Internal expansion type mechanical locking hydraulic supporting leg based on EHA and operation method of internal expansion type mechanical locking hydraulic supporting leg

Abstract

The invention discloses an internal expansion type mechanical locking hydraulic supporting leg based on EHA and an operation method of the internal expansion type mechanical locking hydraulic supporting leg. Comprising an EHA driving assembly and a hydraulic supporting leg assembly. The EHA driving assembly is integrated on the upper portion of the supporting leg, and the working principle of pressure loss self-locking and internal expansion unlocking under the condition that no external oil supply exists can be achieved. Through control over an EHA driving system, when high-pressure oil is input into an upper cavity oil guide pipe, the logic relation that the unlocking pressure p1 of a spiral groove is equal to the minimum opening pressure p2 of an external control sequence valve, is smaller than or equal to the load pressure p3 of an upper cavity of an oil cylinder and is smaller than the set overflow opening pressure p4 of an overflow valve is formed, and the function that the supporting leg oil cylinder is unlocked firstly and then stretched is guaranteed; when high-pressure oil is input into the lower cavity oil guide pipe, the logic relation that the unlocking pressure p1 of the spiral groove is equal to the minimum opening pressure p5 of the external control sequence valve, is smaller than or equal to the energy storage pressure p6 of the energy accumulator and is smaller than the set overflow opening pressure p7 of the overflow valve is formed, and the function that the supporting leg oil cylinder is unlocked firstly and then retracts is guaranteed.

Description

Technical Field

[0001] The 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 operation 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 type mechanical locking hydraulic 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] At present, the high-pressure unlocking oil circuit of the internal expansion type mechanical locking hydraulic outrigger is generally set separately in the outrigger structure, and works independently from the oil inlet and return oil driving oil circuits of the outrigger. These three oil circuits need to be connected to the vehicle-mounted hydraulic power system through three external oil pipes on the hydraulic outrigger. Therefore, compared with ordinary engineering vehicle hydraulic outriggers, the number of oil ports of the internal expansion type mechanical locking hydraulic outrigger increases. During use, there are disadvantages such as the need to modify the vehicle-mounted hydraulic system, small installation space, complex pipeline layout, and many oil leakage 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 outrigger and an operating method thereof.

[0006] The present invention is an independently operated internal expansion type mechanical locking hydraulic outrigger 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, making the system simpler and can be integrated into the hydraulic outrigger. The entire system can operate independently, does not require external hydraulic system access, and can be remotely controlled. The hydraulic outrigger is based on the working characteristics of mechanical friction self-locking, and can achieve the function of unlocking first and then moving under the drive of the EHA system. The EHA system of the hydraulic outrigger is integrated at the end of the outrigger. The movement functions of the hydraulic outrigger 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: An internal expansion type mechanical locking hydraulic outrigger based on EHA, comprising an EHA drive assembly and a hydraulic outrigger assembly; the hydraulic outrigger 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 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 by threaded connection. A spiral sleeve 11 is sandwiched between the upper end cover 10 and the lower end cover 12 of the piston, and the spiral sleeve 11 is sleeved on the piston rod 13 by clearance fit. The piston rod 13 has two oil guide holes axially formed inside, one of which has a radial through hole communicating with the rod chamber of the oil cylinder, and the other has a radial through hole communicating 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 pipe 27 installed inside the piston rod 13; 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; The rod chamber of the hydraulic cylinder is connected to the external oil circuit through the oil guide hole installed with the unlocking oil guide pipe 23, so that the oil inlet and outlet of the rod chamber of the cylinder can be realized.

[0008] 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; 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; through the lower chamber oil guide pipe 27 and the internal oil guide hole of the piston rod 13, they are finally connected to the spiral groove of the spiral sleeve 11.

[0009] 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 connecting 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 connected to the rod chamber through the unlocking oil guide pipe 23 and the internal oil guide hole of the piston rod 13.

[0010] 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 conducting state is turned on, 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.

[0011] 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 connected to the rodless chamber through the upper chamber oil guide pipe 17.

[0012] The control port of the first externally controlled sequential 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.

[0013] When the non-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, the matching surface forms a static friction force, that is, a self-locking force, by which the hydraulic support leg can 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.

[0014] The first externally controlled sequence valve 30 and the second externally controlled sequence valve 32 are respectively set to have the lowest opening pressures p2 and p5, and the set values ​​are equal to the hydraulic cylinder unlocking pressure p1.

[0015] 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, 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.

[0016] The operating method of the internal expansion type mechanical locking hydraulic outrigger based on EHA of the present invention is as follows: 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 undergoes radial elastic deformation. The cylinder is unlocked, and the piston assembly can realize 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, and 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 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 achieve the load lifting, the load leg can move and extend to achieve the lifting of the load platform. Stop locking steps: When the hydraulic outrigger is extended to the specified position, the motor 19 stops rotating, the hydraulic system stops supplying oil to the cylinder 16, and the trace volume 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; 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 circuit 42 and realize diversion: the oil in the three-way oil circuit 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 respectively connected to the external control oil circuits of the first external control sequence valve 30 and the second external control sequence valve 32; when the oil pressure of the third node 37 oil circuit 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 this time; 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 turned on, and the high-pressure oil can flow through the sequence valve 32 and be 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.

[0017] 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.

[0018] Compared with the prior art, the present invention has the following advantages and effects: The present invention can realize the working principle of self-locking under pressure loss and unlocking under internal expansion without external oil supply. By controlling the EHA drive system, when high-pressure oil is input into the upper chamber oil guide pipe 17, a logical relationship of spiral groove unlocking pressure p1 = minimum opening pressure p2 of the first external control sequence valve 30 ≤ load pressure p3 of the upper chamber of the oil cylinder < overflow opening pressure p4 set by the first overflow valve 31 is formed, so as to ensure the function of the outrigger oil cylinder being unlocked first and then extended; when high-pressure oil is input into the lower chamber oil guide pipe 27, a logical relationship of spiral groove unlocking pressure p1 = minimum opening pressure p5 of the second external control sequence valve 32 ≤ accumulator storage pressure p6 < overflow opening pressure p7 set by the second overflow valve 33 is formed, so as to ensure the function of the outrigger oil cylinder being unlocked first and then retracted.

[0019] In the present invention, when the motor of the EHA drive system stops working, the hydraulic outrigger can realize a long-term locking function under load at any position within its travel range. During the outrigger locking period, oil leakage in the hydraulic system has no effect on the outrigger position locking effect.

[0020] The hydraulic outrigger of the present invention can independently unlock, extend, retract and lock the outrigger. It does not need an external hydraulic system and cables, and is more convenient to use than an ordinary outrigger oil cylinder. It avoids the problems of hydraulic system modification, pipeline rearrangement, installation space limitation and increased leakage points caused by the use of the existing internal expansion mechanical locking hydraulic outrigger with three oil ports.

[0021] The hydraulic outrigger of the present invention integrates a permanent magnet synchronous motor, a high energy density lithium battery pack, and a wireless controller to form a hydraulic support system that integrates motor control and hydraulic drive. The entire system transmits control signals to an external remote control via Bluetooth connection, does not require external energy supply, and forms a simplified control system and control method. The entire system can be independently and automatically operated in a special engineering vehicle, and can also be remotely operated by engineering personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a top view schematic diagram of the internal expansion type mechanical locking hydraulic support leg based on EHA of the present invention.

[0023] Figure 2 for Figure 1 Schematic diagram of the longitudinal section along line AA.

[0024] Figure 3 for Figure 1 Schematic diagram of the longitudinal section of the middle BB.

[0025] Figure 4 This is the principle intention of the internal expansion mechanical locking hydraulic outrigger based on EHA of the present invention.

[0026] 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, 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 external control sequence valve 30, first overflow valve 31, second external control 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

[0027] The present invention is further described in detail below in conjunction with specific embodiments.

[0028] The present invention discloses an internal expansion type mechanical locking hydraulic outrigger based on EHA, comprising an EHA drive assembly and a hydraulic outrigger assembly; the hydraulic outrigger 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 overflow valve 31, a second overflow valve 33 and a remote controller 34; 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 by threaded connection. A spiral sleeve 11 is sandwiched between the upper end cover 10 and the lower end cover 12 of the piston, and the spiral sleeve 11 is sleeved on the piston rod 13 by clearance fit. The piston rod 13 has two oil guide holes axially formed inside, one of which has a radial through hole communicating with the rod chamber of the oil cylinder, and the other has a radial through hole communicating 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 pipe 27 installed inside the piston rod 13; 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; The rod chamber of the hydraulic cylinder is connected to the external oil circuit through the oil guide hole installed with the unlocking oil guide pipe 23, so that the oil inlet and outlet of the rod chamber of the cylinder can be realized.

[0029] 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; 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; through the lower chamber oil guide pipe 27 and the internal oil guide hole of the piston rod 13, they are finally connected to the spiral groove of the spiral sleeve 11.

[0030] 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 connecting 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 connected to the rod chamber through the unlocking oil guide pipe 23 and the internal oil guide hole of the piston rod 13.

[0031] 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 conducting state is turned on, 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 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 return and flow out at a very low pressure. The second overflow valve 33 plays a protective role to prevent excessive pressure in the system oil circuit from damaging components during the retraction movement.

[0032] 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 connected to the rodless chamber through the upper chamber oil guide pipe 17.

[0033] The control port of the first external control 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 turned on, allowing the 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. When the cylinder is extending, the fourth check valve 29 is in the cut-off state. When the cylinder is retracting, the fourth check valve 29 allows the oil in the rodless chamber of the cylinder to return oil and flow out at a very low pressure; the second external control sequence valve 32 plays a protective role to prevent the excessive pressure in the system oil circuit from damaging components during the extension movement.

[0034] When the non-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, the matching surface forms a static friction force, that is, a self-locking force, by which the hydraulic support leg can 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.

[0035] The first externally controlled sequence valve 30 and the second externally controlled sequence valve 32 are respectively set to have the lowest opening pressures p2 and p5, and the set values ​​are equal to the hydraulic cylinder unlocking pressure p1.

[0036] 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, 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 the accumulator 7 is provided with three oil channels inside to connect the three oil outlets of the cylindrical valve block 6. The bidirectional gear pump 5, driven by the motor 19, transfers the oil to the hydraulic leg through these three oil channels. The battery pack 18 is the energy source of the entire system, providing energy for the motor 19 and the motor drive controller 2 to ensure that the system does not need external energy input to form an independent individual.

[0037] The remote controller 34 is independent of the hydraulic outrigger, so that the operator can use it to control the hydraulic outrigger. The remote controller 34 is connected to the motor drive controller 2 via Bluetooth. The operator transmits control signals to the motor drive controller 2 through buttons on the remote controller 34, thereby controlling the start and stop, forward and reverse rotation, and speed control functions of the motor.

[0038] The cylinder barrel 16 is separated by the piston assembly installed inside it to form two cavities, one with a rod and one without a rod, and the inlet and outlet oil circuits are connected respectively to form a double-acting hydraulic cylinder. The cylinder barrel 16 and the spiral sleeve 11 are in an interference fit state when there is no unlocking oil pressure, and the friction force generated by the friction pair mating surface is used to balance the axial load of the cylinder when locked. The cylinder barrel is the main load-bearing element of the internal expansion mechanical locking hydraulic leg based on EHA independent operation.

[0039] The piston upper end cover 10 and the piston lower end cover 12 are part of the piston assembly. They isolate the two oil chambers with rod and rodless and the unlocking pressure oil chamber (spiral groove) of the hydraulic cylinder through the sealing rings installed on their respective outer cylindrical surfaces. The piston upper end cover 10, the piston lower end cover 12 and the piston rod 13 are threadedly connected to clamp and fix the two ends of the spiral sleeve 11, and together constitute the piston / piston rod actuator assembly.

[0040] The spiral sleeve 11 is an important component of the mechanical locking friction pair of the internal expansion type mechanical locking hydraulic support leg based on EHA independent operation. The spiral sleeve 11 has an oil guide ring and a radial oil guide hole inside, and a spiral groove on its outer surface. The unlocking high-pressure oil can reach the spiral groove through the oil guide hole and the oil guide ring inside the piston rod. The spiral sleeve is made of a metal material with a large surface friction coefficient.

[0041] The operating method of the internal expansion type mechanical locking hydraulic outrigger based on EHA of the present invention is as follows: Leg extension step: the remote controller 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 realize 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 the motor-pump flow rate to achieve 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.

[0042] At the beginning of the outrigger extension process, the oil in the lower chamber of the outrigger enters the second oil circuit 42 through the unlocking oil guide pipe 23 and the second one-way valve 22, forming an oil return circuit and flowing back to the oil suction port of the bidirectional gear pump 5; at this time, since the volume of the lower chamber of the oil cylinder is smaller than the volume of the upper chamber, the return oil cannot meet the oil suction flow requirement of the bidirectional gear pump 5, and the accumulator 7 needs to release the oil to supplement the return oil flow; in this way, when the motor 19 is in the forward rotation state, when the system oil pressure reaches the set value, the hydraulic outrigger can be unlocked and the load extension action can be completed. The first relief valve 31 plays a safety protection role in the outrigger extension movement process, and its set overflow opening pressure is p4.

[0043] Stop locking steps: When the hydraulic outrigger is extended to a certain leveling designated 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, the cylinder 16 undergoes radial elastic contraction and forms an interference fit with the spiral sleeve 11, and 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; Leg retraction steps: The motor is remotely controlled to reverse (clockwise rotation), 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 in the two-way circuit 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 respectively connected to the external control oil circuits of the first external control sequence valve 30 and the second external control sequence valve 32; when the oil pressure of the third node 37 oil circuit 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 this time; 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 turned on, and the high-pressure oil can flow through the sequence valve 32 (the second one-way valve 22 is cut off) and 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.

[0044] At the beginning of the outrigger retraction process, the oil in the upper chamber of the outrigger enters the first oil circuit 41 through the upper chamber oil guide pipe 17 of the oil cylinder and the fourth one-way valve 29 to form an oil return circuit, and the oil return flows into the oil suction port of the bidirectional gear pump 5. At this time, since the volume of the upper chamber of the outrigger oil cylinder is larger than the volume of the lower chamber, when the piston retracts, the suction and discharge flow of the gear pump exceeds the amount of oil that can be accommodated in the lower chamber of the oil cylinder, and the accumulator 7 will absorb the excess volume of oil to achieve energy storage, and cause the energy storage pressure p6 to gradually increase. At the same time, the output pressure of the gear pump will also increase. In this way, when the system oil pressure reaches the set value in the motor reversal state, the hydraulic outrigger can be unlocked and the no-load retraction action can be completed. When the outrigger retracts, even in the no-load state, the action sequence of unlocking first and then retracting should be ensured. During the outrigger retraction process, the output oil pressure of the pump will gradually increase with the increase of the pressure p6 of the accumulator (gradually exceeding p1), until the outrigger retraction movement stops after reaching the overflow opening pressure of the second overflow valve 33. The second overflow valve 33 plays a safety protection role in the outrigger retraction movement process, and its set overflow opening pressure is p7.

[0045] 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.

[0046] As described above, the present invention can be better implemented.

[0047] 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 shall be equivalent replacement methods and shall be included in the protection scope 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 by means of threaded connection. A spiral sleeve (11) is sandwiched between the upper end cover (10) and the lower end cover (12), and the spiral sleeve (11) is sleeved on the piston rod (13) by means of clearance fit. Two oil guide holes are formed in the piston rod (13) along the axial direction, one of which is provided with a radial through hole for communicating with the rod chamber of the oil cylinder, and the other is provided with a radial through hole for communicating 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 an oil guide hole of a lower cavity oil guide tube (27) installed inside the piston rod (13); The rodless chamber of the hydraulic oil cylinder is connected to an external first oil circuit (41) through an oil guide hole provided with an upper chamber oil guide pipe (17), thereby achieving oil inlet and outlet of the rodless chamber of the hydraulic oil cylinder; The rod chamber of the hydraulic oil cylinder is connected to an external oil circuit through the oil guide hole on which the unlocking oil guide pipe (23) is installed, thereby realizing the oil inlet and outlet of the rod chamber of the oil cylinder.

2. According to claim 1, the internal expansion type mechanical locking hydraulic outrigger based on EHA is characterized in that: 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; 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); the third one-way valve (26) is connected to the middle of the first node (35) and the third node (37); and the oil guide hole inside the piston rod (13) is finally connected to the spiral groove of the spiral sleeve (11) through the lower chamber oil guide pipe (27) and the piston rod (13).

3. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 2, characterized in that: The second one-way valve (22), the second externally controlled sequence valve (32), the accumulator (7), the second overflow 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).

4. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 3, 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 conducting 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.

5. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 3, characterized in that: 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 connected to the rodless chamber through the upper chamber oil guide pipe (17).

6. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 5, characterized in that: The control port of the first externally controlled sequence valve (30) is connected to the third node (37), and 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.

7. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 6, characterized in that: When non-unlocking pressure oil is injected into the unlocking spiral groove, the spiral sleeve (11) and the cylinder barrel (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 formed on the matching surfaces, whereby the hydraulic support leg bears the axial load and forms a self-locking force; When unlocking high-pressure oil is introduced into the unlocking spiral groove of the spiral sleeve (11), the cylinder barrel (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 barrel (16) will change from an interference fit to a clearance fit, and the hydraulic support leg will be unlocked.

8. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 7, characterized in that: The first externally controlled sequence valve (30) and the second externally controlled sequence valve (32) are respectively set to have the lowest opening pressures p2 and p5, and the set values ​​are equal to the hydraulic cylinder unlocking pressure p1.

9. The EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 7, characterized in that: The EHA drive assembly comprises 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 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 communicate with the three oil outlets of the cylindrical valve block (6); the bidirectional gear pump (5) is driven by the motor (19) to transfer oil to the hydraulic support leg through the three oil channels.

10. The operating method of the EHA-based internal expansion mechanical locking hydraulic outrigger according to claim 9, 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 the 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 respectively connected to the external control oil circuits of the first external control sequence valve (30) and the second external control sequence valve (32); when the oil pressure of the third node (37) oil circuit reaches the unlocking pressure p1, the cylinder (1 6) radial elastic deformation occurs to unlock the oil cylinder, and the piston assembly can now realize 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 oil 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 outrigger oil cylinder; when the oil pressure p3 in the upper chamber of the oil 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 outrigger can move and extend, thereby lifting the load platform; Stop locking steps: When the hydraulic outrigger 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, the cylinder (16) undergoes radial elastic contraction and forms an interference fit with the spiral sleeve (11), and 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; Leg retraction step: 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 path flows into the unlocking spiral groove through the unlocking oil path, and the other two paths are respectively connected to the external control oil paths of the first external control sequence valve (30) and the second external control sequence valve (32); when the oil pressure of the oil path of the third node (37) reaches the unlocking pressure p1, the cylinder barrel (16) undergoes radial elastic deformation to realize the unlocking of the cylinder, and the piston assembly can realize axial free movement at this time; 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 turned on, and the high-pressure oil can flow through the sequence valve 32 and be injected into the lower chamber of the leg cylinder, and the pressure of the oil 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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