An electric arc prevention self-adapting structure of an external power distribution switch of an electric energy meter

Abstract

The utility model relates to power distribution switch technical field, concretely is a kind of electric energy meter external power distribution switch's anti-arcing self-adapting structure. Including switch shell, the first terminal mechanism and the second terminal mechanism of being arranged in switch shell, the switch slider for controlling the first terminal mechanism and the second terminal mechanism plug-in power-on is arranged in the top of second terminal mechanism;Pressure regulating mechanism is arranged between the first terminal mechanism and the second terminal mechanism, and the bottom of first terminal mechanism is provided with the sliding compression assembly of compression. Pressure regulating mechanism includes shape memory contraction piece and spring piece, shape memory contraction piece uses shape memory alloy material quality. The first terminal mechanism and the second terminal mechanism are closed by shape memory contraction piece heat shrinkage regulation loop pressure, relieve the overload heating phenomenon caused by frequent circuit switching, avoid arc generation, eliminate fire risk or equipment damage, improve the service life of electrical component, and make power distribution switch have self-adapting overload protection capability, guarantee electrical safety.

Description

Technical Field

[0001] This utility model relates to the field of power distribution switch technology, specifically to an anti-arc adaptive structure for an external power distribution switch of an electricity meter. Background Technology

[0002] With the continuous growth of industrial production and residential electricity demand, distribution switches, as core components in power systems that control circuit switching and protect electrical equipment, directly affect the stability of power supply due to their reliability and safety. Distribution switches are widely used in household distribution boxes, industrial distribution cabinets, and other scenarios, and need to frequently handle circuit switching under different loads, with current overload being a common operating condition.

[0003] Under overload conditions, the Joule heating generated by the increased current in the switch contacts causes a rapid temperature rise. Since the contact resistance is positively correlated with temperature, the increased temperature further exacerbates the increase in contact resistance, creating a vicious cycle of "increased temperature - increased resistance - more heat," ultimately leading to an electric arc. The electric arc not only damages the contact structure but may also puncture the switch insulation, causing equipment damage or even an electrical fire. Existing distribution switches typically use overload protectors to detect current or temperature signals and trigger tripping to cut off the circuit and prevent the arc from continuing to form. This method has significant drawbacks: First, the contact pressure is fixed and cannot be adjusted; under overload, the increased temperature leads to increased contact resistance, making it impossible to adaptively prevent arcing. Second, the tripping method using overload protectors has a time delay, increasing the risk of arc erosion and shortening the switch's lifespan. Third, it incurs high maintenance costs; frequent contact closing and opening increases wear and tear, requiring periodic disassembly and replacement to ensure safety, thus reducing production efficiency. Utility Model Content

[0004] Given that existing technologies suffer from fixed and unadjustable contact pressure, increased contact resistance due to temperature rise under overload, and inability to adaptively prevent arcing, this invention provides an arc-proof adaptive structure for an external distribution switch of an electricity meter. This structure can adaptively adjust the contact pressure according to temperature changes, thereby increasing the contact pressure when the temperature rises, reducing contact resistance, and thus preventing arcing.

[0005] This utility model provides an anti-arc adaptive structure for an external power distribution switch of an electricity meter, including a switch housing, a first terminal mechanism and a second terminal mechanism disposed inside the switch housing, and a switch slider for controlling the insertion and energization of the first terminal mechanism and the second terminal mechanism on the top of the second terminal mechanism.

[0006] A pressure adjustment mechanism for reducing contact resistance is provided between the first terminal mechanism and the second terminal mechanism, and a sliding clamping assembly for sliding and clamping in cooperation with the pressure adjustment mechanism is provided at the bottom of the first terminal mechanism.

[0007] The pressure regulating mechanism includes a shape memory shrinkage member and a spring member mounted between the first terminal mechanism and the second terminal mechanism via a mounting base. The shape memory shrinkage member is made of shape memory alloy, and the shape memory shrinkage member adjusts the circuit closure pressure between the first terminal mechanism and the second terminal mechanism by shrinking under heat.

[0008] Furthermore, the shape memory shrinkage member has a columnar structure, and the spring member is sleeved on the outside of the shape memory shrinkage member.

[0009] Furthermore, the spring component is a stainless steel cylindrical helical spring.

[0010] Furthermore, the shape memory shrinkage member has a sheet-like structure and is attached to the spring member.

[0011] Furthermore, the first terminal mechanism includes: a mounting block installed inside the switch housing, a stationary contact installed on the side of the mounting block, and a first wire passing through the mounting block and electrically connected to the stationary contact.

[0012] Furthermore, the second terminal mechanism includes: a fixed block installed inside the switch housing, a moving contact disposed on the side of the fixed block via a second wire, the second wire sliding through the fixed block, and a switch slider installed on the top of the moving contact, the switch slider controlling the moving contact to communicate with the stationary contact to form a closed circuit.

[0013] Furthermore, the top of the switch housing is provided with a switch control port for the switch slider to extend and slide, and the switch slider is slidably disposed in the switch control port via a ball bearing assembly.

[0014] Furthermore, the ball assembly includes: a groove embedded in the side wall of the switch control port, a ball slidably installed in the groove, and ball locking grooves provided at both ends of the groove, wherein the ball is fixedly installed with the switch slider.

[0015] Furthermore, the sliding clamping assembly includes: a slide rail mounting groove installed inside the switch housing, a slide rail disposed at the bottom of the slide rail mounting groove, and a sliding block that slides in cooperation with the slide rail, the sliding block being disposed at the bottom of the mounting block.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] This utility model patent, through the setting of a pressure regulating mechanism, allows the shape memory shrinking component to shrink when the circuit is overloaded. With the cooperation of the sliding clamping component, the distance between the first terminal mechanism and the second terminal mechanism set at both ends of the shape memory shrinking component is shortened, thereby making the connection between the two more tight, effectively reducing the contact resistance, suppressing the heat accumulation caused by the Joule effect during overload, helping to quickly control the temperature rise, and preventing the generation of electric arc.

[0018] This patent utilizes a force-bearing structure that combines shape memory alloy shrinkage components with spring components in parallel. This fundamentally alleviates the overload and overheating phenomenon caused by frequent circuit switching, avoids the generation of electric arcs, further eliminates the risk of fire or equipment damage that may be caused by electric arcs, significantly improves the overall service life of electrical components, and enables the power distribution switch to have adaptive overload protection capabilities, high reliability, and provides a more solid guarantee for electrical safety.

[0019] It should be understood that the description in this utility model description section is not intended to limit the key or essential features of the embodiments of this utility model, nor is it intended to restrict the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 External structural diagram of the arc-proof adaptive structure.

[0022] Figure 2 Diagram of the internal structure of the arc-proof adaptive structure.

[0023] Figure 3 for Figure 1 Enlarged view of point A in the middle.

[0024] Figure 4 Drawings of some parts of the anti-arc adaptive structure.

[0025] Figure 5 This is a structural diagram of the first terminal mechanism.

[0026] Figure 6 This is a structural diagram of the sliding clamping assembly.

[0027] The diagram shows: 1. Switch housing; 11. Switch control port; 12. Ball assembly; 121. Slide groove; 122. Ball; 123. Ball locking groove.

[0028] 2. First terminal mechanism; 21. Mounting block; 22. Stationary contact; 3. Second terminal mechanism; 31. Fixed block; 32. Moving contact;

[0029] 4. Switch slider; 5. Pressure adjustment mechanism; 51. Mounting base; 52. Shape memory shrinkage component; 53. Spring component; 6. Sliding clamping assembly; 61. Slide rail mounting groove; 62. Slide rail; 63. Sliding block; 7. First wire; 8. Second wire. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0031] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0032] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Example 1:

[0034] Please refer to Figures 1-6 This utility model provides an anti-arc adaptive structure for an external power distribution switch of an electricity meter, including a switch housing 1, a first terminal mechanism 2 and a second terminal mechanism 3 disposed inside the switch housing 1, and a switch slider 4 disposed on the top of the second terminal mechanism 3 for controlling the contact and energization between the first terminal mechanism 2 and the second terminal mechanism 3.

[0035] A pressure adjustment mechanism 5 for reducing contact resistance is provided between the first terminal mechanism 2 and the second terminal mechanism 3. A sliding clamping component 6 for sliding and clamping in cooperation with the pressure adjustment mechanism 5 is provided at the bottom of the first terminal mechanism 2.

[0036] The pressure regulating mechanism 5 includes a shape memory shrinkage member 52 and a spring member 53, which are mounted between the first terminal mechanism 2 and the second terminal mechanism 3 via a mounting base 51. The shape memory shrinkage member 52 shrinks when heated to regulate the closed loop pressure between the first terminal mechanism 2 and the second terminal mechanism 3.

[0037] To further clarify, spring component 53 is a stainless steel cylindrical helical spring.

[0038] In this embodiment, by setting up a pressure regulating mechanism 5, when the circuit is overloaded, the shape memory shrinkage component 52 shrinks due to heat. With the cooperation of the sliding clamping component 6, the distance between the first terminal mechanism 2 and the second terminal mechanism 3 set at both ends of the shape memory shrinkage component 52 is shortened, thereby making the connection between the two more tight, effectively reducing the contact resistance, suppressing the heat accumulation caused by the Joule effect during overload, helping to quickly control the temperature rise and prevent the generation of electric arc.

[0039] Furthermore, the force-bearing structure, which connects the shape memory shrinking component 52 made of shape memory alloy and the spring component 53 made of stainless steel, fundamentally alleviates the overload heating phenomenon caused by frequent circuit switching, avoids the generation of electric arcs, further eliminates the risk of fire or equipment damage that may be caused by electric arcs, significantly improves the overall service life of electrical components, and enables the power distribution switch to have adaptive overload protection capability, high reliability, and provides a more solid guarantee for electrical safety.

[0040] In this embodiment, the switch slider 4 is manually toggled, causing the first terminal mechanism 2 and the second terminal mechanism 3 to connect and form a closed circuit. At this time, the spring 53 is in a compressed state. When the circuit is overloaded, the temperature gradually rises, and the shape memory shrinkage member 52 begins to shrink adaptively due to the temperature rise. The distance between the first terminal mechanism 2 and the second terminal mechanism 3 is shortened accordingly. At this time, the spring 53 shrinks further. With the cooperation of the sliding pressing component 6, the first terminal mechanism 2 can slide towards the second terminal mechanism 3 due to the shrinkage of the shape memory shrinkage member 52, making the connection between the first terminal mechanism 2 and the second terminal mechanism 3 tighter and more compact. The improved connection tightness effectively reduces the contact resistance, suppresses the temperature rise caused by overload, and thus controls the overall temperature to decrease, avoids the generation of electric arc, and ensures circuit safety.

[0041] When the circuit overload is released, the circuit load decreases, the current returns to the rated range, the temperature gradually drops below the shrinkage temperature of the shape memory shrink member 52, the shape memory shrink member 52 returns to its initial length, the spring member 53 rebounds accordingly, and the first terminal mechanism 2 is reset to its initial position under the action of the sliding clamping assembly 6.

[0042] Furthermore, by combining the shape memory shrinkage member 52 and the spring member 53, the contact pressure between the first terminal mechanism 2 and the second terminal mechanism 3 can be dynamically adjusted, thereby precisely controlling the contact resistance and actively adjusting the circuit temperature. This allows for automatic reduction of temperature rise during overload, achieving reliable circuit protection.

[0043] As shown in the figure, the shape memory shrinking component 52 is a columnar structure, and the spring component 53 is sleeved on the outside of the shape memory shrinking component 52.

[0044] In this embodiment, the spring member 53 provides stable support for the shape memory shrink member 52. When the first terminal mechanism 2 and the second terminal mechanism 3 are connected, the temperature is at normal. The shape memory shrink member 52 is under pressure and slightly deformed. At this time, the spring member 53 sleeved on its outer side is compressed and effectively shares the external pressure to support the shape memory shrink member 52, which enhances the stability of the overall structure. The spring member 53 also acts as a flexible protective skeleton, which effectively prevents the shape memory shrink member 52 from being excessively deformed due to external force. This further improves the durability and fatigue resistance of the connection between the first terminal mechanism 2 and the second terminal mechanism 3, ensuring that the electrical connection and mechanical performance can still be maintained under frequent insertion and removal or vibration environments.

[0045] As a preferred embodiment, the shape memory shrinkage component 52 is made of shape memory alloy. Shape memory alloy has excellent memory capability, and its phase transition temperature can be adjusted within the range of 50-80℃, thereby precisely adapting to the specific requirements of temperature-strain relationships in different application scenarios. During the phase transition process, the shape memory alloy can efficiently recover up to 8% of the strain while releasing significant recovery stress, giving it both large strain and high stress characteristics, and exhibiting excellent shrinkage strain capability. Therefore, using shape memory alloy as the shape memory shrinkage component 52 can further enhance the tightness of the connection between the first terminal mechanism 2 and the second terminal mechanism 3.

[0046] Furthermore, nickel-titanium alloys can be used as the base material for shape memory alloys. Nickel-titanium alloys have superelasticity with ultra-large elastic strain and shape memory effect with large recovery strain, and also have high strength, corrosion resistance, high damping and excellent fatigue life, resulting in high comprehensive performance.

[0047] As a preferred embodiment, copper-zinc-aluminum alloy can be used as the base material for shape memory alloy. Copper-zinc-aluminum alloy has the characteristics of low cost, easy processing and fast thermal response, and can be adapted to civilian applications.

[0048] As shown in the figure, the first terminal mechanism 2 includes: a mounting block 21 installed inside the switch housing 1, a stationary contact 22 installed on the side of the mounting block 21, and a first wire 7 passing through the mounting block 21 and electrically connected to the stationary contact 22.

[0049] Furthermore, the second terminal mechanism 3 includes: a fixed block 31 installed inside the switch housing 1, a moving contact 32 disposed on the side of the fixed block 31 via a second wire 8, the second wire 8 slidingly passing through the fixed block 31, and a switch slider 4 installed on the top of the moving contact 32, the switch slider 4 controlling the moving contact 32 to connect with the stationary contact 22 to form a closed circuit.

[0050] In this embodiment, by toggling the switch slider 4, the stationary contact 22 and the moving contact 32 are connected to form a closed circuit. During this process, when the operator manually toggles the switch slider 4, the moving contact 32 installed with the switch slider 4 moves accordingly, thereby pulling the second wire 8 to slide within the fixed block 31. At this time, the stationary contact 22 remains stationary, and the moving contact 32 moves to connect with the stationary contact 22, at which point the circuit is closed and connected.

[0051] When under overload conditions, the circuit current exceeds the rated value, and Joule heat accumulates rapidly at the connection between the stationary contact 22 and the moving contact 32. When the temperature rises to the phase transition temperature of the shape memory shrinkage element 52, the shape memory shrinkage element 52 triggers a phase transition and shrinks, providing greater tension. Under the increased pressure of the shape memory shrinkage element 52, the tightness of the connection between the stationary contact 22 and the moving contact 32 is significantly improved, and the contact resistance decreases, breaking the vicious cycle of "temperature increase - resistance increase" and thus avoiding the generation of electric arc.

[0052] To further explain, the shape memory shrinkage component 52 is specifically installed between the fixed block 31 and the mounting block 21; the moving contact 32 is fixedly installed at the end of the second wire 8, and moves to engage with the stationary contact 22 by the movement of the switch slider 4. The stationary contact 22 is fixedly installed at the end of the first wire 7 and fixedly installed with the mounting block 21. When the circuit is overloaded, the shape memory shrinkage component 52 shrinks due to heat, and the sliding clamping component 6 pulls the mounting block 21 and the stationary contact 22 to slide synchronously towards the moving contact 32, so that the moving contact 32 and the stationary contact 22 are more tightly engaged, further shortening the distance between the fixed block 31 and the mounting block 21, reducing the contact resistance, thereby lowering the temperature and preventing the generation of electric arc.

[0053] Furthermore, both the stationary contact 22 and the moving contact 32 are made of brass and have a silver plating layer on their surface to ensure their durability.

[0054] Furthermore, both the fixing block 31 and the mounting block 21 are made of copper substrate, and each has a first wire hole and a second wire hole respectively. The second wire 8 can move in the second wire hole with the moving contact 32. The first wire 7 cannot move because the stationary contact is fixed, so it slides synchronously with the mounting block 21 through the sliding clamping component 6.

[0055] As shown in the figure, the top of the switch housing 1 has a switch control port 11 for the switch slider 4 to extend and slide. The switch slider 4 is slidably disposed in the switch control port 11 through the ball assembly 12.

[0056] In this embodiment, the switch slider 4 extends out of the switch housing 1 through the switch control port 11. The operator can control the connection between the stationary contact 22 and the moving contact 32 by moving the switch slider 4 outside the switch housing 1, thereby further controlling the closing and opening of the circuit.

[0057] Furthermore, the switch housing 1 is integrally injection molded from insulating and flame-retardant material, and a switch control port 11 is reserved on the top for the sliding control of the switch slider 4. The switch slider 4 is made of ABS engineering plastic, which has good heat resistance and strength.

[0058] As shown in the figure, the ball assembly 12 includes: a slide groove 121 embedded in the side wall of the switch control port 11, a ball 122 slidably installed in the slide groove 121, and ball locking grooves 123 provided at both ends of the slide groove 121. The ball 122 is fixedly installed with the switch slider 4.

[0059] In this embodiment, when the circuit needs to be closed and energized, the operator manually moves the switch slider 4, and the ball bearing 122 slides synchronously within the groove 121. When the ball bearing 122 moves to the end of the groove 121, it is embedded in the ball bearing locking groove 123, achieving mechanical self-locking. At this time, the moving contact 32 and the stationary contact 22 are accurately aligned and connected, forming a stable electrical connection. The circuit is closed, and the circuit achieves reliable conduction. Through the cooperation and locking of the ball bearing 122 and the ball bearing locking groove 123, the connection state of the moving contact 32 and the stationary contact 22 is ensured to be stable, improving the accuracy and reliability of circuit on / off control.

[0060] As shown in the figure, the sliding clamping assembly 6 includes: a slide rail mounting groove 61 installed in the switch housing 1, a slide rail 62 disposed at the bottom of the slide rail mounting groove 61, and a sliding block 63 that slides in cooperation with the slide rail 62. The sliding block 63 is disposed at the bottom of the mounting block 21.

[0061] In this embodiment, when the shape memory shrinking member 52 shrinks due to heat, a pulling force is applied to the mounting block 21 installed at one end, causing the sliding block 63 to slide along the slide rail 62. This shortens the distance between the mounting block 21 and the fixed block 31, resulting in a tighter connection between the stationary contact 22 and the moving contact 32. The increased contact area and pressure directly reduce the contact resistance, thereby effectively suppressing Joule heating at the connection point. This not only improves conductivity but also reduces the risk of overheating from the source, significantly reducing the possibility of arc generation and enhancing the reliability and safety of equipment operation.

[0062] Furthermore, the slide rail mounting groove 61 is made of aluminum alloy, with a polytetrafluoroethylene wear-resistant coating sprayed on the inner wall to ensure its durability. The slide rail mounting groove 61 is used to limit the maximum stroke of the sliding block 63, preventing excessive compression between the stationary contact 22 and the moving contact 32. The sliding block 63 and the mounting block 21 are integrally formed by die casting, and their cooperation with the slide rail 62 ensures smooth sliding of the mounting block 21.

[0063] Example 2:

[0064] The difference between Example 2 and Example 1 is that the shape memory shrinkage member 52 is a sheet structure and is attached to the spring member 53.

[0065] In this embodiment, the sheet-like shape memory shrinkage member 52 is attached to the spring member 53. When the shape memory shrinkage member 52 shrinks due to heat, the spring member 53 shrinks accordingly. The shrinkage of the spring member 53 is controlled by the shrinkage of the shape memory shrinkage member 52, thereby flexibly pulling the mounting block 21 towards the fixed block 31, so that the stationary contact 22 and the moving contact 32 are more tightly connected, thereby reducing the contact resistance value, effectively reducing the generated heat, and further preventing the generation of electric arc.

[0066] Furthermore, the sheet-like shape memory shrinkable component 52 is directly attached to the spring component 53, which increases the contact area, makes heat conduction faster and more uniform, improves the response speed and control accuracy, and enables flexible pulling of the mounting block 21 through the setting of the spring component 53. The combination of the sheet-like shape memory shrinkable component 52 and the spring component 53 can further enhance the space utilization and make the overall movement coordinated and stable.

[0067] It should be understood that the specific embodiments described above are only for explaining the present invention and are not intended to limit the present invention. Obvious variations or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims

1. An arc-resistant adaptive structure for an external power distribution switch of an electricity meter, characterized in that, It includes a switch housing (1), a first terminal mechanism (2) and a second terminal mechanism (3) disposed inside the switch housing (1), and a switch slider (4) for controlling the first terminal mechanism (2) and the second terminal mechanism (3) to be plugged in and energized. A pressure adjustment mechanism (5) for reducing contact resistance is provided between the first terminal mechanism (2) and the second terminal mechanism (3), and a sliding clamping assembly (6) for sliding and clamping in cooperation with the pressure adjustment mechanism (5) is provided at the bottom of the first terminal mechanism (2). The pressure regulating mechanism (5) includes a shape memory shrinkage member (52) and a spring member (53) mounted between the first terminal mechanism (2) and the second terminal mechanism (3) via a mounting base (51). The shape memory shrinkage member (52) is made of shape memory alloy. The shape memory shrinkage member (52) shrinks when heated to regulate the loop closure pressure between the first terminal mechanism (2) and the second terminal mechanism (3).

2. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 1, characterized in that, The shape memory shrinking member (52) is a columnar structure, and the spring member (53) is sleeved on the outside of the shape memory shrinking member (52).

3. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 1, characterized in that, The spring element (53) is a stainless steel cylindrical helical spring.

4. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 1, characterized in that, The shape memory shrinking member (52) is a sheet structure and is attached to the spring member (53).

5. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 1, characterized in that, The first terminal mechanism (2) includes: a mounting block (21) installed inside the switch housing (1), a stationary contact (22) installed on the side of the mounting block (21), and a first wire (7) passing through the mounting block (21) and electrically connected to the stationary contact (22).

6. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 5, characterized in that, The second terminal mechanism (3) includes: a fixed block (31) installed inside the switch housing (1), a moving contact (32) disposed on the side of the fixed block (31) via a second wire (8), the second wire (8) sliding through the fixed block (31), and a switch slider (4) installed on the top of the moving contact (32), the switch slider (4) controlling the moving contact (32) to communicate with the stationary contact (22) to form a closed circuit.

7. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 1, characterized in that, The top of the switch housing (1) is provided with a switch control port (11) for the switch slider (4) to extend and slide. The switch slider (4) is slidably disposed in the switch control port (11) through a ball assembly (12).

8. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 7, characterized in that, The ball assembly (12) includes: a groove (121) embedded in the side wall of the switch control port (11), a ball (122) slidably installed in the groove (121), and ball locking grooves (123) provided at both ends of the groove (121). The ball (122) is fixedly installed with the switch slider (4).

9. The anti-arc adaptive structure of the external power distribution switch for the energy meter according to claim 5, characterized in that, The sliding clamping assembly (6) includes: a slide rail mounting groove (61) installed in the switch housing (1), a slide rail (62) disposed at the bottom of the slide rail mounting groove (61), and a sliding block (63) that slides in cooperation with the slide rail (62), wherein the sliding block (63) is disposed at the bottom of the mounting block (21).

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