Support self-locking device used in medical field
Technical Field
The invention belongs to the technical field of universal rotation of medical instruments, and particularly relates to a support self-locking device used in the medical field.
Background
The support with universal function and space position control in the existing medical field needs a plurality of hinges, if the support is simply realized by two-dimensional hinges, a plurality of two-dimensional hinge devices are needed, so that the structure of the support is complex and is difficult to control, the operation is troublesome, if the support is connected by a spherical hinge mode, the support can be realized by only a plurality of spherical hinges, and the spherical hinges have simple structures, convenient operation and easy control; if the spherical hinge is used in the medical field, the spherical hinge needs to be self-locked in the using process, so that the design of the self-locking spherical hinge for the bracket in the medical field is very necessary.
The invention designs a bracket self-locking device used in the medical field to solve the problems.
Disclosure of Invention
In order to solve the defects in the prior art, the invention discloses a bracket self-locking device used in the medical field, which is realized by adopting the following technical scheme.
The utility model provides a support self-lock device that medical field used which characterized in that: the hydraulic trigger comprises a first hinge rod, a second hinge rod, a piston type hydraulic cylinder, a first connecting rod, a second connecting rod, a trigger spring, a trigger rod and a trigger disc, wherein a first spherical hinge shell is arranged at one end of the first hinge rod; the first hinge rod is hinged with the second hinge rod through the matching of the first spherical hinge shell and a second spherical hinge shell on the second hinge rod; the first hinge rod and the second hinge rod form a spherical hinge structure; the upper end of the first connecting rod is fixedly arranged on the inner circular surface of the first spherical hinge shell, the lower end of the second connecting rod is fixedly arranged on the inner end surface of the second hinge rod, the upper end of the piston type hydraulic cylinder is arranged at the lower end of the first connecting rod through a cross universal joint, and the lower end of the piston type hydraulic cylinder is arranged at the upper end of the second connecting rod through a cross universal joint; when the first hinge rod swings relative to the second hinge rod, the first connecting rod arranged on the first hinge rod swings relative to the second connecting rod arranged on the second hinge rod, and the upper end and the lower end of the piston type hydraulic cylinder are respectively arranged on the first connecting rod and the second connecting rod through a cross universal joint, so that when the first hinge rod swings relative to the second hinge rod, the piston type hydraulic cylinder can swing under the action of the two cross universal joints to adapt to the swing of the first hinge rod relative to the second hinge rod; the lower end of the trigger plate is provided with a trigger inclined plane, and the trigger plate is arranged in the piston type hydraulic cylinder; the trigger rod is arranged on the piston type hydraulic cylinder, and a trigger spring is arranged between the trigger rod and the piston type hydraulic cylinder; the trigger spring has a pre-stress.
The piston type hydraulic cylinder comprises a piston cylinder, a piston rod and a piston column, wherein a second liquid hole is formed in the upper end face of the piston cylinder, a first liquid hole is formed in the lower end face of the piston cylinder, and a circular rod hole is formed in the lower end face of the piston cylinder; the lower end of the piston cylinder is arranged at the upper end of the second connecting rod through a cross universal joint; the upper end of the piston rod is arranged at the lower end of the first connecting rod through a cross universal joint, the lower end of the piston rod penetrates through the upper end face of the piston cylinder and is positioned in the piston cylinder, the piston column is fixedly arranged at the lower end of the piston rod, and the piston column is in sliding fit with the inner circular face of the piston cylinder; when the first hinge rod swings relative to the second hinge rod, the distance between the two cross universal joints for mounting the piston type hydraulic cylinder can also change; the piston type hydraulic cylinder can stretch out and draw back due to the change of the distance between the two cross universal joints, namely, the piston rod drives the piston column to slide in the piston cylinder; the piston column slides in the piston cylinder to extrude liquid in the piston cylinder, so that the liquid on the upper side and the liquid on the lower side of the piston column are communicated with each other through a second pipeline; according to the invention, the first pipeline is connected to the second pipeline, the switch valve is installed on the first pipeline, and the other end of the first pipeline is connected with the elastic liquid sac; the difference of volume change occupied by liquid on the upper side and the lower side of the piston column caused by the piston rod in the sliding process of the piston column is compensated through the expansion and contraction of the elastic liquid bag; if the passage between the elastic liquid bag and the second pipeline is closed, the piston column cannot normally slide up and down in the piston cylinder, namely the piston type hydraulic cylinder cannot stretch and retract, and the first articulated rod cannot swing relative to the second articulated rod.
The triggering plate is fixedly arranged at the lower end of the piston column; the upper end of the trigger rod penetrates through a circular rod hole formed in the piston cylinder and is positioned in the piston cylinder, and the upper end of the trigger rod is matched with a trigger inclined plane on the trigger disc; a trigger spring is arranged between one end of the trigger rod positioned outside the piston cylinder and the lower end surface of the piston cylinder; according to the invention, the first hinge rod and the second hinge rod form a spherical hinge, when the first hinge rod drives the piston rod to rotate relative to the second hinge rod, the piston rod can drive the piston column to rotate, the piston column rotates to drive the trigger plate arranged on the piston column to rotate, because the lower end of the trigger plate is provided with the trigger inclined plane, when the trigger plate rotates, the contact position of the trigger inclined plane on the trigger plate and the upper end of the trigger rod can be changed, in this state, the trigger rod can slide up and down relative to the piston cylinder under the action of the trigger spring, namely, the length of the trigger rod in the piston cylinder is changed, so that the volume occupied by liquid in the space below the piston column in the piston cylinder is changed, and the difference of the volume occupied by the liquid on the upper side and the lower side of the piston column in the sliding process of the piston column is compensated by the expansion and contraction of the; when the channel between elastic liquid bag and the second pipeline is in the closed condition, the liquid that is located piston column upper and lower both sides in the piston cylinder can not carry out the equivalent circulation, triggers the dish promptly and can not rotate, and piston column, piston rod and first articulated rod can not normally rotate relative second articulated rod.
A sliding sealing device is arranged between the piston rod and the piston cylinder, a sliding sealing device is arranged between the piston column and the piston cylinder, and a sliding sealing device is arranged between the trigger rod and the piston cylinder.
The upper end of the second pipeline is fixedly arranged in a second liquid hole formed in the piston cylinder, the lower end of the second pipeline is fixedly arranged in a first liquid hole formed in the piston cylinder, one end of the first pipeline is connected with the second pipeline, and the other end of the first pipeline penetrates through a circular hole formed in the second hinge rod and is positioned outside the second hinge rod; one end of the first pipeline, which penetrates through the second hinged rod, is connected with an elastic liquid bag; the first pipeline is provided with a switch valve; the switch valve is used for controlling the communication state of the second pipeline and the elastic liquid sac, closing a channel between the second pipeline and the elastic liquid sac, opening the switch valve and opening the channel between the second pipeline and the elastic liquid sac.
The invention reduces the degree of freedom of the piston type hydraulic cylinder in the swinging process through the cross universal joints, and the piston type hydraulic cylinder can not rotate automatically under the action of the two cross universal joints, thereby improving the self-locking efficiency of the device.
As a further improvement of the technology, a shaft sleeve is fixedly arranged on the upper end surface of the piston cylinder, and two first sealing rings which are distributed up and down are arranged between the shaft sleeve and the piston rod; the first sealing ring has the function of sealing the sliding of the piston rod and the piston cylinder.
As a further improvement of the technology, two second sealing rings which are distributed up and down are arranged between the piston column and the inner circular surface of the piston cylinder; the second sealing ring plays a sealing role for the piston column and the piston cylinder.
As a further improvement of the present technology, the cross universal joint comprises a first articulated shaft, an articulated block, a first articulated head, a second articulated head and a second articulated shaft, wherein two first articulated shafts are symmetrically installed on two symmetrically distributed side surfaces on the articulated block, and two second articulated shafts are symmetrically installed on the other two symmetrically distributed side surfaces on the articulated block; have the journal stirrup of two symmetric distributions on the first articulated head, first articulated head is installed on articulated piece through the cooperation of two journal stirrups and two second articulated shafts, has the journal stirrup of two symmetric distributions on the second articulated head, and the second articulated head is installed on articulated piece through the cooperation of two journal stirrups and two first articulated shafts.
As a further improvement of the technology, the lower end of the piston cylinder is provided with a third connecting rod, the lower end of the third connecting rod is provided with a cross universal joint, and the piston cylinder is arranged on the second connecting rod through the cross universal joint arranged on the third connecting rod; make the cross universal joint who connects piston cylinder and second connecting rod to be located the downside of trigger bar through the third connecting rod, prevent that piston hydraulic cylinder from taking place to interfere with the trigger bar at the swing in-process.
As a further improvement of the technology, two third sealing rings which are distributed up and down are arranged between the trigger rod and a circular rod hole formed on the piston cylinder; the third sealing ring plays a sealing role in the trigger rod and the piston cylinder.
As a further improvement of the technology, the lower end of the trigger rod is fixedly provided with a mounting plate, the lower end of the trigger spring is fixedly arranged on the mounting plate, and the upper end of the trigger spring is fixedly arranged on the lower end face of the piston cylinder.
As a further improvement of the technology, the trigger spring is an extension spring, the trigger spring has pre-pressure, and the trigger spring has tension on the trigger rod, so that the upper end of the trigger rod is always in contact with the trigger inclined plane on the trigger disk; if the piston column slides relative to the piston cylinder, the piston column drives the trigger plate to slide relative to the piston cylinder, and the upper end of the trigger rod is always kept in contact with the trigger inclined plane on the trigger plate under the tension of the trigger spring in the sliding process of the trigger plate.
As a further improvement of the present technology, the second pipe is a hard pipe; the spatial arrangement of the hard pipe ensures that the piston cylinder cannot interfere with the second pipeline in the swinging process.
As a further improvement of the technology, the trigger plate is mounted on the lower end of the piston post by welding.
Compared with the traditional universal rotation technology of medical instruments, the universal rotation technology has the following beneficial effects:
1. the universal joint device has all functions of a spherical hinge, and compared with two-dimensional hinge, the universal joint device is simple in structure, convenient to operate and easy to control.
2. Compared with the traditional spherical hinge, the device can control the relative swing and rotation between the first hinge rod and the second hinge rod by controlling the switch valve between the second pipeline and the elastic liquid bag; so that the first hinge rod and the second hinge rod achieve the self-locking function.
3. If be applied to the support of medical field with the device, compare in traditional support through two-dimentional articulated and universal articulated cooperation use, this support operation gets up simpler, and easy control has improved staff's work efficiency.
4. According to the device designed by the invention, the same elastic liquid sac can be used for a plurality of piston type hydraulic cylinders, namely, the self-locking of a plurality of hinge points can be controlled simultaneously by controlling the switch of one liquid sac.
Drawings
Fig. 1 is an external view of an entire part.
Fig. 2 is a schematic view of the overall component distribution.
Fig. 3 is a schematic view of the internal structural distribution of the whole component.
Fig. 4 is a schematic view of the internal structure installation of the integral component.
Fig. 5 is a schematic view of the first and second hinge rods in cooperation.
FIG. 6 is a schematic cross-gimbal layout.
Fig. 7 is a schematic view of a cross-shaped gimbal structure.
Fig. 8 is a schematic view of the connection of the first pipe and the second pipe.
Fig. 9 is a schematic view of a piston cylinder structure.
Fig. 10 is a schematic view of the trigger plate mounting.
Fig. 11 is a schematic view of the trigger plate structure.
Fig. 12 is a schematic view of a piston cylinder structure.
Fig. 13 is a schematic view of the third seal ring installation.
Fig. 14 is a schematic view of the trigger spring installation.
Fig. 15 is a schematic view of the switch valve installation.
Number designation in the figures: 1. a first hinge lever; 2. a second hinge lever; 3. a first conduit; 4. a piston type hydraulic cylinder; 5. a cross universal joint; 6. a circular hole; 7. a first spherical hinge housing; 8. a second spherical hinge housing; 9. a first connecting rod; 10. a second connecting rod; 11. a piston cylinder; 12. a piston rod; 13. a first hinge shaft; 14. a hinged block; 15. a first hinge joint; 16. a second hinge joint; 17. a second hinge shaft; 18. a second conduit; 19. a piston post; 20. a first liquid hole; 21. a second liquid hole; 22. a first seal ring; 23. a shaft sleeve; 24. a trigger spring; 25. a trigger lever; 26. a third connecting rod; 27. a trigger plate; 28. a circular rod bore; 29. a second seal ring; 30. a third seal ring; 31. mounting a disc; 32. triggering the inclined plane; 33. an on-off valve; 34. an elastic liquid sac.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples or figures are illustrative of the present invention and are not intended to limit the scope of the present invention.
As shown in fig. 1 and 2, the hydraulic trigger comprises a first hinge rod 1, a second hinge rod 2, a piston type hydraulic cylinder 4, a first connecting rod 9, a second connecting rod 10, a trigger spring 24, a trigger rod 25 and a trigger disk 27, wherein as shown in fig. 5, one end of the first hinge rod 1 is provided with a first spherical hinge shell 7, the second hinge rod 2 is hollow, one end of the second hinge rod 2 is provided with a second spherical hinge shell 8, and a circular hole 6 is formed on the outer circumferential surface of the second hinge rod 2; the first hinge rod 1 is hinged with the second hinge rod 2 through the matching of a first spherical hinge shell 7 and a second spherical hinge shell 8 on the second hinge rod 2; the first hinge rod 1 and the second hinge rod 2 form a spherical hinge structure; as shown in fig. 3 and 6, the upper end of the first connecting rod 9 is fixedly installed on the inner circumferential surface of the first spherical hinge housing 7, as shown in fig. 4 and 6, the lower end of the second connecting rod 10 is fixedly installed on the inner end surface of the second hinge rod 2, as shown in fig. 3 and 4, the upper end of the piston type hydraulic cylinder 4 is installed on the lower end of the first connecting rod 9 through a universal joint 5, and the lower end of the piston type hydraulic cylinder 4 is installed on the upper end of the second connecting rod 10 through a universal joint 5; when the first hinge rod 1 swings relative to the second hinge rod 2, the first connecting rod 9 arranged on the first hinge rod 1 swings relative to the second connecting rod arranged on the second hinge rod 2, and the upper end and the lower end of the piston type hydraulic cylinder 4 are respectively arranged on the first connecting rod 9 and the second connecting rod 10 through a cross universal joint 5, so that when the first hinge rod 1 swings relative to the second hinge rod 2, the piston type hydraulic cylinder 4 swings under the action of the two cross universal joints 5 to adapt to the swing of the first hinge rod 1 relative to the second hinge rod 2; as shown in fig. 11, the lower end of the trigger plate 27 has a trigger slope 32, and as shown in fig. 9 and 10, the trigger plate 27 is installed in the piston cylinder 4; as shown in fig. 9, the trigger lever 25 is mounted on the piston cylinder 4, and the trigger spring 24 is mounted between the trigger lever 25 and the piston cylinder 4; the trigger spring 24 has a pre-stress.
As shown in fig. 9, the piston-type hydraulic cylinder 4 includes a piston cylinder 11, a piston rod 12, and a piston column 19, wherein as shown in fig. 12, a second fluid hole 21 is formed on an upper end surface of the piston cylinder 11, a first fluid hole 20 is formed on a lower end surface of the piston cylinder 11, and a circular rod hole 28 is formed on a lower end surface of the piston cylinder 11; as shown in fig. 6, the lower end of the piston cylinder 11 is mounted on the upper end of the second connecting rod through a cross universal joint 5; the upper end of the piston rod 12 is mounted at the lower end of the first connecting rod through a cross universal joint 5, as shown in fig. 9, the lower end of the piston rod 12 passes through the upper end surface of the piston cylinder 11 and is positioned in the piston cylinder 11, the piston column 19 is fixedly mounted at the lower end of the piston rod 12, and the piston column 19 is in sliding fit with the inner circular surface of the piston cylinder 11; when the first articulated rod 1 swings relative to the second articulated rod 2, the distance between the two cross universal joints 5 for installing the piston type hydraulic cylinder 4 also changes; the piston type hydraulic cylinder 4 can be stretched due to the change of the distance between the two cross universal joints 5, namely, the piston rod 12 drives the piston column 19 to slide in the piston cylinder 11; the piston column 19 slides in the piston cylinder 11 to press the liquid in the piston cylinder 11, so that the liquid on the upper side and the lower side of the piston column 19 are communicated with each other through the second pipeline 18; according to the design of the invention, as shown in fig. 8, the first pipeline 3 is connected to the second pipeline 18, the switch valve 33 is installed on the first pipeline 3, the other end of the first pipeline 3 is connected with the elastic liquid bag 34, when the piston column 19 moves up and down, the volume occupied by the liquid on the upper side and the lower side of the piston column 19 is different due to the existence of the piston rod 12, in this case, the liquid on the upper side and the lower side of the piston column 19 cannot flow in equal quantity in the process that the piston column 19 slides relative to the piston cylinder 11, so the elastic liquid bag 34 is connected to the second pipeline 18 which is connected with the upper end and the lower end of the piston cylinder 11 through the first pipeline 3, and redundant liquid flows into the elastic liquid bag 34 through the first pipeline 3 or the liquid in the elastic liquid bag 34 flows into the piston cylinder 11; the difference of volume change occupied by liquid at the upper side and the lower side of the piston column 19 caused by the piston rod 12 in the sliding process of the piston column 19 is compensated by the expansion and contraction of the elastic liquid bag 34; if the passage between the elastic fluid bladder 34 and the second conduit 18 is closed, the piston rod 19 cannot normally slide up and down in the piston cylinder 11, i.e. the piston cylinder 4 cannot telescope and the first articulation rod 1 cannot pivot relative to the second articulation rod 2.
As shown in fig. 10, the trigger plate 27 is fixedly mounted on the lower end of the piston post 19; as shown in fig. 9, the upper end of the trigger rod 25 is located in the piston cylinder 11 through a circular rod hole 28 formed in the piston cylinder 11, and the upper end of the trigger rod 25 is engaged with a trigger slope 32 on the trigger plate 27; a trigger spring 24 is arranged between one end of the trigger rod 25 positioned outside the piston cylinder 11 and the lower end surface of the piston cylinder 11; because the first hinge rod 1 and the second hinge rod 2 form a spherical hinge, when the first hinge rod 1 drives the piston rod 12 to rotate relative to the second hinge rod 2, the piston rod 12 will drive the piston post 19 to rotate, the piston post 19 will drive the trigger plate 27 mounted thereon to rotate, because the lower end of the trigger plate 27 is provided with the trigger inclined plane 32, when the trigger plate 27 rotates, the contact position between the trigger inclined plane 32 on the trigger plate 27 and the upper end of the trigger rod 25 will change, in this state, under the action of the trigger spring 24, the trigger rod 25 will slide up and down relative to the piston cylinder 11, that is, the length of the trigger rod 25 in the piston cylinder 11 will change, so that the occupied volume of the liquid in the space of the piston post 19 at the lower side of the piston cylinder 11 will change, and the expansion and contraction of the elastic liquid bag 34 will compensate the sliding process of the piston post 19, the volume occupied by the liquid on the upper side and the lower side of the piston column 19 is different; when the passage between the elastic liquid bag 34 and the second pipe 18 is in a closed state, the liquid in the piston cylinder 11 on the upper and lower sides of the piston column 19 cannot flow equally, i.e. the trigger plate 27 cannot rotate, and the piston column 19, the piston rod 12 and the first hinge rod 1 cannot normally rotate relative to the second hinge rod 2.
A sliding seal device is arranged between the piston rod 12 and the piston cylinder 11, a sliding seal device is arranged between the piston column 19 and the piston cylinder 11, a sliding seal device is arranged between the trigger rod 25 and the piston cylinder 11, in order to have a better sliding seal effect, a sliding sleeve can be arranged on the piston rod, and a seal structure is added between the sliding sleeve and the trigger rod, like the sliding seal of the shaft sleeve 23 and the piston rod.
As shown in fig. 4 and 8, the upper end of the second pipe 18 is fixedly installed in the second liquid hole 21 formed in the piston cylinder 11, the lower end of the second pipe 18 is fixedly installed in the first liquid hole 20 formed in the piston cylinder 11, one end of the first pipe 3 is connected with the second pipe 18, and the other end of the first pipe 3 passes through the circular hole 6 formed in the second hinge rod 2 and is positioned outside the second hinge rod 2; as shown in fig. 15, an elastic sac 34 is connected to one end of the first tube 3 passing through the second hinge lever 2; the first pipeline 3 is provided with a switch valve 33; the switching valve 33 is used for controlling the communication state of the second pipeline 18 and the elastic liquid bag 34, closing the switching valve 33, closing the channel between the second pipeline 18 and the elastic liquid bag 34, opening the switching valve 33, and opening the channel between the second pipeline 18 and the elastic liquid bag 34.
The degree of freedom of the piston type hydraulic cylinder 4 in the swinging process is reduced through the cross universal joints 5, the piston type hydraulic cylinder 4 cannot rotate automatically under the action of the two cross universal joints 5, and the self-locking efficiency of the device is improved.
As shown in fig. 12, a shaft sleeve 23 is fixedly mounted on the upper end surface of the piston cylinder 11, and two first sealing rings 22 which are distributed up and down are mounted between the shaft sleeve 23 and the piston rod 12; the first seal ring 22 functions to seal the sliding movement of the piston rod 12 and the piston cylinder 11.
As shown in fig. 9 and 10, two second sealing rings 29 are installed between the piston column 19 and the inner circumferential surface of the piston cylinder 11; the second sealing ring 29 seals the piston rod 19 and the piston cylinder 11.
As shown in fig. 7, the universal joint 5 includes a first hinge shaft 13, a hinge block 14, a first hinge joint 15, a second hinge joint 16, and a second hinge shaft 17, wherein two first hinge shafts 13 are symmetrically installed on two symmetrically distributed side surfaces of the hinge block 14, and two second hinge shafts 17 are symmetrically installed on the other two symmetrically distributed side surfaces of the hinge block 14; the first hinge joint 15 is provided with two symmetrically distributed support lugs, the first hinge joint 15 is arranged on the hinge block 14 through the matching of the two support lugs and the two second hinge shafts 17, the second hinge joint 16 is provided with two symmetrically distributed support lugs, and the second hinge joint 16 is arranged on the hinge block 14 through the matching of the two support lugs and the two first hinge shafts 13.
As shown in fig. 6, the lower end of the piston cylinder 11 is provided with a third connecting rod 26, the lower end of the third connecting rod 26 is provided with a universal joint cross 5, and the piston cylinder 11 is arranged on the second connecting rod 10 through the universal joint cross 5 arranged on the third connecting rod 26; the cross universal joint 5 connecting the piston cylinder 11 and the second connecting rod 10 is located at the lower side of the trigger rod 25 by the third connecting rod 26, and the piston cylinder 4 is prevented from interfering with the trigger rod 25 during the swing.
As shown in fig. 13, two third sealing rings 30 are installed between the trigger rod 25 and the circular rod hole 28 formed in the piston cylinder 11; the third sealing ring 30 seals the trigger rod 25 and the piston cylinder 11.
As shown in fig. 14, a mounting plate 31 is fixedly mounted on a lower end of the trigger rod 25, a lower end of the trigger spring 24 is fixedly mounted on the mounting plate 31, and an upper end of the trigger spring 24 is fixedly mounted on a lower end surface of the piston cylinder 11.
The trigger spring 24 is an extension spring, the trigger spring 24 has pre-pressure, and the trigger spring 24 has tension on the trigger rod 25, so that the upper end of the trigger rod 25 is always in contact with the trigger inclined plane 32 on the trigger disk 27; if the piston column 19 slides relative to the piston cylinder 11, the piston column 19 drives the trigger plate 27 to slide relative to the piston cylinder 11, and the upper end of the trigger rod 25 is always kept in contact with the trigger inclined surface 32 on the trigger plate 27 under the pulling force of the trigger spring 24 during the sliding process of the trigger plate 27, namely the trigger rod 25 slides relative to the piston cylinder 11.
The second conduit 18 is a rigid pipe; the spatial position of the rigid tube ensures that the piston cylinder 11 does not interfere with the second conduit 18 during oscillation. The first conduit is a hose.
The trigger plate 27 is attached to the lower end of the piston post 19 by welding.
The sliding sealing device can be realized by other prior arts to realize sealing.
The specific working process is as follows: when the support self-locking device designed by the invention is used, the first hinge rod 1 is controlled to swing relative to the second hinge rod 2 when the angle is required to be adjusted, and when the first hinge rod 1 swings relative to the second hinge rod 2, the distance between two cross universal joints 5 for mounting the piston type hydraulic cylinder 4 can also be changed; the piston type hydraulic cylinder 4 can be stretched due to the change of the distance between the two cross universal joints 5, namely, the piston rod 12 drives the piston column 19 to slide in the piston cylinder 11; the piston column 19 slides in the piston cylinder 11 to extrude the liquid in the piston cylinder 11, so that the liquid on the upper side and the lower side of the piston column 19 mutually circulates through the second pipeline 18, and the expansion and contraction of the elastic liquid bag 34 compensate for the difference of volume change occupied by the liquid on the upper side and the lower side of the piston column 19 caused by the piston rod 12 in the sliding process of the piston column 19; when the first hinge rod 1 drives the piston rod 12 to rotate relative to the second hinge rod 2, the piston rod 12 drives the piston column 19 to rotate, the piston column 19 rotates to drive the trigger plate 27 mounted on the piston column to rotate, because the lower end of the trigger plate 27 is provided with the trigger inclined plane 32, when the trigger plate 27 rotates, the contact position between the trigger inclined plane 32 on the trigger plate 27 and the upper end of the trigger rod 25 changes, in this state, under the action of the trigger spring 24, the trigger rod 25 slides up and down relative to the piston cylinder 11, that is, the length of the trigger rod 25 in the piston cylinder 11 changes, so that the volume occupied by the liquid in the space below the piston column 19 in the piston cylinder 11 changes, and the difference of the volume occupied by the liquid on the upper side and the lower side of the piston column 19 in the sliding process of the piston column 19 is compensated by the expansion and contraction of the elastic liquid bag 34; after the adjustment is completed, the on-off valve 33 installed on the first pipeline 3 is controlled to be closed, in this state, liquid on the upper side and the lower side of the piston column 19 in the piston cylinder 11 cannot normally circulate, the piston column 19 cannot normally slide up and down in the piston cylinder 11, that is, the piston type hydraulic cylinder 4 cannot stretch out and draw back, the first hinge rod 1 cannot swing relative to the second hinge rod 2, meanwhile, the trigger rod 25 cannot normally slide in the piston cylinder 11, the piston column 19 cannot normally rotate, that is, the trigger disc 27 cannot rotate, the piston column 19, the piston rod 12 and the first hinge rod 1 cannot normally rotate relative to the second hinge rod 2, that is, the first hinge rod 1 is locked relative to the second hinge rod 2 in the swinging and rotating directions, and the device achieves a self-locking function.
In summary, the following steps: the universal joint device designed by the invention has all functions of a spherical hinge, and compared with two-dimensional hinge, the universal joint device has the advantages of simple structure, convenience in operation and easiness in control; compared with the traditional spherical hinge, the device can control the relative swinging and rotation between the first hinge rod 1 and the second hinge rod 2 by controlling the switch valve 33 between the second pipeline 18 and the elastic liquid bag 34; the first hinge rod 1 and the second hinge rod 2 achieve the self-locking function; if the device is applied to a bracket in the medical field, compared with the traditional bracket which is used by matching two-dimensional hinge joint and universal hinge joint, the bracket is simpler to operate and easy to control, and the working efficiency of workers is improved; according to the device designed by the invention, the same elastic liquid sac 34 can be used for a plurality of piston type hydraulic cylinders 4, namely, the self-locking of a plurality of hinge points can be controlled simultaneously by controlling the switch of one liquid sac.