Double-arm grabbing mechanism with fixed-length locking function

Abstract

The invention provides a double-arm grabbing mechanism with a fixed-length locking function, and belongs to the field of mechanical design. Comprising a hollow piston rod hydraulic cylinder, a connecting oil way, a right arm movable pulley trolley, a single-action hydraulic cylinder, a chain pulley transmission mechanism, a left arm movable pulley trolley, a two-way single-rod hydraulic cylinder set, a guide device, a fixed-length rod, a left grabbing mechanical arm, a right grabbing mechanical arm and a machine body shell. A hollow piston rod hydraulic cylinder, a connecting oil way, a right arm movable pulley trolley, a single-action hydraulic cylinder, a chain pulley transmission mechanism, a left arm movable pulley trolley, a two-way single-rod hydraulic cylinder set, a guide device and a fixed-length rod are arranged in the machine body shell, and the upper portion of the left grabbing mechanical arm and the upper portion of the right grabbing mechanical arm are arranged in the machine body shell. The lower portions of the left grabbing mechanical arm and the right grabbing mechanical arm extend out of the machine body shell. By means of the fixed-length rod mechanical locking mechanism and principle, the fixed-length locking function of double-arm grabbing is achieved, and the reliability and safety of equipment are improved.

Description

Technical Field

[0001] The invention relates to the field of mechanical design, and in particular to a double-arm grabbing mechanism with a fixed-length locking function. Background Art

[0002] Nowadays, engineering robots are widely used in various fields. In order to ensure the safety and normal use of such equipment, many devices are equipped with corresponding locking functions. The locking function refers to the limiting function of the locking device on the actuator in the system. The locking device must not only keep the mechanism locked in a certain position, but also ensure that it has reliable strength and rigidity. In the process of engineering use, it is usually required that the locking device can stably withstand external loads for a long time without any displacement when the movement stops, that is, it is required to have a locking and positioning function without "soft leg" phenomenon. In some special fields, such as aviation and military fields, the actuator has high position accuracy when working, and it is required to have no displacement changes for a long time under load, and more reliable safety is also required.

[0003] The hydraulic cylinder in a general engineering hydraulic system is kept at any position and bears a certain load force by using a hydraulic locking circuit. When a hydraulic locking circuit is used, once the hydraulic pipeline is damaged, the locking will fail and internal leakage of the hydraulic valve is inevitable. This puts higher requirements on the matching locking device.

[0004] Therefore, under the condition of long-term load, the existing hydraulic locking circuit has the defect of inevitable leakage in the hydraulic valve, which causes the piston to slip, the locking to fail, and the system to be unstable. Summary of the invention

[0005] The purpose of the present invention is to provide a double-arm grabbing mechanism with a fixed-length locking function, which realizes the fixed-length locking function of the double-arm grabbing through the fixed-length rod mechanical locking mechanism and principle. The locking device thereon realizes the reliable mechanical locking of the grabbing mechanism, improves the reliability and safety of the equipment, and solves the safety hazard caused by the leakage of the hydraulic valve of the original hydraulic locking circuit.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A double-arm grabbing mechanism with a fixed-length locking function, characterized in that:

[0008] It includes a hollow piston rod hydraulic cylinder, a connecting oil circuit, a right arm movable pulley trolley, a single-acting hydraulic cylinder, a first chain pulley transmission mechanism, a left arm movable pulley trolley, a two-way single-rod hydraulic cylinder group, a guide device, a fixed-length rod, a left grabbing mechanical arm, a right grabbing mechanical arm, a body shell and a second chain pulley transmission mechanism. The body shell is internally provided with a hollow piston rod hydraulic cylinder, a connecting oil circuit, a right arm movable pulley trolley, a single-acting hydraulic cylinder, a first chain pulley transmission mechanism, a left arm movable pulley trolley, a two-way single-rod hydraulic cylinder group, a guide device, a fixed-length rod and a second chain pulley transmission mechanism. The upper parts of the left grabbing mechanical arm and the right grabbing mechanical arm are arranged inside the body shell, and the lower parts of the left grabbing mechanical arm and the right grabbing mechanical arm extend out of the body shell.

[0009] The hollow piston rod hydraulic cylinder and the two-way single-rod hydraulic cylinder group are connected in parallel, and the hollow piston rod hydraulic cylinder and the two-way single-rod hydraulic cylinder group are both connected to one side of the right arm movable pulley trolley, and the other side of the right arm movable pulley trolley is connected to the right grabbing mechanical arm through a first chain pulley transmission mechanism, the fixed-length rod is arranged at the lower end of the two-way single-rod hydraulic cylinder group, and the guide device is sleeved on the outside of the fixed-length rod, the two-way single-rod hydraulic cylinder group and the left end of the fixed-length rod are both connected to one side of the left arm movable pulley trolley, and the other side of the left arm movable pulley trolley is connected to the left grabbing mechanical arm through a second chain pulley transmission mechanism.

[0010] A single-acting hydraulic cylinder as a hydraulic actuator is arranged inside the right arm movable pulley trolley, and a hole is opened in the right arm movable pulley trolley toward the movement direction of the single-acting hydraulic cylinder piston. The single-acting hydraulic cylinder can be extended to the outside of the right arm movable pulley trolley when the locking head is extended. The single-acting hydraulic cylinder is connected to the hollow piston rod hydraulic cylinder through the connecting oil circuit inside the right arm movable pulley trolley, and a locking groove is arranged on the right end of the fixed-length rod, and the locking groove can cooperate with the locking head of the single-acting hydraulic cylinder for locking.

[0011] Furthermore, the hollow piston rod hydraulic cylinder includes a first cylinder bottom, a cylinder head, a cylinder barrel, a cylinder cover, a guide sleeve, a through oil pipe and a hollow piston rod, the first cylinder bottom is arranged on one side of the hollow piston rod hydraulic cylinder, the cylinder head is arranged on the other side of the hollow piston rod hydraulic cylinder, the first cylinder bottom and the cylinder head are connected by a plurality of pull rods, one end of the cylinder barrel is connected to the first cylinder bottom, and the other end of the cylinder barrel is connected to the cylinder head, the hollow piston rod is arranged inside the cylinder barrel, the cylinder cover is fixed to the cylinder head by a countersunk screw, and the guide sleeve is arranged between the cylinder head and the hollow piston rod.

[0012] A first opening is provided at the center of the first cylinder bottom, and a second opening is provided at the center of the cylinder head. One end of the through oil pipe is connected to the first opening, and the other end of the through oil pipe is flush with the end surface of the second opening. The through oil pipe passes through the hollow piston rod along the axial center line of the hollow piston rod hydraulic cylinder and the hollow piston rod, and the aperture of the second opening is equal to the outer diameter of the hollow piston rod.

[0013] Furthermore, the hollow piston rod includes a first piston and a sealing device, the first piston is threaded or welded to one end of the hollow piston rod, the first piston is slidably arranged inside the cylinder, the first piston divides the cylinder into a first oil chamber and a second oil chamber, and the sealing device is arranged at the end of the first piston.

[0014] A first oil port is provided at the bottom of the first cylinder, and the first oil port connects the first oil chamber and the outside world. A second oil port connected to the outside world is provided at one end of the through oil pipe close to the bottom of the first cylinder. The through oil pipe and the internal cavity of the hollow piston rod form a through oil path structure. A third oil port is provided at the cylinder head, and the third oil port connects the second oil chamber and the outside world. A fourth oil port is provided at the other end of the hollow piston rod, and the hollow piston rod is connected to one side of the right arm movable pulley trolley.

[0015] Furthermore, the bidirectional single-rod hydraulic cylinder group includes a first single-rod hydraulic cylinder and a second single-rod hydraulic cylinder which share a second cylinder bottom, and the second cylinder bottom is connected in parallel with the first cylinder bottom.

[0016] The first single-rod hydraulic cylinder includes a first piston rod and a third piston. One end of the first piston rod extends out of the first single-rod hydraulic cylinder to the outside, and the other end of the first piston rod is arranged inside the first single-rod hydraulic cylinder. The other end of the first piston rod is connected to the third piston by threaded connection or welding. The third piston divides the internal cavity of the first single-rod hydraulic cylinder into a first rod cavity and a first rodless cavity. A sixth oil port communicating with the first rod cavity and the outside is arranged on the cylinder head of the first single-rod hydraulic cylinder, and a seventh oil port communicating with the first rodless cavity and the outside is arranged on one end of the second cylinder bottom. The first piston rod is connected to one side of the left arm movable pulley trolley.

[0017] The second single-rod hydraulic cylinder includes a second piston rod and a fourth piston. One end of the second piston rod extends out of the second single-rod hydraulic cylinder to the outside, and the other end of the second piston rod is arranged inside the second single-rod hydraulic cylinder. The other end of the second piston rod is connected to the fourth piston by threaded connection or welding. The fourth piston divides the internal cavity of the second single-rod hydraulic cylinder into a second rodless cavity and a second rod cavity. A ninth oil port communicating with the second rod cavity and the outside is arranged on the cylinder head of the second single-rod hydraulic cylinder, and an eighth oil port communicating with the second rodless cavity and the outside is arranged on the other end of the second cylinder bottom. The second piston rod is connected to one side of the right arm movable pulley trolley.

[0018] Furthermore, the base of the single-acting hydraulic cylinder is fixed in the mounting groove on the right arm movable pulley trolley by bolts, and a single output rod matching with it is installed inside the single-acting hydraulic cylinder, and a second piston is connected to the single output rod by threaded connection or welding, and a spring is arranged on the top of the second piston, and the spring is connected to the top of the inner cavity of the single-acting hydraulic cylinder.

[0019] Furthermore, the single-acting hydraulic cylinder is provided with a fifth oil port, and the fifth oil port of the single-acting hydraulic cylinder is connected to the fourth oil port of the hollow piston rod through a connecting oil circuit.

[0020] Furthermore, a plurality of threaded holes are evenly arranged at one end of the cylinder head, one end of a plurality of tie rods is connected to the cylinder head through threads, and the other end of the plurality of tie rods is connected to the first cylinder bottom through a plurality of nuts.

[0021] Furthermore, a sealing ring is provided at the connection between the cylinder barrel and the first cylinder bottom and cylinder head, a dust ring that fits with the middle piston rod is provided at the inner ring groove of the cylinder cover, a sealing ring is provided at the inner ring groove of the guide sleeve, a guide ring and a sealing ring are provided at the side ring groove of the first piston, and a sliding sealing ring that fits with the middle oil pipe is provided in the inner ring groove of the hollow piston rod.

[0022] Furthermore, connection forms of the first oil port, the second oil port, the third oil port, the fourth oil port and the fifth oil port include threaded connection, flange connection, plate connection, stacking connection and plug-in connection.

[0023] Furthermore, the outer ends of the first oil port, the second oil port, the third oil port, the fourth oil port and the fifth oil port are provided with hydraulic reversing valves or solenoid valves, and the first oil port, the second oil port, the third oil port, the fourth oil port and the fifth oil port can all be connected to the oil tank.

[0024] Advantages of the present invention:

[0025] 1. The present invention provides a double-arm grasping mechanism with a fixed-length locking function. The locking position of the fixed-length rod can be changed according to the size of the grasped object, so that the distance between the left and right grasping mechanical arms can remain unchanged, thereby achieving the purpose of locking the fixed-length object.

[0026] 2. The present invention forms a central oil circuit structure through the central oil pipe at the bottom of the cylinder and the cavity structure of the hollow piston rod, which realizes the function of oil passing through the piston rod, avoids the arrangement of external oil pipes and oil circuits, and does not affect the oil circuit of the hydraulic cylinder itself for realizing the telescopic function; at the same time, this central oil circuit structure solves the problem of hydraulic pipeline design of a mobile carrier equipped with a hydraulic system or a hydraulic actuator under the motion condition driven by the hydraulic cylinder piston rod, and optimizes the structure of such hydraulic system; the connecting oil pipe is arranged in the mobile carrier and connected to the oil outlet of the hydraulic cylinder piston rod as the connecting oil circuit with the hydraulic actuator, which also reduces the arrangement of external pipelines originally required; the mobile carrier can be connected to an external oil source when there is no oil pipe in the outside world, thereby simplifying the hydraulic system structure on the mobile carrier; reducing the quality of the hydraulic system and improving the controllability of the system.

[0027] 3. The locking function of the present invention is achieved by the cooperation between the groove of the fixed-length rod and the lock of the single-acting hydraulic cylinder. A groove is provided at the right end of the fixed-length rod, and the aperture size is the same as the diameter of the lock of the single-acting hydraulic cylinder. When the lock is extended, it is tightly matched with the groove of the fixed-length rod to achieve reliable mechanical locking. When the lock is retracted, it is unlocked. The locking / unlocking function is convenient and quick to achieve. Two guide devices are installed on both sides of the fixed-length rod, which effectively improves the running stability of the transmission device.

[0028] 4. The present invention optimizes the connection structure between different hydraulic cylinders. First, two single-rod hydraulic cylinders in different directions are connected in series to form a bidirectional single-rod hydraulic cylinder group, which realizes the reciprocating motion of the left and right grabbing mechanical arms without increasing the length of the body structure; then the hydraulic cylinder group is connected in parallel with the hollow piston rod hydraulic cylinder to meet the different requirements of the reciprocating speed and running distance of the movable pulley trolley on the left and right sides; the technology of passing oil through the rod is used to achieve the purpose of controlling the hydraulic actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a structural cross-sectional view of the present invention;

[0031] Figure 3 It is the hydraulic principle diagram of the present invention;

[0032] In the figure: 1, hollow piston rod hydraulic cylinder; 1-1, first cylinder bottom; 1-2, cylinder head; 1-3, cylinder barrel; 1-4, cylinder cover; 1-5, guide sleeve; 1-6, first oil port; 1-7, second oil port; 1-8, third oil port; 1-9, center oil pipe; 1-10, first oil chamber; 1-11, second oil chamber; 1-12, hollow piston rod; 1-13, first piston; 1-14, sealing device; 1-15, fourth oil port;

[0033] 2. Connect the oil circuit;

[0034] 3. Right arm movable pulley trolley;

[0035] 4. Single-acting hydraulic cylinder; 4-1. Fifth oil port; 4-2. Second piston;

[0036] 5. The first chain pulley transmission mechanism;

[0037] 6. Left arm movable pulley trolley;

[0038] 7. Bidirectional single-rod hydraulic cylinder group; 7-1. First piston rod; 7-2. Third piston; 7-3. Sixth oil port; 7-4. Seventh oil port; 7-5. First rod chamber; 7-6. First rodless chamber; 7-7. Second cylinder bottom; 7-8. Second piston rod; 7-9. Fourth piston; 7-10. Eighth oil port; 7-11. Ninth oil port; 7-12. Second rodless chamber; 7-13. Second rod chamber;

[0039] 8. Guide device;

[0040] 9. Fixed length rod;

[0041] 10. Left grabbing robot arm;

[0042] 11. Right grabbing robot arm;

[0043] 12. Body shell;

[0044] 13. Second chain pulley transmission mechanism. DETAILED DESCRIPTION

[0045] 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. 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. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0046] like Figure 1 As shown, a double-arm grabbing mechanism with a fixed-length locking function comprises a hollow piston rod hydraulic cylinder 1, a connecting oil circuit 2, a right arm movable pulley trolley 3, a single-acting hydraulic cylinder 4, a first chain pulley transmission mechanism 5, a left arm movable pulley trolley 6, a two-way single-rod hydraulic cylinder group 7, a guide device 8, a fixed-length rod 9, a left grabbing mechanical arm 10, a right grabbing mechanical arm 11, a body shell 12 and a second chain pulley transmission mechanism 13, wherein the body shell 12 is provided with a hollow piston rod hydraulic cylinder 1, a connecting oil circuit 2, a right arm movable pulley trolley 3, a single-acting hydraulic cylinder 4, a first chain pulley transmission mechanism 5, a left arm movable pulley trolley 6, a two-way single-rod hydraulic cylinder group 7, a guide device 8, a fixed-length rod 9 and a second chain pulley transmission mechanism 13, wherein the upper parts of the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11 are arranged inside the body shell 12, and the lower parts of the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11 extend out of the body shell 12.

[0047] The hollow piston rod hydraulic cylinder 1 and the two-way single-rod hydraulic cylinder group 7 are connected in parallel, and the hollow piston rod hydraulic cylinder 1 and the two-way single-rod hydraulic cylinder group 7 are both connected to one side of the right arm movable pulley trolley 3, and the other side of the right arm movable pulley trolley 3 is connected to the right grabbing mechanical arm 11 through the first chain pulley transmission mechanism 5, the fixed length rod 9 is arranged at the lower end of the two-way single-rod hydraulic cylinder group 7, and the guide device 8 is sleeved on the outside of the fixed length rod 9. The left ends of the two-way single-rod hydraulic cylinder group 7 and the fixed length rod 9 are both connected to one side of the left arm movable pulley trolley 6, and the fixed length rod 9 is driven by the left arm movable pulley trolley 6 and moves back and forth in the guide device 8. The other side of the left arm movable pulley trolley 6 is connected to the left grabbing mechanical arm 10 through the second chain pulley transmission mechanism 13.

[0048] The right arm movable pulley trolley 3 is internally provided with a single-acting hydraulic cylinder 4 as a hydraulic actuator, the right arm movable pulley trolley 3 has a hole facing the piston movement direction of the single-acting hydraulic cylinder 4, the single-acting hydraulic cylinder 4 can be extended outside the right arm movable pulley trolley 3 when the locking head is extended, the single-acting hydraulic cylinder 4 is connected to the hollow piston rod hydraulic cylinder 1 through the connecting oil circuit 2 inside the right arm movable pulley trolley 3, and a locking groove is provided on the right end of the fixed-length rod 9, and the locking groove can be locked with the locking head of the single-acting hydraulic cylinder 4, and the fixed-length rod 9 with the locking groove and the guide device 8 matched therewith form a moving pair.

[0049] As a preferred embodiment of the present invention, Figure 1 and Figure 2As shown, the hollow piston rod hydraulic cylinder 1 includes a first cylinder bottom 1-1, a cylinder head 1-2, a cylinder barrel 1-3, a cylinder cover 1-4, a guide sleeve 1-5, a central oil pipe 1-9 and a hollow piston rod 1-12. The first cylinder bottom 1-1 is arranged on one side of the hollow piston rod hydraulic cylinder 1, and the cylinder head 1-2 is arranged on the other side of the hollow piston rod hydraulic cylinder 1. The first cylinder bottom 1-1 and the cylinder head 1-2 are connected by a plurality of tie rods. One end of the cylinder barrel 1-3 is connected to the first cylinder bottom 1-1, and the other end of the cylinder barrel 1-3 is connected to the cylinder head 1-2. The hollow piston rod 1-12 is arranged inside the cylinder barrel 1-3. The cylinder cover 1-4 is fixed to the cylinder head 1-2 by countersunk screws, and the guide sleeve 1-5 is arranged between the cylinder head 1-2 and the hollow piston rod 1-12.

[0050] A first opening is provided at the center of the first cylinder bottom 1-1, and a second opening is provided at the center of the cylinder head 1-2. One end of the through oil pipe 1-9 is connected to the first opening, and the other end of the through oil pipe 1-9 is flush with the end surface of the second opening. The through oil pipe 1-9 passes through the hollow piston rod 1-12 along the axial center line of the hollow piston rod hydraulic cylinder 1 and the hollow piston rod 1-12, and the aperture of the second opening is equal to the outer diameter of the hollow piston rod 1-12.

[0051] As a preferred embodiment of the present invention, the hollow piston rod 1-12 includes a first piston 1-13 and a sealing device 1-14. The first piston 1-13 is threaded or welded to one end of the hollow piston rod 1-12. The first piston 1-13 is slidably arranged inside the cylinder barrel 1-3. The first piston 1-13 divides the cylinder barrel 1-3 into a first oil chamber 1-10 and a second oil chamber 1-11. The sealing device 1-14 is arranged at the end of the first piston 1-13.

[0052] The first cylinder bottom 1-1 is provided with a first oil port 1-6, which connects the first oil chamber 1-10 with the outside world. The through oil pipe 1-9 is provided with a second oil port 1-7 connected to the outside world at one end close to the first cylinder bottom 1-1. The through oil pipe 1-9 and the internal cavity of the hollow piston rod 1-12 form a through oil path structure. The cylinder head 1-2 is provided with a third oil port 1-8, which connects the second oil chamber 1-11 with the outside world. The other end of the hollow piston rod 1-12 is provided with a fourth oil port 1-15. The hollow piston rod 1-12 is connected to one side of the right arm movable pulley trolley 3.

[0053] As a preferred embodiment of the present invention, the bidirectional single-rod hydraulic cylinder group 7 includes a first single-rod hydraulic cylinder and a second single-rod hydraulic cylinder which share a second cylinder bottom 7-7, and the second cylinder bottom 7-7 is connected in parallel with the first cylinder bottom 1-1.

[0054] The first single-rod hydraulic cylinder includes a first piston rod 7-1 and a third piston 7-2. One end of the first piston rod 7-1 extends out of the first single-rod hydraulic cylinder to the outside, and the other end of the first piston rod 7-1 is arranged inside the first single-rod hydraulic cylinder. The other end of the first piston rod 7-1 is connected to the third piston 7-2 by threaded connection or welding. The third piston 7-2 divides the internal cavity of the first single-rod hydraulic cylinder into a first rod cavity 7-5 and a first rodless cavity 7-6. A sixth oil port 7-3 communicating with the first rod cavity 7-5 and the outside is arranged on the cylinder head of the first single-rod hydraulic cylinder, and a seventh oil port 7-4 communicating with the first rodless cavity 7-6 and the outside is arranged on one end of the second cylinder bottom 7-7. The first piston rod 7-1 is connected to one side of the left arm movable pulley trolley 6.

[0055] The second single-rod hydraulic cylinder includes a second piston rod 7-8 and a fourth piston 7-9. One end of the second piston rod 7-8 extends out of the second single-rod hydraulic cylinder to the outside, and the other end of the second piston rod 7-8 is arranged inside the second single-rod hydraulic cylinder. The other end of the second piston rod 7-8 is connected to the fourth piston 7-9 by threaded connection or welding. The fourth piston 7-9 divides the internal cavity of the second single-rod hydraulic cylinder into a second rodless cavity 7-12 and a second rod cavity 7-13. A ninth oil port 7-11 communicating with the second rod cavity 7-13 and the outside is provided on the cylinder head of the second single-rod hydraulic cylinder, and an eighth oil port 7-10 communicating with the second rodless cavity 7-12 and the outside is provided on the other end of the second cylinder bottom 7-7. The second piston rod 7-8 is connected to one side of the right arm movable pulley trolley 3.

[0056] As a preferred embodiment of the present invention, the base of the single-acting hydraulic cylinder 4 is fixed in the mounting groove on the right arm movable pulley trolley 3 by bolt connection, and a single output rod matching with it is installed inside the single-acting hydraulic cylinder 4, and a second piston 4-2 is connected to the single output rod by threaded connection or welding, and a spring is arranged on the top of the second piston 4-2, and the spring is connected to the top of the inner cavity of the single-acting hydraulic cylinder 4.

[0057] As a preferred embodiment of the present invention, the single-acting hydraulic cylinder 4 is provided with a fifth oil port 4-1, and the fifth oil port 4-1 of the single-acting hydraulic cylinder 4 is connected to the fourth oil port 1-15 of the hollow piston rod 1-12 through the connecting oil circuit 2.

[0058] As a preferred embodiment of the present invention, one end of the cylinder head 1-2 is evenly provided with a plurality of threaded holes, one end of a plurality of tie rods is connected to the cylinder head 1-2 through threads, and the other end of the plurality of tie rods is connected to the first cylinder bottom 1-1 through a plurality of nuts.

[0059] As a preferred embodiment of the present invention, a sealing ring is provided at the connection between the cylinder barrel 1-3 and the first cylinder bottom 1-1 and the cylinder head 1-2, a dust ring that fits with the middle piston rod 1-12 is provided at the inner ring groove of the cylinder cover 1-4, a sealing ring is provided at the inner ring groove of the guide sleeve 1-5, a guide ring and a sealing ring are provided at the side ring groove of the first piston 1-13, and a sliding sealing ring that fits with the middle oil pipe 1-9 is provided in the inner ring groove of the hollow piston rod 1-12.

[0060] As a preferred embodiment of the present invention, the connection forms of the first oil port 1-6, the second oil port 1-7, the third oil port 1-8, the fourth oil port 1-15 and the fifth oil port 4-1 include threaded connection, flange connection, plate connection, stacking connection and plug-in connection.

[0061] As a preferred embodiment of the present invention, the outer ends of the oil ports of the first oil port 1-6, the second oil port 1-7, the third oil port 1-8, the fourth oil port 1-15 and the fifth oil port 4-1 are provided with hydraulic reversing valves or solenoid valves, and the first oil port 1-6, the second oil port 1-7, the third oil port 1-8, the fourth oil port 1-15 and the fifth oil port 4-1 can all be connected to the oil tank, and hydraulic oil can be introduced into the hydraulic actuator from the outside of the hollow piston rod hydraulic cylinder 1 through the central oil pipe 1-9 and the internal cavity of the hollow piston rod 1-12.

[0062] When the hydraulic pump supplies oil, the hydraulic oil flows from the oil tank through the hydraulic pump into the central oil passage of the hollow piston rod hydraulic cylinder 1, and continues to flow through the connecting oil passage 2 to the single-acting hydraulic cylinder 4, lifting the second piston 4-2 of the single-acting hydraulic cylinder 4, causing the second piston 4-2 to shrink inward, the spring to compress, the lock head to retract, and the single-acting hydraulic cylinder 4 as a hydraulic actuator responds to the unlocking action. When the central oil passage is connected to the oil tank, the hydraulic oil flows back to the oil tank, the spring returns to its original length, pushes the second piston 4-2 to move outward, pops out the lock head, and the single-acting hydraulic cylinder 4 as a hydraulic actuator responds to the locking action.

[0063] When oil is passed into the first rodless chamber 7-6 of the first single-rod hydraulic cylinder and the second rodless chamber 7-12 of the second single-rod hydraulic cylinder, the first piston rod 7-1 and the second piston rod 7-8 are pushed to move outward, thereby pushing the left arm movable pulley trolley 6 and the right arm movable pulley trolley 3 to move to both sides, and then driving the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11 to move to both sides through the second chain pulley transmission mechanism 13 and the first chain pulley transmission mechanism 5. Since the left end of the fixed-length rod 9 is connected to the left arm movable pulley trolley 6, the left arm movable pulley trolley 6 will drive the fixed-length rod 9 to move to the left. When the distance between the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11 is about to reach the length of the object to be grasped, the hydraulic oil is stopped from being passed into the middle oil passage of the hollow piston rod hydraulic cylinder 1, and the single-acting hydraulic cylinder 4 pops out the lock head under the action of the spring to make it cooperate with the locking groove. At this time, one end of the fixed-length rod 9 is fixed to the left-arm movable pulley trolley 6, and the other end is locked by the single-acting hydraulic cylinder 4 of the right-arm movable pulley trolley 3, thereby realizing the locking function of the fixed-length rod 9.

[0064] The fixed-length rod 9 is locked, and the lengths of both ends of the rod are fixed to form a fixed-length rod. When the length of the fixed-length rod 9 is fixed, due to the mechanical connection between the left arm movable pulley trolley 6, the right arm movable pulley trolley 3, the fixed-length rod 9, the first chain pulley transmission mechanism 5, the second chain pulley transmission mechanism 13, the left grabbing mechanical arm 10, and the right grabbing mechanical arm 11, the distance between the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11 is also fixed, which can be used to complete the locking function after grabbing a fixed-length object.

[0065] like Figure 3 As shown, the main oil circuit connection mode of the present invention is:

[0066] 1) Telescopic oil circuit: After the hydraulic oil is passed through the first oil port 1-6 on the first cylinder bottom 1-1 of the hollow piston rod hydraulic cylinder 1, the hydraulic oil flows into the first oil chamber 1-10; after the hydraulic oil is passed through the third oil port 1-8 on the cylinder head 1-2 of the hollow piston rod hydraulic cylinder 1, the hydraulic oil flows into the second oil chamber 1-11.

[0067] 2) Control oil circuit: After the hydraulic oil is passed through the second oil port 1-7 on the central oil pipe 1-9, the hydraulic oil flows through the central oil pipe 1-9, flows into the cavity of the hollow piston rod 1-12, and then passes through the fourth oil port 1-15 of the hollow piston rod 1-12, passes through the connecting oil circuit 2, and then flows into the rod cavity of the single-acting hydraulic cylinder 4 through the fifth oil port 4-1 on the single-acting hydraulic cylinder 4.

[0068] The first oil port 1-6 and the third oil port 1-8, the sixth oil port 7-3 and the seventh oil port 7-4, the eighth oil port 7-10 and the ninth oil port 7-11 are respectively connected to three three-position four-way hydraulic reversing valves, each of which is controlled by two two-position four-way solenoid valves, and the second oil port 1-7 is controlled by one solenoid valve. The accumulator is connected to all the oil ports on the two-way single-rod hydraulic cylinder group 7 to control the rapid reciprocating movement of the first piston rod 7-1 and the second piston rod 7-8 to achieve the rapid movement speed requirement of grabbing the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11.

[0069] The working principle of the telescopic oil circuit of the present invention:

[0070] When the hydraulic pump passes oil into the first rodless chamber 7-6 of the bidirectional single-rod hydraulic cylinder group 7, the hydraulic oil enters the first rodless chamber 7-6 from the seventh oil port 7-4, pushing the third piston 7-2 to move outward, pushing the first piston rod 7-1 to move outward, thereby pushing the left arm movable pulley trolley 6 to move to the left, and then driving the left grabbing mechanical arm 10 to move to the left through the second chain pulley transmission mechanism 13 until the required distance is reached. At the same time, the hydraulic oil in the first rod chamber 7-5 is squeezed and flows back to the oil tank through the sixth oil port 7-3; when the hydraulic pump passes oil into the first rod chamber 7-5 of the bidirectional single-rod hydraulic cylinder group 7, the hydraulic oil enters the first rod chamber 7-5 from the sixth oil port 7-3, pushing the third piston 7-2 to move inward, driving the first piston rod 7-1 to move inward, thereby pushing the left arm movable pulley trolley 6 to move to the right, and then driving the left grabbing mechanical arm 10 to move to the left through the second chain pulley transmission mechanism 13 until the required distance is reached. At the same time, the hydraulic oil in the first rodless chamber 7-6 is squeezed and flows back to the oil tank through the seventh oil port 7-4. By controlling the extension and contraction of the first piston rod 7-1, the reciprocating motion of the left arm movable pulley trolley 6 can be controlled. Since the left end of the fixed length rod 9 is connected to the left arm movable pulley trolley 6, the left arm movable pulley trolley 6 will drive the fixed length rod 9 to move left and right along the guide device 8.

[0071] Similarly, the hydraulic oil flows from the first oil port 1-6 on the first cylinder bottom 1-1 of the hollow piston rod hydraulic cylinder 1 into the first oil chamber 1-10, lifts the first piston 1-13, pushes the hollow piston rod 1-12 to move outward, and then pushes the right arm movable pulley trolley 3 connected thereto to move to the right, and then drives the right grabbing mechanical arm 11 to move to the right through the first chain pulley transmission mechanism 5 until it reaches the required distance, and the hydraulic oil in the second oil chamber 1-11 is squeezed from the cylinder head of the hollow piston rod hydraulic cylinder 1 When the hydraulic oil flows from the third oil port 1-8 of the cylinder head 1-2 of the hollow piston rod hydraulic cylinder 1 into the second oil chamber 1-11, the first piston 1-13 of the hollow piston rod 1-12 is lifted, and the first piston 1-13 retracts inward, driving the hollow piston rod 1-12 to move inward, pulling the right arm movable pulley trolley 3 connected thereto to move to the left, and then driving the right grabbing mechanical arm 11 to move to the left through the chain pulley transmission mechanism 5 until the required distance is reached. At the same time, the hydraulic oil in the first oil chamber 1-10 is squeezed and flows back to the oil tank from the first oil port 1-6 installed on the first cylinder bottom 1-1 of the hollow piston rod hydraulic cylinder 1. By controlling the extension and retraction of the hollow piston rod 1-12, the reciprocating motion of the right arm movable pulley trolley 3 can be controlled.

[0072] When fast operation is required, the hydraulic pump pressurizes the accumulator, and the hydraulic oil quickly enters the second rodless chamber 7-12 from the eighth oil port 7-10 on the second cylinder bottom 7-7 of the two-way single-rod hydraulic cylinder group 7, lifts the fourth piston 7-9, pushes the second piston rod 7-8 to move outward, and then pushes the right arm movable pulley trolley 3 connected to it to move quickly to the right, and then drives the right grabbing mechanical arm 11 to move quickly to the right through the first chain pulley transmission mechanism 5 until it reaches the required distance, and the hydraulic oil in the second rod chamber 7-13 is squeezed out from the first The oil in the ninth oil port 7-11 flows back to the oil tank; in contrast, the hydraulic pump presses the accumulator, and the hydraulic oil quickly enters the second rod chamber 7-13 from the ninth oil port 7-11, lifts the fourth piston 7-9, drives the second piston rod 7-8 to move inward, and then pushes the right arm movable pulley trolley 3 connected thereto to move rapidly to the left, and then drives the right grabbing mechanical arm 11 to move rapidly to the left through the first chain pulley transmission mechanism 5 until it reaches the required distance, and the hydraulic oil in the second rodless chamber 7-12 is squeezed and flows back to the oil tank from the eighth oil port 7-10. The flow rate of the hydraulic oil is controlled by the accumulator, so as to meet the requirement of the rapid reciprocating movement speed of the grabbing mechanical arm.

[0073] The working principle of the oil circuit control of the present invention:

[0074] After the hydraulic oil is passed to the second oil port 1-7 of the hollow piston rod hydraulic cylinder 1, the hydraulic oil flows through the through oil pipe 1-9, enters the cavity of the hollow piston rod 1-12, enters the connecting oil circuit 2 through the fourth oil port 1-15 on the end face of the hollow piston rod 1-12, and then flows into the rod cavity of the single-acting hydraulic cylinder 4 through the fifth oil port 4-1, lifts the second piston 4-2 of the single-acting hydraulic cylinder 4, compresses the cylinder bottom spring, retracts the lock head, and completes the unlocking action; when the distance between the left grabbing mechanical arm 10 and the right grabbing mechanical arm 11 is about to reach the length of the grasped object, stop passing the hydraulic oil to the hollow piston rod. Hydraulic oil is introduced into the central oil circuit of the hydraulic cylinder 1, and then the second oil port 1-7 is connected to the oil tank. The hydraulic oil flows into the connecting oil circuit 2 through the fifth oil port 4-1 of the single-acting hydraulic cylinder 4, and then flows into the cavity of the hollow piston rod 1-12 through the fourth oil port 1-15 on the end face of the hollow piston rod 1-12. Then the hydraulic oil enters the central oil pipe 1-9, and then flows back to the oil tank through the second oil port 1-7. The spring returns to its original length, and the second piston 4-2 of the single-acting hydraulic cylinder 4 moves outward under the action of the spring, pops out the lock, and the lock cooperates with the locking groove of the fixed-length rod 9 to complete the locking action.

[0075] The central oil circuit of the hollow piston rod hydraulic cylinder is the main component of the control oil circuit. It can connect the mobile carrier to an external oil source when there is no oil pipe outside, simplify the hydraulic system structure on the carrier, reduce the mass of the hydraulic system, and improve the controllability of the system. The purpose of controlling the pop-up and retraction of the single-acting hydraulic cylinder lock is achieved; guide devices are installed on both sides of the fixed-length rod to form a sliding pair with the fixed-length rod. In the reciprocating motion of the fixed-length rod, it has a guiding and supporting function to prevent the instability of the fixed-length rod caused by the change of the movement direction and speed; the locking / unlocking function is completed by the mutual cooperation of the groove at the right end of the fixed-length rod and the single-acting hydraulic cylinder lock, which is convenient to control and responds quickly. Due to the mechanical locking structure, it is more stable and reliable when locked; by making the lock head cooperate with the grooves at different positions of the fixed-length rod, the fixed distance between the left and right grabbing mechanical arms can be changed to achieve the purpose of grabbing objects of different sizes; by using a hollow piston rod hydraulic cylinder and a two-way single-out rod hydraulic cylinder group in parallel, the different requirements of the reciprocating speed and running distance of the movable pulley trolley on the left and right sides can be met.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can still adjust the technical solutions described in the above embodiments or replace some of the technical features by equivalents. Therefore, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A double-arm grabbing mechanism with a fixed-length locking function, characterized in that: The invention comprises a hollow piston rod hydraulic cylinder (1), a connecting oil circuit (2), a right arm movable pulley trolley (3), a single-acting hydraulic cylinder (4), a first chain pulley transmission mechanism (5), a left arm movable pulley trolley (6), a bidirectional single-rod hydraulic cylinder group (7), a guide device (8), a fixed-length rod (9), a left grabbing mechanical arm (10), a right grabbing mechanical arm (11), a machine body shell (12) and a second chain pulley transmission mechanism (13), wherein the machine body shell (12) is provided with a hollow piston rod hydraulic cylinder (1), a connecting oil circuit (2), a right arm movable pulley trolley (3), a single-acting hydraulic cylinder (4), a first chain pulley transmission mechanism (5), a left arm movable pulley trolley (6), a bidirectional single-rod hydraulic cylinder group (7), a guide device (8), a fixed-length rod (9), a left grabbing mechanical arm (10), a right grabbing mechanical arm (11), a machine body shell (12) and a second chain pulley transmission mechanism (13). An oil connection circuit (2), a right arm movable pulley trolley (3), a single-acting hydraulic cylinder (4), a first chain pulley transmission mechanism (5), a left arm movable pulley trolley (6), a bidirectional single-rod hydraulic cylinder group (7), a guide device (8), a fixed-length rod (9) and a second chain pulley transmission mechanism (13); the upper parts of the left grabbing mechanical arm (10) and the right grabbing mechanical arm (11) are arranged inside the machine body shell (12), and the lower parts of the left grabbing mechanical arm (10) and the right grabbing mechanical arm (11) extend out of the machine body shell (12); The hollow piston rod hydraulic cylinder (1) and the bidirectional single-rod hydraulic cylinder group (7) are connected in parallel, and the hollow piston rod hydraulic cylinder (1) and the bidirectional single-rod hydraulic cylinder group (7) are both connected to one side of the right arm movable pulley trolley (3), and the other side of the right arm movable pulley trolley (3) is connected to the right grabbing mechanical arm (11) through a first chain pulley transmission mechanism (5), the fixed-length rod (9) is arranged at the lower end of the bidirectional single-rod hydraulic cylinder group (7), and the guide device (8) is sleeved on the outside of the fixed-length rod (9), and the left ends of the bidirectional single-rod hydraulic cylinder group (7) and the fixed-length rod (9) are both connected to one side of the left arm movable pulley trolley (6), and the other side of the left arm movable pulley trolley (6) is connected to the left grabbing mechanical arm (10) through a second chain pulley transmission mechanism (13); A single-acting hydraulic cylinder (4) as a hydraulic actuator is arranged inside the right arm movable pulley trolley (3). The right arm movable pulley trolley (3) has a hole facing the piston movement direction of the single-acting hydraulic cylinder (4). The single-acting hydraulic cylinder (4) can extend out of the right arm movable pulley trolley (3) when the lock head is extended. The single-acting hydraulic cylinder (4) is connected to the hollow piston rod hydraulic cylinder (1) through the connecting oil circuit (2) inside the right arm movable pulley trolley (3). A locking groove is arranged on the right end of the fixed-length rod (9), and the locking groove can cooperate with the lock head of the single-acting hydraulic cylinder (4) for locking.

2. A double-arm grabbing mechanism with a fixed-length locking function according to claim 1, characterized in that: The hollow piston rod hydraulic cylinder (1) comprises a first cylinder bottom (1-1), a cylinder head (1-2), a cylinder barrel (1-3), a cylinder cover (1-4), a guide sleeve (1-5), a central oil pipe (1-9) and a hollow piston rod (1-12); the first cylinder bottom (1-1) is arranged on one side of the hollow piston rod hydraulic cylinder (1), the cylinder head (1-2) is arranged on the other side of the hollow piston rod hydraulic cylinder (1), and the first cylinder bottom (1-1) and the cylinder head (1-2) are arranged on the other side of the hollow piston rod hydraulic cylinder (1). 1-2) are connected by a plurality of pull rods, one end of the cylinder barrel (1-3) is connected to the first cylinder bottom (1-1), the other end of the cylinder barrel (1-3) is connected to the cylinder head (1-2), the hollow piston rod (1-12) is arranged inside the cylinder barrel (1-3), the cylinder cover (1-4) is fixed to the cylinder head (1-2) by countersunk screws, and the guide sleeve (1-5) is arranged between the cylinder head (1-2) and the hollow piston rod (1-12); A first opening is provided at the center of the first cylinder bottom (1-1), and a second opening is provided at the center of the cylinder head (1-2); one end of the through oil pipe (1-9) is connected to the first opening, and the other end of the through oil pipe (1-9) is flush with the end surface of the second opening; the through oil pipe (1-9) passes through the hollow piston rod (1-12) along the axial center line of the hollow piston rod hydraulic cylinder (1) and the hollow piston rod (1-12); and the aperture of the second opening is equal to the outer diameter of the hollow piston rod (1-12).

3. A double-arm grabbing mechanism with a fixed-length locking function according to claim 2, characterized in that: The hollow piston rod (1-12) comprises a first piston (1-13) and a sealing device (1-14); the first piston (1-13) is threadedly connected or welded to one end of the hollow piston rod (1-12); the first piston (1-13) is slidably arranged inside the cylinder barrel (1-3); the first piston (1-13) divides the cylinder barrel (1-3) into a first oil chamber (1-10) and a second oil chamber (1-11); and the sealing device (1-14) is arranged at the end of the first piston (1-13); The first cylinder bottom (1-1) is provided with a first oil port (1-6), the first oil port (1-6) is connected to the first oil chamber (1-10) and the outside world; the through oil pipe (1-9) is provided with a second oil port (1-7) connected to the outside world at one end close to the first cylinder bottom (1-1); the through oil pipe (1-9) and the inner cavity of the hollow piston rod (1-12) form a through oil path structure; the cylinder head (1-2) is provided with a third oil port (1-8), the third oil port (1-8) is connected to the second oil chamber (1-11) and the outside world; the other end of the hollow piston rod (1-12) is provided with a fourth oil port (1-15); the hollow piston rod (1-12) is connected to one side of the right arm movable pulley trolley (3).

4. A double-arm grabbing mechanism with a fixed-length locking function according to claim 3, characterized in that: The bidirectional single-rod hydraulic cylinder group (7) comprises a first single-rod hydraulic cylinder and a second single-rod hydraulic cylinder which share a second cylinder bottom (7-7), wherein the second cylinder bottom (7-7) is connected in parallel with the first cylinder bottom (1-1); The first single-rod hydraulic cylinder comprises a first piston rod (7-1) and a third piston (7-2); one end of the first piston rod (7-1) extends out of the first single-rod hydraulic cylinder to the outside, the other end of the first piston rod (7-1) is arranged inside the first single-rod hydraulic cylinder, the other end of the first piston rod (7-1) is connected to the third piston (7-2) by threaded connection or welding, the third piston (7-2) divides the internal cavity of the first single-rod hydraulic cylinder into a first rod cavity (7-5) and a first rodless cavity (7-6); a sixth oil port (7-3) communicating with the first rod cavity (7-5) and the outside is arranged on the cylinder head of the first single-rod hydraulic cylinder; a seventh oil port (7-4) communicating with the first rodless cavity (7-6) and the outside is arranged on one end of the second cylinder bottom (7-7); the first piston rod (7-1) is connected to one side of the left arm movable pulley trolley (6); The second single-rod hydraulic cylinder comprises a second piston rod (7-8) and a fourth piston (7-9), one end of the second piston rod (7-8) extends out of the second single-rod hydraulic cylinder to the outside, the other end of the second piston rod (7-8) is arranged inside the second single-rod hydraulic cylinder, the other end of the second piston rod (7-8) is connected to the fourth piston (7-9) by threaded connection or welding, the fourth piston (7-9) divides the internal cavity of the second single-rod hydraulic cylinder into a second rodless cavity (7-12) and a second rod cavity (7-13), a ninth oil port (7-11) communicating with the second rod cavity (7-13) and the outside is arranged on the cylinder head of the second single-rod hydraulic cylinder, an eighth oil port (7-10) communicating with the second rodless cavity (7-12) and the outside is arranged on the other end of the second cylinder bottom (7-7), and the second piston rod (7-8) is connected to one side of the right arm movable pulley trolley (3).

5. A double-arm grabbing mechanism with fixed-length locking function according to claim 4, characterized in that: The base of the single-acting hydraulic cylinder (4) is fixed in a mounting groove on the right arm movable pulley trolley (3) by bolt connection. A single output rod matching with the single-acting hydraulic cylinder (4) is installed inside the single-acting hydraulic cylinder (4). A second piston (4-2) is connected to the single output rod by threaded connection or welding. A spring is arranged on the top of the second piston (4-2), and the spring is connected to the top of the inner cavity of the single-acting hydraulic cylinder (4).

6. A double-arm grabbing mechanism with fixed-length locking function according to claim 5, characterized in that: The single-acting hydraulic cylinder (4) is provided with a fifth oil port (4-1), and the fifth oil port (4-1) of the single-acting hydraulic cylinder (4) is connected to the fourth oil port (1-15) of the hollow piston rod (1-12) via a connecting oil path (2).

7. A double-arm grabbing mechanism with fixed-length locking function according to claim 6, characterized in that: One end of the cylinder head (1-2) is evenly provided with a plurality of threaded holes, one end of a plurality of tie rods is connected to the cylinder head (1-2) via threads, and the other ends of the plurality of tie rods are connected to the first cylinder bottom (1-1) via a plurality of nuts.

8. The double-arm grabbing mechanism with fixed-length locking function according to claim 7, characterized in that: A sealing ring is provided at the connection between the cylinder barrel (1-3) and the first cylinder bottom (1-1) and the cylinder head (1-2); a dust ring that fits the through piston rod (1-12) is provided at the inner ring groove of the cylinder cover (1-4); a sealing ring is provided at the inner ring groove of the guide sleeve (1-5); a guide ring and a sealing ring are provided at the side ring groove of the first piston (1-13); and a sliding sealing ring that fits the through oil pipe (1-9) is provided in the inner ring groove of the hollow piston rod (1-12).

9. A double-arm grabbing mechanism with a fixed-length locking function according to claim 8, characterized in that: The connection forms of the first oil port (1-6), the second oil port (1-7), the third oil port (1-8), the fourth oil port (1-15) and the fifth oil port (4-1) include threaded connection, flange connection, plate connection, stacking connection and plug-in connection.

10. A double-arm grabbing mechanism with a fixed-length locking function according to claim 9, characterized in that: The outer ends of the oil ports of the first oil port (1-6), the second oil port (1-7), the third oil port (1-8), the fourth oil port (1-15) and the fifth oil port (4-1) are provided with hydraulic reversing valves or solenoid valves, and the first oil port (1-6), the second oil port (1-7), the third oil port (1-8), the fourth oil port (1-15) and the fifth oil port (4-1) can all be connected to an oil tank.

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