Existing line tunnel geological radar nondestructive testing device

Abstract

The utility model provides a geological radar nondestructive testing device for an existing line tunnel, which belongs to the technical field of tunnel detection and is characterized in that traveling wheels are rotatably mounted on the lower surface or two sides of a lower base; the bottom end of the supporting rod is connected with the upper surface of the lower base, and the top end is connected with the lower surface of the upper support; the bottom end of the fixed cylinder is fixed on the upper surface of the upper support; the rotating rod is inserted from the top end of the fixed cylinder and rotationally connected with the fixed cylinder; the swinging cylinder is rotationally connected with the rotating rod through a connecting shaft I which is horizontally arranged; a compression bolt penetrating through the cylinder wall is arranged on the swinging cylinder; the control rod penetrates through the swinging cylinder, and the first end is connected with the geological radar detector fixer; the two control ropes are respectively positioned at two ends of the swinging cylinder, and the top ends are respectively fixed on the control rod. According to the detection device, the labor intensity of operation is reduced, high-altitude high-intensity operation is not needed, and the technical problem that potential safety hazards of personnel are large is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of tunnel detection, and specifically discloses a nondestructive detection device for an existing tunnel geological radar. Background Art

[0002] Lining inspection of railway operating tunnels is one of the important preventive measures to ensure driving safety. With the increase of tunnels put into operation in domestic infrastructure development, the demand for existing railway inspection is also increasing. However, there is no mature and efficient inspection method for existing railway lining inspection. Compared with the lining inspection of tunnels under construction, the inspection of existing tunnels has more stringent requirements on safety, inspection time and inspection efficiency. In addition, a large number of steel brackets and light strip wires are hung on the inner wall of the tunnel, making the inspection conditions more complicated.

[0003] At present, the existing line tunnel inspection mainly includes manual and vehicle-mounted inspection methods. The tunnel geological radar method requires the assembly of a geological radar inspection workbench, and the staff hold the geological radar inspection instrument on the workbench and stick it to the tunnel lining surface. During the entire geological radar inspection process, the staff must hold the geological radar inspection instrument and stick it to the tunnel lining surface in real time, and ensure that it does not touch the surrounding light strips and wires. The labor intensity of the operation is extremely high. At present, the geological radar inspection stand is a non-standard product and needs to be customized. The commonly used workbench is a simple steel pipe welded structure stand. During the inspection, the staff stood on the workbench in real time to hold the geological radar inspection instrument and operate it. There are great safety hazards to personnel under high-altitude and high-intensity working conditions. When the workbench is unstable, it is easy to cause the staff on the workbench to stand unstable, causing safety accidents such as personnel bumping, instrument falling, and workbench overturning. Utility Model Content

[0004] The utility model provides a nondestructive detection device for geological radar in existing tunnels to solve the following technical problems:

[0005] During the existing geological radar detection process, workers need to hold the geological radar detection instrument on the work platform and keep it in close contact with the tunnel lining surface in real time. The operation is labor-intensive and there are great technical problems such as high safety risks for personnel under high-altitude and high-intensity working conditions.

[0006] The above-mentioned existing line tunnel geological radar nondestructive testing device includes a lower base, a walking wheel, a support rod, an upper support, a fixed cylinder, a rotating rod, a swing cylinder, a connecting shaft I, a control rod, a geological radar detector fixture and a control rope; the walking wheel is rotatably installed on the lower surface or both sides of the lower base; the bottom end of the support rod is connected to the upper surface of the lower base, and the top end is connected to the lower surface of the upper support; the bottom end of the fixed cylinder is fixed to the upper surface of the upper support; the rotating rod is inserted from the top end of the fixed cylinder and is rotatably connected to the fixed cylinder; the swing cylinder and the rotating rod are rotatably connected through a horizontally arranged connecting shaft I; a clamping bolt penetrating the cylinder wall is provided on the swing cylinder; the control rod passes through the swing cylinder, and the first end is connected to the geological radar detector fixture; the two control ropes are respectively located at the two ends of the swing cylinder, and the top ends are respectively fixed on the control rod.

[0007] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the lower base is a retractable base, and the retracting direction is the track gauge direction.

[0008] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the lower base includes a first base, a second base and a limiting bolt; the first base and the second base are respectively equipped with walking wheels; the first base is provided with a plug-in plate; the second base is provided with a plug-in slot, and the upper side plate of the plug-in slot is provided with a limiting threaded circular hole; the plug-in plate is slidably plugged into the plug-in slot; the limiting bolt passes through the limiting threaded circular hole to press the plug-in plate.

[0009] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the lower base includes a first base, a second base, a limit bolt and a limit nut; the first base and the second base are respectively installed with walking wheels; the first base is provided with a plug-in plate, and the plug-in plate is provided with a strip plug-in hole I; the second base is provided with a plug-in slot, and the upper side plate and the lower side plate of the plug-in slot are both provided with strip plug-in holes II; the plug-in plate and the plug-in slot are slidably plugged, and the strip plug-in hole I is aligned with the strip plug-in hole II; the limit bolt passes through the strip plug-in hole I and the strip plug-in hole II; the limit nut is sleeved on the limit bolt, and cooperates with the head of the limit bolt to press the plug-in plate and the plug-in slot.

[0010] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the bottom ends of the three support rods are movably connected to the upper surface of the lower base through riveting, and the top ends are rotatably connected to the lower surface of the upper support through a horizontally arranged connecting shaft II.

[0011] In the above-mentioned existing line tunnel geological radar nondestructive testing device, a connecting ear II is provided on the lower surface of the upper support; a connecting hole II is provided on the connecting ear II and the support rod; and a connecting shaft II passes through the connecting hole II on the connecting ear II and the support rod.

[0012] In the above-mentioned existing line tunnel geological radar nondestructive testing device, a connecting ear I is vertically arranged on the swing cylinder; a connecting hole I is arranged on the connecting ear I and the rotating rod; and a connecting shaft I passes through the connecting ear I and the connecting hole I on the rotating rod.

[0013] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the control rod includes a length adjustment rod, a connecting shaft III, an angle adjustment rod and a connecting shaft IV; the length adjustment rod is a telescopic rod or is formed by connecting multiple sections of connecting rods, the first end of the length adjustment rod is rotatably connected to the second end of the angle adjustment rod through the connecting shaft III, and the first end of the angle adjustment rod is rotatably connected to the geological radar detector fixture through the connecting shaft IV; the connecting shaft III and the connecting shaft IV are both perpendicular to the length adjustment rod and perpendicular to each other.

[0014] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the first end of the length adjustment rod is provided with a connecting ear III; the connecting ear III and the second end of the angle adjustment rod are provided with a connecting hole III; the connecting shaft III passes through the connecting ear III and the connecting hole III of the angle adjustment rod; the geological radar detector fixture is provided with a connecting ear IV; the connecting ear IV and the first end of the angle adjustment rod are provided with a connecting hole IV; the connecting shaft IV passes through the connecting ear IV and the connecting hole IV of the angle adjustment rod.

[0015] In the above-mentioned existing line tunnel geological radar nondestructive testing device, the geological radar detector fixture includes a fixing frame, a connecting plate and a connecting frame; two groups of connecting plates are symmetrically fixed on the first side of the fixing frame, and are penetrated by connecting bolts; two groups of connecting frames are symmetrically fixed on the second side of the fixing frame, forming an isosceles triangle frame with the fixing frame, and connecting ears IV are installed at the connection of the two groups of connecting frames.

[0016] Compared with the prior art, the utility model has the following beneficial effects.

[0017] 1. The utility model abandons the manned function of the mainstream platform, and is supported on the track by walking wheels. The control rod passes through the swing cylinder, and the geological radar detector is installed on the geological radar detector fixture. The length of the control rod and the control ropes on both sides are adjusted to make the geological radar detector close to the tunnel lining surface. During the existing railway inspection process, the staff pushes the above-mentioned existing line tunnel geological radar non-destructive testing device along the track, and the geological radar detector can move along the tunnel lining surface. The staff does not need to hold the geological radar detection instrument on the work platform and make it close to the tunnel lining surface in real time, which reduces the labor intensity of the operation, and does not require high-altitude and high-intensity operations, solving the technical problem of greater safety hazards to personnel.

[0018] 2. The detection efficiency can be improved by increasing the speed of the existing tunnel geological radar non-destructive detection device along the track.

[0019] 3. The difficulty of existing railway inspection lies in the rapid inspection under the interference of existing lines mounted on the tunnel wall. By adjusting the downward pulling force of the control rope, the height of the geological radar detector fixture can be lowered, so that the above-mentioned detection device can quickly and flexibly change the height of the radar detector during movement without affecting the detection efficiency. It can quickly cross the obstacles hanging on the tunnel lining surface, reduce interference and improve efficiency.

[0020] 4. The triangular bracket structure is adopted to ensure the stability of the structure and greatly reduce the weight of the detection device.

[0021] 5. Vehicles are generally unable to enter the existing line tunnel. The detection device can be disassembled into four parts: the lower base, support rod and upper support, rotating rod and swing cylinder, control rod and geological radar detector fixture, which is convenient for storage and quick transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of the geological radar nondestructive testing device for existing tunnels;

[0024] Figure 2 It is a structural schematic diagram of a control rod and a geological radar detector fixture;

[0025] Figure 3 This is a working diagram of the geological radar nondestructive testing device for existing tunnels.

[0026] In the figure: 1-travel wheel; 2-support rod; 3-upper support; 4-fixed cylinder; 5-rotating rod; 6-swinging cylinder; 7-connecting axis I; 8-control rope; 9-tightening bolt; 10.1-first base; 10.2-second base; 10.3-limiting bolt; 11-connecting axis II; 12.1-length adjustment rod; 12.2-connecting axis III; 12.3-angle adjustment rod; 12.4-connecting axis IV; 12.5-connecting ear III; 13.1-fixed frame; 13.2-connecting plate; 13.3-connecting frame; 13.4-connecting bolt; 13.5-connecting ear IV. DETAILED DESCRIPTION

[0027] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] The present embodiment provides a nondestructive testing device for geological radar in an existing tunnel, comprising a lower base, a walking wheel 1, a support rod 2, an upper support 3, a fixed cylinder 4, a rotating rod 5, a swing cylinder 6, a connecting shaft Ⅰ7, a control rod, a geological radar detector fixture and a control rope 8; the walking wheel 1 is rotatably mounted on the lower surface or both sides of the lower base, and adopts a rubber wheel; the bottom end of the support rod 2 is connected to the upper surface of the lower base, and the top end is connected to the lower surface of the upper support 3; the bottom end of the fixed cylinder 4 is fixed to the upper surface of the upper support 3; the rotating rod 5 is inserted from the top end of the fixed cylinder 4 and is rotatably connected to the fixed cylinder 4; the swing cylinder 6 is rotatably connected to the rotating rod 5 through a horizontally arranged connecting shaft Ⅰ7; a clamping bolt 9 penetrating the cylinder wall is provided on the swing cylinder 6; the control rod passes through the swing cylinder 6, and the first end is connected to the geological radar detector fixture; two control ropes 8 are respectively located at the two ends of the swing cylinder 6, and the top ends are respectively fixed on the control rod.

[0029] The above-mentioned geological radar nondestructive testing device for existing tunnels abandons the manned function of the mainstream platform, is supported on the track by the walking wheel 1, the control rod passes through the swing cylinder 6, the geological radar detector is installed on the geological radar detector fixture, and the length of the control rod and the control ropes 8 on both sides are adjusted to make the geological radar detector close to the tunnel lining surface. During the existing railway inspection process, the staff pushes the above-mentioned detection device along the track, and the geological radar detector can move along the tunnel lining surface. The staff does not need to hold the geological radar detection instrument on the working platform to make it close to the tunnel lining surface in real time, which reduces the labor intensity of the operation, and does not require high-intensity operation at high altitude, solving the technical problem of major safety hazards to personnel.

[0030] The difficulty in detecting existing railway lines lies in the rapid detection under the interference of existing lines mounted on the tunnel wall. By adjusting the downward pulling force of the control rope 8, the height of the geological radar detector fixture can be lowered, so that the above-mentioned detection device can quickly and flexibly change the height of the radar detector during movement without affecting the detection efficiency. It can quickly cross the obstacles mounted on the tunnel lining surface, reduce interference and improve efficiency.

[0031] In order to adapt to different track gauges, the lower base is a retractable base, and the retracting direction is the track gauge direction.

[0032] This embodiment provides two retractable structures of the lower base.

[0033] The first telescopic structure: the lower base includes a first base 10.1, a second base 10.2 and a limiting bolt 10.3; the first base 10.1 and the second base 10.2 are respectively provided with walking wheels 1; the first base 10.1 is provided with a plug-in plate; the second base 10.2 is provided with a plug-in slot, and the upper side plate of the plug-in slot is provided with a limiting threaded circular hole; the plug-in plate is slidably plugged into the plug-in slot; the limiting bolt 10.3 passes through the limiting threaded circular hole and presses the plug-in plate to fix the length of the lower base.

[0034] The first telescopic structure: the lower base includes a first base 10.1, a second base 10.2, a limiting bolt 10.3 and a limiting nut; the first base 10.1 and the second base 10.2 are respectively installed with walking wheels 1; the first base 10.1 is provided with a plug-in plate, and the plug-in plate is provided with a strip plug-in hole I; the second base 10.2 is provided with a plug-in slot, and the upper side plate and the lower side plate of the plug-in slot are both provided with strip plug-in holes II; the plug-in plate is slidably plugged into the plug-in slot, and the strip plug-in hole I is aligned with the strip plug-in hole II; the limiting bolt 10.3 passes through the strip plug-in hole I and the strip plug-in hole II; the limiting nut is sleeved on the limiting bolt 10.3, and cooperates with the head of the limiting bolt 10.3 to press the plug-in plate and the plug-in slot to fix the length of the lower base.

[0035] The bottom ends of the three support rods 2 are movably connected to the upper surface of the lower base through riveting, and the top ends are rotatably connected to the lower surface of the upper support 3 through a horizontally arranged connecting shaft II 11. The triangular bracket structure is adopted to ensure the stability of the structure and greatly reduce the weight of the detection device.

[0036] The lower surface of the upper support 3 is provided with a connecting ear II; the connecting ear II and the support rod are provided with a connecting hole II; the connecting shaft II11 passes through the connecting ear II and the connecting hole II on the support rod to realize the rotational connection between the support rod 2 and the upper support 3.

[0037] A connecting ear Ⅰ is vertically provided on the swing cylinder 6; a connecting hole Ⅰ is provided on the connecting ear Ⅰ and the rotating rod 5; a connecting shaft Ⅰ7 passes through the connecting ear Ⅰ and the connecting hole Ⅰ on the rotating rod to realize the rotational connection between the swing cylinder 6 and the rotating rod 5.

[0038] The control rod comprises a length adjustment rod 12.1, a connecting shaft III 12.2, an angle adjustment rod 12.3 and a connecting shaft IV 12.4; the length adjustment rod 12.1 is a telescopic rod or is formed by connecting multiple sections of connecting rods, so that the length adjustment rod 12.1 can be adjusted according to the tunnel diameter, the first end of the length adjustment rod 12.1 is rotatably connected to the second end of the angle adjustment rod 12.3 through the connecting shaft III 12.2, and the first end of the angle adjustment rod 12.3 is rotatably connected to the geological radar detector holder through the connecting shaft IV 12.4; the connecting shaft III 12.2 and the connecting shaft IV 12.4 are both perpendicular to the length adjustment rod 12.1 and perpendicular to each other. When the control rod is placed vertically or horizontally, the geological radar detector holder can be adjusted in the horizontal plane angle and in the vertical plane angle through the connecting shaft III 12.2 and the connecting shaft IV 12.4, so that the angle of the geological radar detector is consistent with the angle of the tunnel lining surface, and the two are kept in close contact in real time.

[0039] A connecting ear III 12.5 is provided at the first end of the length adjustment rod 12.1; a connecting hole III is provided at the second end of the connecting ear III 12.5 and the angle adjustment rod 12.3; a connecting shaft III 12.2 passes through the connecting hole III of the connecting ear III 12.5 and the angle adjustment rod 12.3; a connecting ear IV 13.5 is provided on the geological radar detector fixture; a connecting hole IV is provided at the first end of the connecting ear IV 13.5 and the angle adjustment rod 12.3; a connecting shaft IV 12.4 passes through the connecting ear IV 13.5 and the connecting hole IV of the angle adjustment rod 12.3.

[0040] The geological radar detector fixture includes a fixing frame 13.1, a connecting plate 13.2 and a connecting frame 13.3; two groups of connecting plates 13.2 are symmetrically fixed on the first side of the fixing frame 13.1, and are penetrated with connecting bolts 13.4, and the connecting bolts 13.4 are connected to the geological radar detector; two groups of connecting frames 13.3 are symmetrically fixed on the second side of the fixing frame 13.1, and form an isosceles triangle frame with the fixing frame 13.1, and connecting ears IV 13.5 are installed at the connection of the two groups of connecting frames 13.3.

[0041] When the above-mentioned existing line tunnel geological radar nondestructive testing device is actually used, the various parts are assembled into a complete testing device in the existing line tunnel, the telescopic amount of the lower base is determined according to the track width, locked by the limit bolt 10.3, and the lower base is placed on the track so that the device can move freely forward and backward along the track. According to the tunnel diameter, the appropriate control rod length is selected, and each connecting rod of the length adjustment rod 12.1 is connected by a screw hole rotation, and the radar detector is fixed to the geological radar detector fixture by a connecting bolt 13.4. After the length adjustment rod 12.1 passes through the swing cylinder 6, it is fixed by the clamping bolt 9 and cannot be displaced. The staff uses the control rope 8 close to the second end of the control rod to make the geological radar detector close to the tunnel lining detection line position, wherein the direction angle is adjusted by the connecting shaft I7, the connecting shaft III 12.2, and the connecting shaft IV 12.4. At the beginning of the detection, the staff pushes the detection device forward. When encountering an obstacle on the tunnel lining surface, the downward force of the control rope 8 near the second end of the control rod is reduced, or the downward force of the control rope 8 near the first end of the control rod is increased. The height of the geological radar detector can be safely and freely controlled to achieve rapid obstacle avoidance.

[0042] The above-mentioned existing tunnel geological radar nondestructive testing device can realize continuous detection of the existing tunnel lining in the longitudinal direction of the tunnel during the movement along the existing tunnel track. Moreover, the detection device can be disassembled and assembled anytime and anywhere, which is convenient for transportation and transfer. The materials used are common, the manufacturing difficulty is relatively low, and it is easy to promote and apply.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A nondestructive testing device for existing tunnel geological radar, characterized in that: It includes a lower base, a walking wheel, a support rod, an upper support, a fixing cylinder, a rotating rod, a swing cylinder, a connecting shaft I, a control rod, a geological radar detector fixer and a control rope; The travel wheels are rotatably mounted on the lower surface or both sides of the lower base; The bottom end of the support rod is connected to the upper surface of the lower base, and the top end is connected to the lower surface of the upper support; The bottom end of the fixed cylinder is fixed to the upper surface of the upper support; The rotating rod is inserted from the top of the fixed tube and is rotatably connected to the fixed tube; The swing cylinder is rotatably connected to the rotating rod via a horizontally arranged connecting shaft I; The swing cylinder is provided with a clamping bolt penetrating through the cylinder wall; The control rod passes through the swing cylinder, and the first end is connected to the fixture of the geological radar detector; Two control ropes are respectively located at two ends of the swing cylinder, and the top ends are respectively fixed on the control rods.

2. The existing line tunnel geological radar nondestructive testing device according to claim 1 is characterized in that: The lower base is a retractable base, and the retracting direction is the track gauge direction.

3. The existing line tunnel geological radar nondestructive testing device according to claim 2 is characterized in that: The lower base includes a first base, a second base and a limiting bolt; The first base and the second base are respectively provided with walking wheels; The first base is provided with a plug-in board; The second base is provided with a plug-in slot, and the upper side plate of the plug-in slot is provided with a limited threaded circular hole; The plug-in board is slidably plugged into the plug-in slot; The limiting bolt passes through the limiting threaded circular hole to press the plug-in plate.

4. The existing line tunnel geological radar nondestructive testing device according to claim 2 is characterized in that: The lower base includes a first base, a second base, a limiting bolt and a limiting nut; The first base and the second base are respectively provided with walking wheels; The first base is provided with a plug-in board, and the plug-in board is provided with a strip-shaped plug-in hole I; The second base is provided with a plug-in slot, and the upper side plate and the lower side plate of the plug-in slot are both provided with a strip-shaped plug-in hole II; The plug-in board is slidably plugged into the plug-in slot, and the strip plug-in hole I is aligned with the strip plug-in hole II; The limiting bolt passes through the strip-shaped plug-in hole I and the strip-shaped plug-in hole II; The limiting nut is sleeved on the limiting bolt and cooperates with the head of the limiting bolt to press the plug-in plate and the plug-in slot.

5. The existing line tunnel geological radar nondestructive testing device according to claim 1 is characterized in that: The bottom ends of the three support rods are movably connected to the upper surface of the lower base through riveting, and the top ends are rotatably connected to the lower surface of the upper support through a horizontally arranged connecting shaft II.

6. The existing line tunnel geological radar nondestructive testing device according to claim 1 is characterized in that: The lower surface of the upper support is provided with a connecting ear II; The connecting ear II and the supporting rod are provided with a connecting hole II; The connecting shaft II passes through the connecting ear II and the connecting hole II on the supporting rod.

7. The existing line tunnel geological radar nondestructive testing device according to claim 1 is characterized in that: A connecting ear Ⅰ is vertically arranged on the swing cylinder; The connecting ear Ⅰ and the rotating rod are provided with a connecting hole Ⅰ; The connecting shaft I passes through the connecting ear I and the connecting hole I on the rotating rod.

8. The existing line tunnel geological radar nondestructive testing device according to claim 1 is characterized in that: The control rod comprises a length adjustment rod, a connecting shaft III, an angle adjustment rod and a connecting shaft IV; The length adjustment rod is a telescopic rod or is formed by connecting multiple connecting rods. The first end of the length adjustment rod is rotatably connected to the second end of the angle adjustment rod through a connecting shaft III, and the first end of the angle adjustment rod is rotatably connected to the geological radar detector fixture through a connecting shaft IV. The connecting axis III and the connecting axis IV are both perpendicular to the length adjustment rod and perpendicular to each other.

9. The existing line tunnel geological radar nondestructive testing device according to claim 8 is characterized in that: The first end of the length adjustment rod is provided with a connecting ear III; The connecting ear III and the second end of the angle adjustment rod are provided with a connecting hole III; The connecting shaft III passes through the connecting ear III and the connecting hole III of the angle adjustment rod; The geological radar detector fixture is provided with a connecting ear IV; The connecting ear IV and the first end of the angle adjustment rod are provided with a connecting hole IV; The connecting shaft IV passes through the connecting ear IV and the connecting hole IV of the angle adjustment rod.

10. The existing line tunnel geological radar nondestructive testing device according to claim 9 is characterized in that: The geological radar detector fixture comprises a fixing frame, a connecting plate and a connecting frame; Two sets of connecting plates are symmetrically fixed on the first side surface of the fixing frame and are provided with connecting bolts; The two groups of connection frames are symmetrically fixed on the second side surface of the fixed frame to form an isosceles triangle frame with the fixed frame. The connection of the two groups of connection frames is equipped with connection ears IV.

Images