Cooling jacket
By adopting a semi-circular structure and an independent cold water flow channel in the cooling jacket, combined with the siphon principle and air extraction hole, the problems of uneven cooling and inconvenient replacement are solved, achieving efficient and uniform cooling effect and convenient replacement, thus improving the cooling and forming quality of the pipe.
Patent Information
- Application Number
- CN202422909327.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-11-27
AI Technical Summary
The existing cooling jacket is cumbersome to replace during production, and the cooling is uneven, resulting in poor control over the appearance and dimensions of the pipe.
The first and second Haval blocks adopt a semi-circular structure, with independent cold water channels and air extraction holes. They utilize the siphon principle and water pressure difference to achieve independent cooling for each cooling jacket. The jackets are connected to the Haval blocks via detachable sliders to ensure uniform cooling and convenient replacement.
It improves cooling efficiency and uniformity, simplifies the replacement process of the cooling jacket, and ensures cooling forming effect and control over the appearance and dimensions of the pipe.
Smart Images
Figure CN223532825U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cooling jacket technology, and in particular to a cooling jacket. Background Technology
[0002] Double-wall corrugated pipes require a water supply and cooling jacket during production to effectively reduce the internal temperature of the pipe and prevent high-temperature corrosion.
[0003] In existing technology, five cooling jackets are typically connected in series with short hoses, and then a separate cooling water circuit is used for circulation. Since the five cooling jackets are connected in series, it is quite troublesome to replace one of them if it malfunctions. Furthermore, the temperatures of the different cooling jackets in this group are different, with the cooling jackets near the water inlet being cooler and the cooling jackets at the end being warmer, ultimately resulting in uneven cooling and poor control over the appearance and dimensions of the pipes. Utility Model Content
[0004] To address the shortcomings of existing technologies, this utility model provides a cooling jacket to solve the technical problems mentioned in the background art, such as the cumbersome replacement operation when some cooling jackets malfunction, and the uneven cooling leading to poor control of the pipe's appearance and dimensions.
[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution:
[0006] A cooling jacket includes a first Haver block with a semi-annular structure and a second Haver block with a semi-annular structure. The first Haver block has a first cold water flow channel inside, and the second Haver block has a second cold water flow channel inside. The first Haver block and the second Haver block are joined together to form an annular cavity for clamping, cooling and shaping a plastic tube.
[0007] The first Haval block has a first slider detachably snapped onto one side. The first slider has a first cavity and a second cavity inside the side near the first Haval block, and the side wall of this side is provided with a first water inlet and a first water outlet. The top of the first slider is provided with a first through hole, and a first water inlet pipe is fixedly inserted through the first through hole. The first Haval block has a first through hole near the first slider, and the first through hole communicates with a first cold water channel. The first water inlet pipe, the first through hole, the first cavity, the first water inlet, the first through hole, and the first cold water channel are interconnected. The bottom of the first slider is provided with a second through hole, and a first drain pipe is fixedly inserted through the second through hole. The first Haval block also has a second through hole near the first slider, and the second through hole communicates with a first cold water channel. The first drain pipe, the second through hole, the second cavity, the first water outlet, the second through hole, and the first cold water channel are interconnected.
[0008] The second Haval block has a second slider detachably snapped onto one side. The second slider has a third cavity and a fourth cavity inside its side near the second Haval block, and a second water inlet and a second water outlet are provided on its sidewall. The top of the second slider has a third through hole, through which a second water inlet pipe is fixedly inserted. The second Haval block has a third through hole near the second slider, which communicates with a second cold water channel. The second water inlet pipe, the third through hole, the third cavity, the second water inlet, the third through hole, and the second cold water channel are interconnected. The bottom of the second slider has a fourth through hole, through which a second drain pipe is fixedly inserted. The second Haval block also has a fourth through hole near the second slider, which communicates with a second cold water channel. The second drain pipe, the fourth through hole, the fourth cavity, the second water outlet, the fourth through hole, and the second cold water channel are interconnected.
[0009] The first and second Haval blocks are provided with a row of air extraction holes on their bottom sides near the first and second drainage pipes, respectively. The inner ring walls of the first and second Haval blocks are provided with several grooves, and there are gaps between each groove. The two rows of air extraction holes are respectively connected to the grooves on the inner ring walls of the first and second Haval blocks.
[0010] Working principle:
[0011] Cooling water flows into the interior of the first Haval block through the first inlet pipe, the first through hole, the first cavity, the first inlet, the first through hole, and the first cold water channel to cool the first Haval block. Then the water flows out through the second through hole, the first outlet, the second cavity, the second through hole, and the first drain pipe.
[0012] Similarly, cooling water also flows into the interior of the second Haval block through the second inlet pipe, the third through hole, the third cavity, the second inlet, the third through hole, and the second cold water channel to cool the second Haval block. Then the water flows out through the fourth through hole, the second outlet, the fourth cavity, the fourth through hole, and the second drain pipe, so that each cooling jacket can be fully cooled.
[0013] Beneficial effects:
[0014] 1. In this solution, by utilizing the siphon principle and the water pressure difference formed by the height, water flows into the first Haval block from the first inlet pipe and then flows out from the first drain pipe, and into the second Haval block from the second inlet pipe and then flows out from the second drain pipe. This achieves that each cooling jacket has an independent cooling water path, so that each cooling jacket can be fully cooled, improving cooling efficiency and cooling uniformity, and resulting in better cooling and forming effect.
[0015] 2. By setting the first slider and the first Haval block to be detachably connected, and the second slider and the second Haval block to be detachably connected, an assembly structure is formed, which allows the first slider, the second slider, and the first Haval blocks and the second Haval blocks of different specifications to be assembled, making it easy to change specifications;
[0016] 3. By setting up a first cold water flow channel and a second cold water flow channel, uniform cooling and higher cooling efficiency are ensured;
[0017] 4. By setting evacuation holes and grooves, air needs to be evacuated from the cooling jackets during production, so that a vacuum is generated inside each cooling jacket. This allows the molten plastic to be adsorbed and adhered to the inner surface of the cooling jacket, ensuring that each cooling jacket and mold can be vented smoothly during cooling and molding, making it easy to achieve the desired shape of the corrugated pipe. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;
[0019] Figure 2 for Figure 1 Assembly diagram of the first Haver block and the first slider;
[0020] Figure 3 for Figure 1 A schematic diagram of the structure inside the first Haval block;
[0021] Figure 4 for Figure 1 A schematic diagram of the structure on the outer side of the first Haver block;
[0022] Figure 5 for Figure 1 A schematic diagram of the structure at the top of the first slider;
[0023] Figure 6 for Figure 1 A schematic diagram of the structure at the bottom of the first slider;
[0024] Figure 7 for Figure 1 Assembly diagram of the second Haver block and the second slider;
[0025] Figure 8 for Figure 1 A schematic diagram of the structure inside the second Haver block;
[0026] Figure 9 for Figure 1 A schematic diagram of the structure on the outer side of the second Haver block;
[0027] Figure 10 for Figure 1 A schematic diagram of the structure at the top of the second slider;
[0028] Figure 11 for Figure 1 A schematic diagram of the structure at the bottom of the second slider.
[0029] In the above attached figures: First Haval Block 1, Second Haval Block 2, First Slider 3, First Inlet 4, First Outlet 5, First Through Hole 6, First Inlet Pipe 7, First Through Hole 8, Second Through Hole 9, First Drain Pipe 10, Second Through Hole 11, Second Slider 12, Second Inlet 13, Second Outlet 14, Third Through Hole 15, Second Inlet Pipe 16, Third Through Hole 17, Fourth Through Hole 18, Second Drain Pipe 19, Fourth Through Hole 20, Air Extraction Hole 21, Groove 22, First Elongated Hole 23, Second Elongated Hole 24, First Mounting Groove 25, Second Mounting Groove 26, First Locking Groove 27, First Locking Block 28, First Bolt 29, Second Locking Groove 30, Second Locking Block 31, Second Bolt 32, First Positioning Hole 33, First Positioning Rod 34, Second Positioning Hole 35, Second Positioning Rod 36, First Slot 37, First Insert Block 38, Second Slot 39, Second Insert Block 40. Detailed Implementation
[0030] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.
[0031] Example:
[0032] like Figure 1 As shown, a cooling jacket includes a first Haver block 1 with a semi-annular structure and a second Haver block 2 with a semi-annular structure. The first Haver block 1 is provided with a first cold water flow channel, and the second Haver block 2 is provided with a second cold water flow channel. The first Haver block 1 and the second Haver block 2 are combined to form an annular cavity. In specific operation, there are several sets of cooling jackets, which are installed on a cooling and forming device for producing double-layer corrugated pipes. By feeding material into the device, the annular cavity of each set of cooling jackets adsorbs and adheres the molten plastic to the inner surface of the cooling jacket, thereby clamping it into a plastic pipe and conveying the plastic pipe.
[0033] like Figure 2 , Figures 4-6As shown, a first slider 3 is detachably snapped onto one side of the first Haval block 1. The first Haval block 1 is connected to the cooling and forming device through the first slider 3. The first slider 3 has a first cavity and a second cavity inside on the side near the first Haval block 1, and a first water inlet 4 and a first water outlet 5 are provided on the side wall of this side. A first through hole 6 is provided on the top of the first slider 3, and a first water inlet pipe 7 is fixedly inserted through the first through hole 6. This fixed insertion is specifically manifested as welding. The welded structure has high connection rigidity and good sealing performance, effectively preventing water leakage and affecting the cooling effect. A first through hole 8 is provided on the side of the first Haval block 1 near the first slider 3. The first through hole 8 is connected to the first cold water channel. The first water inlet pipe 7, the first through hole 6, the first cavity, the first water inlet 4, the first through hole 8, and the first cold water channel are interconnected. The bottom of the first slider 3 is provided with a second through hole 9. The first drain pipe 10 is fixedly inserted in the second through hole 9. The fixed insertion is specifically manifested as welding. The first Haver block 1 is also provided with a second through hole 11 on the side near the first slider 3. The second through hole 11 is connected to the first cold water channel. The first drain pipe 10, the second through hole 9, the second cavity, the first water outlet 5, the second through hole 11, and the first cold water channel are interconnected.
[0034] like Figure 7 , Figures 9-11 As shown, a second slider 12 is detachably snapped onto one side of the second Haval block 2. The second Haval block 2 is connected to the cooling and forming device through the second slider 12. The second slider 12 has a third cavity and a fourth cavity inside on the side near the second Haval block 2, and a second water inlet 13 and a second water outlet 14 are provided on the side wall of this side. A third through hole 15 is provided on the top of the second slider 12, and a second water inlet pipe 16 is fixedly inserted through the third through hole 15. This fixed insertion is specifically manifested as welding. A third through hole 17 is provided on the side of the second Haval block 2 near the second slider 12, and the third through hole 17 connects with the second cold water flow channel. The second water inlet pipe 16, the third through hole 15, the third cavity, the second water inlet 13, the third through hole 17, and the second cold water channel are interconnected; the bottom of the second slider 12 is provided with a fourth through hole 18, and a second drain pipe 19 is fixedly inserted through the fourth through hole 18. The fixed insertion is specifically manifested as welding. The second Haver block 2 is also provided with a fourth through hole 20 on the side near the second slider 12. The fourth through hole 20 is connected to the second cold water channel. The second drain pipe 19, the fourth through hole 18, the fourth cavity, the second water outlet 14, the fourth through hole 20, and the second cold water channel are interconnected.
[0035] like Figure 4 and Figure 9As shown, the first Haval block 1 and the second Haval block 2 are respectively provided with a row of air extraction holes 21 near the bottom side of the first drainage pipe 10 and the second drainage pipe 19. The air extraction holes 21 are connected to an external air extraction device. The inner ring wall of the first Haval block 1 and the second Haval block 2 is provided with a number of grooves 22, and there is a gap between each groove 22. The two rows of air extraction holes 21 are respectively connected to the grooves 22 on the inner ring wall of the first Haval block 1 and the second Haval block 2. When the air extraction device is started during production, a vacuum is generated inside each cooling jacket through the gap between each groove, so that the molten plastic is adsorbed and adhered to the inner surface of the cooling jacket.
[0036] In this scheme, by utilizing the siphon principle and the water pressure difference formed by the height, water flows from the first inlet pipe 7 into the interior of the first Haver block 1, and then flows out from the first drain pipe 10. Water also flows from the second inlet pipe 16 into the interior of the second Haver block 2, and then flows out from the second drain pipe 19. This achieves that each cooling jacket has its own cooling water path, so that each cooling jacket can be fully cooled, improving cooling efficiency and cooling uniformity, and resulting in better cooling and forming effect.
[0037] By setting the first slider 3 to be detachably connected to the first Haval block 1, and the second slider 12 to be detachably connected to the second Haval block 2, an assembly structure is formed, which allows the first slider 3, the second slider 12 and the first Haval block 1 and the second Haval block 2 of different specifications to be assembled, making it easy to change specifications.
[0038] By setting up a first cold water flow channel and a second cold water flow channel, uniform cooling and higher cooling efficiency are ensured. By setting up an air extraction hole 21 and a groove 22, air needs to be extracted from the cooling jacket during production, so that a vacuum is generated inside each cooling jacket, thereby adsorbing and adhering the molten plastic to the inner surface of the cooling jacket. This ensures that air is smoothly expelled from each cooling jacket and mold during cooling and molding, and the shape of the corrugated pipe is easily achieved.
[0039] like Figure 3 and Figure 4 As shown, the first cold water flow channel includes five parallel first elongated holes 23, the two ends of the five first elongated holes 23 are respectively connected through first arc-shaped holes, and the first through hole 8 and the second through hole 11 are respectively connected to two first arc-shaped holes; as shown Figure 8 and Figure 9As shown, the second cold water flow channel includes five parallel second elongated holes 24. The two ends of the five second elongated holes 24 are respectively connected through second arc-shaped holes, and the third through hole 17 and the fourth through hole 20 are respectively connected to the two second arc-shaped holes. The five first elongated holes 23 and the five second elongated holes 24 are all internal structures of the first Haver block 1 and the second Haver block 2. After the holes are machined and the cooling water flows through, they will be sealed. The five first elongated holes 23 and five second elongated holes 24 arranged in parallel represent the first and second cold water flow channels inside the first Haval block 1 and the second Haval block 2, respectively. This allows the cooling water to enter the first through hole 8, disperse through the first arc-shaped hole into the five first elongated holes 23, and then converge and flow out from the second through hole 11. Similarly, the cooling water enters the third through hole 17, disperses through the second arc-shaped hole into the five second elongated holes 24, and then converges and flows out from the fourth through hole 20. As a result, the cooling water fills the entire interior of the first Haval block 1 and the second Haval block 2.
[0040] like Figure 3 and Figure 8 As shown, the first Haval block 1 and the second Haval block 2 are respectively provided with a first mounting groove 25 and a second mounting groove 26 on their side walls. Both the first mounting groove 25 and the second mounting groove 26 are used to embed rubber sealing strips. The rubber sealing strips, together with the air extraction hole 21 and the groove 22, prevent the cooling jacket from deforming during air extraction, thus improving the sealing effect.
[0041] like Figure 2 and Figure 4 As shown, the first Haval block 1 has a first locking groove 27 on the side near the first slider 3. First locking blocks 28 are fixed to the top and bottom of the first slider 3 by welding. The two first locking blocks 28 are engaged with the first locking groove 27. Each of the two first locking blocks 28 is threaded with a first bolt 29. The two first bolts 29 are used to pass through the corresponding first locking blocks 28 and then into the first Haval block 1. Figure 7 and Figure 9 As shown, the second Haver block 2 has a second locking groove 30 on the side facing the second slider 12. The top and bottom of the second slider 12 are both fixed with second locking blocks 31, which are welded together. The two second locking blocks 31 are engaged with the second locking groove 30, and each of the two second locking blocks 31 is threaded with a second bolt 32. The two second bolts 32 are used to pass through the corresponding second locking blocks 31 and then into the second Haver block 2. This locking method using the first bolt 29 and the second bolt 32 is simple and easy to operate.
[0042] like Figures 4-6As shown, a first positioning hole 33 is provided on the inner wall of the first locking groove 27, and a first positioning rod 34 is fixed on the side of the first slider 3 near the first Haver block 1. The first positioning rod 34 corresponds to the first positioning hole 33; Figures 9-11 As shown, the inner wall of the second locking groove 30 is provided with a second positioning hole 35, and the second slider 12 is fixed with a second positioning rod 36 on the side near the second Haver block 2. The second positioning rod 36 corresponds to the second positioning hole 35.
[0043] By setting the first positioning hole 33, the first positioning rod 34, the second positioning hole 35, and the second positioning rod 36, the first Haval block 1 and the second Haval block 2 can be positioned more accurately on the first slider 3 and the second Haval block 2 on the second slider 12 when installing the first Haval block 1 and the second Haval block 2, which facilitates installation.
[0044] like Figures 4-6 As shown, the first Haval block 1 has a first slot 37 on the side near the first slider 3, and the first slider 3 has a first insert 38 fixed on the side near the first Haval block 1, the first insert 38 corresponding to the first slot 37; as shown Figures 9-11 As shown, the second Haval block 2 has a second slot 39 on the side facing the second slider 12, and a second insert 40 is fixed on the side of the second slider 12 near the second Haval block 2, with the second insert 40 corresponding to the second slot 39. The arrangement of the first slot 37, the first insert 38, the second slot 39, and the second insert 40 makes the connection between the first Haval block 1 and the first slider 3, and between the second Haval block 2 and the second slider 12, more secure.
[0045] Working principle:
[0046] By screwing in the first bolt 29 and the second bolt 32, the first Haval block 1 and the second Haval block 2 are respectively installed with the first slider 3 and the second slider 12. Then, the first slider 3 and the second slider 12 are installed on the cooling and forming device for producing double-layer corrugated pipes. During operation, materials are fed into the device.
[0047] Cooling water flows into the interior of the first Haval block 1 through the first inlet pipe 7, the first through hole 6, the first cavity, the first inlet 4, the first through hole 8, and the first cold water channel to cool the first Haval block 1. Then the water flows out through the second through hole 11, the first outlet 5, the second cavity, the second through hole 9, and the first drain pipe 10.
[0048] Similarly, cooling water also flows into the interior of the second Haver block 2 through the second inlet pipe 16, the third through hole 15, the third cavity, the second inlet 13, the third through hole 17, and the second cold water channel to cool the second Haver block 2. Then the water flows out through the fourth through hole 20, the second outlet 14, the fourth cavity, the fourth through hole 18, and the second drain pipe 19, so that each cooling jacket can be fully cooled.
[0049] Simultaneously, the vacuum equipment is activated. Through the vacuum hole 21 and groove 22, the vacuum equipment creates a vacuum inside each cooling jacket, thereby adsorbing and adhering the molten plastic to the inner surface of the cooling jacket. The cooling jacket clamps the plastic into a plastic tube and transports the plastic tube, thus completing the entire operation.
[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A cooling jacket, characterized in that: It includes a first Haver block (1) with a semi-annular structure and a second Haver block (2) with a semi-annular structure. The first Haver block (1) has a first cold water channel inside, and the second Haver block (2) has a second cold water channel inside. The first Haver block (1) and the second Haver block (2) are joined together to form an annular cavity for clamping, cooling and molding plastic tubes. The first Hover block (1) is detachably snapped with a first slider (3) on one side. The first slider (3) has a first cavity and a second cavity inside the side of the first Hover block (1), and the side wall of this side is provided with a first water inlet (4) and a first water outlet (5). The top of the first slider (3) is provided with a first through hole (6), and a first water inlet pipe (7) is fixedly inserted in the first through hole (6). The side of the first Hover block (1) near the first slider (3) is provided with a first through hole (8), which is connected to the first cold water channel. The first water inlet pipe (7) and the first... The through hole (6), the first cavity, the first water inlet (4), the first through hole (8) and the first cold water channel are interconnected; the bottom of the first slider (3) is provided with a second through hole (9), and a first drain pipe (10) is fixedly installed in the second through hole (9); the first Haver block (1) is also provided with a second through hole (11) on the side near the first slider (3), and the second through hole (11) is connected to the first cold water channel; the first drain pipe (10), the second through hole (9), the second cavity, the first water outlet (5), the second through hole (11) and the first cold water channel are interconnected; The second slide block (12) is detachably snapped to one side of the second Haver block (2). The second slide block (12) has a third cavity and a fourth cavity inside the side of the second Haver block (2), and the side wall of this side is provided with a second water inlet (13) and a second water outlet (14). The top of the second slide block (12) is provided with a third through hole (15), and a second water inlet pipe (16) is fixedly inserted in the third through hole (15). The second Haver block (2) is provided with a third through hole (17) on the side of the second slide block (12), and the third through hole (17) is connected to the second cold water flow channel. The second water inlet pipe (16) The third through hole (15), the third cavity, the second inlet (13), the third through hole (17) and the second cold water channel are interconnected; the bottom of the second slider (12) is provided with a fourth through hole (18), and a second drain pipe (19) is fixedly installed in the fourth through hole (18); the second Haver block (2) is also provided with a fourth through hole (20) on the side near the second slider (12), and the fourth through hole (20) is connected to the second cold water channel; the second drain pipe (19), the fourth through hole (18), the fourth cavity, the second outlet (14), the fourth through hole (20) and the second cold water channel are interconnected; The first Haval block (1) and the second Haval block (2) are respectively provided with a row of air extraction holes (21) near the bottom side of the first drainage pipe (10) and the second drainage pipe (19). The inner ring wall of the first Haval block (1) and the second Haval block (2) is provided with a number of grooves (22), and there is a gap between each groove (22). The two rows of air extraction holes (21) are respectively connected to the grooves (22) on the inner ring wall of the first Haval block (1) and the second Haval block (2).
2. A cooling jacket according to claim 1, characterized in that: The first cold water channel includes five parallel first elongated holes (23), the two ends of the five first elongated holes (23) are respectively connected through first arc-shaped holes, and the first through hole (8) and the second through hole (11) are respectively connected to the two first arc-shaped holes; the second cold water channel includes five parallel second elongated holes (24), the two ends of the five second elongated holes (24) are respectively connected through second arc-shaped holes, and the third through hole (17) and the fourth through hole (20) are respectively connected to the two second arc-shaped holes.
3. A cooling jacket according to claim 1, characterized in that: The first Haval block (1) and the second Haval block (2) are respectively provided with a first mounting groove (25) and a second mounting groove (26) on their side walls. The first mounting groove (25) and the second mounting groove (26) are both used to embed rubber sealing strips.
4. A cooling jacket according to claim 1, characterized in that: The first Haval block (1) has a first locking groove (27) on the side near the first slider (3). The first slider (3) is fixed with first locking blocks (28) at the top and bottom. The two first locking blocks (28) are engaged with the first locking groove (27). The two first locking blocks (28) are threaded with first bolts (29). The two first bolts (29) are used to pass through the corresponding first locking blocks (28) and then into the first Haval block (1). The second Haval block (2) has a second locking groove (30) on the side facing the second slider (12). The second slider (12) is fixed with second locking blocks (31) at the top and bottom. The two second locking blocks (31) are engaged with the second locking groove (30). The two second locking blocks (31) are threaded with second bolts (32). The two second bolts (32) are used to pass through the corresponding second locking blocks (31) and then into the second Haval block (2).
5. A cooling jacket according to claim 4, characterized in that: The inner wall of the first locking groove (27) is provided with a first positioning hole (33), and the first slider (3) is fixedly provided with a first positioning rod (34) on the side near the first Haval block (1), and the first positioning rod (34) corresponds to the first positioning hole (33); the inner wall of the second locking groove (30) is provided with a second positioning hole (35), and the second slider (12) is fixedly provided with a second positioning rod (36) on the side near the second Haval block (2), and the second positioning rod (36) corresponds to the second positioning hole (35).
6. A cooling jacket according to claim 5, characterized in that: The first Haval block (1) has a first slot (37) on the side near the first slider (3), and the first slider (3) has a first insert (38) fixed on the side near the first Haval block (1), and the first insert (38) corresponds to the first slot (37); the second Haval block (2) has a second slot (39) on the side facing the second slider (12), and the second slider (12) has a second insert (40) fixed on the side near the second Haval block (2), and the second insert (40) corresponds to the second slot (39).