A cable branch box for a cable accessory

Abstract

The present application relates to the technical field of smart grid, in particular to a cable branch box for cable accessories, comprising a box body and a clamping mechanism arranged above the box door part, the clamping mechanism comprising a shell, a knob, a worm and gear transmission assembly and a clamping jaw with polyurethane spring; the clamping jaw is closed by rotating the knob to drive the worm to drive the worm gear, so as to clamp the rear part of the plug-in head, the polyurethane spring provides elastic compensation and makes the worm and gear realize stable self-locking. The present application can effectively transfer the dead load of the plug-in head and cable to the box body, prevent the deformation and failure of the double-end bolt inside the plug-in head due to long-term stress, overcome the problems of loose electrical connection, overheating and insulation aging caused by gravity under the condition of multiple outgoing lines, and ensure the safety and stability of long-term operation of the cable branch box.

Description

Technical Field

[0001] This invention relates to the field of smart grid technology, and more specifically to a cable branch box for cable accessories. Background Technology

[0002] With the advancement of smart grid and urban power distribution network construction, cable branch boxes, as key equipment for cable splitting and transfer, are facing increasingly complex application scenarios. In particular, when the branch box needs to connect multiple outgoing circuits at the same time, the structural stability of the internal plugs and connecting components faces severe challenges.

[0003] In actual operation, multi-outlet cables have numerous overlapping plugs and are quite long. Due to the cable's weight, continuous vertical downward force and bending moment are exerted on the double-ended bolts inside the plugs. Under long-term stress, the double-ended bolts are prone to thread plastic deformation, tensile elongation, and even fatigue cracks at the root. This leads to a decrease in plug contact pressure, loosening of electrical connections, and abnormally increased contact resistance. Under heavy load conditions, this can cause severe overheating, accelerating the aging of insulation materials and oxidation of metal components, and even leading to thermal breakdown or burnout. Simultaneously, the insulation shell may undergo irreversible bending under long-term gravity, disrupting the internal electric field distribution and triggering partial discharge, further causing a series of chain reactions. Deformation can cause the plug's sealing structure to fail, allowing moisture and dust to intrude, reducing insulation performance and increasing the risk of surface flashover. More seriously, if the double-ended bolts break or the plug falls off, it will directly cause an open circuit and power outage, possibly accompanied by arc discharge, burning other accessories inside the branch box, threatening the safety of inspection personnel, and significantly increasing maintenance costs and power outage losses.

[0004] Therefore, it is urgent to improve the internal support and connection structure of existing cable branch boxes to effectively resist the long-term mechanical action of plugs, cable weight, and especially in the case of multiple outgoing lines, and to prevent key components such as double-ended bolts from deforming or failing, thereby ensuring the long-term stability, sealing reliability and operational safety of electrical connections. Summary of the Invention

[0005] The purpose of this invention is to provide a cable branch box for cable accessories, in order to solve the problem that in existing cable branch boxes, the plug and cable weight causes the internal double-ended bolts to easily deform, loosen or break under long-term mechanical action, which in turn leads to overheating, insulation failure or even burn-out accidents, posing safety hazards.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a cable branch box for cable accessories, comprising a box body, a box door portion provided in the box body, a plug-in head for connecting to the cable installed inside the box body, and a clamping mechanism disposed above the box door portion, wherein the clamping mechanism cooperates with the cylindrical plug-in portion on the rear side of the cable connection portion of the plug-in head to transfer the gravity load of the plug-in head and the cable to the box body; The clamping mechanism includes a worm, a worm wheel, and grippers; the worm wheel is located on both sides of the worm and meshes with the worm; the grippers are fixedly connected to the worm wheel, and the grippers close or open under the drive of the worm wheel to clamp or release the cylindrical insertion part. The inner side of the gripper, that is, the clamping part that mates with the cylindrical plug-in part on the rear side of the plug-in cable connection part, is provided with an elastic body. When clamped, the elastic body generates elastic compression deformation, which ensures stable clamping of one or more cylindrical plug-in parts at the same time, and provides a reaction force to stabilize and self-lock the worm gear.

[0007] Furthermore, the enclosure includes an upper enclosure located at the top and a lower enclosure located at the bottom. The upper enclosure includes a support portion, and the upper side of the enclosure door is hinged to the upper end of the support portion. A gas spring is provided between the enclosure door and the support portion.

[0008] Furthermore, the elastic body is a polyurethane spring, which is hemispherical in shape and fixedly connected to the inner side of the gripper.

[0009] Furthermore, the clamping mechanism also includes a housing and a knob. The housing is installed above the door section, the worm gear and worm are located inside the housing, and the knob is located above the housing and is connected to the worm gear drive.

[0010] Furthermore, the knob is provided with an internal hexagonal groove above it to cooperate with the operating tool.

[0011] Furthermore, the clamping mechanism includes a first clamping mechanism, in which only one pair of cooperating jaws are provided; the first clamping mechanism includes a first housing, a first knob, a first worm, two first worm wheels respectively disposed on both sides of the first worm, and two first jaws respectively connected to the two first worm wheels; the upper end of the first worm is supported by the upper part of the first housing and extends to the outside of the first housing to be connected to the first knob, and the two sides of the two first worm wheels are respectively supported by the side walls of the first housing.

[0012] Furthermore, the clamping mechanism includes a second clamping mechanism, in which multiple pairs of cooperating jaws are provided; the second clamping mechanism includes a second housing, a second knob, a transmission mechanism, several sets of meshing second worm gears and second worm wheels, and a second jaw connected to each second worm wheel; the transmission mechanism is disposed in the second housing and synchronously transmits the rotational movement of the second knob to each second worm gear.

[0013] Furthermore, the transmission mechanism includes a first bevel gear set, a rotating shaft, and several second bevel gear sets; the drive shaft of one bevel gear in the first bevel gear set extends to the outside of the second housing and is connected to the second knob, while the other bevel gear is fixedly connected to the rotating shaft; both ends of the rotating shaft are respectively supported on the side wall of the second housing, and several second bevel gear sets are spaced apart on the rotating shaft; in each second bevel gear set, one bevel gear is fixedly connected to the rotating shaft, and the drive shaft of the other bevel gear is connected to the corresponding second worm gear.

[0014] Furthermore, below the rotating shaft, a mounting plate is fixedly installed by the second housing. The drive shaft of the bevel gear connected to the second worm in the second bevel gear set passes downward through the mounting plate and connects to the second worm. The second worm wheel is located on both sides of the second worm and meshes with the second worm. The two sides of the second worm wheel are respectively supported on the side wall of the second housing.

[0015] Furthermore, the gripper includes a metal part and an insulating part, the metal part being connected to a worm gear, the insulating part being engaged with a cylindrical insertion part, and the front end of the metal part being embedded in the insulating part.

[0016] The beneficial effects of this invention are: 1. This invention, by setting a worm gear clamping mechanism with a self-locking function, transfers the gravity load of the plug and cable to the housing, effectively preventing plastic deformation, tension and fatigue fracture of the double-ended bolts inside the plug due to long-term downward force and bending moment. It fundamentally avoids the risk of increased contact resistance, overheating and thermal breakdown caused by loose connection, and ensures the long-term stability of electrical connection.

[0017] 2. The present invention incorporates polyurethane springs within the grippers, which on the one hand automatically compensate for manufacturing and assembly errors of the multiple grippers, ensuring that all plug-in heads are reliably clamped; on the other hand, its elasticity ensures the reliability of the worm gear self-locking mechanism, meaning that even without external force, the clamping force will not disappear, maintaining a stable clamping state during long-term operation. It also achieves flexible clamping, avoiding damage to the insulating shell of the plug-in head caused by rigid clamping.

[0018] 3. The present invention has an ingenious structural design and can be directly installed on the top of the door of an existing cable branch box. It is highly applicable and can significantly reduce unplanned power outage losses and maintenance costs caused by plug-in connection failures, thereby significantly improving the reliability of power grid supply and the safety of inspection personnel. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the cable branch box of the present invention; Figure 2 This is a schematic diagram of the first clamping mechanism of the present invention; Figure 3 This is a schematic diagram of the second clamping mechanism of the present invention; Figure 4 This is a schematic diagram of the transmission mechanism structure of the present invention.

[0020] The names corresponding to each mark in the diagram: 1. Box body; 11. Upper box body; 111. Support part; 112. Box door part; 12. Lower box body; 2. Clamping mechanism; 21. First clamping mechanism; 211. First housing; 212. First knob; 213. First worm gear; 214. First worm wheel; 215. First gripper; 216. First polyurethane spring; 22. Second clamping mechanism; 221. Second housing; 222. Second knob; 223. Transmission mechanism; 2231. First bevel gear set; 2232. Rotating shaft; 2233. Second bevel gear set; 2234. Mounting plate; 224. Second worm gear; 225. Second worm wheel; 226. Second gripper; 227. Second polyurethane spring; 3. Plug-in head. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0022] Example 1 like Figure 1-2 As shown, the cable branch box of the present invention includes a box body 1, which includes an upper box body 11 located at the top and a lower box body 12 located at the bottom. A fixed support part 111 is provided in the middle of the upper box body 11, and a box door part 112 is hinged to the upper end of the support part 111. A live indicator is provided on the support part 111, a gas spring is installed between the box door part 112 and the support part 111, and a lock is provided on the box door part 112.

[0023] A clamping mechanism 2 is provided above the door section 112, which cooperates with the plug-in head 3 installed inside the box body 1. Inside the box body 1, a connecting sleeve is installed on the partition between the cable branch box inlet side and the cable outlet side, and then the plug-in head 3 is installed through the connecting sleeve. The plug-in head 3 is connected to the cable to realize the branching and switching of the cable. Since this is a mature existing technology, the structural principle will not be described in detail. In this invention, the clamping mechanism 2 cooperates with the plug-in head 3 to avoid deformation of the internal components of the plug-in head 3, such as double-ended bolts, under the long-term gravity of the plug-in head 3 itself and the cable, thereby ensuring safe and stable use.

[0024] For the clamping mechanism 2, in this embodiment it is the first clamping mechanism 21. The first clamping mechanism 21 is provided with only a single first clamping claw 215, which is used when the number of plugs 3 on the inlet or outlet side is small, such as one inlet and two outlets; the first clamping mechanism 21 is provided with a first housing 211, which is installed above the door part 112; the first housing 211 is provided with a first worm gear 213, the upper end of the first worm gear 213 is connected to the upper part of the first housing 211 and extends to the outside of the first housing 211 to connect with the first knob 212. The first knob 212 is provided with an internal hexagonal flower-shaped groove. A first worm wheel 214 is provided on the front and rear sides of the first worm gear 213, and the two sides of the first worm wheel 214 are respectively supported on the left and right side walls of the first housing 211. Figure 1 As shown, the first clamping mechanism 21 is on the right.

[0025] The first worm gears 214 on both sides are connected to the first gripper 215 respectively. The first gripper 215 cooperates with the cylindrical plug-in part on the rear side of the connection part between the plug-in head 3 and the cable (this plug-in part can continue to connect to the plug-in head 3 or a surge arrester or directly connect to an insulating plug). A first polyurethane spring 216 is provided on the inner side of the clamping part where the first gripper 215 cooperates with the plug-in head 3. In this embodiment, the first polyurethane spring 216 is hemispherical and is glued and fixed to the inner side of the first gripper 215.

[0026] Example 2 like Figure 1-4 As shown, unlike the single first gripper 215 of the first clamping mechanism 21 in Embodiment 1, this embodiment uses a second clamping mechanism 22, which is provided with multiple second grippers 226 for situations where there are many plugs / plugs 3 on the inlet or outlet side, such as two inlets and six outlets.

[0027] Unlike Embodiment 1, a second housing 221 is provided in the second clamping mechanism 22. The second housing 221 is installed above the door portion 112. A transmission mechanism 223 is located in the second housing 221. The transmission mechanism 223 includes a first bevel gear set 2231. In the first bevel gear set 2231, the transmission shaft of one bevel gear is connected to the upper part of the second housing 221 and extends to the outside of the second housing 221 to connect with the second knob 222. An internal hexagonal flower-shaped groove is provided above the second knob 222. The other bevel gear is connected to a rotating shaft 2232. The two ends of the rotating shaft 2232 are respectively connected to the left and right side walls of the second housing 221. Figure 1 As shown in the direction, the left side is the first clamping mechanism 21). Several second bevel gear sets 2233 are provided on the rotating shaft 2232. In the second bevel gear set 2233, one bevel gear is fixedly connected to the rotating shaft 2232, and a mounting plate 2234 is installed below the rotating shaft 2232 against the second housing 221. The drive shaft of the other bevel gear is supported by the mounting plate 2234 and extends to the lower part of the mounting plate 2234 to connect with the second worm 224. A second worm wheel 225 is provided on the front and rear sides of the second worm 224 respectively. The two sides of the second worm wheel 225 are supported on the left and right side walls of the second housing 221 respectively. The rest is similar to that of Embodiment 1, such as the second gripper 226, the second polyurethane spring 227, etc., and will not be described in detail.

[0028] The principle of this invention is as follows: The operator first completes the normal insertion of the plug-in head 3 and the docking sleeve, and then installs the clamping mechanism 2 on the top of the door part 112, so that the initial opening position of its claws is directly opposite the cylindrical insertion part on the rear side of the plug-in head 3, thus completing the preparation before clamping.

[0029] After the cable is split or transferred, the door 112 is closed. The operator uses a tool that matches the hexagonal groove on the knob to rotate it as a power input. In the first clamping mechanism 21 for single-loop scenarios, rotating the first knob 212 directly drives the first worm gear 213 to rotate. In the second clamping mechanism 22 for multi-loop scenarios, rotating the second knob 222 first transmits power to the rotating shaft 2232 via the first bevel gear set 2231, and then the power is synchronously distributed to each parallel path by multiple second bevel gear sets 2233 on the rotating shaft 2232, which drive their respective second worm gears 224 to rotate. In either scenario, the rotation of the worm gear drives the meshing worm wheels located on the front and rear sides to rotate simultaneously and in opposite directions.

[0030] The worm gears on both sides drive the grippers to retract from both sides towards the cylindrical insertion part of the plug-in head 3 until the hemispherical polyurethane spring on the inner side of the gripper presses against the surface of the insertion part. During this process, the polyurethane spring undergoes elastic compression deformation, utilizing its flexible deformation capability to dynamically and adaptively compensate for the manufacturing tolerances and assembly gaps in the multi-gripper system, ensuring that each set of grippers can stably and firmly clamp, while avoiding micro-crack damage to the insulating shell caused by rigid clamping. Once clamping is completed, most of the vertical downward pull and bending moment generated by the weight of the plug-in head 3 and the cable are no longer borne by the internal double-ended bolts, but are directly transmitted to the housing structure through the rigid path of "gripper-worm gear-worm-shell-box", fundamentally protecting the internal fragile components. It should be noted that in this invention, the gripper includes two parts: the part directly connected to the worm gear is a metal part, made of materials such as stainless steel, and the part that cooperates with the plug-in head 3 is an insulating part, made of materials such as glass fiber epoxy resin FR-4, with the front end of the metal part embedded in the insulating part.

[0031] After the operator stops rotating the knob, the mechanism enters a long-term stable self-locking state. The compressed polyurethane spring generates a reaction force that attempts to open the gripper. This force is applied to the worm gear as a reverse driving force. Utilizing the mechanical self-locking principle of the worm gear mechanism, which states that "the worm can only drive the worm gear and cannot drive it in the reverse direction," the friction between the gear meshing surfaces firmly locks this reverse force, preventing the transmission chain from reversing. As a result, the gripper is permanently locked in the clamping position without any continuous external power input. The constant elastic preload provided by the polyurethane spring further ensures the stability of the self-locking, ensuring that the clamping state remains stable throughout the entire operating cycle.

[0032] This invention is not limited to the preferred embodiments described above. Anyone can derive other forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A cable branch box for cable accessories, comprising a box body (1), a door portion (112) provided in the box body (1), and a plug-in head (3) for connecting to a cable installed inside the box body (1), characterized in that: It also includes a clamping mechanism (2) located above the door section (112), which cooperates with the cylindrical plug-in part on the rear side of the cable connection part of the plug-in head (3) to transfer the gravity load of the plug-in head (3) and the cable to the box body (1). The clamping mechanism (2) includes a worm, a worm wheel, and a gripper; the worm wheel is disposed on both sides of the worm and meshes with the worm; the gripper is fixedly connected to the worm wheel, and the gripper closes or opens under the drive of the worm wheel to clamp or release the cylindrical insertion part. The inner side of the gripper, that is, the clamping part that cooperates with the cylindrical plug-in part behind the cable connection part of the plug-in head (3), is provided with an elastic body. When the elastic body is clamped, it generates elastic compression deformation, which ensures stable clamping of one or more cylindrical plug-in parts at the same time, and provides a reaction force to stabilize and self-lock the worm gear.

2. A cable branch box for cable accessories according to claim 1, characterized in that: The box (1) includes an upper box (11) located above and a lower box (12) located below. The upper box (11) includes a support part (111). The upper side of the box door part (112) is hinged to the upper end of the support part (111). A gas spring is provided between the box door part (112) and the support part (111).

3. A cable branch box for cable accessories according to claim 1, characterized in that: The elastic body is a polyurethane spring, which is hemispherical in shape and fixedly connected to the inner side of the gripper.

4. A cable branch box for cable accessories according to claim 1, characterized in that: The clamping mechanism also includes a housing and a knob. The housing is installed above the door part (112), the worm gear and worm are located inside the housing, and the knob is located above the housing and is connected to the worm gear drive.

5. A cable branch box for cable accessories according to claim 4, characterized in that: The knob is provided with an internal hexagonal groove above it to cooperate with the operating tool.

6. A cable branch box for cable accessories according to claim 4, characterized in that: The clamping mechanism (2) includes a first clamping mechanism (21), in which only one pair of cooperating jaws are provided; the first clamping mechanism (21) includes a first housing (211), a first knob (212), a first worm (213), two first worm wheels (214) respectively disposed on both sides of the first worm (213), and two first jaws (215) respectively connected to the two first worm wheels (214); the upper end of the first worm (213) is connected to the upper part of the first housing (211) and extends to the outside of the first housing (211) to be connected to the first knob (212); the two sides of the two first worm wheels (214) are respectively connected to the side wall of the first housing (211).

7. A cable branch box for cable accessories according to claim 4, characterized in that: The clamping mechanism (2) includes a second clamping mechanism (22), in which multiple pairs of cooperating jaws are provided; the second clamping mechanism (22) includes a second housing (221), a second knob (222), a transmission mechanism (223), several sets of meshing second worm gears (224) and second worm wheels (225), and a second jaw (226) correspondingly connected to each second worm wheel (225); the transmission mechanism (223) is provided in the second housing (221) and synchronously transmits the rotational movement of the second knob (222) to each second worm gear (224).

8. A cable branch box for cable accessories according to claim 7, characterized in that: The transmission mechanism (223) includes a first bevel gear set (2231), a rotating shaft (2232), and several second bevel gear sets (2233). The drive shaft of one bevel gear in the first bevel gear set (2231) extends to the outside of the second housing (221) and is connected to the second knob (222), while the other bevel gear is fixedly connected to the rotating shaft (2232). The two ends of the rotating shaft (2232) are respectively supported on the side wall of the second housing (221), and several second bevel gear sets (2233) are spaced apart on the rotating shaft (2232). In each second bevel gear set (2233), one bevel gear is fixedly connected to the rotating shaft (2232), and the drive shaft of the other bevel gear is connected to the corresponding second worm gear (224).

9. A cable branch box for cable accessories according to claim 8, characterized in that: Below the rotating shaft (2232), a mounting plate (2234) is fixedly installed on the second housing (221). The drive shaft of the bevel gear in the second bevel gear set (2233) that is connected to the second worm (224) passes downward through the mounting plate (2234) and connects to the second worm (224). The second worm wheel (225) is located on both sides of the second worm (224) and meshes with the second worm (224). The two sides of the second worm wheel (225) are respectively supported on the side wall of the second housing (221).

10. A cable branch box for cable accessories according to any one of claims 1-9, characterized in that: The gripper includes a metal part and an insulating part. The metal part is connected to a worm gear, and the insulating part is engaged with a cylindrical insertion part. The front end of the metal part is embedded in the insulating part.

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