefficient of the sample is greater than that of the fixed pin and the outer mold. When assembling, if the sample is in an interference fit with the center hole of the outer mold, its radial expansion will be restricted, but it can still expand freely in the axial direction; The expansion of is also restricted, so it cannot expand freely in all directions.

In the cylindrical pin-fixed thermal pressure device, the upper and lower end surfaces of the sample are in the same radian as the fixed pins located at the upper and lower ends of the sample, and are closely attached to each other.

Its working principle is: the whole device is assembled at room temperature. Since the thermal expansion coefficients of different materials are not the same, the material with a smaller thermal expansion coefficient can be tightly wrapped with the material with a larger thermal expansion coefficient. When the whole device is heated, the internal thermal expansion coefficient is large. The material is under pressure because it cannot expand freely; the higher the heating temperature, the greater the pressure on the material with a large internal thermal expansion coefficient. In this design, the thermal expansion coefficient of the sample is greater than that of the outer mold, so the sample will bear compressive stress because it cannot expand freely when heated. The outer mold and the fixed cylindrical pin are subjected to tensile stress, and when the tensile stress exceeds the tensile strength of the outer mold material, the outer mold will crack. When the size of the sample is determined, the higher the heating temperature, the greater the thermal expansion. At a certain temperature, the sample produces a fixed pressure. Since its appearance size is determined, the surface area remains unchanged, that is, the reaction force of the sample to the external mold is constant, so the size of the external mold is increased to increase its cross-sectional area. It can effectively increase the pressure on the outer mold, that is, increase the pressure on the sample. Therefore, the pressure on the sample inside the cavity can be controlled by changing the size of the outer mold, adjusting the axial and radial dimensions of the central hole, and adjusting the heating temperature.

Compared with the prior art, the utility model has the following advantages: the design is simple, the volume is small and exquisite; the materials used are cheap, each part of the device is easy to machine, and the whole device is easy to assemble; the new device reduces the manufacturing cost and is more suitable for the laboratory Study the effect of high-pressure environment treatment on the structure and properties of materials.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment;

Fig. 2 is a top view of the embodiment shown in Fig. 1;

Fig. 3 is the A-A sectional view of the embodiment shown in Fig. 2;

Fig. 4 is a B-B sectional view of the embodiment shown in Fig. 2 .

In the figure: 1. Mounting hole 2. Outer mold 3. Fixing pin 4. Sample

Detailed ways

Both the outer mold 2 and the sample 4 are cylindrical, and the sample 4 is coaxially installed in the center of the outer mold 2 through the installation hole 1 located at the axis center above the outer mold 2 with an interference fit. The corresponding positions of the upper and lower ends of 4 are provided with through holes vertically passing through the axis, and the two through holes are perpendicular to each other, and a fixed pin 3 is installed in each through hole with interference fit. The upper and lower end surfaces of sample 4 It is consistent with the radian of the fixed pin 3 separated from its upper and lower ends, closely fit, and the coefficient of thermal expansion of the sample 4 is greater than that of the fixed pin 3 and the outer mold 2 .

During assembly, the sample 4 and the outer mold 2 are in an interference fit, coaxially installed in the center of the outer mold 2, its radial expansion will be limited, but its axial expansion can still be free; then its upper and lower ends are assembled separately If the pin 3 is fixed, the axial expansion of the sample 4 is also restricted, so that it cannot expand freely in any direction.

Claims (2)

1. A cylindrical pin fixed thermal pressure device, comprising an outer mold (2), a fixed pin (3) and a sample (4), characterized in that: the outer mold (2) and the sample (4) are cylindrical shape, the sample (4) is installed in the center of the outer mold (2) through the installation hole (1) located at the upper axis of the outer mold (2) coaxially and with an interference fit, and the outer mold (2) is The upper and lower ends of the sample (4) are provided with through holes vertically passing through the axis, and the two through holes are perpendicular to each other, and a fixed pin (3) is installed in each through hole for interference fit. The two ends of (4) are in close contact with the fixed pins (3) separated from the upper and lower ends, and the thermal expansion coefficient of the sample (4) is greater than that of the fixed pins (3) and the outer mold (2). 2. The cylindrical pin fixed thermal pressure device according to claim 1, characterized in that: the upper and lower end surfaces of the sample (4) are in the same radian as the fixed pins (3) at the upper and lower ends of the sample (4), and are closely fitted .

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