SPD knife switch

Abstract

The utility model discloses an SPD knife switch, which comprises an insulating shell, a rotating rod and metal terminals, a terminal accommodating cavity is formed in the insulating shell, the two metal terminals are fixedly arranged in the insulating shell at intervals, and contact arms and connecting pins are formed on the two metal terminals. The contact arms of the two metal terminals are accommodated in the terminal accommodating cavity at intervals, the connecting pins of the two metal terminals can be electrically connected with two wires needing to be connected and conducted respectively, and one end of the rotating rod made of the insulating material can be inserted into the terminal accommodating cavity in a manner of rotating by a set angle. A metal protrusion is fixedly installed on the outer side wall of the circumference of one end of the rotating rod, the rotating rod rotates to different angles so that the metal protrusion on the rotating rod can be in close contact with the two metal terminals or be separated from at least one metal terminal at the same time, and a rotating operation end capable of being exposed out of the surface of the insulating shell is formed at the other end of the rotating rod. The circuit can be installed and used in a narrow space, and the circuit connection stability is good.

Description

Technical Field

[0001] The utility model relates to a switch, in particular to an SPD knife switch. Background Art

[0002] Existing surge protectors all use knife switches to achieve on-off control of circuits. A common knife switch 100 consists of a knife blade, a bracket, an insulating base, terminal blocks, etc. The knife blade is a metal plate or strip with electrical contacts. One end of the knife blade is hinged to the bracket, and the bracket is connected to a circuit to achieve conduction between one end of the knife blade and a circuit. A handle is provided at the other end of the knife blade for turning the knife blade. When the knife blade is forcefully turned so that the electrical contacts on it contact the terminal blocks, the conduction of the entire circuit is achieved. When the knife blade is turned in the reverse direction, the electrical contacts on the knife blade are separated from the terminal blocks, achieving the disconnection of the entire circuit.

[0003] Currently, due to the need for the knife blade of this traditional knife switch structure to swing back and forth, it occupies a large space, and when subjected to vibration, it is also easy to cause the knife blade to swing and result in circuit disconnection. Summary of the Utility Model

[0004] In order to make up for the above deficiencies, the utility model provides an SPD knife switch, which has a simple structure, small occupied space, convenient operation, and will not cause circuit disconnection due to vibration.

[0005] The technical solution adopted by the utility model to solve its technical problems is: an SPD knife switch, including an insulating housing, a rotating rod, and metal terminals. A terminal accommodating cavity is formed inside the insulating housing. Two metal terminals are fixedly installed inside the insulating housing at intervals, and contact arms and connecting feet are formed on both metal terminals. The contact arms of the two metal terminals are accommodated in the terminal accommodating cavity at intervals. The connecting feet of the two metal terminals can be electrically connected to two wires that need to be connected and conducted respectively. One end of the rotating rod made of insulating material can be inserted into the terminal accommodating cavity and rotated by a set angle. A metal protrusion is fixedly installed on the outer circumferential side wall at one end of the rotating rod. When the rotating rod rotates to different angles, the metal protrusion on it can be in close contact and conduction with the two metal terminals simultaneously or separated from at least one metal terminal to achieve disconnection. The other end of the rotating rod forms a rotating operation end that can be exposed on the surface of the insulating housing.

[0006] As a further improvement of the utility model, an installation groove extending along the arrangement direction of the metal terminals is provided on the outer circumferential side wall at one end of the rotating rod. The metal protrusion is a strip-shaped metal sheet. One end of the strip-shaped metal sheet is fixedly inserted into the installation groove, and the other end of the strip-shaped metal sheet protrudes from the surface of the outer circumferential side wall at one end of the rotating rod.

[0007] As a further improvement of the present utility model, two metal terminals are arranged at intervals along the axial direction of the rotating rod. The installation groove on the side wall at one end of the rotating rod extends along the axial direction of the rotating rod. Interference ribs protruding inwards are respectively provided on both side walls of the installation groove along the thickness direction of the strip-shaped metal sheet. One end of the strip-shaped metal sheet is fixedly inserted into the installation groove by an interference fit manner. When the strip-shaped metal sheet rotates with the rotating rod, it can be in close contact and conduction with the contact arms of the two metal terminals at the same time or separated from the contact arms of the two metal terminals at the same time.

[0008] As a further improvement of the present utility model, chamfered surfaces or rounded surfaces are respectively formed on both side edges of the other end of the strip-shaped metal sheet along the circumferential direction of the rotating rod. When the strip-shaped metal sheet rotates with the rotating rod, it contacts the two metal terminals first through the chamfered surfaces or rounded surfaces.

[0009] As a further improvement of the present utility model, a spiral cavity coaxially facing the terminal accommodation cavity is further provided in the insulating housing. The other end of the rotating rod is inserted into the spiral cavity, and the other end of the rotating rod is meshed and connected with the spiral cavity of the insulating housing through a spiral structure.

[0010] As a further improvement of the present utility model, a radially protruding limiting retaining ring is further provided on the outer circumferential side wall of the rotating rod. The radially protruding limiting retaining ring abuts against the opposite outer side walls of the terminal accommodation cavity and the spiral cavity in the insulating housing to limit the axial movement distance of the spiral rod. A guiding column with a reduced diameter is further provided at the end of one end of the rotating rod. A guiding slot is provided on the inner side wall of the end of the terminal accommodation cavity facing away from the spiral cavity. The guiding column can be slidably inserted into the guiding slot.

[0011] As a further improvement of the present utility model, a countersunk head structure is formed at the end of the spiral cavity facing away from the terminal accommodation cavity. A head with an increased diameter is formed at the end of the other end of the rotating rod. The head can be completely accommodated in the countersunk head structure, and the head at the other end of the rotating rod abuts against the bottom surface of the countersunk head structure. A flower-shaped groove for inserting and screwing a hardware tool is provided on the end surface of the head at the other end of the rotating rod.

[0012] As a further improvement of the present utility model, the insulating housing includes an insulating body, a front cover of the terminal accommodating cavity, a rear cover of the terminal accommodating cavity, an inner frame of the terminal accommodating cavity, a front cover of the spiral cavity, and a rear cover of the spiral cavity. The rear cover of the terminal accommodating cavity and the rear cover of the spiral cavity are fixedly installed on the insulating body at intervals. The front cover of the terminal accommodating cavity and the front cover of the spiral cavity can be respectively fixedly installed on the rear cover of the terminal accommodating cavity and the rear cover of the spiral cavity through connecting members or snap structures. A spiral cavity is formed by splicing between the rear cover of the spiral cavity and the front cover of the spiral cavity. The inner frame of the terminal accommodating cavity can be fixedly clamped between the front cover of the terminal accommodating cavity and the rear cover of the terminal accommodating cavity. A terminal accommodating cavity is jointly formed among the inner frame of the terminal accommodating cavity, the front cover of the terminal accommodating cavity, and the rear cover of the terminal accommodating cavity. A metal terminal positioning groove penetrating through the front and rear is provided on the side wall of the inner frame of the terminal accommodating cavity. A metal terminal positioning cavity is jointly formed among the metal terminal positioning groove, the front cover of the terminal accommodating cavity, and the rear cover of the terminal accommodating cavity. The metal terminal further includes a terminal body. The terminal body can be stop-ably accommodated in the metal terminal positioning cavity. The contact arm and the connecting leg of the metal terminal are respectively fixedly connected to the terminal body to form an integral structure. And notches for the contact arm to extend into the terminal accommodating cavity and for the connecting leg to extend out of the outer side of the insulating housing are respectively formed on the side wall of the inner frame of the terminal accommodating cavity.

[0013] As a further improvement of the present utility model, a "2"-shaped metal terminal positioning groove is formed on the side wall of the inner frame of the terminal accommodating cavity. The contact arm is an elastic arm with a cantilever structure formed by bending from one end of the terminal body. The elastic arm can elastically swing in the radial direction of the rotating rod. The connecting leg is integrally formed at the other end of the terminal body by bending.

[0014] As a further improvement of the present utility model, the contact arm is bent to form a V-shaped structure. The opening end of the V-shaped structure faces the inner side wall of the inner frame of the terminal accommodating cavity. And the end of its free end abuts against the surface of the inner side wall of the inner frame of the terminal accommodating cavity. The outwardly convex bent portion of the V-shaped structure of the contact arm forms a contact portion that contacts the metal protrusion on the rotating rod. A guiding surface with a chamfer structure or a convex arc structure is formed on the side wall of the contact arm along the rotating direction of the rotating rod. The metal protrusion contact portion on the rotating rod contacts this guiding surface first during the rotation process.

[0015] The beneficial technical effects of the present utility model are as follows: By fixedly installing metal protrusions on the outer circumferential arm of the rotating rod, when the rotating rod rotates by a certain angle, the metal protrusions can contact two metal terminals simultaneously, achieving the conduction of the two metal terminals and further realizing the conduction of the entire circuit. When the rotating rod rotates in the reverse direction, the metal protrusions thereon are separated from one or two metal terminals, thereby realizing the disconnection of the entire circuit. This structure is simple, the rotation diameter of the rotating rod is small, and the occupied space is small, enabling installation and use in a narrow space. Moreover, since the circuit conduction is achieved by the close contact between the metal protrusions on the outer circumferential wall of the rotating rod and the two metal terminals, the structure is prone to reverse rotation of the rotating rod and cause circuit disconnection when subjected to vibration, and the circuit connection stability is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the usage state of the present utility model;

[0017] Figure 2 is the front view of the disconnection state of the present utility model;

[0018] Figure 3 is Figure 2 the sectional view taken along the line A-A in

[0019] Figure 4 is the front view of the closed state of the present utility model;

[0020] Figure 5 is Figure 4 the sectional view taken along the line B-B in

[0021] Figure 6 is the front view of the insulating housing of the present utility model;

[0022] Figure 7 is the front view of the rotating rod of the present utility model;

[0023] Figure 8 is Figure 7 the sectional view taken along the line C-C in

[0024] Figure 9 is the left view of the rotating rod of the present utility model;

[0025] Figure 10 is the top view of the rotating rod of the present utility model;

[0026] Figure 11 is the three-dimensional view of the rotating rod of the present utility model;

[0027] Figure 12 is the front view of the long strip-shaped metal sheet of the present utility model;

[0028] Figure 13 is the front view of the metal terminal of the present utility model;

[0029] Figure 14 It is the left view of the metal terminal of the present utility model;

[0030] Figure 15 It is the right view of the metal terminal of the present utility model. Specific embodiments

[0031] Embodiment: An SPD knife switch includes an insulating housing 1, a rotating rod 2 and metal terminals 3. A terminal receiving cavity 11 is formed inside the insulating housing 1. Two metal terminals 3 are fixedly installed inside the insulating housing 1 at intervals, and contact arms 31 and connecting feet 32 are formed on both of the two metal terminals 3. The contact arms 31 of the two metal terminals 3 are received in the terminal receiving cavity 11 at intervals. The connecting feet 32 of the two metal terminals 3 can be electrically connected to two wires that need to be connected and conducted respectively. One end of the rotating rod 2 made of insulating material can be inserted into the terminal receiving cavity 11 at a set angle. A metal protrusion 21 is fixedly installed on the outer circumferential side wall of one end of the rotating rod 2. When the rotating rod 2 rotates to different angles, the metal protrusion 21 on it can be in close contact and conduction with the two metal terminals 3 at the same time or separated and disconnected from at least one metal terminal 3. The other end of the rotating rod 2 forms a rotating operation end that can be exposed on the surface of the insulating housing 1.

[0032] During use, rotate the rotating rod 2. When the metal protrusion 21 on the outer circumferential side wall of one end of it is not connected to one or both of the two metal terminals 3, the entire circuit is in an open state; rotate the rotating rod 2 in the reverse direction. When the metal protrusion 21 on the outer circumferential side wall of one end of it is connected to both of the two metal terminals 3, the entire circuit is in a conducting state. The rotating rod 2 preferably rotates within a range of 180° to achieve the transformation between conduction and disconnection. During the rotation process of this structure, the rotating rod 2 does not occupy additional external space, and it can be installed and used in a narrow space. Moreover, the rotating rod 2 rotates around a rotating shaft extending in the vertical direction to achieve simultaneous contact conduction with the two metal terminals 3 or disconnection without simultaneous contact with the two metal terminals 3. The structure is simple and the operation is convenient. This structure will not cause the rotating rod 2 to swing downward due to vibration, resulting in abnormal disconnection of the circuit, which is beneficial to ensuring the stability of the circuit connection.

[0033] An installation groove 22 extending along the arrangement direction of its metal terminals 3 is provided on the outer circumferential side wall at one end of the rotating rod 2. The metal protrusion 21 is a strip-shaped metal sheet. One end of the strip-shaped metal sheet is fixedly inserted into the installation groove 22, and the other end of the strip-shaped metal sheet protrudes from the surface of the outer circumferential side wall at one end of the rotating rod 2. By embedding a strip-shaped metal sheet on the rotating rod 2 to form the metal protrusion 21, it can effectively ensure that the two metal terminals 3 are in contact simultaneously, and this structure facilitates the fixed positioning of the metal protrusion 21 on the rotating rod 2. In addition, metal blocks or metal sheets fixed on the outer circumferential side wall of the rotating rod 2 through buckles or connectors, or metal parts integrally formed on the side wall of the rotating rod 2 by in-mold injection molding, such equivalent replacement structures that are easily conceivable by those skilled in the art according to the technical solution of this patent belong to the protection scope of this patent.

[0034] The two metal terminals 3 are arranged at intervals along the axial direction of the rotating rod 2. The installation groove 22 on the side wall at one end of the rotating rod 2 extends along the axial direction of the rotating rod 2. Interference ribs 221 protruding inwards are respectively provided on the two side walls of the installation groove 22 along the thickness direction of the strip-shaped metal sheet. One end of the strip-shaped metal sheet is fixedly inserted into the installation groove 22 by an interference fit method. When the strip-shaped metal sheet rotates with the rotating rod 2, it can be in close contact and conduction with the contact arms 31 of the two metal terminals 3 simultaneously or separated from the contact arms 31 of the two metal terminals 3 simultaneously. The two metal terminals 3 are arranged vertically along the axial direction of the rotating rod 2. The strip-shaped metal sheet can be a flat sheet structure. When the rotating rod 2 rotates, it can contact the contact arms 31 of the two metal terminals 3 simultaneously or separate from the contact arms 31 of the two metal terminals 3 simultaneously. In addition, the two metal terminals 3 can also be arranged at intervals along the circumferential direction of the rotating rod 2, and the strip-shaped metal sheet also forms an arc structure. During its rotation process, it can contact the contact arm 31 of one metal terminal 3, or contact the contact arms 31 of the two metal terminals 3. It can also be a spiral arrangement method, etc. Such equivalent replacement structures that are easily conceivable by those skilled in the art according to the technical solution of this patent belong to the protection scope of this patent.

[0035] Chamfered surfaces or rounded surfaces 211 are respectively formed on the two side edges along the circumferential direction of the other end of the strip-shaped metal sheet. When the strip-shaped metal sheet rotates with the rotating rod 2, it first contacts the two metal terminals 3 through the chamfered surfaces or rounded surfaces 211.

[0036] Inside the insulating housing 1, there is also a spiral cavity 12 coaxially and directly opposite to the terminal accommodating cavity 11. The other end of the rotating rod 2 is inserted into the spiral cavity 12, and the other end of the rotating rod 2 is meshed and connected with the spiral cavity 12 of the insulating housing 1 through a spiral structure. The inner side wall of the spiral cavity 12 may be provided with a spiral groove 121, and the side wall of the other end of the rotating rod 2 may be provided with a spiral protrusion 23. The inner side wall of the spiral cavity 12 may also be a spiral protrusion, and the side wall of the other end of the rotating rod 2 may be a spiral groove. Such equivalent replacement structures are easily conceivable by those skilled in the art according to the technical solution of this patent and belong to the protection scope of this patent.

[0037] On the circumferential outer side wall of the rotating rod 2, there is also a radially outward protruding limiting retaining ring 24. The radially outward protruding limiting retaining ring 24 abuts against the opposite outer side wall of the terminal accommodating cavity 11 and the spiral cavity 12 in the insulating housing 1 to limit the axial movement distance of the spiral rod. At the end of one end of the rotating rod 2, there is also a guiding column 25 with a reduced diameter. On the inner side wall of the end of the terminal accommodating cavity 11 facing away from the spiral cavity 12, there is a guiding slot. The guiding column 25 can be slidably inserted into the guiding slot. The radially outward protruding limiting retaining ring 24 moves up and down as the rotating rod 2 rotates spirally. When the rotating rod 2 rotates forward and backward to a limited angle, the radially outward protruding limiting retaining ring 24 will be blocked by the outer side walls of the terminal accommodating cavity 11 and the spiral cavity 12. At this time, the rotating rod 2 cannot continue to rotate, thereby forming a limit on the rotation angle of the rotating rod 2, so that the rotating rod 2 can only rotate forward and backward within the designed angle range to open or close the circuit.

[0038] At the end of the spiral cavity 12 facing away from the terminal accommodating cavity 11, a counterbore structure 13 is formed. At the end of the other end of the rotating rod 2, a head 26 with an increased diameter is formed. The head 26 can be completely accommodated in the counterbore structure 13, and the head 26 at the other end of the rotating rod 2 abuts against the bottom surface of the counterbore structure 13. On the end surface of the head 26 at the other end of the rotating rod 2, there is a flower-shaped groove 261 for inserting and screwing a hardware tool. When the rotating rod 2 rotates to separate the metal protrusion 21 thereon from the metal terminal 3 to disconnect the circuit, due to the spiral structure, the rotating rod 2 will move axially, causing the head 26 at its other end to protrude outside the insulating housing 1. When the rotating rod 2 rotates in the reverse direction until the metal protrusion 21 thereon contacts the metal terminal 3 to close the circuit, the head 26 at its other end sinks into the counterbore structure 13 of the insulating housing 1. Therefore, by observing whether the head 26 at the other end of the rotating rod 2 protrudes from the surface of the insulating housing 1 or is completely sunk into the insulating housing 1, it is possible to determine whether the circuit is in a conducting state or a disconnected state at this time, which is convenient for the user to judge the state of the knife switch.

[0039] The insulating housing 1 includes an insulating body, a front cover of the terminal accommodating cavity 11, a rear cover of the terminal accommodating cavity 11, an inner frame of the terminal accommodating cavity 11, a front cover of the spiral cavity 12, and a rear cover of the spiral cavity 12. The rear cover of the terminal accommodating cavity 11 and the rear cover of the spiral cavity 12 are fixedly installed on the insulating body at intervals. The front cover of the terminal accommodating cavity 11 and the front cover of the spiral cavity 12 can be fixedly installed on the rear cover of the terminal accommodating cavity 11 and the rear cover of the spiral cavity 12 respectively through connecting pieces or snap structures. The spiral cavity 12 is formed by splicing between the rear cover of the spiral cavity 12 and the front cover of the spiral cavity 12. The inner frame of the terminal accommodating cavity 11 can be fixedly clamped between the front cover of the terminal accommodating cavity 11 and the rear cover of the terminal accommodating cavity 11. The inner frame of the terminal accommodating cavity 11, the front cover of the terminal accommodating cavity 11, and the rear cover of the terminal accommodating cavity 11 together form the terminal accommodating cavity 11. A metal terminal positioning groove penetrating through the front and rear is provided on the side wall of the inner frame of the terminal accommodating cavity 11. The metal terminal positioning groove, the front cover of the terminal accommodating cavity 11, and the rear cover of the terminal accommodating cavity 11 together form a metal terminal positioning cavity. The metal terminal 3 further includes a terminal body 33. The terminal body 33 can be stop-accommodated in the metal terminal positioning cavity. The contact arm 31 and the connecting leg 32 of the metal terminal 3 are respectively fixedly connected to the terminal body 33 to form an integral structure. And notches for the contact arm 31 to extend into the terminal accommodating cavity 11 and for the connecting leg 32 to extend out of the outside of the insulating housing 1 are respectively formed on the side wall of the inner frame of the terminal accommodating cavity 11. The insulating housing 1 adopts a split assembly structure, which is convenient for the assembly and positioning of the rotating rod 2 and the metal terminal 3, and is also convenient for the injection molding of the insulating housing 1.

[0040] A metal terminal positioning groove in a "2" shape is formed on the side wall of the inner frame of the terminal accommodating cavity 11. The contact arm 31 is an elastic arm with a cantilever structure formed by bending from one end of the terminal body 33. The elastic arm can elastically swing in the radial direction of the rotating rod 2. The connecting leg 32 is integrally formed at the other end of the terminal body 33 by bending. The contact arm 31 of the metal terminal 3 adopts an elastic cantilever structure, enabling it to elastically swing in the radial direction of the rotating rod 2, which can ensure that the metal protrusion 21 on the rotating rod 2 smoothly contacts the contact arm 31, and the two are tightly connected after contact.

[0041] The contact arm 31 is bent to form a V-shaped structure. The open end of its V-shaped structure faces the inner side wall of the inner frame of the terminal accommodating cavity 11, and the end of its free end stops against the surface of the inner side wall of the inner frame of the terminal accommodating cavity 11. The outwardly convex bent part of the V-shaped structure of the contact arm 31 forms a contact part that contacts the metal protrusion 21 on the rotating rod 2. A guiding surface 311 with a chamfer structure or a convex arc structure is formed on the side wall of the contact arm 31 along the rotation direction of the rotating rod 2. The contact part of the metal protrusion 21 on the rotating rod 2 contacts the guiding surface 311 first during the rotation process.

Claims

1. An SPD knife switch, characterized in that: It includes an insulating housing (1), a rotating rod (2) and metal terminals (3). A terminal receiving cavity (11) is formed inside the insulating housing. Two metal terminals are fixedly installed inside the insulating housing at intervals, and contact arms (31) and connecting feet (32) are formed on both metal terminals. The contact arms of the two metal terminals are received in the terminal receiving cavity at intervals. The connecting feet of the two metal terminals can be electrically connected to two wires that need to be connected and conducted respectively. One end of the rotating rod made of insulating material can be inserted into the terminal receiving cavity and rotated by a set angle. A metal protrusion (21) is fixedly installed on the outer circumferential side wall at one end of the rotating rod. When the rotating rod rotates to different angles, the metal protrusion on it can be in close contact and conduction with the two metal terminals simultaneously or separated from at least one metal terminal. The other end of the rotating rod forms a rotating operation end that can be exposed on the surface of the insulating housing.

2. The SPD knife switch according to claim 1, characterized in that: An installation groove (22) extending along the arrangement direction of the metal terminals is provided on the outer circumferential side wall at one end of the rotating rod. The metal protrusion is a strip-shaped metal sheet. One end of the strip-shaped metal sheet is fixedly inserted into the installation groove, and the other end of the strip-shaped metal sheet protrudes from the surface of the outer circumferential side wall at one end of the rotating rod.

3. The SPD knife switch according to claim 2, characterized in that: The two metal terminals are arranged at intervals along the axial direction of the rotating rod. The installation groove on the side wall at one end of the rotating rod extends along the axial direction of the rotating rod. Interference ribs (221) protruding inwards are provided on the two side walls of the installation groove along the thickness direction of the strip-shaped metal sheet. One end of the strip-shaped metal sheet is fixedly inserted into the installation groove by an interference fit method. The strip-shaped metal sheet can be in close contact and conduction with the contact arms of the two metal terminals simultaneously or separated from the contact arms of the two metal terminals simultaneously as the rotating rod rotates.

4. The SPD knife switch according to claim 2, characterized in that: Chamfered surfaces or rounded surfaces (211) are respectively formed on the two side edges along the circumferential direction of the other end of the strip-shaped metal sheet. When the strip-shaped metal sheet rotates with the rotating rod, it contacts the two metal terminals first through the chamfered surfaces or rounded surfaces.

5. The SPD knife switch according to claim 1, characterized in that: A spiral cavity (12) coaxially facing the terminal receiving cavity is also provided inside the insulating housing. The other end of the rotating rod is inserted into the spiral cavity, and the other end of the rotating rod is meshed and connected with the spiral cavity of the insulating housing through a spiral structure.

6. The SPD knife switch according to claim 5, characterized in that: A radially protruding limiting ring (24) is also provided on the outer circumferential side wall of the rotating rod. The radially protruding limiting ring stops at the relative outer side walls of the terminal receiving cavity and the spiral cavity inside the insulating housing to limit the axial movement distance of the spiral rod. A guiding column (25) with a reduced diameter is also provided at the end of one end of the rotating rod. A guiding slot is provided on the inner side wall of the end of the terminal receiving cavity facing away from the spiral cavity. The guiding column can be slidably inserted into the guiding slot.

7. The SPD knife switch according to claim 5, characterized in that: A countersunk head structure (13) is formed at the end of the spiral cavity facing away from the terminal receiving cavity. A head (26) with an increased diameter is formed at the end of the other end of the rotating rod. The head can be completely received in the countersunk head structure, and the head at the other end of the rotating rod stops at the bottom surface of the countersunk head structure. A flower-shaped groove (261) for inserting and screwing a hardware tool is provided on the end surface of the head at the other end of the rotating rod.

8. The SPD knife switch according to claim 5, characterized in that: The insulating housing includes an insulating body, a front cover of the terminal accommodating cavity, a rear cover of the terminal accommodating cavity, an inner frame of the terminal accommodating cavity, a front cover of the spiral cavity, and a rear cover of the spiral cavity. The rear cover of the terminal accommodating cavity and the rear cover of the spiral cavity are fixedly installed on the insulating body at intervals. The front cover of the terminal accommodating cavity and the front cover of the spiral cavity can be fixedly installed on the rear cover of the terminal accommodating cavity and the rear cover of the spiral cavity respectively through connecting members or snap structures. A spiral cavity is formed by splicing between the rear cover of the spiral cavity and the front cover of the spiral cavity. The inner frame of the terminal accommodating cavity can be fixedly clamped between the front cover of the terminal accommodating cavity and the rear cover of the terminal accommodating cavity. A terminal accommodating cavity is jointly formed among the inner frame of the terminal accommodating cavity, the front cover of the terminal accommodating cavity, and the rear cover of the terminal accommodating cavity. A metal terminal positioning groove penetrating through from front to back is provided on the side wall of the inner frame of the terminal accommodating cavity. A metal terminal positioning cavity (14) is jointly formed among the metal terminal positioning groove, the front cover of the terminal accommodating cavity, and the rear cover of the terminal accommodating cavity. The metal terminal further includes a terminal body (33). The terminal body can be received in the metal terminal positioning cavity in a stopping manner. The contact arm and the connecting leg of the metal terminal are respectively fixedly connected to the terminal body to form an integral structure. Notches for the contact arm to extend into the terminal accommodating cavity and for the connecting leg to extend out of the insulating housing are respectively formed on the side wall of the inner frame of the terminal accommodating cavity.

9. The SPD knife switch according to claim 8, characterized in that: A "2"-shaped metal terminal positioning groove is formed on the side wall of the inner frame of the terminal accommodating cavity. The contact arm is an elastic arm with a cantilever structure formed by bending from one end of the terminal body. The elastic arm can elastically swing in the radial direction of the rotating rod. The connecting leg is integrally formed at the other end of the terminal body by bending.

10. The SPD knife switch according to claim 9, characterized in that: The contact arm is bent to form a V-shaped structure. The open end of the V-shaped structure faces the inner side wall of the inner frame of the terminal accommodating cavity. The free end of the contact arm abuts against the surface of the inner side wall of the inner frame of the terminal accommodating cavity. The outwardly convex bent portion of the V-shaped structure of the contact arm forms a contact portion that contacts the metal protrusion on the rotating rod. A chamfer structure or a convex arc-shaped guiding surface (311) is formed on the side wall of the contact arm along the rotating direction of the rotating rod. The metal protrusion contact portion on the rotating rod contacts this guiding surface first during the rotation process.

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