Vacuum chucking fixture

Abstract

This application discloses a vacuum suction cup clamp, which mainly includes a connecting component and grippers. One end of the connecting component is connected to the grippers, and the other end is connected to a tensile testing machine. The grippers include a first clamping plate and a second clamping plate arranged opposite each other, with their inner surfaces parallel to each other. An adjusting rod drives the first clamping plate to move towards or away from each other, parallel to the inner surface of the second clamping plate. The distance between the two clamping plates can be controlled within a preset range. The first clamping plate and the second clamping plate are respectively provided with a first suction cup and a second suction cup, with the suction cup body fixed to the side of the clamping plate through a mounting hole. The suction cup has an air extraction hole at the top located on the outer surface of the clamping plate, and the bottom suction cup opening plane is located on the inner surface of the clamping plate. The two suction cup opening planes are opposite and parallel. This application achieves stable clamping of glass adhesive test pieces through vacuum adsorption, avoiding glass breakage due to high bonding strength during testing and greatly improving the upper limit of glass shear strength.

Description

Technical Field

[0001] This application belongs to the field of mold processing technology, and in particular relates to a vacuum suction cup clamp. Background Technology

[0002] Adhesive shear strength is a criterion for judging the adhesion of adhesives to substrates and the stability and reliability of bonded structures. Among existing common adhesive shear strength testing fixtures, metal shear strength testing often uses toothed fixtures to increase clamping force. While these fixtures provide sufficient clamping force, they are very prone to causing glass substrates to crack during use, with breakage rates exceeding 80%. Tensile property testing of graphite materials generally uses pads with soft materials such as rubber to prevent material breakage, but these fixtures have insufficient clamping force and can only test samples with adhesive shear strength less than 2 MPa, thus failing to meet the needs of testing the adhesive shear strength of high-adhesion glass in production processes. Utility Model Content

[0003] To address the shortcomings of the existing technology, this application provides a vacuum suction cup clamp that achieves stable clamping of glass adhesive test pieces through vacuum adsorption, thus solving the problem of cracking of glass and other materials caused by traditional clamps.

[0004] To achieve the above objectives, this application provides a vacuum suction cup clamp, which mainly includes: a connecting component 100 and a gripper 200; one end of the connecting component 100 is connected to the gripper 200, and the other end is connected to a tensile testing machine; the gripper 200 includes a first clamping plate 210, an adjusting rod 220, and a second clamping plate 230.

[0005] The first clamp 210 and the second clamp 230 are arranged opposite to each other, and their inner surfaces are parallel to each other. The adjusting rod 220 connects the first clamp 210 and the second clamp 230 and is used to drive the inner surface of the first clamp 210 to move in opposite directions or away from each other, parallel to the inner surface of the second clamp 230. The distance between the first clamp 210 and the second clamp 230 is within a preset threshold range.

[0006] In this application, the gripper 200 further includes a first suction cup 240 and a second suction cup 250; wherein, a first mounting hole 211 is provided on the side of the first clamping piece 210, and the body of the first suction cup 240 passes through the first mounting hole 211 and is fixed to the side of the first clamping piece 210; a first suction hole 241 is provided on the top of the first suction cup 240, and the bottom of the first suction cup 240 is a first suction cup opening plane 242; the first suction cup opening plane 242 is located on the inner side of the first clamping piece 210, and the first suction hole 241 is located on the outer side of the first clamping piece 210.

[0007] The second clamping piece 230 has a second mounting hole 231 on its side, and the body of the second suction cup 250 passes through the second mounting hole 231 and is fixed to the side of the second clamping piece 230; the top of the second suction cup 250 has a second suction hole 251, and the bottom of the second suction cup 250 is a second suction cup opening plane 252; the second suction cup opening plane 252 is located on the inner side of the second clamping piece 230, and the second suction hole 251 is located on the outer side of the second clamping piece 230; the first suction cup opening plane 242 is arranged opposite to and parallel to the second suction cup opening plane 252.

[0008] In this application, the connecting component 100 includes at least: a connecting rod 110, a first threaded rod 120, and a first nut 130; one end of the connecting rod 110 is fixedly connected to one end of the first threaded rod 120 through the first nut 130, and the other end of the first threaded rod 120 is connected to the gripper 200; the other end of the connecting rod 110 is connected to the tensile testing machine.

[0009] In this application, the first clip 210 has a third mounting hole 212 on its side, and the second clip 230 has a fourth mounting hole 232 on its side; the body of the adjusting rod 220 passes through the fourth mounting hole 232 and is fitted into the third mounting hole 212.

[0010] In this application, the adjusting rod 220 includes at least a second threaded rod 221 and a knob 222; wherein, the knob 222 is mounted on one end of the second threaded rod 221; the other end of the second threaded rod 221 passes through the second clamp 230 and is connected to the inner side of the first clamp 210.

[0011] In this application, the gripper 200 further includes a positioning shaft 260; the first clamping piece 210 is provided with a fifth mounting hole 213 on its side, and the second clamping piece 230 is provided with a sixth mounting hole 233 on its side; the positioning shaft 260 body passes through the sixth mounting hole 233 and is fitted into the fifth mounting hole 213.

[0012] In this application, the first suction cup 240 further includes at least a first hollow rod 243, a first inner fixing member 244, and a first outer fixing member 245; one end of the first hollow rod 243 is connected to the first suction cup opening plane 242 through the first inner fixing member 244, and the other end of the first hollow rod 243 passes through the outer side of the first clamping piece 210 and is connected through the first outer fixing member 245.

[0013] Furthermore, the first air extraction hole 241 is located in the central region of the other end of the first hollow rod 243; the other end of the first hollow rod 243 is equipped with a first air pipe interface 246, which is used to connect to an external air pipe.

[0014] The second suction cup 250 also includes at least a second hollow rod 253, a second inner fixing member 254, and a second outer fixing member 255; one end of the second hollow rod 253 is connected to the second suction cup opening plane 252 through the second inner fixing member 254, and the other end of the second hollow rod 253 passes through the outer side of the second clamping piece 230 and is connected through the second outer fixing member 255.

[0015] In this application, the second air extraction hole 251 is located in the central region of the other end of the second hollow rod 253; the other end of the second hollow rod 253 is equipped with a second air pipe interface 256, which is used to connect to the external air pipe.

[0016] Compared with the prior art, the advantages of this application are as follows:

[0017] This application proposes a vacuum suction cup clamp, which, by employing a vacuum adsorption clamping structure, avoids the mechanical hard contact and point stress concentration of traditional toothed clamps on the surfaces of brittle materials such as glass and graphite, greatly reducing the risk of substrate breakage during testing. Vacuum adsorption can generate a uniform and huge adsorption force perpendicular to the contact surface, ensuring that the clamp will not slip when testing high-strength adhesives, thus meeting the testing requirements for high bond shear strength in production. In principle, this application is applicable to the bond shear strength testing of brittle materials with any smooth surface, such as various types of glass, ceramics, and silicon wafers, demonstrating strong versatility and providing a reliable and efficient solution for high-strength bond testing of brittle materials, rather than being limited to specific materials. Attached Figure Description

[0018] Figure 1 This is a front view of a vacuum suction cup clamp according to one embodiment of this application.

[0019] Figure 2 This is a front view of the gripper in one embodiment of this application.

[0020] Figure 3 This is a side view of a vacuum suction cup clamp according to one embodiment of this application.

[0021] Figure 4 This is a front view of the first suction cup in one embodiment of this application.

[0022] Figure 5 This is a top view of the second suction cup in one embodiment of this application.

[0023] Wherein, 100-connecting component; 110-connecting rod; 120-first threaded rod; 130-first nut; 200-clamp; 210-first clamping piece; 211-first mounting hole; 212-third mounting hole; 220-adjusting rod; 221-second threaded rod; 222-knob; 230-second clamping piece; 231-second mounting hole; 232-fourth mounting hole; 233-sixth mounting hole; 240-first suction cup; 241-first air extraction hole; 242-first suction cup opening plane; 243-first hollow rod; 244-first inner fixing component; 245-first outer fixing component; 246-first air pipe interface; 250-second suction cup; 251-second air extraction hole; 252-second suction cup opening plane; 254-second inner fixing component; 260-positioning shaft. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] Example 1:

[0026] As attached Figure 1 As shown, in order to solve the above-mentioned technical problems, this application provides a vacuum suction cup clamp, which mainly includes: a connecting component 100 and a gripper 200; one end of the connecting component 100 is connected to the gripper 200, and the other end is connected to a tensile testing machine; the gripper 200 includes a first clamping piece 210, an adjusting rod 220, and a second clamping piece 230.

[0027] It should be noted that the connecting component 100 is an integral structure used to connect the tensile testing machine and the fixture; the tensile testing machine refers to a material testing machine that applies a controllable tensile or compressive force to the test sample and continuously measures the force value when the test sample breaks.

[0028] In this embodiment of the application, the connecting component 100 includes at least: a connecting rod 110, a first threaded rod 120, and a first nut 130; one end of the connecting rod 110 is fixedly connected to one end of the first threaded rod 120 through the first nut 130, and the other end of the first threaded rod 120 is connected to the gripper 200; the other end of the connecting rod 110 is connected to the tensile testing machine.

[0029] It should be noted that the structure of the connecting component 100 in this embodiment is not unique. Connecting devices can be added according to the actual situation to ensure a firm connection.

[0030] The first clamp 210 and the second clamp 230 are arranged opposite to each other, and their inner surfaces are parallel to each other. The adjusting rod 220 connects the first clamp 210 and the second clamp 230 and is used to drive the inner surface of the first clamp 210 to move in opposite directions or away from each other, parallel to the inner surface of the second clamp 230. The distance between the first clamp 210 and the second clamp 230 is within a preset threshold range.

[0031] It should be noted that the first clamp 210 and the second clamp 230 mentioned above are used to provide a platform for fixing the vacuum suction cup. Their thickness and size can be manufactured and replaced according to the shape and size of the test sample. Correspondingly, they can be replaced with clamps, clamp arms, and other structures for application in other test events.

[0032] In this embodiment, the first suction cup surface 242 and the second suction cup surface 252 can only simultaneously and completely adhere to the upper and lower surfaces of the sample when they are completely parallel. This ensures that the enormous pressure generated by vacuum adsorption is evenly distributed across the entire contact surface. If the two inner surfaces are not parallel, one side will contact first, and the other side will contact later. During vacuuming, the side that contacts first has already formed a seal and begun to bear force, while the side that contacts later may still have gaps, resulting in extremely uneven force distribution. This uneven force can cause enormous shear stress or bending moment inside the sample, such as glass, which can easily lead to sample breakage before testing.

[0033] Preferably, for example, when a thicker glass sample needs to be clamped, the operator rotates the knob to separate the two clamps. When the distance reaches 15mm, the thread length of the adjusting rod 220 unscrewed from the second clamp 230 has reached the limit of the safety design. If the distance exceeds this upper limit, the connection between the first clamp 210 and the adjusting rod 220 will become very unstable. In tensile testing, the huge tensile force may cause the first clamp 210 to tilt, shake, or even detach from the rod, leading to test failure or danger. Therefore, the preset threshold range can be flexibly adjusted according to the actual test conditions.

[0034] In this application, the gripper 200 further includes a first suction cup 240 and a second suction cup 250; wherein, a first mounting hole 211 is provided on the side of the first clamping piece 210, and the body of the first suction cup 240 passes through the first mounting hole 211 and is fixed to the side of the first clamping piece 210; a first suction hole 241 is provided on the top of the first suction cup 240, and the bottom of the first suction cup 240 is a first suction cup opening plane 242; the first suction cup opening plane 242 is located on the inner side of the first clamping piece 210, and the first suction hole 241 is located on the outer side of the first clamping piece 210.

[0035] The second clamping piece 230 has a second mounting hole 231 on its side, and the body of the second suction cup 250 passes through the second mounting hole 231 and is fixed to the side of the second clamping piece 230; the top of the second suction cup 250 has a second suction hole 251, and the bottom of the second suction cup 250 is a second suction cup opening plane 252; the second suction cup opening plane 252 is located on the inner side of the second clamping piece 230, and the second suction hole 251 is located on the outer side of the second clamping piece 230; the first suction cup opening plane 242 is arranged opposite to and parallel to the second suction cup opening plane 252.

[0036] It should be noted that in this embodiment, the first suction cup 240 and the second suction cup 250 have the same shape and size, and the positions and diameters of the first mounting hole 211 and the second mounting hole 231 are also consistent, ensuring reliable and effective data. This application utilizes the principle of vacuum adsorption to provide clamping force. The suction cups in the first suction cup 240 and the second suction cup 250 can be circular or elliptical in shape, and the material of the suction cups can be rubber, soft scratch-resistant materials such as silicone, etc., and are not limited to these. When the test fixture is used to test the sample, its surface is in surface contact, which can make the clamping force evenly distributed across the entire contact surface, fundamentally avoiding the risk of crushing or breaking brittle samples such as glass and ceramics due to stress concentration.

[0037] Preferably, the soft suction cup surface will not leave indentations, scratches, or clamping marks on the smooth sample surface, which is crucial for failure analysis after testing or for the protection of valuable samples.

[0038] In this application, the first clip 210 has a third mounting hole 212 on its side, and the second clip 230 has a fourth mounting hole 232 on its side; the body of the adjusting rod 220 passes through the fourth mounting hole 232 and is fitted into the third mounting hole 212.

[0039] As attached Figure 2As shown, the function of the adjusting rod 220 is to adjust the position of the test specimen. The adjusting rod 220 includes at least a second threaded rod 221 and a knob 222; the knob 222 is mounted at one end of the second threaded rod 221; the other end of the second threaded rod 221 passes through the second clamping piece 230 and connects to the inner surface of the first clamping piece 210.

[0040] In this application, the gripper 200 further includes a positioning shaft 260; the first clamping piece 210 is provided with a fifth mounting hole 213 on its side, and the second clamping piece 230 is provided with a sixth mounting hole 233 on its side; the positioning shaft 260 body passes through the sixth mounting hole 233 and is fitted into the fifth mounting hole 213.

[0041] In this embodiment, the first clamping piece 210 and the second clamping piece 230 are used to fix the overall structure of the clamp via the adjusting rod 220 and the positioning shaft 260. The position of the positioning shaft 260 is shown in the attached figure. Figure 3 As shown, the positioning shaft provides a mandatory and unique movement path for the first clamp 210 during its movement, meaning it can only move along the axial direction of the positioning shaft. This ensures that the inner surface of the first clamp 210 remains strictly parallel to the inner surface of the second clamp 230 throughout the entire movement. Without the positioning shaft, when the adjusting rod is turned, the first clamp might rotate along with it instead of moving in a straight line.

[0042] In this application, the first suction cup 240 further includes at least a first hollow rod 243, a first inner fixing member 244, and a first outer fixing member 245; one end of the first hollow rod 243 is connected to the first suction cup opening plane 242 through the first inner fixing member 244, and the other end of the first hollow rod 243 passes through the outer side of the first clamping piece 210 and is connected through the first outer fixing member 245.

[0043] Furthermore, the first air extraction hole 241 is located in the central region of the other end of the first hollow rod 243; the other end of the first hollow rod 243 is equipped with a first air pipe interface 246, which is used to connect to an external air pipe.

[0044] It should be noted that the exploded view of the first suction cup 240 is attached. Figure 4As shown, both the first inner fixing member 244 and the first outer fixing member 245 can be secured using nuts. The first hollow rod 243 is a sealed space connecting the first suction hole 241 and the first suction cup opening plane 242, serving as a suction channel. Furthermore, the first inner fixing member 244 and the first outer fixing member 245 work together, both using paired locking nuts, to rigidly and reliably fix the first hollow rod 243 and its connected first suction cup opening plane 242 to the first clamping piece 210, forming an independent, detachable suction cup module.

[0045] The second suction cup 250 also includes at least a second hollow rod 253, a second inner fixing member 254, and a second outer fixing member 255; one end of the second hollow rod 253 is connected to the second suction cup opening plane 252 through the second inner fixing member 254, and the other end of the second hollow rod 253 passes through the outer side of the second clamping piece 230 and is connected through the second outer fixing member 255.

[0046] In this application, the second air extraction hole 251 is located in the central region of the other end of the second hollow rod 253; the other end of the second hollow rod 253 is equipped with a second air pipe interface 256, which is used to connect to the external air pipe.

[0047] Preferably, both the first tracheal inlet 246 and the second tracheal inlet 256 can be pagoda-type tracheal inlets, but are not limited to this.

[0048] It should be noted that the top view of the first suction cup 250 in this embodiment is shown in the attached figure. Figure 5 As shown, in this embodiment, the first suction cup 250 and the first suction cup 240 have the same structural shape, so the structure of the second suction cup 250 will not be shown and described again.

[0049] In summary, the embodiments of this application provide clamping force to the fixture through vacuum adsorption, avoiding stress concentration and damage to brittle materials caused by mechanical clamping. It is suitable for measuring high-strength bond shear of materials such as glass, ceramics, and silicon wafers, and greatly improves the test success rate of the measured samples.

[0050] Example 2:

[0051] In this embodiment, the test procedure for testing the bonding strength of high borosilicate glass using the above-mentioned vacuum chuck fixture is as follows:

[0052] 1. Place the test piece against the suction port surfaces of the two elliptical vacuum suction cups, and remove the air from the suction surface through the air tube via the air hole, thus adsorbing the test piece.

[0053] 2. Rotate the knob 222 of the adjusting rod 220 to increase the distance between the first clamp 210 and the second clamp 230. Place the glass bonding sample to be tested between the first suction cup port plane 242 and the second suction cup port plane 252. Rotate the knob 222 in the opposite direction to gently contact and press the upper and lower surfaces of the sample between the two suction cup port planes. Connect the first air pipe interface 246 and the second air pipe interface 256 to the vacuum pump through pipes;

[0054] 3. Fix the other half according to steps 1 and 2; start the vacuum pump to extract the air from the two suction cups, and use atmospheric pressure to form a huge vertical adsorption force on both sides of the sample, thereby firmly clamping the sample.

[0055] 4. Shear strength was tested using a computer-controlled electronic universal testing machine;

[0056] 5. Start the tensile testing machine, and the connecting rod 110 begins to apply tensile force. This force is transmitted to the adsorbed sample through the gripper 200 until the adhesive layer in the sample undergoes shear failure or the sample is broken. Record the maximum load value.

[0057] 6. After the test is completed, release the vacuum to easily remove the sample or fragment.

[0058] It should be noted that the above test pieces are made by overlapping and bonding, and their manufacturing and testing methods refer to GB / T7124-2008. The microcomputer-controlled electronic universal testing machine includes, but is not limited to, the CTM8010 manufactured by Xieqiang Instrument Manufacturing Co., Ltd. (Shanghai).

[0059] Preferably, the length of the first clamping piece 210 can be set to 80mm, the width to 40mm, and the thickness to 6mm; the diameter of the first suction hole 241 is set to 9mm, the center of which is 40mm from the lower edge of the first clamping piece 210 and 20mm from the side edge; the relevant dimensions of the first clamping piece 230 and the position of the second suction hole 251 are the same as those of the first clamping piece 210.

[0060] The final test results are shown in the table below: (Note: The bonding area is 25mm*5mm)

[0061]

[0062] According to test data, the clamp described in this invention greatly increases the upper limit of glass shear strength and completely avoids glass breakage during the test.

[0063] In summary, the fixture of this application can test glass adhesives with high bonding strength, solving the problem of cracking of glass and other materials caused by traditional fixtures. Furthermore, the fixture itself has a simple structure, is easy to operate, and is easy to promote.

[0064] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0065] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application for those skilled in the art.

Claims

1. A vacuum suction cup clamp, comprising: A connecting component (100) and a gripper (200); one end of the connecting component (100) is connected to the gripper (200), and the other end is connected to a tensile testing machine; the gripper (200) includes a first clamping plate (210), an adjusting rod (220), and a second clamping plate (230); characterized in that, The first clip (210) and the second clip (230) are arranged opposite to each other, and their opposite inner surfaces are parallel to each other. The adjusting rod (220) connects the first clip (210) and the second clip (230) and is used to drive the inner surface of the first clip (210) to move towards or away from each other, parallel to the inner surface of the second clip (230); wherein, the distance between the first clip (210) and the second clip (230) is within a preset threshold range; The gripper (200) further includes a first suction cup (240) and a second suction cup (250); wherein, the first clamping piece (210) has a first mounting hole (211) on its side, and the body of the first suction cup (240) passes through the first mounting hole (211) and is fixed to the side of the first clamping piece (210); the top of the first suction cup (240) has a first air extraction hole (241), and the bottom of the first suction cup (240) is a first suction cup opening plane (242); the first suction cup opening plane (242) is located on the inner side of the first clamping piece (210), and the first air extraction hole (241) is located on the outer side of the first clamping piece (210); The second clamping piece (230) has a second mounting hole (231) on its side, and the body of the second suction cup (250) passes through the second mounting hole (231) and is fixed to the side of the second clamping piece (230); the top of the second suction cup (250) has a second suction hole (251), and the bottom of the second suction cup (250) is a second suction cup opening plane (252); the second suction cup opening plane (252) is located on the inner side of the second clamping piece (230), and the second suction hole (251) is located on the outer side of the second clamping piece (230); the first suction cup opening plane (242) and the second suction cup opening plane (252) are arranged opposite to and parallel to each other.

2. The vacuum suction cup clamp according to claim 1, characterized in that, The connecting component (100) includes at least: a connecting rod (110), a first threaded rod (120), and a first nut (130); One end of the connecting rod (110) is fixedly connected to one end of the first threaded rod (120) via the first nut (130), and the other end of the first threaded rod (120) is connected to the gripper (200); the other end of the connecting rod (110) is connected to the tensioning machine.

3. A vacuum suction cup clamp according to claim 1, characterized in that, The first clip (210) has a third mounting hole (212) on its side, and the second clip (230) has a fourth mounting hole (232) on its side. The body of the adjusting rod (220) passes through the fourth mounting hole (232) and is fitted into the third mounting hole (212).

4. A vacuum suction cup clamp according to claim 3, characterized in that, The adjusting rod (220) includes at least a second threaded rod (221) and a knob (222); wherein the knob (222) is installed at one end of the second threaded rod (221); the other end of the second threaded rod (221) passes through the second clamp (230) and is connected to the inner side of the first clamp (210).

5. A vacuum suction cup clamp according to claim 1, characterized in that, The gripper (200) also includes a positioning shaft (260); The first clip (210) is also provided with a fifth mounting hole (213) on its side, and the second clip (230) is also provided with a sixth mounting hole (233) on its side. The positioning shaft (260) body passes through the sixth mounting hole (233) and is fitted into the fifth mounting hole (213).

6. A vacuum suction cup clamp according to claim 1, characterized in that, The first suction cup (240) also includes at least a first hollow rod (243), a first inner fixing member (244), and a first outer fixing member (245); One end of the first hollow rod (243) is connected to the first suction cup opening plane (242) through the first inner fixing member (244), and the other end of the first hollow rod (243) passes through the outer side of the first clip (210) and is connected through the first outer fixing member (245).

7. A vacuum suction cup clamp according to claim 6, characterized in that, The first air extraction hole (241) is located in the center region of the end of the other end of the first hollow rod (243); The other end of the first hollow rod (243) is equipped with a first tracheal interface (246), which is used to connect to an external tracheal tube.

8. A vacuum suction cup clamp according to claim 1, characterized in that, The second suction cup (250) also includes at least a second hollow rod (253), a second inner fixing member (254), and a second outer fixing member (255); One end of the second hollow rod (253) is connected to the second suction cup opening plane (252) through the second inner fixing member (254), and the other end of the second hollow rod (253) passes through the outer side of the second clip (230) and is connected through the second outer fixing member (255).

9. A vacuum suction cup clamp according to claim 8, characterized in that, The second air extraction hole (251) is located in the center region of the end of the other end of the second hollow rod (253); The other end of the second hollow rod (253) is equipped with a second air pipe interface (256), which is used to connect to an external air pipe.

Images