Fatigue test equipment for corrugated pipe in vacuum state

Abstract

The invention discloses corrugated pipe fatigue test equipment in a vacuum state, which comprises a machine body and a moving assembly arranged at the bottom of the machine body, and a hollow pull pipe is arranged on the machine body in a sliding manner. A to-be-tested corrugated pipe is fixed through a flange plate and covered with a transparent cover, a connecting rod and a threaded base are connected and fixed through a nut pipe sleeve, a lower disc and an upper disc are arranged on a guide rod, a fastening nut is rotated, the upper disc is pressed downwards, the upper disc transmits pressure to the lower disc through an elastic piece a, and the transparent cover is fixed; a closed space is formed inside the corrugated pipe, the vacuum pump vacuumizes the inside and the outside of the corrugated pipe through the connecting pipe c and the connecting pipe a, at the moment, the driving unit drives the cam, the corrugated pipe is repeatedly stretched and compressed under the action of the elastic piece b, the fatigue strength of the corrugated pipe is tested in a vacuum state, and the fatigue strength is measured according to the length of the corrugated pipe to be tested. The height of the driving unit is controlled through the electric control telescopic rod, it is guaranteed that the corrugated pipe has enough space for testing, and the applicability is good.

Description

Technical Field

[0001] The invention relates to the technical field of bellows, and in particular to a bellows fatigue testing device under vacuum state. Background Art

[0002] Bellows refers to a tubular elastic sensitive element connected by foldable corrugated sheets along the folding and stretching direction. Bellows are widely used in instruments and meters. Their main purpose is to be used as measuring elements of pressure measuring instruments to convert pressure into displacement or force. The bellows has a thinner wall and higher sensitivity, with a measuring range of tens of Pa to tens of MPa. Its open end is fixed, the sealed end is in a free state, and an auxiliary spiral spring or reed is used to increase elasticity. When working, it stretches along the length of the tube under the action of internal pressure, causing the movable end to produce a displacement that is related to the pressure. The movable end drives the pointer to directly indicate the size of the pressure. Bellows are often combined with displacement sensors to form a pressure sensor with an output of electrical quantity, and are sometimes used as isolation elements. Since the extension of bellows requires a large volume change, its response speed is lower than that of Bourdon tubes. Bellows are suitable for measuring low pressure; during the bellows processing process, the fatigue strength of the bellows needs to be tested, but the existing test equipment can only be tested under normal pressure conditions and cannot meet the test needs. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a bellows fatigue testing device under vacuum state.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A bellows fatigue testing device under vacuum state comprises a machine body and a moving assembly installed at the bottom thereof, wherein a hollow drawing tube is slidably arranged on the machine body, and the hollow drawing tube reciprocates under the action of a rotating driving assembly arranged below the machine body, a transparent cover and a crimping mechanism are arranged above the machine body, the transparent cover is fixed above the machine body by the crimping mechanism, a bellows is installed between the crimping mechanism and the hollow drawing tube, and vacuum extraction assemblies are arranged inside and outside the hollow drawing tube.

[0005] Preferably, the rotary drive assembly comprises a drive unit, which is connected to the machine body via a lifting mechanism, an output end of the drive unit is connected to a cam, and the lower end of the hollow pull tube is rotatably connected to a rotating wheel.

[0006] Preferably, the lifting mechanism comprises an electrically controlled telescopic rod connected to the machine body, the upper end of the electrically controlled telescopic rod is connected to a lifting platform, and the driving unit is mounted on the lifting platform.

[0007] Preferably, the crimping mechanism includes a plurality of guide rods arranged around the hollow pull tube, the guide rods are installed on the machine body, and a lower disc and an upper disc are slidably arranged on the guide rods, an elastic member a is arranged between the lower disc and the upper disc, and a connecting rod is slidably connected to the lower disc and the upper disc, and a fastening nut is threadedly connected to the connecting rod, and the fastening nut is located above the upper disc, and the connecting rod is connected to the machine body through a fixing mechanism.

[0008] Preferably, the fixing mechanism comprises a threaded base connected to the machine body, the threaded base and the end of the connecting rod are connected via a nut sleeve, and reverse threads are provided on the threaded base and the connecting rod.

[0009] Preferably, the vacuum pumping assembly includes a connecting pipe a communicated with the hollow pulling tube, the lower disc is connected with a connecting pipe c, the connecting pipe c is connected with a connecting pipe b through a hose, both the connecting pipe b and the connecting pipe a are connected with a vacuum pump through pipelines, and both the connecting pipe b and the connecting pipe a are provided with electric control valves.

[0010] Preferably, a pressure gauge is installed on the lower disc, and a through hole corresponding to the pressure gauge and the connecting pipe c is provided on the upper disc.

[0011] Preferably, flanges for fixing the bellows are provided on the upper end and the lower disc of the hollow pull tube, and an elastic member b is provided on the hollow pull tube.

[0012] Preferably, the top of the body and the bottom of the lower disc are both provided with sealing gaskets corresponding to the transparent cover.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention fixes the bellows to be tested through a flange, and covers the transparent cover, uses a nut sleeve to connect and fix the connecting rod and the threaded base, the lower disc and the upper disc are arranged on the guide rod, the nut is rotated and tightened, the upper disc is pressed down, the upper disc transmits the pressure to the lower disc through the elastic member a, the lower disc presses down the transparent cover, fixes the transparent cover, and forms a closed space inside, the vacuum pump draws vacuum inside and outside the bellows through the connecting pipes c and the connecting pipes a, and can also draw vacuum only inside or outside according to the test needs, at this time, the driving unit drives the cam, and under the action of the elastic member b, the bellows is repeatedly stretched and compressed, and its fatigue strength is tested under a vacuum state, and according to the length of the bellows to be tested, the height of the driving unit is controlled by the electrically controlled telescopic rod to ensure that the bellows has enough space for testing, and the applicability is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more specifically and intuitively illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0015] Figure 1 The structure of the present invention is shown in FIG. Figure 1 ; Figure 2 The structure of the present invention is shown in FIG. Figure 2 ; Figure 3 The structure of the present invention is shown in FIG. Figure 3 ; Figure 4 The structure of the present invention is shown in FIG. Figure 4 ; Figure 5 The structure of the present invention is shown in FIG. Figure 5 .

[0016] In the figure: body 1, vacuum pump 2, mesh guard plate 3, lifting platform 4, electric control telescopic rod 5, moving assembly 6, drive unit 7, cam 8, rotating wheel 9, hollow pulling tube 10, connecting tube a11, connecting tube b12, transparent cover 13, guide rod 14, lower disc 15, elastic part a16, connecting tube c17, upper disc 18, connecting rod 19, fastening nut 20, pressure gauge 21, elastic part b22, flange 23, nut sleeve 24, sealing gasket 25, threaded base 26. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] Reference Figure 1-5 A bellows fatigue testing device under vacuum state includes a body 1 and a moving component 6 installed at the bottom thereof, a hollow drawing tube 10 is slidably arranged on the body 1, and the hollow drawing tube 10 reciprocates under the action of a rotating driving component arranged below the body 1, a transparent cover 13 and a crimping mechanism are arranged above the body 1, the transparent cover 13 is fixed on the body 1 through the crimping mechanism, a bellows is installed between the crimping mechanism and the hollow drawing tube 10, and vacuum pumping components are arranged inside and outside the hollow drawing tube 10.

[0019] The bellows to be tested is fixed by the flange 23, and the transparent cover 13 is covered, and the connecting rod 19 is connected and fixed to the threaded base 26 by the nut sleeve 24. The lower disc 15 and the upper disc 18 are set on the guide rod 14, and the nut 20 is rotated and tightened to press the upper disc 18 downward. The upper disc 18 transmits the pressure to the lower disc 15 through the elastic member a16. The lower disc 15 presses down the transparent cover 13 to fix the transparent cover 13, and a closed space is formed inside. The vacuum pump 2 draws vacuum inside and outside the bellows through the connecting pipe c17 and the connecting pipe a11. It can also be used to vacuum only the inside or the outside according to the test needs. At this time, the driving unit 7 drives the cam 8, and under the action of the elastic member b22, the bellows is repeatedly stretched and compressed to test its fatigue strength under vacuum. In addition, according to the length of the bellows to be tested, the height of the driving unit 7 is controlled by the electrically controlled telescopic rod 5 to ensure that the bellows has enough space for testing, and the applicability is good.

[0020] In this embodiment, the rotary drive assembly includes a drive unit 7, which is connected to the body 1 through a lifting mechanism. The output end of the drive unit 7 is connected to a cam 8, and the lower end of the hollow pull tube 10 is rotatably connected to a rotating wheel 9. The lifting mechanism includes an electrically controlled telescopic rod 5 connected to the body 1, and the upper end of the electrically controlled telescopic rod 5 is connected to a lifting platform 4. The drive unit 7 is installed on the lifting platform 4. According to the length of the corrugated pipe to be tested, the height of the drive unit 7 is controlled by the electrically controlled telescopic rod 5 to ensure that the corrugated pipe has sufficient space for testing, and the applicability is good.

[0021] In this embodiment, the crimping mechanism includes a plurality of guide rods 14 arranged around the hollow pull tube 10, the guide rods 14 are installed on the body 1, and a lower disc 15 and an upper disc 18 are slidably arranged on the guide rods 14, an elastic member a16 is arranged between the lower disc 15 and the upper disc 18, the lower disc 15 and the upper disc 18 are slidably connected by a connecting rod 19, a fastening nut 20 is threadedly connected to the connecting rod 19, and the fastening nut 20 is located above the upper disc 18, the connecting rod 19 is connected to the body 1 through a fixing mechanism, and the lower disc 15 is pressed tightly against the transparent cover 13 by the rebound force of the elastic member a16.

[0022] In this embodiment, the fixing mechanism includes a threaded base 26 connected to the body 1, and the threaded base 26 and the end of the connecting rod 19 are connected through a nut sleeve 24. The threaded base 26 and the connecting rod 19 are provided with reverse threads for fixing the connecting rod 19 and also for facilitating disassembly.

[0023] In this embodiment, the vacuum pumping assembly includes a connecting pipe a11 communicated with the hollow pulling tube 10, a connecting pipe c17 is connected to the lower disc 15, the connecting pipe c17 is connected to the connecting pipe b12 through a hose, the connecting pipe b12 and the connecting pipe a11 are both connected to the vacuum pump 2 through pipelines, and the connecting pipe b12 and the connecting pipe a11 are both provided with electric control valves.

[0024] In this embodiment, a pressure gauge 21 is installed on the lower disc 15, and a through hole corresponding to the pressure gauge 21 and the connecting pipe c17 is provided on the upper disc 18. Flanges 23 for fixing the bellows are provided on the upper end of the hollow pull tube 10 and the lower disc 15, and an elastic member b22 is provided on the hollow pull tube 10.

[0025] In this embodiment, sealing gaskets 25 corresponding to the transparent cover 13 are provided on the top of the body 1 and the bottom of the lower disc 15 to improve the sealing performance.

[0026] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A bellows fatigue testing device under vacuum, comprising a body (1) and a moving assembly (6) mounted at the bottom thereof, characterized in that: A hollow draw tube (10) is slidably arranged on the machine body (1), and the hollow draw tube (10) reciprocates under the action of a rotary drive assembly arranged below the hollow draw tube (10). A transparent cover (13) and a crimping mechanism are arranged above the machine body (1), and the transparent cover (13) is fixed to the top of the machine body (1) by the crimping mechanism. A bellows is installed between the crimping mechanism and the hollow draw tube (10), and vacuum assemblies are arranged inside and outside the hollow draw tube (10).

2. The bellows fatigue testing device under vacuum state according to claim 1, characterized in that: The rotary drive assembly comprises a drive unit (7), the drive unit (7) being connected to the machine body (1) via a lifting mechanism, the output end of the drive unit (7) being connected to a cam (8), and the lower end of the hollow pull tube (10) being rotatably connected to a rotating wheel (9).

3. The bellows fatigue testing device under vacuum state according to claim 2, characterized in that: The lifting mechanism comprises an electrically controlled telescopic rod (5) connected to the machine body (1); the upper end of the electrically controlled telescopic rod (5) is connected to a lifting platform (4); and the drive unit (7) is mounted on the lifting platform (4).

4. The bellows fatigue testing device under vacuum state according to claim 3, characterized in that: The crimping mechanism comprises a plurality of guide rods (14) arranged around the hollow draw tube (10), the guide rods (14) being mounted on the machine body (1), a lower disc (15) and an upper disc (18) being slidably mounted on the guide rods (14), an elastic member a (16) being arranged between the lower disc (15) and the upper disc (18), a connecting rod (19) being slidably connected to the lower disc (15) and the upper disc (18), a fastening nut (20) being threadedly connected to the connecting rod (19), the fastening nut (20) being located above the upper disc (18), and the connecting rod (19) being connected to the machine body (1) via a fixing mechanism.

5. The bellows fatigue testing device under vacuum state according to claim 4, characterized in that: The fixing mechanism comprises a threaded base (26) connected to the machine body (1); the threaded base (26) and the end of the connecting rod (19) are connected via a nut sleeve (24); and the threaded base (26) and the connecting rod (19) are provided with reverse threads.

6. The bellows fatigue testing device under vacuum state according to claim 5, characterized in that: The vacuum pumping assembly comprises a connecting pipe a (11) communicating with the hollow pulling tube (10); the lower disc (15) is connected with a connecting pipe c (17); the connecting pipe c (17) is connected with a connecting pipe b (12) via a hose; the connecting pipe b (12) and the connecting pipe a (11) are both connected with a vacuum pump (2) via pipelines; and the connecting pipe b (12) and the connecting pipe a (11) are both provided with electric control valves.

7. The bellows fatigue testing device under vacuum state according to claim 6, characterized in that: A pressure gauge (21) is mounted on the lower disc (15), and a through hole corresponding to the pressure gauge (21) and the connecting pipe c (17) is provided on the upper disc (18).

8. The bellows fatigue testing device under vacuum state according to claim 7, characterized in that: Flanges (23) for fixing the bellows are provided on the upper end of the hollow pull tube (10) and the lower disc (15), and an elastic member b (22) is provided on the hollow pull tube (10).

9. The bellows fatigue testing device under vacuum state according to claim 8, characterized in that: The top of the machine body (1) and the bottom of the lower disc (15) are both provided with sealing gaskets (25) corresponding to the transparent cover (13).

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