Modular air heat exchanger

Abstract

The utility model discloses a modularized air heat exchanger which comprises a left vertical plate, a right vertical plate, an upper limiting assembly, a lower limiting assembly, a pipeline box assembly and a pressing plate, and the pressing plate and the limiting assembly are arranged in the mode that the pipeline box assembly is transversely arranged, airflow penetrates through box bodies through communication openings, the physical structure is independent, and the pressing plate and the limiting assembly are matched with an air cylinder to drive. Rapid extraction and overall pressing sealing of single box bodies are achieved, adjacent units do not need to be disassembled, the connecting pipe assemblies are arranged, an annular pipeline is formed by the connecting pipe assemblies in the multiple pipeline box assemblies, the telescopic design that second connecting pipes are nested in first connecting pipes is adopted for the connecting pipe assemblies, and the installation tolerance is automatically compensated through first springs; the connecting pipe assembly can be pulled out or inserted by operating and holding the supporting plate / the compression spring with one hand, the connecting pipe assembly can be disassembled, assembled and replaced conveniently, compared with an integral pipeline, when the connecting pipe assembly is damaged, only the damaged connecting pipe assembly needs to be replaced, the whole pipeline does not need to be replaced, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of air heat exchanger technology, specifically a modular air heat exchanger. Background Technology

[0002] Air heat exchangers, as core heat exchange equipment, are widely used in heating, ventilation and air conditioning (HVAC), industrial waste heat recovery, data center cooling and other fields. Their core function is to realize the energy transfer between hot and cold fluids.

[0003] Traditional air heat exchangers mostly adopt an integral welded or fixed structure. When the internal pipes are damaged or require maintenance, the entire equipment must be shut down and disassembled, resulting in high maintenance costs and long cycles. In addition, the internal pipes of existing air heat exchangers are generally set up as a whole. Although this can ensure good air tightness, when the pipes are damaged, the entire pipe needs to be disassembled. The integral pipes are long, bulky, inconvenient to disassemble and assemble, and have high maintenance costs. Therefore, there is an urgent need for a modular heat exchanger structure. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a modular air heat exchanger that solves the aforementioned problems.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, this utility model is implemented through the following technical solution: a modular air heat exchanger, including a left vertical plate, a right vertical plate, an upper limit assembly, a lower limit assembly, and a pipe box assembly, wherein the upper limit assembly and the lower limit assembly are respectively fixed on the upper and lower sides between the left vertical plate and the right vertical plate, and the pipe box assembly is installed between the upper limit assembly and the lower limit assembly;

[0008] The pipe box assembly includes a box body, a cover plate, locking buckles, a handle, pipe interfaces, connecting pipe assemblies, and connecting ports. The front end of the box body is sealed by the cover plate, and the upper and lower sides of the cover plate are locked and fixed to the box body by locking buckles. A handle is fixed to the middle of the front end of the cover plate. Pipe interfaces are provided on both the left and right sides of the box body, and the left and right ends of the connecting pipe assemblies are connected to the pipe interfaces at the same horizontal level on the left and right sides of the box body. Connecting ports are provided on both the left and right sides of the box body. The pipe box assemblies are arranged horizontally, and the boxes of the pipe box assemblies are tightly fitted together and connected to each other through the connecting ports. The left and right ends of the connecting pipe assemblies are connected to the connecting pipe assemblies of adjacent pipe box assemblies through pipe interfaces.

[0009] Preferably, the left vertical plate is connected to an air inlet pipe 1 and an air inlet pipe 2 on its upper and lower sides respectively, and the right vertical plate is connected to an air outlet pipe 1 and an air outlet pipe 2 on its upper and lower sides respectively.

[0010] Preferably, a cylinder is horizontally fixed at the middle of the right end of the right upright plate, and the piston rod on the left side of the cylinder is fixedly connected to the pressing plate. The pressing plate is located on the right side of the pipe box assembly. The upper and lower ends of the right side of the pressing plate are connected to the first air outlet pipe and the second air outlet pipe through corrugated pipes, respectively. A limit rod is fixed at the right end of the pressing plate, and the limit rod extends horizontally through the right upright plate.

[0011] Preferably, a rear baffle is fixed to the rear end of the left and right upright plates, and the rear baffle is used to support the rear side of the pipe box assembly.

[0012] Preferably, the connecting pipe assembly includes a first connecting pipe, a second connecting pipe, a sealing ring, a first support plate, a second support plate, a second limiting rod, and a first spring. The right end of the second connecting pipe extends into the first connecting pipe. A sealing ring is fitted on the right side of the outer wall of the second connecting pipe, and the inner wall of the first connecting pipe is in contact with the sealing ring. The tops of the first connecting pipe and the second connecting pipe are respectively fixed with the first support plate and the second support plate. The left end of the second limiting rod is fixedly connected to the first support plate and passes through the second support plate. The first support plate and the second support plate are elastically connected by the first spring, and the first spring is fitted on the outside of the second limiting rod. The left end of the first connecting pipe and the right end of the second connecting pipe are respectively inserted into the pipe interfaces on the left and right sides inside the housing.

[0013] Preferably, the upper limit component and the lower limit component have the same structure and are arranged symmetrically. The lower limit component includes a shell, a locking plate, a movable plate, a magnetic block, an electromagnet, a third limiting rod, and a second spring. The bottom end of the locking plate is fixedly connected to the movable plate. The movable plate is located on the inner top of the shell, and the top end of the locking plate extends out of the shell. A magnetic block is fixed in the middle of the bottom end of the movable plate. An electromagnet is fixed in the middle of the inner bottom end of the shell. The left and right sides of the interior of the movable plate are vertically penetrated by the third limiting rod, and the upper and lower ends of the third limiting rod are fixedly connected to the shell. The bottom of the movable plate is elastically connected to the shell through the second spring, and the second spring is fitted onto the outer wall of the third limiting rod. The left and right sides of the shell are fixedly connected to the left and right upright plates, respectively.

[0014] Preferably, the front end face of the card plate is inclined, and the card plate of the lower limit component is inclined upward from front to back, while the card plate of the upper limit component is inclined downward from front to back.

[0015] (III) Beneficial Effects

[0016] This utility model provides a modular air heat exchanger. It offers the following advantages: By incorporating pipe box assemblies arranged horizontally, with airflow flowing between the boxes via connecting ports, and featuring independent physical structures, the system, combined with a cylinder-driven clamping plate and limiting components, allows for rapid extraction of individual boxes and overall sealing without disassembling adjacent units. Furthermore, by incorporating connecting pipe assemblies, several pipe box assemblies form a ring-shaped pipeline. The connecting pipe assembly employs a telescopic design where two connecting pipes are nested within one, with a spring automatically compensating for installation tolerances. The assembly can be easily pulled out or inserted by hand by gripping the support plate / compressing the spring, facilitating disassembly and replacement. Compared to a monolithic pipeline, in case of damage, only the damaged connecting pipe assembly needs replacement, eliminating the need to replace the entire pipeline, thus reducing maintenance costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0019] Figure 3 This is a schematic diagram of the pipe box assembly structure in this utility model;

[0020] Figure 4 This is a front view of the internal structure of the pipe box assembly in this utility model;

[0021] Figure 5 This is a left view of the internal structure of the pipe box assembly in this utility model;

[0022] Figure 6 This is a schematic diagram of the internal structure of the connecting pipe assembly in this utility model;

[0023] Figure 7 This utility model Figure 6 A magnified view of a portion of area A;

[0024] Figure 8 This is a schematic diagram of the internal structure of the lower limit component in this utility model;

[0025] Figure 9 This is a schematic diagram of the movable plate structure in this utility model;

[0026] In the diagram: Left vertical plate-1, Right vertical plate-2, Upper limit assembly-3, Lower limit assembly-4, Pipe box assembly-5, Pressing plate-6, Inlet pipe one-7, Inlet pipe two-8, Outlet pipe one-9, Outlet pipe two-10, Cylinder-11, Limit rod one-12, Corrugated pipe-13, Rear baffle-14, U-shaped connecting pipe-15;

[0027] 51. Box body - 52. Cover plate - 53. Locking buckle - 54. Handle - 55. Pipe interface - 56. Connecting pipe assembly - 57. Connection port;

[0028] Connecting pipe 1-561, connecting pipe 2-562, sealing ring-563, support plate 1-564, support plate 2-565, limiting rod 2-566, spring 1-567;

[0029] Outer shell - 41, clamping plate - 42, movable plate - 43, magnetic block - 44, electromagnet - 45, limit rod three - 46, spring two - 47. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Please see Figure 1-5 This utility model provides a modular air heat exchanger technical solution: a modular air heat exchanger, including a left vertical plate 1, a right vertical plate 2, an upper limit component 3, a lower limit component 4 and a pipe box component 5, with the upper limit component 3 and the lower limit component 4 respectively fixed on the upper and lower sides between the left vertical plate 1 and the right vertical plate 2, and the pipe box component 5 installed between the upper limit component 3 and the lower limit component 4.

[0032] The pipe box assembly 5 includes a box body 51, a cover plate 52, a locking buckle 53, a handle 54, a pipe interface 55, a connecting pipe assembly 56, and a connecting port 57. The front end of the box body 51 is covered by the cover plate 52. The upper and lower sides of the cover plate 52 are locked and fixed to the box body 51 by the locking buckle 53. The handle 54 is fixed in the middle of the front end of the cover plate 52. The left and right sides of the box body 51 are provided with pipe interfaces 55. The left and right ends of the connecting pipe assembly 56 are connected to the pipe interfaces 55 at the same horizontal level on the left and right sides of the box body 51. The left and right sides of the box body 51 are provided with connecting ports 57. The pipe box assemblies 5 are arranged horizontally, and the boxes 51 of the pipe box assemblies 5 are tightly fitted together. The boxes 51 are connected to each other through the connecting ports 57. The left and right ends of the connecting pipe assembly 56 are connected to the connecting pipe assembly 56 of the adjacent pipe box assembly 5 through the pipe interfaces 55.

[0033] The left vertical plate 1 has an air inlet pipe 7 and an air inlet pipe 8 connected to the upper and lower sides of its left end, respectively. The right vertical plate 2 has an air outlet pipe 9 and an air outlet pipe 10 connected to the upper and lower sides of its right end, respectively.

[0034] U-shaped connecting pipes 15 are provided in the pipe box assembly 5 located on the far left and far right. The U-shaped connecting pipes 15 are used to connect two adjacent pipe interfaces 55, so that the connecting pipe assemblies 56 and U-shaped connecting pipes 15 in several pipe box assemblies 5 form a ring pipeline, and the two ends of the ring pipeline are respectively connected to the air inlet pipe 7 and the air outlet pipe 10.

[0035] The pipe interface 55 located at the top left end of the leftmost pipe box assembly 5 is connected to the first air intake pipe 7, and the left end of the connecting port 57 located at the bottom of the leftmost pipe box assembly 5 is connected to the second air intake pipe 8.

[0036] The connection between the clamping plate 6 and the corrugated pipe 13 is hollow. The connecting port 57 at the top right end of the left and right side pipe box assembly 5 is connected to the first air outlet pipe 9 through the corrugated pipe 13. The right end of the pipe interface 55 at the bottom right end of the left and right side pipe box assembly 5 is connected to the second air outlet pipe 10 through the corrugated pipe 13.

[0037] The connecting ports 57 on the left and right sides of the housing 51 are located on the upper and lower sides of the housing 51, respectively. The connecting ports 57 of adjacent housings 51 are set at the same height, and the connecting ports 57 are arranged alternately up and down, so that the air flowing inside the housing 51 can flow vertically, increase the contact effect with the connecting pipe assembly 56, and thus ensure the heat exchange effect.

[0038] A cylinder 11 is horizontally fixed at the middle of the right end of the right upright plate 2. The piston rod on the left side of the cylinder 11 is fixedly connected to the pressing plate 6. The pressing plate 6 is located on the right side of the pipe box assembly 5. The upper and lower ends of the right side of the pressing plate 6 are connected to the first air outlet pipe 9 and the second air outlet pipe 10 through the corrugated pipe 13, respectively. The right end of the pressing plate 6 is fixed with a limit rod 12, which horizontally penetrates the right upright plate 2.

[0039] A sealing strip is provided on the outer edge of the pipe interface 55 and the connection port 57, and the cylinder 11 drives the pressing plate 6 to press the pipe box assembly 5 together to ensure the connection and sealing effect of the pipe interface 55 and the connection port 57 between the boxes 51.

[0040] The rear ends of the left upright plate 1 and the right upright plate 2 are fixed with rear baffles 14, which are used to support the rear side of the pipe box assembly 5.

[0041] Both the connecting pipe assembly 56 and the U-shaped connecting pipe 15 are made of copper, which has a good heat exchange effect. Furthermore, the outer walls of the connecting pipe 1 561 and the connecting pipe 2 562 of the connecting pipe assembly 56 are provided with fins to increase the heat exchange effect.

[0042] The locking buckle 56 is a conventional mechanical fastening component in the prior art. Its function is conventional, namely, to lock and fix the cover plate 52 to the box body 51.

[0043] Please see Figure 6-7 The connecting pipe assembly 56 includes a first connecting pipe 561, a second connecting pipe 562, a sealing ring 563, a first support plate 564, a second support plate 565, a second limiting rod 566, and a first spring 567. The right end of the second connecting pipe 562 extends into the first connecting pipe 561. The sealing ring 563 is fitted onto the right side of the outer wall of the second connecting pipe 562, and the inner wall of the first connecting pipe 561 is in contact with the sealing ring 563. The tops of the first connecting pipe 561 and the second connecting pipe 562 are respectively fixed. There are two support plates, namely support plate 1 564 and support plate 2 565. The left end of the limiting rod 2 566 is fixedly connected to support plate 1 564 and the limiting rod 2 566 passes through support plate 2 565. Support plate 1 564 and support plate 2 565 are elastically connected by spring 1 567 and spring 1 567 is fitted on the outside of the limiting rod 2 566. The left end of connecting pipe 1 561 and the right end of connecting pipe 2 562 are respectively inserted into the pipe interfaces 55 on the left and right sides inside the box 51.

[0044] Please see Figure 8-9 The upper limit component 3 and the lower limit component 4 have the same structure and are arranged symmetrically. The lower limit component 4 includes a shell 41, a locking plate 42, a movable plate 43, a magnetic block 44, an electromagnet 45, a third limiting rod 46, and a second spring 47. The bottom end of the locking plate 42 is fixedly connected to the movable plate 43. The movable plate 43 is located on the inner top of the shell 41, and the top end of the locking plate 42 extends out of the shell 41. A magnetic block 44 is fixed in the middle of the bottom end of the movable plate 43. An electromagnet 45 is fixed in the middle of the inner bottom end of the shell 41. The left and right sides of the interior of the movable plate 43 are vertically penetrated by the third limiting rod 46, and the upper and lower ends of the third limiting rod 46 are fixedly connected to the shell 41. The bottom of the movable plate 43 is elastically connected to the shell 41 through the second spring 47, and the second spring 47 is fitted on the outer wall of the third limiting rod 46. The left and right sides of the shell 41 are fixedly connected to the left upright plate 1 and the right upright plate 2, respectively.

[0045] The front end face of the card plate 42 is inclined, and the card plate 42 of the lower limit component 4 is inclined upward from front to back, while the card plate 42 of the upper limit component 3 is inclined downward from front to back, so that when the housing 51 is installed, the front end face of the card plate 42 is squeezed and the card plate 42 retracts into the outer shell 41.

[0046] The magnetic block 44 is a permanent magnet with constant magnetism (such as ferrite, neodymium iron boron, etc.). When energized, the electromagnet 45 generates magnetism opposite to that of the magnetic block 44, attracting the magnetic block 44 to move downward.

[0047] In use, cold air enters the annular pipe consisting of the connecting pipe assembly 56 and the U-shaped connecting pipe 15 through the inlet pipe 7, and is discharged through the lower corrugated pipe 13 and then through the outlet pipe 10. Hot air enters the housing 51 of the pipe box assembly 5 through the inlet pipe 8, exchanges heat with the cold air in the connecting pipe assembly 56 and the U-shaped connecting pipe 15, and is discharged through the upper corrugated pipe 13 and then through the outlet pipe 9.

[0048] When the connecting pipe assembly 56 needs to be replaced, the cover 52 on the front side of the corresponding housing 51 can be opened by disengaging the locking buckle 53 connecting the cover 52 and the housing 51. To remove the connecting pipe assembly 56, simply hold the first support plate 564 and the second support plate 565, causing them to retract. This retraction causes the first connecting pipe 561 and the second connecting pipe 562 to retract, shortening the length of the connecting pipe assembly 56. When installing the connecting pipe assembly 56, hold the first support plate 564 and the second support plate 565 to maintain the connection. In the contracted state, align both ends of the connecting pipe assembly 56 with the corresponding pipe interfaces 55, loosen the first branch plate 564 and the second branch plate 565, and the elastic potential energy generated by the spring 567 between the first branch plate 564 and the second branch plate 565 will push the expansion between the first branch plate 564 and the second branch plate 565. The first branch plate 564 and the second branch plate 565 will drive the expansion between the first connecting pipe 561 and the second connecting pipe 562, so that the first connecting pipe 561 and the second connecting pipe 562 are respectively inserted into the pipe interfaces 55 on both sides of the box 51. Then, cover the cover plate 52 and lock the cover plate 52 to the box 51 with the locking buckle 53 to complete the replacement of the connecting pipe assembly 56.

[0049] When the pipe box assembly 5 needs to be replaced, the control cylinder 11 moves the clamping plate 6 to the right. As the clamping plate 6 moves to the right, the bellows 13 retracts synchronously with the clamping plate 6, releasing the pressure of the clamping plate 6 on the pipe box assembly 5. Then, the electromagnets 45 in the upper limit assembly 3 and the lower limit assembly 4 are controlled to generate magnetism to attract the magnetic block 44. The magnetic block 44 moves the clamping plate 42 and the movable plate 43 downward, allowing the pipe box assembly 5 to be replaced to be pulled out using the handle 54. When installing the pipe box assembly 5, simply... When component 5 is inserted between the upper limit assembly 3 and the lower limit assembly 4, it presses the front end face of the clamping plate 42 of the upper limit assembly 3 and the lower limit assembly 4, causing the clamping plate 42 to retract into the outer shell 41. After the pipe box assembly 5 is fully inserted, the elastic potential energy generated by the second spring 47 pushes the clamping plate 42 and the movable plate 43 upward, thereby limiting the front side of the pipe box assembly 5. Then, the cylinder 11 is controlled to push the pressing plate 6 to move to the left, thereby pressing the pipe box assembly 5 together, thus completing the replacement of the pipe box assembly 5.

[0050] The control method of this utility model is to control the device by manually starting and stopping the switch. The wiring diagram of the power element and the supply of power are common knowledge in the field. Since this utility model is mainly used to protect mechanical devices, the control method and wiring layout will not be explained in detail.

[0051] The control method of this utility model is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the field. Since this utility model is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail.

[0052] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular air heat exchanger, characterized in that: It includes a left vertical plate (1), a right vertical plate (2), an upper limit component (3), a lower limit component (4) and a pipe box component (5). The upper limit component (3) and the lower limit component (4) are fixed on the upper and lower sides of the left vertical plate (1) and the right vertical plate (2) respectively. The pipe box component (5) is installed between the upper limit component (3) and the lower limit component (4). The pipe box assembly (5) includes a box body (51), a cover plate (52), a locking buckle (53), a handle (54), a pipe interface (55), a connecting pipe assembly (56), and a connecting port (57). The front end of the box body (51) is sealed by the cover plate (52). The upper and lower sides of the cover plate (52) are locked and fixed to the box body (51) by the locking buckle (53). A handle (54) is fixed to the middle of the front end of the cover plate (52). Pipe interfaces (55) are provided on both the left and right sides of the box body (51), and are connected to... The left and right ends of the pipe assembly (56) are connected to the pipe interfaces (55) at the same horizontal height on the left and right sides of the box (51). The left and right sides of the box (51) are respectively provided with connecting ports (57). The pipe box assemblies (5) are arranged horizontally, and the boxes (51) of the pipe box assemblies (5) are tightly fitted together. The boxes (51) are connected to each other through the connecting ports (57). The left and right ends of the connecting pipe assembly (56) are respectively connected to the connecting pipe assembly (56) of the adjacent pipe box assembly (5) through the pipe interfaces (55).

2. A modular air heat exchanger according to claim 1, characterized in that: The left vertical plate (1) is connected to the upper and lower sides of the left end with an air inlet pipe 1 (7) and an air inlet pipe 2 (8) respectively, and the right vertical plate (2) is connected to the upper and lower sides of the right end with an air outlet pipe 1 (9) and an air outlet pipe 2 (10) respectively.

3. A modular air heat exchanger according to claim 1, characterized in that: A cylinder (11) is horizontally fixed at the middle of the right end of the right upright plate (2). The piston rod on the left side of the cylinder (11) is fixedly connected to the pressing plate (6). The pressing plate (6) is located on the right side of the pipe box assembly (5). The upper and lower ends of the right side of the pressing plate (6) are connected to the first air outlet pipe (9) and the second air outlet pipe (10) respectively through the corrugated pipe (13). The right end of the pressing plate (6) is fixed with a limiting rod (12), and the limiting rod (12) horizontally penetrates the right upright plate (2).

4. A modular air heat exchanger according to claim 1, characterized in that: The rear ends of the left upright plate (1) and the right upright plate (2) are fixed with rear baffles (14), which are used to support the rear side of the pipe box assembly (5).

5. A modular air heat exchanger according to claim 1, characterized in that: The connecting pipe assembly (56) includes a first connecting pipe (561), a second connecting pipe (562), a sealing ring (563), a first support plate (564), a second support plate (565), a second limiting rod (566), and a first spring (567). The right end of the second connecting pipe (562) extends into the first connecting pipe (561). The right side of the outer wall of the second connecting pipe (562) is fitted with a sealing ring (563), and the inner wall of the first connecting pipe (561) is in contact with the sealing ring (563). The top portions of the first connecting pipe (561) and the second connecting pipe (562) are... The support plate is fixed with support plate one (564) and support plate two (565). The left end of the limiting rod two (566) is fixedly connected to support plate one (564), and the limiting rod two (566) passes through support plate two (565). Support plate one (564) and support plate two (565) are elastically connected by spring one (567), and spring one (567) is fitted on the outside of limiting rod two (566). The left end of connecting pipe one (561) and the right end of connecting pipe two (562) are respectively inserted into the pipe interfaces (55) on the left and right sides of the box body (51).

6. A modular air heat exchanger according to claim 1, characterized in that: The upper limit component (3) and the lower limit component (4) have the same structure and are arranged symmetrically. The lower limit component (4) includes a shell (41), a locking plate (42), a movable plate (43), a magnetic block (44), an electromagnet (45), a limiting rod (46), and a spring (47). The bottom end of the locking plate (42) is fixedly connected to the movable plate (43). The movable plate (43) is located on the top inner side of the shell (41), and the top end of the locking plate (42) extends out of the shell (41). 3) A magnetic block (44) is fixed at the bottom center. An electromagnet (45) is fixed at the bottom center of the inner side of the outer shell (41). The left and right sides of the interior of the movable plate (43) are vertically penetrated by the limiting rod three (46), and the upper and lower ends of the limiting rod three (46) are fixedly connected to the outer shell (41). The bottom of the movable plate (43) is elastically connected to the outer shell (41) through the spring two (47), and the spring two (47) is fitted on the outer wall of the limiting rod three (46). The left and right sides of the outer shell (41) are fixedly connected to the left upright plate (1) and the right upright plate (2) respectively.

7. A modular air heat exchanger according to claim 6, characterized in that: The front end face of the card plate (42) is inclined, and the card plate (42) of the lower limit component (4) is inclined upward from front to back, while the card plate (42) of the upper limit component (3) is inclined downward from front to back.

Images