Cabin door latch mechanism for manned centrifugal machine

Abstract

The invention discloses a cabin door latch mechanism for a manned centrifugal machine. The cabin door latch mechanism comprises a 1 # bolt mechanism, two pull rods, a 2 # bolt mechanism and a handle mechanism, each of the 1 # bolt mechanism and the 2 # bolt mechanism comprises a first hinged support, a first connecting rod, a second connecting rod, a bolt, a bolt seat and a linear proximity sensor; the handle mechanism comprises an inner handle, a mandrel, a handle mounting seat, a rocker arm and an outer handle. The double-dead-point self-locking design of the plug pin mechanism and the handle mechanism is adopted, it is guaranteed that under the overload environment or the vibration environment, opening is not prone to occurring under the action of external force, and unlocking is convenient and fast; a linear proximity sensor is adopted to directly monitor the state of the bolt, and it is ensured that locking state signals are real and reliable; the double-bolt parallel design is adopted, the state of each bolt is monitored, and safe locking is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of manned centrifuges, and in particular to a door latch mechanism for manned centrifuges. Background Art

[0002] The continuous acceleration generated by the maneuvering flight of modern high-performance fighters can easily cause pilots to lose consciousness (G-induced loss of consciousness, G-LOC), reduce combat capabilities, and threaten flight safety. Using manned centrifuges to carry out flight simulation training can enable pilots to practice and master anti-g-action skills, experience the physiological effects of acceleration loads, and enhance high-load protection awareness. It is the safest and most economical means to improve pilots' own G endurance. Moreover, this training method is not affected by weather and can be carried out all day long. It has been widely adopted by various countries and has achieved good training results.

[0003] Among them, the cockpit, as the core component of the manned centrifuge, provides pilots with driving environment simulation and overload simulation environment. During flight training, the cockpit is always in an overload environment. Therefore, during flight training, the door latch must always be in a safe locked state, and the state can be monitored and the signal is reliable to ensure the safety of the pilot. In addition, considering that the subjects may faint during endurance training using manned centrifuges, the latch mechanism needs to be able to unlock quickly.

[0004] The disadvantages of the latch mechanism in the prior art are: (1) Traditional latch mechanisms may not be designed with a self-locking function. For example, if a padlock is used, it is not suitable for quick unlocking for emergency first aid, or the self-locking mechanism is not safe and reliable enough to be used in an overload environment.

[0005] (2) Traditional latch mechanisms are not designed with a latch locking status monitoring function, or only monitor the door's opening and closing status, which is not reliable enough and may result in the door being closed but not locked.

[0006] (3) Traditional latch mechanisms are generally not designed with installation adjustment mechanisms, and installation deviations may result in reduced locking effects.

[0007] (4) Traditional latch mechanisms generally only have one latch mechanism, which is not reliable enough.

[0008] Cause: (1) Traditional latch mechanisms may not take into account the need for rapid unlocking in emergency situations and may use a padlock to ensure the locked state; or they may not take into account the need for use in an overload environment and may use a hasp lock to ensure rapid unlocking. However, neither padlocks nor hasps can guarantee that the door can be quickly unlocked in an emergency situation and can be used safely and reliably in an overload environment.

[0009] (2) In daily life, doors are common, and in industrial production where the safety requirements for doors are not very high, the locking status of the doors is generally not monitored. In situations where there are strict requirements for the safety of the doors, the opening and closing status of the doors is often monitored. For example, if a proximity switch is used, this may lead to the situation where the door is closed but not locked, and the sensor will give an erroneous signal.

[0010] (3) The traditional latch mechanism is not designed with an installation adjustment mechanism. The manufacturing error of the latch mechanism or the mounting plate will affect the installation accuracy, resulting in poor insertion or locking.

[0011] (4) Traditional latch mechanisms generally only have one latch mechanism, such as common padlocks, tongue locks, hasp locks, etc., which means that a failure of a latch mechanism will cause the latch mechanism to fail.

[0012] Therefore, it is necessary to develop a door latch mechanism for a manned centrifuge to solve the above problems. Summary of the invention

[0013] The purpose of the present invention is to design a door latch mechanism for a manned centrifuge in order to solve the above-mentioned problem.

[0014] The present invention achieves the above-mentioned purpose through the following technical solutions: A door latch mechanism for a manned centrifuge, comprising: 1# latch mechanism; Two tie rods; 2# latch mechanism; The structures of 1# latch mechanism and 2# latch mechanism are the same, both including a first hinge seat, a first connecting rod, a second connecting rod, a latch, a latch seat, and a linear proximity sensor; the first end of the first hinge seat is installed in a fixed position, the first end of the first connecting rod is hinged to the second end of the first hinge seat, the second end of the first connecting rod is respectively hinged to the first end of a pull rod and the first end of the second connecting rod, the second end of the second connecting rod is hinged to the first end of the latch, the latch seat is set in a fixed position, a socket is set in the latch seat, the latch is used to be inserted from the first end of the socket to form a latch fit with the latch seat, and the linear proximity sensor is installed close to the second end of the socket.

[0015] Handle mechanism; the handle mechanism is placed between the 1# latch mechanism and the 2# latch mechanism, the handle mechanism includes an inner handle, a spindle, a handle mounting seat, a rocker arm, and an outer handle, the inner handle is arranged in parallel with the outer handle, the spindle is rotatably mounted on the handle mounting seat, the bottom of the handle mounting seat is installed in a fixed position, the rocker arm is formed into a triangle, one end of the inner handle, the first end of the rocker arm, and one end of the outer handle are respectively mounted on the first end, the middle, and the second end of the spindle, two limit blocks are radially installed on the side wall of the spindle, and a stop block is correspondingly arranged on the handle mounting seat, and the upper limit block and the stop block are placed on the same length in the axial direction of the spindle. degree position, the second end and the third end of the rocker arm are hinged to the second ends of the two pull rods respectively; when the 1# latch mechanism and the 2# latch mechanism are in a locked state, the first connecting rod structure composed of the first hinge seat, the first connecting rod, the second connecting rod, the latch and the pull rod, and the second connecting rod structure composed of the pull rod and the handle mechanism are all at the dead point, at which time a limit block contacts the first end of the block; when the 1# latch mechanism and the 2# latch mechanism are unlocked, the rocker arm is rotated, the first connecting rod structure and the second connecting rod structure both pass the dead point, and finally the other limit block contacts the second end of the block, and the 1# latch mechanism and the 2# latch mechanism are unlocked.

[0016] The beneficial effects of the present invention are: 1. The double dead-point self-locking design of the latch mechanism and the handle mechanism is adopted to ensure that it is not easy to open under the action of external force in an overload or vibration environment, and the unlocking is convenient and quick; 2. Use linear proximity sensors to directly monitor the state of the latch to ensure that the locking state signal is true and reliable; 3. Adopt double-pin parallel design and monitor the status of each pin to ensure safe locking. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of this application; Figure 2 This is a schematic diagram of the partial structure of the handle mechanism in this application Figure 1 ; Figure 3 This is a schematic diagram of the partial structure of the handle mechanism in this application Figure 2 ; Figure 4 It is a partial structural schematic diagram of the latch mechanism in this application; Figure 5 It is a schematic diagram of the structure of the pull rod in this application.

[0018] Legend: 1—1# latch mechanism; 2—1# pull rod; 3—handle mechanism; 4—2# pull rod; 5—2# latch mechanism; 6—inner handle; 7—spindle; 8—handle mounting seat; 81—block; 9—limit block; 10—outer handle; 11—rocker arm; 111—first connecting hole; 112—second connecting hole; 113—third connecting hole; 12—linear proximity sensor; 13—sensor mounting seat; 14—latch seat; 15—latch; 16—bushing; 17—latch mounting seat; 18—latch adjustment rod; 19—latch locking nut; 20—1# connecting joint; 21—1# joint locking nut; 22—hollow connecting rod; 23—2# joint locking nut; 24—2# connecting joint; 25—first hinge seat; 26—first connecting rod; 27—second connecting rod; 28—second hinge seat; 29—spring rod. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0023] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0026] like Figure 1-4 As shown, a door latch mechanism for a manned centrifuge comprises: 1# latch mechanism 1; 1# tie rod 2, 2# tie rod 4; 2# latch mechanism 5; 1# latch mechanism 1 and 2# latch mechanism 5 have the same structure, both including a first hinge seat 25, a first connecting rod 26, a second connecting rod 27, a latch 15, a latch seat 14, and a linear proximity sensor 12; the first end of the first hinge seat 25 is installed in a fixed position, the first end of the first connecting rod 26 is hinged to the second end of the first hinge seat 25, the second end of the first connecting rod 26 is respectively hinged to the first end of a pull rod (1# pull rod 2 or 2# pull rod 4) and the first end of the second connecting rod 27, the second end of the second connecting rod 27 is hinged to the first end of the latch 15, the latch seat 14 is fixed in a position, a socket is provided in the latch seat 14, the latch 15 is used to be inserted from the first end of the socket to form a latch fit with the latch seat 14, and the linear proximity sensor 12 is installed near the second end of the socket.

[0027] The handle mechanism 3 is placed between the 1# latch mechanism 1 and the 2# latch mechanism 5. The handle mechanism 3 includes an inner handle 6, a spindle 7, a handle mounting seat 8, a rocker arm 11, and an outer handle 10. The inner handle 6 is arranged in parallel with the outer handle 10. The spindle 7 is rotatably mounted on the handle mounting seat 8. The bottom of the handle mounting seat 8 is fixedly mounted. The rocker arm 11 is formed into a triangle. One end of the inner handle 6, the first end of the rocker arm 11, and one end of the outer handle 10 are respectively mounted on the first end of the spindle 7. , middle, and second ends, two limit blocks 9 are radially installed on the side wall of the spindle 7, and a stop block 81 is correspondingly arranged on the handle mounting seat 8. The upper limit block 9 and the stop block 81 are placed at the same length position in the axial direction of the spindle 7. The second end and the third end of the rocker arm 11 are respectively hinged to the second ends of the two pull rods ((1# pull rod 2, 2# pull rod 4)) (here, in essence, a first connecting hole 111 is arranged on the second end of the rocker arm 11; a third connecting hole 113 is arranged on the third end, and the hinge is respectively and the first connecting hole 111 and the third connecting hole 113); when the 1# latch mechanism 1 and the 2# latch mechanism 5 are in the locked state (the latch 15 is inserted into the hole for a certain distance), the first hinge seat 25, the first connecting rod 26, the second connecting rod 27, the latch 15, and the pull rod form the first connecting rod 26 structure (the 1# pull rod 2 and the 2# pull rod 4 respectively form two groups of the first hinge seat 25, the first connecting rod 26, the second connecting rod 27, and the latch 15 to form two groups of the first connecting rod 26 structure), and the pull rod and the hand The second connecting rod 27 structure composed of the handle mechanism 3 (1# pull rod 2 and 2# pull rod 4 respectively form two groups of second connecting rod 27 structures with the handle mechanism 3) are all at the dead point, at which time a limit block 9 contacts the first end of the block 81; when the 1# latch mechanism 1 and the 2# latch mechanism 5 are unlocked, the rocker arm 11 is rotated, the first connecting rod 26 structure and the second connecting rod 27 structure both pass the dead point, and finally the other limit block 9 contacts the second end of the block 81, and the 1# latch mechanism 1 and the 2# latch mechanism 5 are unlocked.

[0028] In some embodiments, Figure 1-3 As shown, the handle mechanism 3 also includes a second hinge seat 28 and a spring rod 29. The second hinge seat 28 is placed above the rocker arm 11, and the top of the second hinge seat 28 is fixed. The upper end of the spring rod 29 is hinged to the second hinge seat 28. A connecting portion is provided between the second end and the third end of the rocker arm 11, and the lower end of the spring rod 29 is hinged to the connecting portion (here, in essence, a second connecting hole 112 is provided between the first connecting hole 111 and the third connecting hole 113, and the hinge here acts on the second connecting hole 112). The spring rod 29 is always in a compressed state. The purpose of the use of the spring rod 29 is to use the thrust of the spring rod 29 to press the rocker arm 11 tightly when the door latch mechanism is in the two positions of unlocking and unlocking, stabilize the posture of the rocker arm 11, and ensure the stability of the two states of unlocking and unlocking of the door latch mechanism.

[0029] In some embodiments, Figure 4 As shown, the 1# latch mechanism 1 and the 2# latch mechanism 5 both further include a latch mounting seat 17, the latch mounting seat 17 and the latch seat 14 are spaced apart, the latch mounting seat 17 is fixed in position, a mounting hole is provided in the latch mounting seat 17, the mounting hole is coaxially provided with the socket, and the latch 15 can be guided and moved in the mounting hole.

[0030] In some embodiments, Figure 4 As shown, both the 1# latch mechanism 1 and the 2# latch mechanism 5 further include a bushing 16, which is formed into a circular columnar structure, and the bushing 16 is installed in the mounting hole, and the latch 15 can be guided and moved in the bushing 16. A bushing 16 is designed between the latch 15 and the latch mounting seat 17, which can effectively reduce the wear of the latch 15. In the future, maintenance is mainly carried out by replacing the bushing 16, which ensures that the locking effect is not reduced and facilitates subsequent maintenance.

[0031] In some embodiments, Figure 4 As shown, both the 1# latch mechanism 1 and the 2# latch mechanism 5 further include a sensor mounting seat 13 . The sensor mounting seat 13 is mounted below the latch seat 14 , and the linear proximity sensor 12 is fixedly mounted on the sensor mounting seat 13 .

[0032] In some embodiments, Figure 4 As shown, the 1# latch mechanism 1 and the 2# latch mechanism 5 both further include a latch adjusting rod 18 and a latch locking nut 19. An inner screw hole is firstly provided on one end of the latch 15, and an outer side wall of the pin adjusting rod is provided with an outer thread. The latch locking nut 19 and the latch 15 are both threadedly matched with the latch adjusting rod 18. One end face of the latch locking nut 19 contacts with the end face of the latch 15, and the end of the latch adjusting rod 18 away from the latch 15 is hinged to the second end of the second connecting rod 27.

[0033] In some embodiments, Figure 5 As shown, the pull rod includes a 1# connection joint 20, a 1# joint locking nut 21, a hollow connecting rod 22, a 2# joint locking nut 23, and a 2# connection joint 24. A threaded through hole is axially arranged in the hollow connecting rod 22. External threads are arranged on the outer side walls of the 1# connection joint 20 and the 2# connection joint 24. The first ends of the threaded through holes of the 1# joint locking nut 21 and the hollow connecting rod 22 are threadedly matched with the 1# connection joint 20. The second ends of the threaded through holes of the 2# joint locking nut 23 and the hollow connecting rod 22 are threadedly matched with the 2# connection joint 24. One end face of the 1# joint locking nut 21 contacts the first end face of the hollow connecting rod 22, and one end face of the 2# joint locking nut 23 contacts the second end face of the hollow connecting rod 22. .

[0034] When the latch mechanism of the manned centrifuge door is in the locked state, the latch 15 is in place, and then the limit block 9 on the handle mechanism 3 contacts the handle mounting seat 8, and the latch 15 cannot move forward to ensure locking. Figure 2 and 3 shown.

[0035] according to Figure 2 and Figure 3 In the direction shown, turn the inner handle 6 or outer handle 10 of the handle mechanism 3, and unlock when the other limit block 9 contacts the other end of the block 81 of the handle mounting seat 8. During the unlocking process, both the 1# latch mechanism 1 and the 2# latch mechanism 5 need to pass the dead point, and at the same time, the connecting rod mechanism composed of the 1# pull rod 2 and the handle mechanism 3 also needs to pass the dead point, that is, the two latch mechanisms and the handle mechanism 3 are both designed to pass the dead point and self-lock. This design scheme can ensure that the latch 15 is not easily opened by mistake when it is disturbed by the outside world, and is suitable for use in overload environments to ensure the safety of pilot training in the cockpit. In addition, it can be seen from the unlocking process that it only needs to rotate the inner handle 6 or outer handle 10 of the handle mechanism 3 to unlock, without the need for unnecessary actions, which is convenient and quick. The two limit blocks 9 are symmetrically distributed relative to the axis of the spindle 7, and the two limit blocks 9 are set coaxially. When one limit block 9 contacts (blocks) one end of the stopper 81, the other limit block 9 and the other end of the stopper 81 form an angle of 60° relative to the axis of the spindle 7.

[0036] In the present application, the linear proximity sensor, sensor mounting seat, and latch seat are placed as a group on the movable part or fixed part of the door, and the remaining components are placed as another group on the fixed part or movable part of the opposite door, and the inner handle and outer handle are placed on the inner and outer sides of the cabin respectively.

[0037] The present application monitors the state of the latch 15 through the linear proximity sensor 12, outputs a switch signal, and determines that the latch 15 is locked after entering the latch seat 14 for a certain distance. The present application can solve the risk of false alarms in traditional solutions and ensure the training safety of pilots in the manned centrifuge cockpit. In addition, the present application sets monitoring points for both the 1# latch mechanism 1 and the 2# latch mechanism 5 as a safety redundancy design consideration.

[0038] The latch 15 is designed with a length adjustment structure. When adjusting, if it needs to be lengthened, the latch adjustment rod 18 should be relatively screwed out, and then the latch locking nut 19 should be tightened; if it needs to be shortened, the latch locking nut 19 should be screwed out first, and then the latch adjustment rod 18 should be screwed into the inner screw hole of the latch 15, and then the latch locking nut 19 should be tightened; the latch locking nut 19 is used to lock the position of the latch adjustment rod 18 and the latch 15; The length adjustment of the 1# pull rod 2 and the 2# pull rod 4 is consistent with the working principle of the length adjustment of the pin 15. When adjusting, if it is necessary to lengthen, the 1# connecting joint 20 / 2# connecting joint 24 should be relatively screwed out, and then the 1# joint locking nut 21 / 2# joint locking nut 23 should be tightened; if it is necessary to shorten, the 1# joint locking nut 21 / 2# joint locking nut 23 should be screwed out first, and then the 1# connecting joint 20 / 2# connecting joint 24 should be screwed into the threaded through hole of the hollow connecting rod 22, and then the 1# joint locking nut 21 / 2# joint locking nut 23 should be tightened; the 1# joint locking nut 21 / 2# joint locking nut 23 is used to lock the position of the 1# connecting joint 20 / 2# connecting joint 24 and the hollow connecting rod 22; by adjusting the length of the pull rod and the pin 15, the connection relationship requirements of the first connecting rod 26 structure and the second connecting rod 27 structure can be ensured.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A door latch mechanism for a manned centrifuge, characterized in that: include: 1# latch mechanism; Two tie rods; 2# latch mechanism; The structures of the 1# latch mechanism and the 2# latch mechanism are the same, both of which include a first hinge seat, a first connecting rod, a second connecting rod, a latch, a latch seat, and a linear proximity sensor; the first end of the first hinge seat is fixedly installed, the first end of the first connecting rod is hinged to the second end of the first hinge seat, the second end of the first connecting rod is respectively hinged to the first end of a pull rod and the first end of the second connecting rod, the second end of the second connecting rod is hinged to the first end of the latch, the latch seat is fixedly installed, a socket is provided in the latch seat, the latch is used to be inserted from the first end of the socket to form a latch lock with the latch seat, and the linear proximity sensor is installed near the second end of the socket; Handle mechanism; the handle mechanism is placed between the 1# latch mechanism and the 2# latch mechanism, the handle mechanism includes an inner handle, a spindle, a handle mounting seat, a rocker arm, and an outer handle, the inner handle is arranged in parallel with the outer handle, the spindle is rotatably mounted on the handle mounting seat, the bottom of the handle mounting seat is installed in a fixed position, the rocker arm is formed into a triangle, one end of the inner handle, the first end of the rocker arm, and one end of the outer handle are respectively mounted on the first end, the middle, and the second end of the spindle, two limit blocks are radially installed on the side wall of the spindle, and a stop block is correspondingly arranged on the handle mounting seat, and the upper limit block and the stop block are placed on the same length in the axial direction of the spindle. degree position, the second end and the third end of the rocker arm are hinged to the second ends of the two pull rods respectively; when the 1# latch mechanism and the 2# latch mechanism are in a locked state, the first connecting rod structure composed of the first hinge seat, the first connecting rod, the second connecting rod, the latch and the pull rod, and the second connecting rod structure composed of the pull rod and the handle mechanism are all at the dead point, at which time a limit block contacts the first end of the block; when the 1# latch mechanism and the 2# latch mechanism are unlocked, the rocker arm is rotated, the first connecting rod structure and the second connecting rod structure both pass the dead point, and finally the other limit block contacts the second end of the block, and the 1# latch mechanism and the 2# latch mechanism are unlocked.

2. A door latch mechanism for a centrifuge with personnel according to claim 1, characterized in that: The handle mechanism also includes a second hinge seat and a spring rod. The second hinge seat is placed above the rocker arm. The top of the second hinge seat is set in a fixed position. The upper end of the spring rod is hinged to the second hinge seat. A connecting part is set between the second end and the third end of the rocker arm. The lower end of the spring rod is hinged to the connecting part. The spring rod is always in a compressed state.

3. A door latch mechanism for a centrifuge with personnel according to claim 1, characterized in that: The 1# latch mechanism and the 2# latch mechanism both further include a latch mounting seat, the latch mounting seat and the latch seat are spaced apart, the latch mounting seat is fixed in position, a mounting hole is provided in the latch mounting seat, the mounting hole is coaxially provided with the jack, and the latch can be guided and moved in the mounting hole.

4. A door latch mechanism for a centrifuge with personnel according to claim 3, characterized in that: Both the 1# latch mechanism and the 2# latch mechanism further include a bushing, which is formed into a circular columnar structure. The bushing is installed in the installation hole, and the latch can be guided and moved in the bushing.

5. A door latch mechanism for a centrifuge with personnel according to claim 1, characterized in that: Both the 1# latch mechanism and the 2# latch mechanism also include a latch adjusting rod and a latch locking nut. An internal screw hole is firstly provided on one end of the latch, and an external thread is provided on the outer side wall of the pin adjusting rod. Both the latch locking nut and the latch are threadedly matched with the latch adjusting rod. One end face of the latch locking nut contacts the end face of the latch, and the end of the latch adjusting rod away from the latch is hinged to the second end of the second connecting rod.

6. A door latch mechanism for a centrifuge with personnel according to claim 1, characterized in that: The pull rod includes a 1# connecting joint, a 1# connecting joint locking nut, a hollow connecting rod, a 2# connecting joint locking nut, and a 2# connecting joint. A threaded through hole is axially arranged in the hollow connecting rod. External threads are arranged on the outer side walls of the 1# connecting joint and the 2# connecting joint. The first ends of the threaded through holes of the 1# connecting joint locking nut and the hollow connecting rod are threadedly matched with the 1# connecting joint. The second ends of the threaded through holes of the 2# connecting joint locking nut and the hollow connecting rod are threadedly matched with the 2# connecting joint. One end face of the 1# connecting joint locking nut contacts the first end face of the hollow connecting rod, and one end face of the 2# connecting joint locking nut contacts the second end face of the hollow connecting rod.

Images