An EHA-based internal expansion mechanical locking hydraulic support leg and its operation method

Abstract

The present invention discloses an EHA-based internal expansion mechanical locking hydraulic outrigger and its operating method. The outrigger comprises an EHA drive assembly and a hydraulic outrigger assembly. The EHA drive assembly is integrated into the upper portion of the outrigger and can implement the working principles of pressure loss self-locking and internal expansion unlocking without external oil supply. By controlling the EHA drive system, when high-pressure oil is input into the upper chamber oil guide pipe, a logical relationship is formed in which the spiral groove unlocking pressure p1 = the external control sequence valve minimum opening pressure p2 ≤ the oil cylinder upper chamber load pressure p3 < the overflow valve set overflow opening pressure p4, ensuring that the outrigger cylinder unlocks first and extends later. Alternatively, when high-pressure oil is input into the lower chamber oil guide pipe, a logical relationship is formed in which the spiral groove unlocking pressure p1 = the external control sequence valve minimum opening pressure p5 ≤ the accumulator storage pressure p6 < the overflow valve set overflow opening pressure p7, ensuring that the outrigger cylinder unlocks first and retracts later.

Description

Technical Field

[0001] The present invention relates to hydraulic outrigger equipment of an electrostatic hydraulic direct drive system, and in particular to an EHA-based internal expansion type mechanical locking hydraulic outrigger and an operating method thereof. Background Art

[0002] In the hydraulic support and leveling system of special heavy-duty engineering vehicles, in order to ensure the durability of the support and leveling accuracy, internal expansion mechanical locking hydraulic support legs are generally used as their support and leveling mechanism.

[0003] In principle, the internal expansion mechanical locking outrigger requires that the mechanical lock must be released hydraulically before the telescopic adjustment function of the hydraulic outrigger can be realized.

[0004] Currently, the high-pressure release oil circuit for internally expanding, mechanically locked hydraulic outriggers is typically located separately within the outrigger structure and operates independently from the outrigger's oil supply and return drive circuits. These three oil circuits must be connected to the vehicle's hydraulic power system via three external oil pipes. This increases the number of oil ports compared to conventional hydraulic outriggers for construction vehicles. This leads to disadvantages such as the need for modification of the vehicle's hydraulic system, limited installation space, complex piping layout, and numerous oil leak points. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and deficiencies of the prior art and to provide an EHA-based internal expansion mechanical locking hydraulic support leg and an operating method thereof.

[0006] The present invention is an independently operated internal expansion mechanical locking hydraulic support leg based on an electrostatic hydraulic direct drive system. The EHA system is different from the traditional hydraulic servo valve system based on pressure control. Instead, it adopts the volume control principle, which makes the system simpler and can be integrated into the hydraulic support leg. The entire system can operate independently, does not require external hydraulic system access, and can be remotely controlled. The hydraulic support leg is based on the working characteristics of mechanical friction self-locking, and can realize the function of unlocking first and then moving under the drive of the EHA system. The EHA system of the hydraulic support leg is integrated at the end of the support leg. The movement functions of the hydraulic support leg with load extension, load locking, load retraction, and recovery stop can be realized through remote control.

[0007] The present invention is achieved through the following technical solutions:

[0008] An EHA-based internal expansion mechanical locking hydraulic support leg includes an EHA drive assembly and a hydraulic support leg assembly; the hydraulic support leg assembly includes a cylindrical valve block 6, an accumulator 7, a transition block 8, an oil cylinder upper end cover 9, a piston upper end cover 10, a spiral pipe sleeve 11, a piston lower end cover 12, a piston rod 13, an oil cylinder lower end cover 14, a cylinder barrel 16, an upper chamber oil guide pipe 17, an unlocking oil guide pipe 23, a lower chamber oil guide pipe 27, a first one-way valve 21, a second one-way valve 22, a third one-way valve 26, a fourth one-way valve 29, a first externally controlled sequence valve 30, a second externally controlled sequence valve 32, a first relief valve 31, and a second relief valve 33;

[0009] Three oil passages are formed in the transition block 8 and the upper end cover 9 of the oil cylinder. These three oil passages are connected to the oil circuit inside the cylindrical valve block 6. The piston rod 13 in the hydraulic cylinder is connected to the upper end cover 10 and the lower end cover 12 of the piston via a threaded connection. A spiral sleeve 11 is sandwiched between the upper end cover 10 and the lower end cover 12 of the piston. The spiral sleeve 11 is fitted onto the piston rod 13 with a clearance fit.

[0010] The piston rod 13 has two oil guide holes axially formed inside, one of which has a radial through hole communicating with the rod cavity of the oil cylinder, and the other has a radial through hole communicating with the spiral groove of the spiral sleeve 11;

[0011] The spiral groove cavity on the outer surface of the spiral sleeve 11 is connected to the third oil path 43 through the oil guide hole of the lower cavity oil guide pipe 27 installed inside the piston rod 13;

[0012] The rodless cavity of the hydraulic cylinder is connected to the external first oil circuit 41 through the oil guide hole installed with the upper cavity oil guide pipe 17, so as to realize the oil inlet and outlet of the rodless cavity of the hydraulic cylinder;

[0013] The rod chamber of the hydraulic cylinder is connected to the external oil circuit through the oil guide hole in which the unlocking oil guide pipe 23 is installed, thereby realizing the oil inflow and outflow of the rod chamber of the cylinder.

[0014] The first one-way valve 21, the third one-way valve 26, the lower chamber oil guide pipe 27, the spiral sleeve 11 and the piston rod 13 form a hydraulic unlocking oil circuit;

[0015] The first one-way valve 21 and the third one-way valve 26 in the hydraulic unlocking oil circuit are integrated in the cylindrical valve block 6. The first one-way valve 21 is connected between the second node 36 and the third node 37 through the flow channel inside the cylindrical valve block 6, and the third one-way valve 26 is connected between the first node 35 and the third node 37. They are finally connected to the spiral groove of the spiral sleeve 11 through the lower chamber oil guide pipe 27 and the oil guide hole inside the piston rod 13.

[0016] The second one-way valve 22, the second externally controlled sequence valve 32, the accumulator 7, the second relief valve 33, the unlocking oil guide pipe 23 and the piston rod 13 form an oil circuit connected to the rod chamber of the hydraulic cylinder;

[0017] The second one-way valve 22, the second externally controlled sequence valve 32, and the second overflow valve 33 in the oil circuit of the rod chamber are integrated in the cylindrical valve block 6. The second one-way valve 22 and the second externally controlled sequence valve 32 are connected in parallel between the second node 36 and the fourth node 38 through the internal flow channel in the cylindrical valve block 6. The accumulator 7 and the cylindrical valve block 6 are connected to the fourth node 38 through the internal oil channel, and finally connected to the rod chamber through the unlocking oil guide pipe 23 and the internal oil guide hole of the piston rod 13.

[0018] The control port of the second externally controlled sequence valve 32 is connected to the third node 37. When the pressure of the third node 37 reaches or exceeds the unlocking pressure, the valve opens to a conducting state, allowing high-pressure oil to flow through the flow channel thereof into the rod chamber, causing the oil cylinder to retract.

[0019] When the oil cylinder retracts, the second one-way valve 22 is in a cut-off state. When the oil cylinder extends, the second one-way valve 22 allows the oil in the rod chamber of the oil cylinder to return and flow out.

[0020] The fourth one-way valve 29, the first externally controlled sequence valve 30, the first relief valve 31, and the upper chamber oil guide pipe 17 form an oil circuit connecting the rodless chamber of the oil cylinder;

[0021] The fourth one-way valve 29, the first externally controlled sequence valve 30 and the first overflow valve 31 in the rodless chamber oil circuit are all integrated in the cylindrical valve block 6. The fourth one-way valve 29 and the first externally controlled sequence valve 30 are connected in parallel between the first node 35 and the fifth node 39 through the internal flow channel in the cylindrical valve block 6, and finally connected to the rodless chamber through the upper chamber oil guide pipe 17.

[0022] The control port of the first externally controlled sequence valve 30 is connected to the third node 37. When the pressure of the third node 37 reaches or exceeds the unlocking pressure, the conducting state is opened, allowing high-pressure oil to enter the rodless chamber of the cylinder through its flow channel, so that the cylinder can achieve extension movement.

[0023] When no unlocking pressure oil is injected into the unlocking spiral groove, the spiral sleeve 11 and the cylinder 16 are in an interference fit state. Under the positive pressure generated by the interference fit, static friction force is generated on the mating surfaces, that is, self-locking force, by which the hydraulic support leg can withstand axial load and form self-locking.

[0024] When unlocking high-pressure oil is introduced into the unlocking spiral groove of the spiral sleeve 11, the cylinder 16 will undergo radial elastic deformation and expand under the action of oil pressure, and the fitting state of the spiral sleeve 11 and the cylinder 16 will change from interference fit to clearance fit, and the hydraulic support leg will be unlocked.

[0025] The first externally controlled sequence valve 30 and the second externally controlled sequence valve 32 are respectively set to have the minimum opening pressures p2 and p5, and the set values ​​are equal to the hydraulic cylinder unlocking pressure p1.

[0026] The EHA drive assembly includes a motor drive controller 2, a coupling seat 4, a battery pack 18, a motor 19, a right valve block 20, a left valve block 25 and a bidirectional gear pump 5;

[0027] The motor drive controller 2, battery pack 18 and motor 19 are integrated on the coupling seat 4; a heat dissipation cover 3 is provided on the outside of the motor 19, and an end cover 1 is provided on the top of the motor 19; a bidirectional gear pump 5 is connected to the motor 18; the oil inlet and outlet of the bidirectional gear pump 5 are interconnected with the internal oil circuits of the right valve block 20, the left valve block 25 and the cylindrical valve block 6; the cylindrical valve block 6 is connected to the accumulator 7, and three oil channels are provided inside the accumulator 7 to connect the three oil outlets of the cylindrical valve block 6. Driven by the motor 19, the bidirectional gear pump 5 transfers the oil to the hydraulic support leg through these three oil channels.

[0028] The operating method of the EHA-based internal expansion mechanical locking hydraulic support leg of the present invention is as follows:

[0029] Leg extension step: the remote control 34 controls the motor 19 to rotate forward, and the motor 19 drives the high-pressure oil output by the bidirectional gear pump 5 to reach the first node 35 through the first oil circuit 41 and realize diversion: one path of oil is diverted at the third node 37 through the third one-way valve 26, one path flows into the unlocking spiral groove through the unlocking oil circuit, and the other two paths are connected to the external control oil circuits of the first external control sequence valve 30 and the second external control sequence valve 32 respectively; when the oil pressure of the third node 37 oil circuit reaches the unlocking pressure p1, the cylinder 16 undergoes radial elastic deformation The cylinder is unlocked, and the piston assembly can now move freely in the axial direction. At the same time, because the minimum opening pressure p2 set by the first external control sequence valve 30 is also p1, when the cylinder is unlocked, the sequence valve 30 will also be opened, and the fourth one-way valve 29 will be closed, allowing the high-pressure oil flow to flow through the sequence valve 30 and into the upper chamber of the support leg cylinder. When the oil pressure p3 in the upper chamber of the cylinder continues to increase under the action of the increase in motor-pump flow to reach the load lifting level, the load support leg can move and extend, thereby lifting the load platform.

[0030] Stay locking steps: When the hydraulic support leg is extended to the specified position, the motor 19 stops rotating, the hydraulic system stops supplying oil to the cylinder 16, and the small amount of high-pressure oil between the spiral sleeve 11 and the cylinder assembly is quickly discharged through the leakage gap of the control element. The unlocking oil pressure in the spiral groove of the spiral sleeve 11 is lost, and the cylinder 16 undergoes radial elastic contraction and forms an interference fit with the spiral sleeve 11. The spiral sleeve 11 and the piston rod assembly are locked under the action of friction. The hydraulic support leg thus achieves long-term stable support at any position.

[0031] Leg retraction steps: remote control controls the motor to reverse, and the motor 19 drives the high-pressure oil output by the bidirectional gear pump 5 to reach the second node 36 through the second oil path 42 and realize diversion: the oil in the two paths is diverted at the third node 37 through the third one-way valve 26, one of which flows into the unlocking spiral groove through the unlocking oil path, and the other two paths are connected to the external control oil paths of the first external control sequence valve 30 and the second external control sequence valve 32 respectively; when the oil pressure in the oil path of the third node 37 reaches the unlocking pressure p1, the cylinder 16 undergoes radial elastic deformation to realize the unlocking of the cylinder, and the piston assembly can now realize free axial movement; at the same time, because the minimum opening pressure p5 set by the second external control sequence valve 32 is the same as the cylinder unlocking pressure p1, when the cylinder is unlocked, the sequence valve 32 will also be opened, and the high-pressure oil can flow through the sequence valve 32 and be injected into the lower chamber of the leg cylinder. The pressure of the liquid in the lower chamber of the leg cylinder is p6.

[0032] Recovery stop step: When the outrigger piston assembly is fully retracted to the end of its stroke, the motor 19 stops rotating, the hydraulic system stops supplying oil, and the piston is locked under the action of mechanical friction.

[0033] Compared with the prior art, the present invention has the following advantages and effects:

[0034] The present invention implements the principles of self-locking under pressure loss and unlocking under internal expansion conditions without external oil supply. By controlling the EHA drive system, when high-pressure oil is fed into the upper chamber oil conduit 17, the following logic relationship is established: the spiral groove unlocking pressure p1 = the minimum opening pressure p2 of the first externally controlled sequence valve 30 ≤ the upper chamber load pressure p3 of the oil cylinder < the set overflow opening pressure p4 of the first relief valve 31, ensuring that the outrigger cylinders unlock first and extend later. Alternatively, when high-pressure oil is fed into the lower chamber oil conduit 27, the following logic relationship is established: the spiral groove unlocking pressure p1 = the minimum opening pressure p5 of the second externally controlled sequence valve 32 ≤ the accumulator pressure p6 < the set overflow opening pressure p7 of the second relief valve 33, ensuring that the outrigger cylinders unlock first and retract later.

[0035] The invention provides a long-term locking function for the hydraulic outrigger under load at any position within its travel range when the motor of the EHA drive system stops working. During the locking period, oil leakage in the hydraulic system has no effect on the locking effect of the outrigger position.

[0036] The hydraulic outriggers of the present invention can independently unlock, extend, retract, and lock the outriggers. They do not require external hydraulic systems or cables, making them more convenient to use than conventional outrigger cylinders. They avoid the numerous problems associated with existing three-port internal expansion mechanical locking hydraulic outriggers, which often require hydraulic system modifications, piping rerouting, installation space restrictions, and increased leak points.

[0037] The hydraulic outriggers of this invention integrate a permanent magnet synchronous motor, a high-energy-density lithium battery pack, and a wireless controller, forming a hydraulic support system that combines motor control and hydraulic drive. The entire system transmits control signals to an external remote control via Bluetooth, eliminating the need for an external power supply and simplifying the control system and method. The entire system can operate independently and automatically in a special engineering vehicle, or remotely by an engineer. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a top view of the EHA-based internal expansion mechanical locking hydraulic support leg of the present invention.

[0039] Figure 2 for Figure 1 Schematic diagram of the AA longitudinal section.

[0040] Figure 3 for Figure 1 Schematic diagram of the longitudinal section of the middle BB.

[0041] Figure 4 This is the principle intention of the internal expansion mechanical locking hydraulic support leg based on EHA of the present invention.

[0042] Reference numerals in the figure: upper end cover 1, motor drive controller 2, heat dissipation cover 3, coupling seat 4, bidirectional gear pump 5, cylindrical valve block 6, accumulator 7, transition block 8, cylinder upper end cover 9, piston upper end cover 10, spiral pipe sleeve 11, piston lower end cover 12, piston rod 13, cylinder lower end cover 14, support leg base 15, cylinder barrel 16, upper chamber oil guide pipe 17, high-energy lithium battery pack 18, motor 19, right valve block 20, first one-way valve 21, second one-way valve 22 , unlocking oil guide pipe 23, first blind oil channel 24, left valve block 25, third one-way valve 26, lower chamber oil guide pipe 27, second blind oil channel 28, fourth one-way valve 29, first externally controlled sequence valve 30, first overflow valve 31, second externally controlled sequence valve 32, second overflow valve 33, remote control 34, first node 35, second node 36, third node 37, fourth node 38, fifth node 39, first oil circuit 41, second oil circuit 42, third oil circuit 43. DETAILED DESCRIPTION

[0043] The present invention is described in further detail below with reference to specific embodiments.

[0044] The present invention discloses an EHA-based internal expansion mechanical locking hydraulic support leg, comprising an EHA drive assembly and a hydraulic support leg assembly; the hydraulic support leg assembly comprises a cylindrical valve block 6, an accumulator 7, a transition block 8, an oil cylinder upper end cover 9, a piston upper end cover 10, a spiral pipe sleeve 11, a piston lower end cover 12, a piston rod 13, an oil cylinder lower end cover 14, a cylinder barrel 16, an upper chamber oil guide pipe 17, an unlocking oil guide pipe 23, a lower chamber oil guide pipe 27, a first one-way valve 21, a second one-way valve 22, a third one-way valve 26, a fourth one-way valve 29, a first externally controlled sequence valve 30, a second externally controlled sequence valve 32, a first relief valve 31, a second relief valve 33, and a remote controller 34;

[0045] Three oil passages are formed in the transition block 8 and the upper end cover 9 of the oil cylinder. These three oil passages are connected to the oil circuit inside the cylindrical valve block 6. The piston rod 13 in the hydraulic cylinder is connected to the upper end cover 10 and the lower end cover 12 of the piston via a threaded connection. A spiral sleeve 11 is sandwiched between the upper end cover 10 and the lower end cover 12 of the piston. The spiral sleeve 11 is fitted onto the piston rod 13 with a clearance fit.

[0046] The piston rod 13 has two oil guide holes axially formed inside, one of which has a radial through hole communicating with the rod cavity of the oil cylinder, and the other has a radial through hole communicating with the spiral groove of the spiral sleeve 11;

[0047] The spiral groove cavity on the outer surface of the spiral sleeve 11 is connected to the third oil path 43 through the oil guide hole of the lower cavity oil guide pipe 27 installed inside the piston rod 13;

[0048] The rodless cavity of the hydraulic cylinder is connected to the external first oil circuit 41 through the oil guide hole installed with the upper cavity oil guide pipe 17, so as to realize the oil inlet and outlet of the rodless cavity of the hydraulic cylinder;

[0049] The rod chamber of the hydraulic cylinder is connected to the external oil circuit through the oil guide hole in which the unlocking oil guide pipe 23 is installed, thereby realizing the oil inflow and outflow of the rod chamber of the cylinder.

[0050] The first one-way valve 21, the third one-way valve 26, the lower chamber oil guide pipe 27, the spiral sleeve 11 and the piston rod 13 form a hydraulic unlocking oil circuit;

[0051] The first one-way valve 21 and the third one-way valve 26 in the hydraulic unlocking oil circuit are integrated in the cylindrical valve block 6. The first one-way valve 21 is connected between the second node 36 and the third node 37 through the flow channel inside the cylindrical valve block 6, and the third one-way valve 26 is connected between the first node 35 and the third node 37. They are finally connected to the spiral groove of the spiral sleeve 11 through the lower chamber oil guide pipe 27 and the oil guide hole inside the piston rod 13.

[0052] The second one-way valve 22, the second externally controlled sequence valve 32, the accumulator 7, the second relief valve 33, the unlocking oil guide pipe 23 and the piston rod 13 form an oil circuit connected to the rod chamber of the hydraulic cylinder;

[0053] The second one-way valve 22, the second externally controlled sequence valve 32, and the second overflow valve 33 in the oil circuit of the rod chamber are integrated in the cylindrical valve block 6. The second one-way valve 22 and the second externally controlled sequence valve 32 are connected in parallel between the second node 36 and the fourth node 38 through the internal flow channel in the cylindrical valve block 6. The accumulator 7 and the cylindrical valve block 6 are connected to the fourth node 38 through the internal oil channel, and finally connected to the rod chamber through the unlocking oil guide pipe 23 and the internal oil guide hole of the piston rod 13.

[0054] The control port of the second externally controlled sequence valve 32 is connected to the third node 37. When the pressure of the third node 37 reaches or exceeds the unlocking pressure, the valve opens to a conducting state, allowing high-pressure oil to flow through the flow channel thereof into the rod chamber, causing the oil cylinder to retract.

[0055] When the cylinder retracts, the second one-way valve 22 is in the cut-off state. When the cylinder extends, the second one-way valve 22 allows the oil in the rod chamber of the cylinder to flow out at a very low pressure. The second overflow valve 33 plays a protective role to prevent the excessive pressure in the system oil circuit from damaging components during the retraction movement.

[0056] The fourth one-way valve 29, the first externally controlled sequence valve 30, the first relief valve 31, and the upper chamber oil guide pipe 17 form an oil circuit connecting the rodless chamber of the oil cylinder;

[0057] The fourth one-way valve 29, the first externally controlled sequence valve 30 and the first overflow valve 31 in the rodless chamber oil circuit are all integrated in the cylindrical valve block 6. The fourth one-way valve 29 and the first externally controlled sequence valve 30 are connected in parallel between the first node 35 and the fifth node 39 through the internal flow channel in the cylindrical valve block 6, and finally connected to the rodless chamber through the upper chamber oil guide pipe 17.

[0058] The control port of the first externally controlled sequence valve 30 is connected to a third node 37. When the pressure at third node 37 reaches or exceeds the unlocking pressure, it opens, allowing high-pressure oil to flow through its channel into the rodless chamber of the cylinder, causing the cylinder to extend. During cylinder extension, the fourth one-way valve 29 is closed. During cylinder retraction, the fourth one-way valve 29 allows the oil in the rodless chamber to return at very low pressure. The second externally controlled sequence valve 32 provides protection, preventing excessive pressure in the system oil circuit from damaging components during extension.

[0059] When no unlocking pressure oil is injected into the unlocking spiral groove, the spiral sleeve 11 and the cylinder 16 are in an interference fit state. Under the positive pressure generated by the interference fit, static friction force is generated on the mating surfaces, that is, self-locking force, by which the hydraulic support leg can withstand axial load and form self-locking.

[0060] When unlocking high-pressure oil is introduced into the unlocking spiral groove of the spiral sleeve 11, the cylinder 16 will undergo radial elastic deformation and expand under the action of oil pressure, and the fitting state of the spiral sleeve 11 and the cylinder 16 will change from interference fit to clearance fit, and the hydraulic support leg will be unlocked.

[0061] The first externally controlled sequence valve 30 and the second externally controlled sequence valve 32 are respectively set to have the minimum opening pressures p2 and p5, and the set values ​​are equal to the hydraulic cylinder unlocking pressure p1.

[0062] The EHA drive assembly includes a motor drive controller 2, a coupling seat 4, a battery pack 18, a motor 19, a right valve block 20, a left valve block 25 and a bidirectional gear pump 5;

[0063] The motor drive controller 2, battery pack 18, and motor 19 are integrated onto the coupling 4. A heat sink 3 is provided on the exterior of the motor 19, and an end cap 1 is located on the top of the motor 19. A bidirectional gear pump 5 is connected to the motor 18. The oil inlet and outlet of the bidirectional gear pump 5 are interconnected with the internal oil circuits of the right valve block 20, the left valve block 25, and the cylindrical valve block 6. The cylindrical valve block 6 is connected to the accumulator 7, and three oil passages are provided within the accumulator 7, connecting the three oil outlets of the cylindrical valve block 6. Driven by the motor 19, the bidirectional gear pump 5 delivers oil to the hydraulic support leg through these three oil passages. The battery pack 18 is the energy source for the entire system, providing energy to the motor 19 and the motor drive controller 2, ensuring that the system operates independently without external energy input.

[0064] The remote control 34 is independent of the hydraulic outriggers, allowing the operator to easily control them. The remote control 34 is connected to the motor drive controller 2 via Bluetooth. The operator uses buttons on the remote control 34 to send control signals to the motor drive controller 2, thereby controlling functions such as starting and stopping the motor, forward and reverse rotation, and speed control.

[0065] Cylinder barrel 16 is separated by a piston assembly within it, forming two chambers: a rod chamber and a rodless chamber. These chambers connect the inlet and outlet oil lines, forming a double-acting hydraulic cylinder. Cylinder barrel 16 and spiral sleeve 11 form an interference fit when no unlocking oil pressure is applied. The friction generated by the mating surfaces of the friction pair balances the axial load when the cylinder is locked. The cylinder barrel is the primary load-bearing component of the EHA-based, independently operated, internal expansion mechanical locking hydraulic outrigger.

[0066] The piston upper end cap 10 and piston lower end cap 12 are part of the piston assembly. They isolate the hydraulic cylinder's rod and rodless oil chambers, as well as the unlocking pressure oil chamber (the spiral groove), through sealing rings installed on their respective outer surfaces. The piston upper end cap 10, piston lower end cap 12, and piston rod 13 are threadedly connected to clamp the ends of the spiral sleeve 11, forming the piston / piston rod actuator assembly.

[0067] The spiral sleeve 11 is a key component of the mechanical locking friction pair of the EHA-based, independently operated, internally expanding, mechanically locked hydraulic outrigger. The sleeve 11 features an oil guide ring and radial oil holes within the sleeve, and a spiral groove on its outer surface. The high-pressure oil for unlocking the system flows through the oil guide holes and ring within the piston rod and into the groove. The sleeve is made of a metal material with a high surface friction coefficient.

[0068] The operating method of the EHA-based internal expansion mechanical locking hydraulic support leg of the present invention is as follows:

[0069] Leg extension step: The remote control 34 controls the motor 19 to rotate forward (counterclockwise), and the motor 19 drives the high-pressure oil output by the bidirectional gear pump 5 to reach the first node 35 through the first oil circuit 41 and realize diversion: one path of oil is diverted at the third node 37 through the third one-way valve 26, one path flows into the unlocking spiral groove through the unlocking oil circuit, and the other two paths are connected to the external control oil circuits of the first external control sequence valve 30 and the second external control sequence valve 32 respectively; when the oil pressure of the third node 37 oil circuit reaches the unlocking pressure p1, the cylinder 16 undergoes sufficient radial elastic deformation to realize the unlocking of the cylinder, and the piston The component can achieve free axial movement; at the same time, because the minimum opening pressure p2 set by the first external control sequence valve 30 is also p1, when the cylinder is unlocked, the sequence valve 30 will also be turned on, the fourth one-way valve 29 will be cut off, and the high-pressure oil flow can flow through the sequence valve 30 and be injected into the upper chamber of the support leg cylinder; when the oil pressure p3 in the upper chamber of the cylinder continues to increase under the action of the increase in motor-pump flow to reach the load lifting, the load support leg can move and extend to achieve the lifting of the load platform; in this process, in order to ensure the action sequence of unlocking first and extending later, each oil pressure value should ensure the relationship of p1=p2≤p3.

[0070] At the start of the outrigger extension process, oil in the lower chamber of the outrigger passes through the unlocking oil guide pipe 23 and the second one-way valve 22 and enters the second oil circuit 42, forming a return oil circuit and flowing back to the suction port of the bidirectional gear pump 5. At this time, because the volume of the lower chamber of the cylinder is smaller than that of the upper chamber, the return oil cannot meet the suction flow requirement of the bidirectional gear pump 5, and the accumulator 7 needs to release oil to replenish the return oil flow. In this way, when the system oil pressure reaches the set value when the motor 19 is in the forward rotation state, the hydraulic outrigger can be unlocked and the loaded extension action can be completed. The first relief valve 31 provides safety protection during the outrigger extension movement, and its set relief opening pressure is p4.

[0071] Stop and lock steps: When the hydraulic outrigger is extended to a certain leveling position, the motor 19 stops rotating, the hydraulic system stops supplying oil to the cylinder 16, and the small amount of high-pressure oil between the spiral sleeve 11 and the cylinder assembly is quickly discharged through the leakage gap of the control element. The spiral groove of the spiral sleeve 11 loses the unlocking oil pressure, and the cylinder 16 undergoes radial elastic contraction and forms an interference fit with the spiral sleeve 11. The spiral sleeve 11 and the piston rod assembly are locked under the action of friction. The hydraulic outrigger thus achieves long-term stable support at any position.

[0072] Outrigger retraction steps: The motor is remotely controlled to reverse (clockwise rotation). Motor 19 drives the high-pressure oil output from the bidirectional gear pump 5 through the second oil passage 42 to the second node 36, where it is split. The oil is then diverted at the third node 37 by the third one-way valve 26. One path flows through the unlocking oil passage into the unlocking spiral groove, while the other two paths connect to the external control oil passages of the first externally controlled sequence valve 30 and the second externally controlled sequence valve 32, respectively. When the oil pressure in the third node 37 reaches the unlocking pressure p1, the cylinder barrel 16 undergoes radial elastic deformation, unlocking the cylinder. This allows the piston assembly to move freely axially. Simultaneously, because the minimum opening pressure p5 set for the second externally controlled sequence valve 32 is the same as the cylinder unlocking pressure p1, the sequence valve 32 is also opened upon cylinder unlocking. High-pressure oil can flow through the sequence valve 32 (with the second one-way valve 22 closed) and into the lower chamber of the outrigger cylinder. The pressure of the fluid in the lower chamber of the outrigger cylinder is p6.

[0073] At the start of the outrigger retraction process, oil in the upper chamber of the outrigger flows through the upper chamber oil guide pipe 17 and the fourth one-way valve 29 into the first oil circuit 41, forming a return oil circuit. The return oil flows into the suction port of the bidirectional gear pump 5. At this time, because the upper chamber volume of the outrigger cylinder is larger than the lower chamber volume, when the piston retracts, the intake and discharge flow rates of the gear pump exceed the oil capacity of the lower chamber of the cylinder. The accumulator 7 absorbs the excess oil volume, storing energy and gradually increasing the stored pressure p6. This also causes the output pressure of the gear pump to rise. In this way, when the motor is reversed and the system oil pressure reaches the set value, the hydraulic outrigger can be unlocked and the no-load retraction action can be completed. When the outrigger is retracting, even in the no-load state, the action sequence of unlocking first and then retracting should be maintained. During outrigger retraction, the pump's output oil pressure gradually increases as accumulator pressure p6 rises (gradually exceeding p1) until it reaches the relief opening pressure of second relief valve 33, at which point outrigger retraction ceases. Second relief valve 33 provides safety during outrigger retraction, and its set relief opening pressure is p7.

[0074] Recovery stop step: When the outrigger piston assembly is fully retracted to the end of its stroke, the motor 19 stops rotating, the hydraulic system stops supplying oil, and the piston is locked under the action of mechanical friction.

[0075] As described above, the present invention can be implemented better.

[0076] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An EHA-based internal expansion mechanical locking hydraulic outrigger, comprising an EHA drive assembly and a hydraulic outrigger assembly, characterized in that: The hydraulic support leg assembly comprises a cylindrical valve block (6), an accumulator (7), a transition block (8), an oil cylinder upper end cover (9), a piston upper end cover (10), a spiral sleeve (11), a piston lower end cover (12), a piston rod (13), an oil cylinder lower end cover (14), a cylinder barrel (16), an upper chamber oil guide pipe (17), an unlocking oil guide pipe (23), a lower chamber oil guide pipe (27), a first one-way valve (21), a second one-way valve (22), a third one-way valve (26), a fourth one-way valve (29), a first externally controlled sequence valve (30), a second externally controlled sequence valve (32), a first relief valve (31) and a second relief valve (33); The transition block (8) and the upper end cover (9) of the oil cylinder are provided with three oil passages, which are connected to the oil passage inside the cylindrical valve block (6). The piston rod (13) in the hydraulic cylinder is connected to the upper end cover (10) and the lower end cover (12) of the piston through a threaded connection. A spiral sleeve (11) is sandwiched between the upper end cover (10) and the lower end cover (12). The spiral sleeve (11) is fitted onto the piston rod (13) through a clearance fit. Two oil guide holes are opened in the axial direction inside the piston rod (13), one of which is opened with a radial through hole to communicate with the rod cavity of the oil cylinder, and the other is opened with a radial through hole to communicate with the spiral groove of the spiral sleeve (11); The spiral groove cavity on the outer surface of the spiral sleeve (11) is connected to the third oil path (43) through the oil guide hole of the lower cavity oil guide tube (27) installed inside the piston rod (13); The rodless cavity of the hydraulic oil cylinder is connected to the external first oil circuit (41) through the oil guide hole installed with the upper cavity oil guide pipe (17), thereby realizing the oil inlet and outlet of the rodless cavity of the hydraulic oil cylinder; The rod chamber of the hydraulic oil cylinder is connected to the external oil circuit through the oil guide hole equipped with the unlocking oil guide pipe (23), thereby realizing the oil inlet and outlet of the rod chamber of the oil cylinder; The first one-way valve (21), the third one-way valve (26), the lower chamber oil guide pipe (27), the spiral sleeve (11) and the piston rod (13) constitute a hydraulic unlocking oil circuit; The first one-way valve (21) and the third one-way valve (26) in the hydraulic unlocking oil circuit are integrated in the cylindrical valve block (6). The first one-way valve (21) is connected to the middle of the second node (36) and the third node (37) through the flow channel inside the cylindrical valve block (6), and the third one-way valve (26) is connected to the middle of the first node (35) and the third node (37). The oil guide hole inside the piston rod (13) is finally connected to the spiral groove of the spiral sleeve (11). The second one-way valve (22), the second externally controlled sequence valve (32), the accumulator (7), the second relief valve (33), the unlocking oil guide pipe (23) and the piston rod (13) form an oil circuit connected to the rod chamber of the hydraulic cylinder; The second one-way valve (22), the second externally controlled sequence valve (32), and the second overflow valve (33) in the oil circuit of the rod chamber are integrated in the cylindrical valve block (6). The second one-way valve (22) and the second externally controlled sequence valve (32) are connected in parallel between the second node (36) and the fourth node (38) through the internal flow channel in the cylindrical valve block (6). The accumulator (7) and the cylindrical valve block (6) are connected to the fourth node (38) through the internal oil channel, and finally communicate with the rod chamber through the unlocking oil guide pipe (23) and the internal oil guide hole of the piston rod (13); The fourth one-way valve (29), the first externally controlled sequence valve (30), the first relief valve (31), and the upper chamber oil guide pipe (17) form an oil circuit connecting the rodless chamber of the oil cylinder; The fourth one-way valve (29), the first externally controlled sequence valve (30), and the first overflow valve (31) in the rodless chamber oil circuit are all integrated in the cylindrical valve block (6). The fourth one-way valve (29) and the first externally controlled sequence valve (30) are connected in parallel between the first node (35) and the fifth node (39) through the internal flow channel in the cylindrical valve block (6), and finally communicated with the rodless chamber through the upper chamber oil guide pipe (17).

2. The EHA-based internal expansion mechanical locking hydraulic support leg according to claim 1, characterized in that: The control port of the second externally controlled sequence valve (32) is connected to the third node (37), and when the pressure of the third node (37) reaches or exceeds the unlocking pressure, the conduction state is opened, allowing the high-pressure oil to enter the rod chamber through the flow channel where it is located, so that the oil cylinder can achieve retraction movement; When the oil cylinder retracts, the second one-way valve (22) is in a cut-off state. When the oil cylinder extends, the second one-way valve (22) allows the oil in the rod chamber of the oil cylinder to return and flow out.

3. The EHA-based internal expansion mechanical locking hydraulic support leg according to claim 2, characterized in that: The control port of the first externally controlled sequence valve (30) is connected to the third node (37). When the pressure of the third node (37) reaches or exceeds the unlocking pressure, the conducting state is opened, allowing high-pressure oil to enter the rodless chamber of the cylinder through the flow channel where it is located, so that the cylinder can achieve extension movement.

4. The EHA-based internal expansion mechanical locking hydraulic support leg according to claim 1, characterized in that: When no unlocking pressure oil is injected into the unlocking spiral groove, the spiral sleeve (11) and the cylinder (16) are in an interference fit state; under the positive pressure generated by the interference fit, static friction force, i.e., self-locking force, is generated on the matching surfaces, thereby allowing the hydraulic support leg to bear the axial load and form a self-locking force; When unlocking high-pressure oil is introduced into the unlocking spiral groove of the spiral sleeve (11), the cylinder (16) will undergo radial elastic deformation and expand under the action of the oil pressure, and the fitting state of the spiral sleeve (11) and the cylinder (16) will change from interference fit to clearance fit, and the hydraulic support leg will be unlocked.

5. The EHA-based internal expansion mechanical locking hydraulic support leg according to claim 1, characterized in that: The first externally controlled sequence valve (30) and the second externally controlled sequence valve (32) are respectively set to have minimum opening pressures p2 and p5, and the set values ​​are equal to the hydraulic cylinder unlocking pressure p1.

6. The EHA-based internal expansion mechanical locking hydraulic support leg according to claim 1, characterized in that: The EHA drive assembly includes a motor drive controller (2), a coupling seat (4), a battery pack (18), a motor (19), a right valve block (20), a left valve block (25) and a bidirectional gear pump (5); The motor drive controller (2), the battery pack (18) and the motor (19) are integrated on the coupling seat (4); a heat dissipation cover (3) is provided on the outside of the motor (19), and an end cover (1) is provided on the top of the motor (19); a bidirectional gear pump (5) is connected to the motor (19); the oil inlet and outlet of the bidirectional gear pump (5) are interconnected with the internal oil circuits of the right valve block (20), the left valve block (25) and the cylindrical valve block (6); the cylindrical valve block (6) is connected to the accumulator (7), and three oil channels are provided inside the accumulator (7) to communicate with the three oil outlets of the cylindrical valve block (6). Under the drive of the motor (19), the bidirectional gear pump (5) transmits oil to the hydraulic support leg through the three oil channels.

7. The method for operating the EHA-based internal expansion mechanical locking hydraulic support leg according to any one of claims 1 to 3, characterized in that include: Leg extension step: The remote controller (34) controls the motor (19) to rotate forward, and the motor (19) drives the high-pressure oil output by the bidirectional gear pump (5) to reach the first node (35) through the first oil circuit (41) and realize diversion: one path of oil is diverted at the third node (37) through the third one-way valve (26), one path flows into the unlocking spiral groove through the unlocking oil circuit, and the other two paths are connected to the external control oil circuits of the first external control sequence valve (30) and the second external control sequence valve (32) respectively; when the oil pressure of the third node (37) oil circuit reaches the unlocking pressure p1, the cylinder (16) is generated. The cylinder is unlocked by radial elastic deformation, and the piston assembly can now realize free axial movement. At the same time, since the minimum opening pressure p2 set by the first external control sequence valve (30) is also p1, when the cylinder is unlocked, the first external control sequence valve (30) will also be turned on, the fourth one-way valve (29) will be cut off, and the high-pressure oil will flow through the first external control sequence valve (30) and be injected into the upper chamber of the support leg cylinder. When the oil pressure p3 in the upper chamber of the cylinder continues to increase under the action of the increase in the flow rate of the motor-pump to reach the load lifting, the load support leg can move and extend, thereby lifting the load platform. Stop locking step: When the hydraulic support leg is extended to the specified position, the motor (19) stops rotating, the hydraulic system stops supplying oil to the cylinder (16), and a small amount of high-pressure oil between the spiral sleeve (11) and the cylinder assembly is quickly discharged through the leakage gap of the control element. The spiral groove of the spiral sleeve (11) loses the unlocking oil pressure, and the cylinder (16) undergoes radial elastic contraction and forms an interference fit with the spiral sleeve (11). The spiral sleeve (11) and the piston rod assembly are locked under the action of friction; the hydraulic support leg thus achieves long-term stable support at any position; Leg retraction step: the remote control motor is reversed, and the motor (19) drives the high-pressure oil output by the bidirectional gear pump (5) to reach the second node (36) through the second oil circuit (42) and realize diversion: the oil is diverted at the third node (37) through the third one-way valve (26), one of which flows into the unlocking spiral groove through the unlocking oil circuit, and the other two are connected to the external control oil circuits of the first external control sequence valve (30) and the second external control sequence valve (32) respectively; when the oil pressure of the oil circuit of the third node (37) reaches the unlocking pressure p1, the cylinder (16) undergoes radial elastic deformation to realize the unlocking of the cylinder, and the piston assembly can realize axial free movement; at the same time, because the minimum opening pressure p5 set by the second external control sequence valve (32) is the same as the cylinder unlocking pressure p1, when the cylinder is unlocked, the second external control sequence valve (32) will also be turned on, and the high-pressure oil flows through the second external control sequence valve (32) and is injected into the lower chamber of the leg cylinder, and the pressure of the liquid in the lower chamber of the leg cylinder is p6; Recovery stop step: When the outrigger piston assembly is fully retracted to the end of the stroke, the motor (19) stops rotating, the hydraulic system stops supplying oil, and the piston is locked under the action of mechanical friction.

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