Gas generating agent testing device

By designing a gas generator testing device and utilizing pressure monitoring and pressure relief protection within a sealed cavity, the problems of long testing cycles and high costs in existing technologies have been solved, achieving efficient and safe burning rate testing.

CN121027405APending Publication Date: 2025-11-28HUBEI HANGPENG CHEM POWER TECH
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202511470944.X
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-10-15
Publication Date
2025-11-28

AI Technical Summary

Technical Problem

Existing methods for testing the burning rate of gas generators are time-consuming, costly, require specialized equipment, and have stringent testing conditions, making them unsuitable for quickly guiding reagent production.

Method used

Design a gas generator testing device, including a container, a pressure cap, an ignition unit, a pressure testing unit, and a pressure relief unit. It can detect the burning rate of the gas generator in a sealed cavity. After ignition by the ignition unit, the pressure change is monitored by the pressure testing unit. The pressure relief unit automatically releases pressure when the pressure exceeds the threshold, simplifying the testing process and reducing costs.

Benefits of technology

It achieves efficient and low-cost gas generator burning rate detection, simplifies the testing process, improves testing efficiency, and ensures testing safety through pressure relief protection.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN121027405A_ABST
    Figure CN121027405A_ABST
Patent Text Reader

Abstract

The invention relates to the technical field of gas generating agent detection, in particular to a gas generating agent testing device. The gas generating agent testing device comprises an accommodating cylinder, a gland, an ignition unit, a pressure testing unit and a pressure relief unit, the gland is detachably connected with the accommodating cylinder, and the gland is used for forming an accommodating cavity for accommodating a gas generating agent to be detected together with the accommodating cylinder; the ignition unit is connected with the gland and is used for igniting the to-be-detected gas generating agent in the accommodating cavity; the pressure testing unit and the pressure relief unit are both connected with the gland and communicated with the containing cavity. The gas generating agent testing device can directly detect the gas generating agent, does not need to limit the shape and characteristics of the gas generating agent, and is high in detection efficiency and low in detection cost.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] This invention relates to the field of gas generator detection technology, and more specifically, to a gas generator testing device. Background Technology

[0002] Currently, when testing the burning rate of gas generators, the reagent to be tested needs to be compressed into a certain strip or column shape and tested using a dedicated burning rate meter. This testing method has the problems of long testing cycle and high cost. Moreover, the dedicated burning rate meter is expensive and the testing conditions are strict, so it cannot quickly guide the subsequent reagent production. Summary of the Invention

[0003] The present invention aims to provide a gas generator testing device that can directly detect gas generators without limiting the shape and properties of the gas generators, and has high detection efficiency and low detection cost.

[0004] The embodiments of the present invention can be implemented as follows: This invention provides a gas generator testing device, which includes a container, a pressure cap, an ignition unit, a pressure testing unit, and a pressure relief unit. The cap is detachably connected to the container, and the cap is used together with the container to form a cavity for containing the gas generator to be tested; The ignition unit is connected to the pressure cap and is used to ignite the gas generator in the cavity; Both the pressure testing unit and the pressure relief unit are connected to the pressure cap and are in communication with the cavity.

[0005] In an optional embodiment, the gland has a first channel and a second channel communicating with the cavity; The pressure testing unit is connected to the cavity through the first channel, and the pressure relief unit is connected to the cavity through the second channel; The first channel and the second channel are spaced apart around the center line of the container cylinder.

[0006] In an alternative implementation, at least a portion of the first channel and the second channel are bent or flexed.

[0007] In an optional implementation, the first channel includes a first segment and a second segment, the first segment and the second segment are connected, the first segment is connected to the pressure testing unit, and the second segment is connected to the cavity; the second channel includes a third segment and a fourth segment, the third segment and the fourth segment are connected, the third segment is connected to the pressure relief unit, and the fourth segment is connected to the cavity. The first segment bends or extends at the intersection of the second segment, and the third segment bends or extends at the intersection of the fourth segment.

[0008] In an optional embodiment, the first and third segments extend in a direction perpendicular to the centerline of the receiving cylinder, and the second and fourth segments extend in the direction of the centerline of the receiving cylinder.

[0009] In an optional implementation, the gland has an ignition channel; The ignition unit includes an electric detonator installed in the ignition channel; or, the ignition unit includes an electrode and a resistance wire installed in the ignition channel, wherein the electrode and the resistance wire extend through the ignition channel into the cavity.

[0010] In an optional embodiment, the cap includes a cap body and a cap fitting; the cap body is detachably connected to the receiving cylinder, an ignition channel is formed in the cap body, the cap fitting is detachably connected to the cap body and the cap fitting, and the cap fitting is used to close the ignition channel.

[0011] In an optional embodiment, the gas generator testing device further includes an adjusting block placed in the cavity. The adjusting block is detachably connected to the container or the cap, and the container has an ignition channel, a first connecting channel and a second connecting channel. The ignition channel, the first connecting channel and the second connecting channel pass through the adjusting block along the center line of the container. Among them, the ignition channel is connected to the ignition channel, the first connecting channel is connected to the first channel, and the second connecting channel is connected to the second channel.

[0012] In an optional embodiment, the adjusting block has a connection hole for mounting a fastener, which is used to connect the adjusting block to the pressure cover.

[0013] In an optional embodiment, the receiving cylinder includes a main cylinder and at least one sub-cylinder, the sub-cylinder being detachably connected to the open end of the main cylinder, and the centerline of the sub-cylinder coinciding with the centerline of the main cylinder; the pressure cap is connected to the main cylinder or the sub-cylinder.

[0014] The beneficial effects of the gas generator testing device provided in this embodiment of the invention include: This gas generator testing device features a sealed cavity into which the gas generator to be tested is placed. Ignition is achieved via an ignition unit, and the pressure within the cavity is monitored by a pressure testing unit, allowing for the detection of the burning rate after ignition. Furthermore, the testing is conducted within this sealed cavity. This means that only the appropriate weight of the gas generator needs to be set, and additional ignition-promoting agents can be added as required. The gas generator can then be directly tested by ignition without restrictions on its shape or properties. Therefore, this gas generator testing device simplifies the testing process, improves efficiency, and reduces costs. Simultaneously, the pressure relief unit automatically releases pressure when it reaches a threshold, ensuring the overall structural safety during testing. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the gas generator testing device provided in this embodiment; Figure 2 This is a schematic diagram of the structure of the accommodating cylinder and the pressure cap provided in this embodiment; Figure 3 This is a schematic diagram of the structure of the gland provided in this embodiment; Figure 4 This is a schematic diagram of the resistance wire setup provided in this embodiment; Figure 5 This is a schematic diagram illustrating the configuration of the adjustment block provided in this embodiment; Figure 6 This is a schematic diagram of the structure of the accommodating cylinder, the pressure cap, and the adjusting block provided in this embodiment.

[0017] Icons: 100-Gas generator testing device; 110-Container cylinder; 120-Grip cap; 130-Ignition unit; 40-Pressure testing unit; 150-Pressure relief unit; 101-Cavity; 10-Gas generator to be tested; 121-First channel; 122-Second channel; 123-First segment; 124-Second segment; 125-Third segment; 126-Fourth segment; 127-Ignition channel; 131-Electro-explosive tube; 132-Resistance wire; 128-Cover body; 129-Cover assembly; 160-Adjusting block; 161-Ignition channel; 162-First connecting channel; 163-Second connecting channel; 164-Fixing component. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0023] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0024] Please refer to Figure 1 This embodiment provides a gas generator testing device 100, which is used to detect and determine the burning rate of the gas generator, thereby accurately determining whether the burning rate of the gas generator meets the requirements and guiding subsequent work. Specifically, the gas generator testing device 100 includes a container 110, a pressure cap 120, an ignition unit 130, a pressure testing unit 40, and a pressure relief unit 150. The cap 120 is detachably connected to the container 110, and the cap 120 is used together with the container 110 to form a cavity 101 for accommodating the gas generator 10 to be tested; The ignition unit 130 is connected to the cap 120 and is used to ignite the test gas generator 10 in the cavity 101; Both the pressure testing unit 40 and the pressure relief unit 150 are connected to the pressure cap 120 and are connected to the cavity 101.

[0025] It should be noted that this embodiment is illustrated by taking the gas generator 10 to be tested as a gas-generating agent used in the airbag gas generator; and when configuring the container 110, the thickness of its body can be 5 to 8 mm, and its thickness can be selected according to the burning rate of the test agent.

[0026] Please refer to Figure 1 The working principle of the gas generator testing device 100 is as follows: The gas generator testing device 100 includes a container 110, a pressure cap 120, an ignition unit 130, a pressure testing unit 40, and a pressure relief unit 150. The pressure cap 120 is detachably connected to the container 110, and the pressure cap 120, together with the container 110, forms a cavity 101 for accommodating the gas generator 10 to be tested. This arrangement can form a corresponding sealed testing space. Moreover, by detachably connecting the pressure cap 120 to the container 110, after the test is completed, the container 110, pressure cap 120, ignition unit 130, pressure testing unit 40, and pressure relief unit 150 can be cleaned and reset, thereby enabling the device to be tested repeatedly. The cleaning work is simple and convenient, which helps to reduce the cost of testing. During the test, after the ignition unit 130 ignites the test gas generator 10 in the ignition cavity 101, the internal pressure changes rapidly. The pressure testing unit 40 can monitor the pressure in the cavity 101 in real time, and the combustion can be analyzed by monitoring the pressure changes, thus achieving the purpose of testing the gas generator. In addition, during the test, as the pressure in the cavity 101 increases, the pressure relief unit 150 can provide pressure relief protection, and its pressure relief threshold can be adjusted according to requirements. It should be noted that when configuring its pressure testing unit 40 and pressure relief unit 150, based on the realization of pressure monitoring and pressure relief protection functions, it can select the pressure detection sensor structure and pressure relief valve structure in the existing technology.

[0027] The gas generator testing device 100 sets up a sealed cavity 101, puts the gas generator to be tested into the cavity 101, and ignites it through the ignition unit 130. The pressure inside the cavity 101 can be detected by the pressure testing unit 40, thereby detecting the burning rate of the gas generator after ignition. Moreover, during the testing process, the test is conducted in a closed cavity 101. That is, only the appropriate amount of reagent needs to be set according to the test requirements, and ignition agent can be added as needed. The gas generator can be directly tested by ignition unit 130 without restricting the shape and characteristics of the gas generator. Therefore, the gas generator testing device 100 can simplify the testing steps of the gas generator, improve its testing efficiency, and reduce its testing cost. At the same time, through the setting of the pressure relief unit 150, it can automatically relieve pressure after the internal pressure increases to the pressure relief threshold, thereby ensuring the safety of the overall structure during the testing process.

[0028] Further, please refer to Figures 1-3 In this embodiment, when the pressure cap 120 is configured, its function is to connect with the accommodating cylinder 110 to form a closed space. Based on this, in order to facilitate its installation and connection with the pressure testing unit 40 and the pressure relief unit 150, the pressure cap 120 is provided with a first channel 121 and a second channel 122 communicating with the cavity 101. The pressure testing unit 40 is connected to the cavity 101 through the first channel 121, and the pressure relief unit 150 is connected to the cavity 101 through the second channel 122. The first channel 121 and the second channel 122 are arranged at intervals around the center line of the accommodating cylinder 110. In this way, the pressure testing unit 40 and the pressure relief unit 150 can be connected to the pressure cover 120, thereby facilitating pressure detection and pressure relief. Furthermore, to prevent residues generated by the combustion of the gas generator during the test from entering the first channel 121 or the second channel 122, at least part of the first channel 121 and the second channel 122 can be bent or extended in an L-shape. This reduces the probability of residues entering the pressure testing unit and the pressure relief unit 150 through the first channel 121 and the second channel 122, and also facilitates the cleaning of the first channel 121 and the second channel 122.

[0029] It should be noted that when connecting the pressure detection unit and the pressure relief unit 150 to the pressure cover 120, the pressure detection unit and the pressure relief unit 150 can be connected to the first channel 121 and the second channel 122 respectively through transition joints, and the joint threads at the connection between the transition joint and the first channel 121 and the second channel 122 are sealing threads, and the size design requirements ensure strength.

[0030] Specifically, in configuring the first channel 121 and the second channel 122, the first channel 121 includes a first segment 123 and a second segment 124, with the first segment 123 connected to the second segment 124 and the first segment 123 connected to the pressure testing unit 40, and the second segment 124 connected to the cavity 101; the second channel 122 includes a third segment 125 and a fourth segment 126, with the third segment 125 connected to the fourth segment 126 and the third segment 125 connected to the pressure relief unit 150, and the fourth segment 126 connected to the cavity 101. This arrangement allows the junction of the first segment 123 and the second segment 124 to bend or extend, and the junction of the third segment 125 and the fourth segment 126 to bend or extend, thereby preventing residue from entering the pressure testing unit and the pressure relief unit 150 through the first channel 121 and the second channel 122.

[0031] In this embodiment, when configuring the curved first channel 121 and the second channel 122, the first segment 123 and the third segment 125 extend in a direction perpendicular to the center line of the receiving cylinder 110, and the second segment 124 and the fourth segment 126 extend in the direction of the center line of the receiving cylinder 110. In other embodiments of the present invention, the curved configuration may also be used, which will not be described in detail here.

[0032] Further, please refer to Figures 1-3 In this embodiment, when the pressure cap 120 is configured, its function is to form a sealed cavity 101, and on this basis, the ignition unit 130 is installed. When installing the ignition unit 130, in order to simplify the installation of the ignition unit 130, the pressure cap 120 is provided with an ignition channel 127, so that the ignition unit 130 can extend into or communicate with the cavity 101 to ignite the gas generator in the cavity 101. Please refer to Figures 1-4 When configuring the ignition unit 130, the ignition unit 130 may include an electric detonator 131 installed in the ignition channel 127; the ignition unit 130 may also include an electrode and a resistance wire 132 installed in the ignition channel 127, that is, using direct current ignition, and the electrode and resistance wire 132 extend through the ignition channel 127 into the cavity 101; the two methods can be selected according to the needs of use.

[0033] Based on the above structure, to seal the ignition unit 130 and prevent leakage caused by the ignition channel 127 communicating with the outside, the pressure cap 120 includes a cover body 128 and a cover fitting 129. The cover body 128 is detachably connected to the receiving cylinder 110, the ignition channel 127 is opened in the cover body 128, and the cover fitting 129 is detachably connected to the cover body 128 and the cover fitting 129, and the cover fitting 129 is used to close the ignition channel 127. That is, through the aforementioned structural arrangement of the pressure cap 120, the cover fitting 129 can close the ignition channel 127 to block it from the outside, while also supporting it against the ignition unit 130, thereby maintaining the correct installation of the ignition unit 130. It should be noted that when the cap 120 is connected to the accommodating cylinder 110, it can be connected by thread or quick clamp. Similarly, the cover 129 and the cover body 128 can also be connected by thread or quick clamp.

[0034] As can be seen from the above, during the use of this device, an appropriate dose of gas generator can be placed into the cavity 101 according to the testing requirements. Therefore, in order to adjust the volume of the cavity 101, please refer to... Figures 1-6 The gas generator testing device 100 also includes an adjusting block 160 placed in the cavity 101. The adjusting block 160 is detachably connected to the accommodating cylinder 110 or the pressure cap 120. The accommodating cylinder 110 has an ignition channel 161, a first connecting channel 162, and a second connecting channel 163. The ignition channel 161, the first connecting channel 162, and the second connecting channel 163 pass through the adjusting block 160 along the center line of the accommodating cylinder 110. The ignition channel 161 is connected to the ignition channel 127, the first connecting channel 162 is connected to the first channel 121, and the second connecting channel 163 is connected to the second channel 122.

[0035] By adjusting the installation state of the adjusting block 160 or by adjusting the adjusting block 160 of different sizes, the volume of the cavity 101 can be adjusted. The adjusting block 160 is equipped with an ignition channel 161, a first connecting channel 162, and a second connecting channel 163, thus ensuring the proper installation of the ignition unit 130, the pressure testing unit 40, and the pressure relief unit 150. It should be noted that when the adjusting block 160 is installed into the cavity 101, the volume of the cavity 101 decreases; conversely, when the adjusting block 160 is removed, the volume of the cavity 101 increases. Furthermore, when configuring the adjusting block 160, adjusting blocks of different sizes can be configured according to requirements, allowing adjustment of the size of the installed adjusting block 160 to adjust the volume of the cavity 101.

[0036] In this embodiment, the adjusting block 160 is connected to the pressure cap 120. Therefore, the adjusting block 160 has a connecting hole for mounting the fixing member 164, which is used to connect the adjusting block 160 to the pressure cap 120. When the fixing member 164 is a screw connector, a through connecting hole can be made in the adjusting block 160 so that the screw connector can pass through the connecting hole and connect to the pressure cap 120. By abutting or connecting with the adjusting block 160, the adjusting block 160 is connected to the pressure cap 120.

[0037] In other embodiments of the present invention, the accommodating cylinder 110 may further include a main cylinder and at least one sub-cylinder, the sub-cylinder being detachably connected to the open end of the main cylinder, and the centerline of the sub-cylinder coinciding with the centerline of the main cylinder; the pressure cap 120 is connected to the main cylinder or the sub-cylinder. Thus, by adjusting the number of sub-cylinders on the accommodating cylinder 110, the volume of the accommodating cylinder 110 can be adjusted. It should be noted that this method can be used in conjunction with the aforementioned arrangement of the adjusting block 160, thereby improving the flexibility of adjusting the volume of the cavity 101.

[0038] Based on the above structure, in order to improve the overall sealing performance of the device, a conical sealing gasket is provided at the connection between the ignition unit 130 and the pressure cap 120 to achieve sealing; a copper sealing gasket is provided at the connection between the transition joint and the first channel 121 and the second channel 122; and the sealing between the pressure cap 120 and the accommodating cylinder 110 is achieved by an end face sealing ring, which is an O-ring and made of EPDM rubber for high temperature resistance.

[0039] Please refer to Figures 1-6 Based on the above, the testing steps of the gas generator testing device 100 are as follows: Taking the burning rate of the gas generator used in the airbag gas generator as an example, in a room with suitable temperature and humidity, weigh 5-8g of the gas generator. The generator is in tablet form. Weigh it and place it in the cavity 101. The tablet should be laid flat at the bottom. Then weigh 1g of PBKN (or black powder) ignition powder and pour it on top of the generator tablet. An ignition unit 130 is installed on the gland 120. Taking the ignition unit 130 as an electric detonating tube 131 as an example, the head of the electric detonating tube 131 faces the cavity 101, and a sealing gasket is inserted into the conical surface of its connection surface. The cover fitting 129 is used to cooperate with the cover body 128, thereby pressing the ignition unit 130 into the cavity 101. The electric detonating tube 131 is positioned and pressed through its top annular inner conical surface, ensuring that the sealing gasket is deformed under pressure, thus ensuring that it can play a sealing role. Then assemble the transition joint, and seal the end face of the joint with a copper gasket. The joint should press the gasket tightly to complete the installation of the pressure test unit 40 and the pressure relief unit 150. The sealing method is as described above and will not be repeated here. Adjust the switch of the pressure relief unit 150 to the off state, connect the pressure test unit 40 to the pressure test system, and connect the electric detonator 131 to the pulse ignition system. Operate remotely in a sealed and safe room. After ignition, the pressure test system will automatically generate a pressure curve. Refer to the attached figure. The burning rate of the agent can be determined by calculating and comparing a certain point on the curve. Therefore, based on the obtained pressure curve and other data, the burning rate of the gas generator can be detected and determined, thereby accurately determining whether the burning rate of the gas generator meets the requirements and guiding subsequent work.

[0040] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A gas generator testing device, characterized in that: The gas generator testing device includes a container, a pressure cap, an ignition unit, a pressure testing unit, and a pressure relief unit. The cap is detachably connected to the container cylinder, and the cap is used together with the container cylinder to form a cavity for accommodating the gas generator to be tested; The ignition unit is connected to the pressure cap and is used to ignite the gas generator to be tested in the cavity; Both the pressure testing unit and the pressure relief unit are connected to the pressure cap and are in communication with the cavity.

2. The gas generator testing device according to claim 1, characterized in that: The pressure cap has a first channel and a second channel communicating with the cavity; The pressure testing unit is connected to the cavity through the first channel, and the pressure relief unit is connected to the cavity through the second channel; The first channel and the second channel are spaced apart around the center line of the receiving cylinder.

3. The gas generator testing device according to claim 2, characterized in that: At least a portion of the first channel and the second channel are bent or flexed.

4. The gas generator testing device according to claim 3, characterized in that: The first channel includes a first segment and a second segment, the first segment and the second segment are connected, the first segment is connected to the pressure testing unit, and the second segment is connected to the cavity; the second channel includes a third segment and a fourth segment, the third segment and the fourth segment are connected, the third segment is connected to the pressure relief unit, and the fourth segment is connected to the cavity. Wherein, the intersection of the first segment and the second segment is bent or extended, and the intersection of the third segment and the fourth segment is bent or extended.

5. The gas generator testing device according to claim 4, characterized in that: The first segment and the third segment extend in a direction perpendicular to the center line of the accommodating cylinder, and the second segment and the fourth segment extend in the direction of the center line of the accommodating cylinder.

6. The gas generator testing device according to claim 2, characterized in that: The pressure cap has an ignition channel; The ignition unit includes an electric detonator installed in the ignition channel; or, the ignition unit includes an electrode and a resistance wire installed in the ignition channel, and the electrode and the resistance wire extend through the ignition channel into the cavity.

7. The gas generator testing device according to claim 6, characterized in that: The cap includes a cap body and a cap fitting; the cap body is detachably connected to the receiving cylinder, the ignition channel is opened in the cap body, the cap fitting is detachably connected to the cap body and the cap fitting, and the cap fitting is used to close the ignition channel.

8. The gas generator testing device according to claim 6, characterized in that: The gas generator testing device further includes an adjusting block placed in the cavity. The adjusting block is detachably connected to the container or the pressure cap. The container has an ignition channel, a first connecting channel, and a second connecting channel. The ignition channel, the first connecting channel, and the second connecting channel pass through the adjusting block along the center line of the container. The ignition channel is connected to the ignition channel, the first connecting channel is connected to the first channel, and the second connecting channel is connected to the second channel.

9. The gas generator testing device according to claim 8, characterized in that: The adjusting block has a connecting hole for mounting a fastener, which is used to connect the adjusting block to the pressure cover.

10. The gas generator testing apparatus according to any one of claims 1-9, characterized in that: The accommodating cylinder includes a main cylinder and at least one sub-cylinder. The sub-cylinder is detachably connected to the open end of the main cylinder, and the centerline of the sub-cylinder coincides with the centerline of the main cylinder. The pressure cap is connected to the main cylinder or the sub-cylinder.