Armored double shielded dry reed relay and its manufacturing method

Abstract

The application discloses a kind of armored double-layer shielded dry reed relay and its manufacturing method.The dry reed relay includes dry reed tube, inner shield tube, coil framework, coil, outer shield shell, coil lead, shield lead, side plate, sealing assembly and switch lead.The armored double-layer shielded structure of the above-mentioned dry reed relay can solve the problem of dry reed tube contact characteristic impedance matching uniformity by means of inner layer shielding, solve the problem of relay coil magnetic field leakage and low-frequency electromagnetic field shielding by means of outer layer shielding, and realize the problem of relay structure complete shielding and distributed parameter uniformity by means of coaxial structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electrical engineering, and particularly relates to an armored double-layer shielded dry reed relay and a manufacturing method thereof. BACKGROUND

[0002] Since the dry reed switch was invented by Bell Laboratory in the United States in 1936, it has been nearly a hundred years. With its simple structure, high reliability, strong environmental adaptability, low noise, electrical isolation, low cost and other irreplaceable advantages, it has not been replaced by the rapid development of semiconductor technology. With the development and popularization of microelectronic control technology, the electronic component has been widely used as an executive control component in many fields such as communication, security, electrical signal detection, integrated circuit online testing, household appliances, automobiles, rail transit, relay protection, aviation electrical appliances and space control. Due to the inherent defects of the dry reed relay such as long contact action rebound and stable time, and the vibration of the reed plate easily leading to the cracking of the sealing glass tube and thus leading to the failure of the dry reed tube, it is difficult to meet the requirements of testing and some industrial control fields. In order to overcome the inherent defects of the dry reed relay, people have invented a wet reed relay with liquid mercury as the contact. However, due to the fact that metallic mercury is a toxic heavy metal and has a low evaporation temperature, the wet reed relay is harmful to the environment and human health during manufacturing and use, and has a high manufacturing cost, which is not conducive to large-scale application. Based on the above reasons, although the dry reed relay technology has been mature for many years, it still needs to be further improved. SUMMARY

[0003] The present application aims to provide an armored double-layer shielded dry reed relay with low contact jitter and performance close to that of a mercury dry reed relay, and a manufacturing method thereof.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] According to an embodiment of the present application, an armored double-layer shielded dry reed relay is provided, which comprises a dry reed tube, an inner shield tube, a coil framework, a coil, an outer shield shell, a coil lead, a shield lead, a side plate, a sealing assembly and a switch lead, wherein:

[0006] The dry reed tube is composed of a glass tube, magnetic reed plates sealed inside the glass tube at both ends and contacts at the heads of the magnetic reed plates;

[0007] The switch lead is electrically connected to the magnetic reed plates, respectively;

[0008] The inner shield tube is in the form of a hollow tube and tightly surrounds the dry reed tube to form a coaxial inner layer shield structure;

[0009] The coil former is in a hollow H-shaped structure, and has an axial accommodating space inside; the coaxial inner layer shielding structure formed by the reed and the inner shielding tube is arranged in the axial accommodating space of the coil former in an axial direction, forming a relay structure;

[0010] The coil is wound on the coil former;

[0011] The coil lead is electrically connected with the coil;

[0012] The outer shielding shell is in a hollow tubular shape, and has an axial accommodating space inside; the relay structure is arranged in the axial accommodating space of the outer shielding shell in an axial direction, and both ends of the outer shielding shell are provided with side plates; the side plates are connected with the outer shielding shell, the inner shielding tube, the shielding lead and the switch lead, forming an armored double-layer shielding structure;

[0013] One end of the coil former is provided with a first positioning hole; the shielding lead is electrically connected with the inner shielding tube and the outer shielding shell through the first positioning hole and the side plates, forming an inner layer shielding reed contact structure;

[0014] Both ends of the inner shielding tube are provided with sealing assemblies, so that the reed, the inner shielding tube, the coil former and the coil are sealed inside the outer shielding shell; the coil lead, the shielding lead and the switch lead connected with the side plates form an armored double-layer shielding axial reed relay structure.

[0015] In an embodiment of the present application, the glass tube of the reed is internally evacuated or filled with nitrogen.

[0016] In an embodiment of the present application, the magnetic reed is made of a soft magnetic metal base, the middle section is plated with a nano carbon copper composite layer, and the head is plated with rhodium or ruthenium as a contact.

[0017] In an embodiment of the present application, the inner shielding tube is made of a first metal, and the outer shielding shell and the side plates are made of a second metal.

[0018] In an embodiment of the present application, the switch lead is welded with the magnetic reed, the coil lead is welded with the coil, and the shielding lead is welded with the inner shielding tube, the outer shielding shell and the side plates.

[0019] In an embodiment of the present application, the sealing assembly is made of an electrically insulating material with sealing property.

[0020] In an embodiment of the present application, the other end of the coil former is provided with a second positioning hole, and the coil lead is electrically connected with the coil through the second positioning hole and the side plates.

[0021] According to another embodiment of the present application, a manufacturing method of a reed relay with an armored double-layer shielding structure is provided, and the method comprises the following steps:

[0022] Step S301, plating the middle section surface of the magnetic reed with a nano carbon copper composite plating layer, and plating the head of the magnetic reed with rhodium or ruthenium as a contact;

[0023] Step S302, evacuating the glass tube to high vacuum or filling it with nitrogen, and sealing the magnetic reed at both ends inside the glass tube to form a dry reed tube, wherein the magnetic reed is connected with a switch lead wire outside the dry reed tube;

[0024] Step S303, placing an inner shielding tube closely outside the dry reed tube to form a coaxial inner layer shielding structure, which plays a role of contact characteristic impedance matching and uniformity;

[0025] Step S304, placing the coaxial inner layer shielding structure axially in an axial accommodation space inside a coil skeleton in a hollow I-shaped structure to form a relay structure;

[0026] Step S305, winding a coil on the coil skeleton, and electrically connecting the coil lead wire with the coil;

[0027] Step S306, placing the relay structure axially in an axial accommodation space inside an outer shielding shell in a hollow tubular structure, and mounting side plates at both ends to form an armored double-layer shielding structure;

[0028] Step S307, electrically connecting the shielding lead wire with the inner shielding tube and the outer shielding shell through a first positioning hole provided at one end of the coil skeleton and the side plate to form an inner layer shielding dry reed contact structure, and passing the coil lead wire out through a second positioning hole provided at the other end of the coil skeleton and the side plate;

[0029] Step S308, using resin to fill and seal both ends of the inner shielding tube, so that the dry reed tube, the inner shielding tube, the coil skeleton and the coil are sealed inside the outer shielding shell, and the coil lead wire, the shielding lead wire and the switch lead wire are exposed, to form an armored double-layer shielding axial dry reed relay structure.

[0030] In an embodiment of the present application, the inner shielding tube is made of a first metal, and the outer shielding shell and the side plates are made of a second metal.

[0031] In an embodiment of the present application, the switch lead wire is welded with the magnetic reed, the coil lead wire is welded with the coil, and the shielding lead wire is welded with the inner shielding tube, the outer shielding shell and the side plates.

[0032] The present application has the following beneficial effects:

[0033] The armored double-layer shielding structure of the dry reed relay can solve the problem of uniformity of the contact characteristic impedance matching of the dry reed by means of the inner shielding, solve the problem of leakage of the magnetic field of the relay coil and shielding of the low-frequency electromagnetic field by means of the outer shielding, and realize complete shielding of the relay structure and uniformity of the distributed parameters by means of the coaxial structure. In addition, the magnetic spring piece of the dry reed is coated with a copper composite coating added with nano-carbon, which can attenuate the mechanical vibration energy of the magnetic spring piece of the dry reed during the action of the relay, thereby reducing the number of contact shaking and shortening the contact stabilization time, reducing the electrical burning loss and mechanical wear during the action of the relay contact, prolonging the service life of the dry reed relay contact, reducing the vibration stress of the magnetic spring piece at the glass tube and magnetic spring piece sealing part, thereby reducing the probability of rupture and air leakage at the glass sealing part, improving the reliability of the dry reed, making the performance of the relay contact close to that of the mercury wet spring relay, being beneficial to expanding the application range of the dry reed relay, and further improving the performance, service life and reliability of the electronic detection and measurement system. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a design structure diagram of an armored double-layer shielding dry reed relay according to an embodiment of the present application;

[0035] Figure 2 is a structure diagram of a nano-carbon copper composite coating of a magnetic spring piece of a dry reed according to an embodiment of the present application;

[0036] Figure 3 is a flow chart of a manufacturing method of an armored double-layer shielding dry reed relay according to an embodiment of the present application.

[0037] BRIEF DESCRIPTION OF DRAWINGS

[0038] 1 - switch lead, 2 - sealing assembly, 3 - inner shielding tube, 4 - glass tube, 5 - side plate, 6 - coil frame, 7 - outer shielding shell, 8 - electromagnetic coil, 9 - contact, 10 - coil lead, 11 - magnetic spring piece, 12 - dry reed, 13 - shielding lead DETAILED DESCRIPTION

[0039] In order to make the object, technical scheme and effect of the present application more clear and definite, the present application will be further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0040] According to an aspect of the present application, an armored double-layer shielding dry reed relay is provided, as shown in Figure 1 The dry reed relay includes a dry reed 12, an inner shielding tube 3, a coil frame 6, a coil 8, an outer shielding shell 7, a coil lead 10, a shielding lead 13, a side plate 5, a sealing assembly 2 and a switch lead 1, wherein:

[0041] The dry reed 12 is composed of a glass tube 4, magnetic reed 11 sealed inside the glass tube 4 at both ends, and contact 9 of the head of the magnetic reed 11;

[0042] The switch lead 1 is electrically connected with the magnetic reed 11 respectively;

[0043] The inner shielding tube 3 is in a hollow tube shape, tightly surrounds the dry reed 12, forms a coaxial inner layer shielding structure, and plays a role of contact characteristic impedance matching and uniformity;

[0044] The coil skeleton 6 is in a hollow H-shaped structure, and an axial containing space is arranged inside, the coaxial inner layer shielding structure formed by the dry reed 12 and the inner shielding tube 2 is arranged in the axial containing space of the coil skeleton 6 in an axial direction, and a relay structure is formed;

[0045] The coil 8 is wound on the coil skeleton 6;

[0046] The coil lead 10 is electrically connected with the coil 8;

[0047] The outer shielding shell 7 is in a hollow tube shape, and an axial containing space is arranged inside, the relay structure is arranged in the axial containing space of the outer shielding shell 7 in an axial direction, and side plates 5 are arranged at both ends, the side plates 5 are connected with the outer shielding shell 7, the inner shielding tube 3, the shielding lead 13 and the switch lead 1, and a double-layer shielding structure is formed;

[0048] One end of the coil skeleton 6 is provided with a first positioning hole, the shielding lead 13 is electrically connected with the inner shielding tube 3 and the outer shielding shell 7 through the first positioning hole and the side plate 5, and an inner layer shielding dry reed contact structure is formed;

[0049] Sealing assemblies 2 are arranged at both ends of the inner shielding tube 3, so that the dry reed 12, the inner shielding tube 3, the coil skeleton 6 and the coil 8 are sealed inside the outer shielding shell 7, the coil lead 10 is exposed, the shielding lead 13 and the switch lead 1 connected with the side plate 5 are formed, and a double-layer shielding axial dry reed relay structure is formed.

[0050] In an embodiment of the present application, high vacuum is extracted or nitrogen or other gas is filled inside the glass tube 4 of the dry reed 12.

[0051] In an embodiment of the present application, the inner shielding tube 3 is made of a first metal, and the outer shielding shell 7 and the side plate 5 are made of a second metal, which can be made of a soft magnetic metal material, so as to constitute a relay magnetic circuit and prevent the magnetic field of the internal electromagnetic coil 8 from leaking and shield external low-frequency electromagnetic interference. The first metal is a non-magnetic high-conductivity metal such as copper, and the second metal is a soft magnetic metal material.

[0052] The armored double-layer shielding structure formed by the outer shielding shell and the inner shielding tube has shielding effect on high and low frequency electromagnetic field, can improve the magnetic circuit of the relay, is beneficial to improve the sensitivity of the product and reduce the electromagnetic radiation of the product, meanwhile, the inner shielding tube and the magnetic reed form a coaxial transmission line structure, so that the characteristic impedance of the contact is uniformly distributed, thereby improving the high frequency signal transmission performance and signal anti-interference performance of the contact.

[0053] In an embodiment of the present application, the other end of the coil former 6 is provided with a second positioning hole, and the coil lead 10 is electrically connected with the coil 8 through the second positioning hole and the side plate 5. The second positioning hole is provided with a step outside, so that the coil lead 10 is electrically isolated from the side plate 5.

[0054] In an embodiment of the present application, the switch lead 1, the coil lead 10, the shielding lead 13, the inner shielding tube 3, the outer shielding shell 7 and the side plate 5 are all welded.

[0055] In an embodiment of the present application, the sealing assembly is made of electrically insulating material with sealing property such as resin.

[0056] In an embodiment of the present application, the magnetic reed 11 is made of soft magnetic metal as a base, and the middle section is plated with a nano carbon copper composite coating, such as a nano graphite microsphere copper composite coating, as shown in the figure. Figure 2 The thickness of the coating is 1-10 um, the particle size of the nano graphite microspheres in the coating is 20-50 nm, and the mass ratio of the nano graphite microspheres and copper in the coating is 10-25%. The head of the magnetic reed 11 is plated with rhodium or ruthenium as the contact 9. The nano graphite microspheres uniformly distributed in the coating convert mechanical energy into heat energy when the two-dimensional graphite layers slide under stress, thereby consuming the mechanical vibration energy generated and transmitted on the cantilever beam due to the collision of the contact, reducing the contact jitter, reducing the stress of the magnetic reed vibration at the sealing part of the reed and the glass tube, and reducing the probability of glass tube rupture and gas leakage at the sealing part. Meanwhile, the excellent heat conduction and lubrication performance of graphite is also conducive to the heat conduction and dissipation of the magnetic reed, which reduces the stress of copper in the coating and increases the surface area of copper in the coating, which is conducive to improving the electrical conductivity.

[0057] According to another aspect of the present application, a manufacturing method of the armored double-layer shielding dry reed relay is also provided, as shown in the figure. Figure 3 The manufacturing method of the armored double-layer shielding dry reed relay comprises the following steps:

[0058] In step S301, the middle section of the magnetic reed is plated with a nano carbon copper composite coating, and the head of the magnetic reed is plated with rhodium or ruthenium as the contact.

[0059] The thickness of the plating layer is 1-10 um, the particle size of the nano-graphite microspheres in the plating layer is 20-50 nm, and the mass ratio of the nano-graphite microspheres and copper in the plating layer is 10-25%.

[0060] In step S302, the glass tube is evacuated to high vacuum or filled with nitrogen, and the magnetic reed is sealed and arranged at both ends of the glass tube inside to form a dry reed tube, wherein the magnetic reed is connected with switch leads outside the dry reed tube.

[0061] In step S303, an inner shielding tube is closely arranged outside the dry reed tube to form a coaxial inner layer shielding structure, which plays a role of contact characteristic impedance matching and uniformity.

[0062] In step S304, the coaxial inner layer shielding structure is axially arranged in an axial accommodation space inside a coil skeleton in a hollow I-shaped structure to form a relay structure.

[0063] In step S305, a coil is wound on the coil skeleton, and the coil leads are electrically connected with the coil.

[0064] In step S306, the relay structure is axially arranged in an axial accommodation space inside an outer shielding shell in a hollow tubular structure, and side plates are arranged at both ends to form an armored double-layer shielding structure.

[0065] In step S307, shielding leads are electrically connected with the inner shielding tube and the outer shielding shell through a first positioning hole arranged at one end of the coil skeleton and the side plates, and the coil leads are led out through a second positioning hole arranged at the other end of the coil skeleton and the side plates, to form an inner layer shielding dry reed contact structure.

[0066] In step S308, resin is used to seal both ends of the inner shielding tube, so that the dry reed tube, the inner shielding tube, the coil skeleton and the coil are sealed inside the outer shielding shell, and the coil leads, the shielding leads and the switch leads are exposed, to form an armored double-layer shielding axial dry reed relay structure.

[0067] In an embodiment of the present application, the glass tube 4 inside the dry reed tube 12 is evacuated to high vacuum or filled with nitrogen or other gas.

[0068] In an embodiment of the present application, the inner shielding tube 3 is made of a first metal, and the outer shielding shell 7 and the side plates 5 are made of a second metal, such as a soft magnetic metal material, to constitute a relay magnetic circuit and prevent the magnetic field of the internal electromagnetic coil 8 from leaking and shield external low-frequency electromagnetic interference. The first metal is a non-magnetic high-conductivity metal such as copper, and the second metal is a soft magnetic metal material.

[0069] In an embodiment of the present application, a step is arranged outside the second positioning hole, so that the coil leads 10 are electrically isolated from the side plates 5.

[0070] In an embodiment of the present application, the switch lead 1 is welded to the magnetic reed 11, the coil lead 10 is welded to the coil 8, the shield lead 13 is welded to the inner shield tube 3, the outer shield shell 7 and the side plate 5.

[0071] Compared with the prior art, the relay has the following advantages and effects:

[0072] 1. The copper composite coating added with nano-carbon is coated on the magnetic reed of the dry reed tube, which can attenuate the mechanical vibration energy of the magnetic reed of the dry reed tube during the relay operation, thereby reducing the contact shaking frequency and shortening the contact stabilization time, reducing the electrical burning loss and mechanical wear during the relay contact operation, prolonging the service life of the dry reed relay contact, reducing the vibration stress of the magnetic reed at the glass tube and magnetic reed sealing part, thereby reducing the probability of glass sealing part rupture and air leakage, improving the reliability of the dry reed tube, making the relay contact performance close to that of the mercury wet reed relay, and being beneficial to expanding the application range of the dry reed relay, and further improving the performance, service life and reliability of the electronic detection and measurement system.

[0073] 2. The dry reed relay adopts the coaxial inner layer shielding structure to change the contact distribution parameters of the dry reed tube, so that the contact characteristic impedance can be uniformly distributed along the transmission path, achieving the performance of the high-frequency transmission line, and being capable of improving the signal transmission bandwidth, reducing the signal distortion caused by parasitic parameters during high-speed signal transmission, reducing the transmission loss of signal high harmonics, preventing waveform distortion and reducing distortion, and improving signal sampling quality.

[0074] 3. The outer shield shell and the side plate made of soft magnetic metal material of the dry reed relay form part of the coil magnetic circuit, which not only reduces the magnetic resistance of the relay magnetic circuit, improves the product sensitivity, controls the coil magnetic field within the product size range, prevents the leakage of the relay coil magnetic field from interfering with the surrounding circuit, but also can play a role in magnetic shielding of the center contact, reducing the interference of the external low-frequency magnetic field on the contact transmission signal, and making up for the defect that the inner layer shielding has good shielding effect on high-frequency electromagnetic field but poor shielding performance on low-frequency electromagnetic field.

[0075] 4. The dry reed relay can shield the contact high and low frequency electromagnetic field by means of the above-mentioned armored double-layer shielding structure, which can reduce the external interference on the test signal to the greatest extent and prevent the transmission signal and coil magnetic field from interfering with the surrounding circuit.

[0076] 5. Compared with other types of electromagnetic relays, the reed relay of this invention has the advantages of low contact bounce, fast stabilization speed, low stress at the glass tube sealing part, long life and high reliability. Its performance is close to that of wet reed relays, and it can avoid the use of highly toxic heavy metal mercury. Compared with other electronic switching devices, it has low noise, no conduction voltage drop and conduction voltage requirements. The same test channel has switching capabilities from millivolt and nanoampere level to ampere and kilovolt level. It is an ideal key switching element in the fields of instrument test bus, communication, relay protection, aerospace isolation control and other fields.

[0077] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An armoured double shielded dry reed relay characterised in that, The dry reed relay comprises a dry reed, an inner shielding tube, a coil frame, a coil, an outer shielding shell, coil leads, shielding leads, side plates, sealing components and switch leads, wherein: The dry reed is composed of a glass tube, magnetic reed pieces sealed inside the glass tube and contacts at the head of the magnetic reed pieces. The switch leads are electrically connected to the magnetic reed pieces respectively. The inner shielding tube is in a hollow tube shape and tightly surrounds the dry reed to form a coaxial inner shielding structure. The coil frame is in a hollow H-shaped structure and has an axial accommodation space inside, the coaxial inner shielding structure formed by the dry reed and the inner shielding tube is placed in the axial accommodation space of the coil frame in an axial direction to form a relay structure. The coil is wound on the coil frame. The coil leads are electrically connected to the coil. The outer shielding shell is in a hollow tube shape and has an axial accommodation space inside, the relay structure is placed in the axial accommodation space of the outer shielding shell in an axial direction, and the outer shielding shell is provided with side plates at both ends, the side plates are connected to the outer shielding shell, the inner shielding tube, the shielding leads and the switch leads to form an armored double-layer shielding structure. One end of the coil frame is provided with a first positioning hole, the shielding leads are electrically connected to the inner shielding tube and the outer shielding shell through the first positioning hole and the side plates to form an inner shielding dry reed contact structure. Both ends of the inner shielding tube are provided with sealing components to seal the dry reed, the inner shielding tube, the coil frame and the coil inside the outer shielding shell, expose the coil leads, and connect the shielding leads and the switch leads to the side plates to form an armored double-layer shielding axial dry reed relay structure.

2. The dry reed relay of claim 1, wherein, The glass tube of the dry reed is evacuated to high vacuum or filled with nitrogen.

3. A reed relay according to claim 1 or 2, characterised in that The magnetic reed pieces are made of a soft magnetic metal base, a nanometer carbon copper composite coating is plated on the surface of the middle section, and rhodium or ruthenium is plated on the head as a contact.

4. The dry reed relay according to any one of claims 1 to 3, wherein The inner shielding tube is made of a first metal, and the outer shielding shell and the side plates are made of a second metal.

5. The dry reed relay according to any one of claims 1-4, wherein The switch leads are welded to the magnetic reed pieces, the coil leads are welded to the coil, and the shielding leads are welded to the inner shielding tube, the outer shielding shell and the side plates.

6. The dry reed relay according to any one of claims 1-5, wherein, The sealing components are made of an electrically insulating material with sealing properties.

7. The dry reed relay according to any one of claims 1-6, wherein, The other end of the coil frame is provided with a second positioning hole, and the coil leads are electrically connected to the coil through the second positioning hole and the side plates.

8. A method of fabricating an armored dual shielded dry reed relay, comprising: The method comprises the following steps: In step S301, a nanometer carbon copper composite coating is plated on the surface of the middle section of the magnetic reed pieces, and rhodium or ruthenium is plated on the head of the magnetic reed pieces as a contact. In step S302, the glass tube is evacuated to high vacuum or filled with nitrogen, and the magnetic reed pieces are sealed and placed at both ends inside the glass tube to form a dry reed, wherein the magnetic reed pieces are connected to switch leads outside the dry reed. In step S303, the inner shielding tube is tightly placed outside the dry reed to form a coaxial inner shielding structure, which plays a role in matching the contact characteristic impedance and uniformity. In step S304, the coaxial inner shielding structure is placed in an axial accommodation space inside the coil frame in an axial direction to form a relay structure. In step S305, the coil is wound on the coil frame, and the coil leads are electrically connected to the coil. Step S306, the relay structure is axially placed in the axial accommodation space inside the hollow tubular outer shielding shell, both ends are equipped with side plates, forming a double armored shielding structure; Step S307, the shielding lead wire is electrically connected with the inner shielding tube and the outer shielding shell through the first positioning hole and the side plate arranged at one end of the coil skeleton, forming an inner layer shielding reed switch contact structure, and the coil lead wire is led out through the second positioning hole and the side plate arranged at the other end of the coil skeleton; Step S308, the two ends of the inner shielding tube are filled with resin, so that the reed switch, the inner shielding tube, the coil skeleton and the coil are sealed inside the outer shielding shell, and the coil lead wire, the shielding lead wire and the switch lead wire are exposed, forming an armored double shielding axial reed relay structure.

9. The method of claim 8, wherein, The inner shielding tube is made of a first metal, and the outer shielding shell and the side plates are made of a second metal.

10. The method according to claim 8 or 9, characterized in that, The switch lead wire is welded with the magnetic reed, the coil lead wire is welded with the coil, and the shielding lead wire is welded with the inner shielding tube, the outer shielding shell and the side plates.

Images