Electric control multi-way reversing valve for tower crane jacking hydraulic system

Abstract

The invention relates to the technical field of tower crane jacking hydraulic system control, in particular to an electric control multi-way reversing valve for a tower crane jacking hydraulic system, which comprises a valve body, a valve rod, a spring, a spring seat, an electromagnet assembly, a throttling screw, a shunting screw and a safety overflow valve assembly. Installation operation can be achieved by two persons, safety operation risks can be reduced, labor intensity of workers is reduced, working efficiency is improved, specifically, a three-position six-way reversing valve structure is adopted, the pressure and flow fine adjustment performance is achieved, hydraulic impact is small, oil ways are connected in series, when valve rods are in the middle position, oil inlets and outlets are completely closed, and the pressure maintaining effect is achieved; the throttling screw and the flow dividing screw are installed in the valve body, the movement speed of oil cylinders with different cylinder diameters can be controlled, a hydraulic system is controlled through a PLC program, one-key operation can be achieved in tower crane jacking operation, the safety risk is reduced, the labor cost is saved, and the working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tower crane jacking hydraulic system control, in particular to an electrically controlled multi-way reversing valve used in a tower crane jacking hydraulic system. Background Art

[0002] As we all know, the tower crane lifting hydraulic system increases or decreases standard sections by lifting and lowering the tower crane frame mechanism to meet the needs of vertical transportation of buildings of different heights. The lifting hydraulic system is generally composed of a hydraulic oil tank, an electric motor, a hydraulic pump, a reversing valve, a lifting cylinder, a hydraulic hose, hydraulic accessories, etc. The hydraulic reversing valve changes the direction of the fluid flow and connects or closes the hydraulic circuit through the movement of the valve stem in the valve body hole to achieve the predetermined action of the tower crane lifting cylinder and the pin cylinder.

[0003] The existing tower crane jacking process generally manually operates the hydraulic reversing valve to realize the jacking operation of the main oil cylinder, and the pin shaft disassembly and assembly rely on workers to climb up and down manually, which can no longer meet the needs of industry development. With the continuous improvement of society's requirements for intelligence, safety and work efficiency, it is necessary to improve the hydraulic system and upgrade the tower crane lifting and loading and unloading operations from manual to automated operations. In order to solve the above problems, an electrically controlled multi-way reversing valve for the tower crane jacking hydraulic system is needed. Summary of the invention

[0004] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides an electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system to solve the problems raised in the above background technology.

[0005] (II) Technical solution To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system, comprising a valve body, a valve stem, a spring, a spring seat, an electromagnet assembly, a throttling screw, a diverter screw and a safety relief valve assembly, wherein an independent unloading oil passage is arranged in the valve body, and each oil passage is connected in series, the valve stem is located in the middle position of each valve hole in the valve body, the inlet and outlet oil ports are completely closed when the valve stem is in the middle position, and a throttling groove is provided in the valve stem, the spring is fixedly arranged on both sides of the valve stem, the spring seat is fixedly arranged on both sides of the valve stem, the electromagnet assembly is fixedly arranged on both sides of the valve stem, the electromagnet assembly has a manual reset function, the throttling screw is fixedly arranged on the valve body, the diverter screw is fixedly arranged on the valve body, and the safety relief valve assembly is used to limit the maximum pressure of the hydraulic system.

[0006] Preferably, when each valve rod is in the middle position, the unloading oil passage allows the hydraulic oil supplied by the hydraulic pump to return directly to the oil tank, thereby realizing the middle position unloading function.

[0007] Furthermore, the valve stem of the rear link can only move when the valve stem of the front link is in the middle position, thereby realizing the oil circuit interlocking function, and the electric-controlled multi-way reversing valve can be made into different numbers of links such as 1 link, 2 links, 3 links, 4 links, etc. according to needs.

[0008] Furthermore, when the valve stem is in the middle position, the oil inlet and outlet ports are completely closed, so that the oil cylinders of the jacking link, the locking pin link I and II oil circuits have a pressure-maintaining function.

[0009] In a further solution, the throttling groove designed on the valve stem is used to reduce the impact of starting and closing the oil cylinder.

[0010] On the basis of the above scheme, the throttling screw and the diverter screw enable the oil inlet and outlet ports and the oil circuit to have throttling and diverter functions, and the movement speed of the locking pin-linked cylinder can be controlled by changing the flow area of ​​the screw hole by replacing the screw.

[0011] On the basis of the above scheme, time relay A and time relay B are further arranged at the power supply of the electromagnetic coils at both ends of the jacking link to control the power-off timing of the electromagnet assembly, so as to control the opening frequency of the valve body, extend the service life of the valve body, avoid high-pressure shock when the hydraulic cylinder reaches the maximum stroke, and improve the stability of the hydraulic jacking system. Time relay A and time relay B can set the oil supply time according to the actual oil supply of the hydraulic pump, and the control mode of the electronically controlled multi-way reversing valve can be changed to hydraulic control or manual control, which is suitable for hydraulic systems with different requirements.

[0012] (III) Beneficial effects Compared with the prior art, the present invention provides an electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system, which has the following beneficial effects: The electric-controlled multi-way reversing valve used in the tower crane lifting hydraulic system, through the application of the electric-controlled multi-way reversing valve and PLC program control, the tower crane lifting and installation operations that currently require about 5 people to operate can be realized by 2 people, which can reduce the risk of safe operations, reduce the labor intensity of workers, and improve work efficiency. The social benefits brought are obvious. Specifically, it can realize mid-position unloading and achieve the purpose of energy saving in the hydraulic system. The three-position six-way reversing valve structure has the performance of fine-tuning pressure and flow, and the hydraulic shock is small. The oil circuits are connected in series, and the oil circuits have interlocking characteristics. The throttling groove is designed on the valve stem to make the hydraulic cylinder start and close more smoothly. When the valve stem is in the middle position, the inlet and outlet oil ports are completely closed, which has a pressure-maintaining effect and makes the tower crane jacking operation safer. The valve body is equipped with a throttling screw and a diverter screw, which can control the movement speed of cylinders with different cylinder diameters by changing the size of the screw hole. The hydraulic system is controlled by a PLC program, and the tower crane jacking operation can be achieved by one-button operation, which reduces safety risks, saves labor costs, and improves work efficiency. The control valve has a compact structure design, low cost, and is easy to install and use. The electromagnet has a manual reset function. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a side view structural schematic diagram of the present invention; Figure 2 It is a structural schematic diagram of the spring of the present invention; Figure 3 It is a schematic diagram of the cross-sectional structure of the valve body of the present invention; Figure 4 It is a structural schematic diagram of the throttling screw of the present invention; Figure 5 It is a structural schematic diagram of the safety relief valve assembly of the present invention; Figure 6 This is a schematic diagram of the tower crane lifting hydraulic system of the present invention; Figure 7 It is a structural schematic diagram of the valve body of the present invention.

[0014] In the figure: 1. valve body; 2. electromagnet assembly; 3. safety relief valve assembly; 4. spring; 5. spring seat; 6. valve stem; 7. throttling screw; 8. diverter screw; 9. hydraulic pump; 11. time relay A; 12. time relay B. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example 1 See also Figures 1 to 7An electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system comprises a valve body 1, a valve stem 6, a spring 4, a spring seat 5, an electromagnet assembly 2, a throttling screw 7, a diverter screw 8 and a safety relief valve assembly 3. An independent unloading oil passage is arranged in the valve body 1, and each oil passage is connected in series. The valve body 1 is the basic structural component of the entire electrically controlled multi-way reversing valve, and an independent unloading oil passage is arranged inside. Each oil passage is arranged in series. For example, each oil passage is like being connected in series on a "pipeline chain", and the hydraulic oil flows through each part that needs to be acted on in turn according to the set series order. This series connection method is helpful for the entire The oil flow direction of the hydraulic system is orderly controlled to ensure that the hydraulic pressure can be accurately transmitted to the corresponding actuators (such as cylinders, etc.) to play a role. A plurality of valve-joining holes are arranged on the valve body 1. These valve-joining holes provide space for the installation and movement of components such as the valve stem 6, and are the key foundation for the construction of the entire internal structure of the valve. Valve bodies 1 with different numbers of joints (1, 2, 3, 4, etc.) can be selected according to the complexity and specific needs of the actual tower crane lifting hydraulic system, just like choosing bricks of different specifications for building buildings of different sizes. Valve bodies 1 with different numbers of joints can adapt to hydraulic circuit configurations with different functional requirements.

[0017] The valve stem 6 is located in the middle position of each valve hole of the valve body 1. When the valve stem 6 is in the middle position, the oil inlet and outlet are completely closed, and the valve stem 6 is provided with a throttling groove. The valve stem 6 is located in the middle position of each valve hole of the valve body 1. It has a close matching relationship with the valve hole of the valve body 1, and realizes the switching control of the oil circuit by axial movement in the hole. When the valve stem 6 is in the middle position, the oil inlet and outlet are completely closed. This feature enables the jacking link, lock pin link Ⅰ and Ⅱ oil circuit cylinders to have a pressure maintaining function. That is to say, at this time, the hydraulic oil is "locked" in the oil circuit where the cylinder is located, and will not leak or flow at will, so that the cylinder can maintain stable operation under the current pressure state, just like giving the hydraulic air where the cylinder is located The valve stem 6 is provided with a throttling groove, which plays a key role in the process of starting and closing the oil cylinder. When the oil cylinder is started or closed, the hydraulic oil flows through the throttling groove. The existence of the throttling groove changes the flow rate and flow characteristics of the hydraulic oil, making the flow of the hydraulic oil smoother, so that the impact on the oil cylinder when starting and closing is smaller, just like setting a "buffer zone" for the flow of hydraulic oil, avoiding the large impact force on the oil cylinder caused by the sudden influx of hydraulic oil or the rapid cessation of flow, thereby extending the service life of the oil cylinder and the entire hydraulic system. The spring 4 is fixedly arranged on both sides of the valve stem 6. The spring 4 plays a role of resetting and auxiliary positioning during the entire working process of the valve. When the electromagnet assembly 2 applies a force to the valve stem 6 to move it, once the force of the electromagnet assembly 2 disappears, the spring 4 relies on its own elastic deformation recovery force to push the valve stem 6 back to the initial middle position or other set equilibrium position, ensuring that the valve stem 6 can be accurately reset without continuous external drive and maintaining the normal initial state of the hydraulic system oil circuit, just like an elastic "pull rope" to pull the valve stem 6 back to its position.

[0018] The spring seat 5 is fixedly arranged on both sides of the valve stem 6. The spring seat 5 is fixedly arranged on both sides of the valve stem 6. It has a fixed connection relationship with the valve body 1 and is usually installed at the corresponding position on the valve body 1 by means of threaded connection or tight fit. The main function of the spring seat 5 is to provide a stable supporting foundation for the spring 4, to ensure that the spring 4 can elastically expand and contract along the correct axial direction during operation, and to accurately transmit the elastic force of the spring 4 to the valve stem 6, so that the entire reset and auxiliary positioning mechanism can operate stably and reliably. If the spring 4 is compared to an elastic "pillar", then the spring seat 5 is the stable "foundation" that supports this "pillar".

[0019] The electromagnet assembly 2 is fixedly arranged on both sides of the valve stem 6, and the electromagnet assembly 2 has a manual reset function. The electromagnet assembly 2 is fixedly arranged on both sides of the valve stem 6, and is also correspondingly fixedly connected to the valve body 1, and is connected to the mounting seat reserved in the valve body 1 by bolts. The electromagnet assembly 2 has a manual reset function. During normal operation, it generates electromagnetic force by energizing. This electromagnetic force acts on the valve stem 6, overcomes the elastic force of the spring 4 and makes the valve stem 6 move axially along the valve connecting hole, thereby realizing the switching control of the oil circuit, which is equivalent to applying a "thrust" that can be artificially controlled to the valve stem 6, so that it changes its position to change the flow direction of the hydraulic oil. When special circumstances occur (such as power failure or manual operation is required), the reset mechanism on the electromagnet assembly 2 can be manually operated to make the valve stem 6 return to the middle position or other set positions, thereby ensuring that the hydraulic system can be flexibly adjusted and operate normally under various working conditions.

[0020] The throttling screw 7 is fixedly arranged on the valve body 1. The throttling screw 7 is fixedly arranged on the valve body 1, and is usually fixedly installed by screwing into a specially designed threaded hole on the valve body 1. The function of the throttling screw 7 is to make the oil inlet and outlet and the oil circuit have a throttling function, and to control the flow size of the hydraulic oil by changing the flow area of ​​the screw hole. For example, when it is necessary to reduce the hydraulic oil flow rate of a certain oil circuit, the throttling screw 7 can be properly screwed in to reduce the flow cross-sectional area of ​​the screw hole, so that the hydraulic oil is hindered when passing through, the flow rate becomes slower, and the flow becomes smaller, thereby realizing precise control of the flow rate of different oil circuits in the hydraulic system, just like installing an adjustable "valve" in the flow channel of the hydraulic oil.

[0021] The shunt screw 8 is fixedly set on the valve body 1. The shunt screw 8 is also fixedly set on the valve body 1 and is also installed in the shunt screw 8 mounting hole corresponding to the valve body 1 in a threaded connection manner. Its main function is to enable the inlet and outlet oil ports and the oil circuit to have a shunt function. During the flow of hydraulic oil, one oil flow is divided into multiple oil flows with different flow directions or different flow rates according to actual needs. By replacing the shunt screws 8 of different specifications (such as different apertures, different internal structures, etc.), the flow area of ​​the screw hole and the internal flow channel structure can be changed, thereby controlling the flow distribution of different branch oil circuits. It is like setting a device that can flexibly adjust the branch flow size at a "fork in the road" to ensure that the hydraulic oil can be accurately distributed to each required part according to the predetermined shunt scheme.

[0022] The safety relief valve assembly 3 is used to limit the maximum pressure of the hydraulic system. The safety relief valve assembly 3 is installed at a specific position on the valve body 1 and is tightly connected to the valve body 1 by flange connection or threaded connection. Its core function is to limit the maximum pressure of the hydraulic system. When the pressure in the hydraulic system exceeds the maximum pressure value preset by the safety relief valve assembly 3 due to some reason (such as sudden increase in load, oil circuit blockage, etc. causing abnormal pressure increase), the safety relief valve assembly 3 will automatically open to allow excess hydraulic oil to flow back to the oil tank through the overflow channel, thereby avoiding damage to the hydraulic system due to excessive pressure (such as oil pipe rupture, cylinder seal damage, etc.), and plays the role of pressure protection "valve body 1" for the entire hydraulic system, ensuring that the hydraulic system operates stably within a safe pressure range.

[0023] In this embodiment, when the valve stem 6 of each joint is in the middle position, the unloading oil passage allows the hydraulic oil supplied by the hydraulic pump 9 to return directly to the oil tank, thereby realizing the middle unloading function. When the valve stem 6 of each joint is in the middle position, the unloading oil passage plays a key role, allowing the hydraulic oil supplied by the hydraulic pump 9 to return directly to the oil tank, thereby realizing the middle unloading function. Specifically, the unloading oil passage has an ingenious connection with the oil circuits of each joint inside the valve body 1. When the valve stem 6 is in the middle position and the oil inlets and outlets are closed, the hydraulic oil output by the hydraulic pump 9 will flow directly back to the oil tank along the specially designed passage of the unloading oil passage. It avoids the meaningless pressure build-up of hydraulic oil in the system, reduces the load of hydraulic pump 9 when the equipment is not performing operations such as lifting, saves energy consumption, and also helps to extend the service life of hydraulic pump 9, just like opening a "flood discharge channel" for the hydraulic system when it does not need to work, allowing the hydraulic oil to smoothly return to the "water reservoir" of the oil tank. When the valve stem 6 of the previous link is in the middle position, the valve stem 6 of the next link can move to realize the oil circuit interlocking function, and the electronically controlled multi-way reversing valve can be made into different numbers of links such as 1 link, 2 links, 3 links, 4 links, etc. according to needs. The valve stem 6 is in the middle position. When the oil inlet and outlet are completely closed, the oil cylinders of the jacking link, the lock pin link Ⅰ and Ⅱ oil circuits have the function of maintaining pressure. The throttling groove designed on the valve stem 6 is used to reduce the impact of starting and closing the oil cylinder. The throttling screw 7 and the diverter screw 8 make the oil inlet and outlet and the oil circuit have throttling and diverting functions. The movement speed of the lock pin link oil cylinder can be controlled by changing the flow area of ​​the screw hole by replacing the screws. When the valve stem 6 of the previous link is in the middle position, the valve stem 6 of the next link can move, thereby realizing the oil circuit interlocking function. This is achieved through the series design of the oil circuit inside the valve body 1 and the logical control relationship between the valve stems 6. For example, in terms of design, the action of the valve stem 6 of the rear link needs to rely on a certain oil circuit state brought about by the valve stem 6 of the front link being in the middle position (such as the satisfaction of pressure, flow and other conditions) in order to unlock the restriction of its action. This avoids the chaos of the hydraulic system caused by the simultaneous and arbitrary action of oil circuits of different links, and ensures that the hydraulic oil flows to the corresponding actuators in the correct order and logic, just like setting "keys" (the middle position state of the valve stem 6 of the front link) for opening different "doors" (each oil circuit), thus ensuring the orderliness and safety of the operation of the entire hydraulic system.

[0024] In this embodiment, time relay A11 and time relay B12 are set at the power supply of the electromagnetic coil at both ends of the jacking link, which are used to control the power-off timing of the electromagnet, so as to control the opening frequency of the valve body 1, extend the service life of the valve body 1, avoid high-pressure shock when the hydraulic cylinder reaches the maximum stroke, and improve the stability of the hydraulic jacking system. The time relay A11 and the time relay B12 can set the oil supply time according to the actual oil supply of the hydraulic pump 9, and the control mode of the electronically controlled multi-way reversing valve can be changed to hydraulic control or manual control, which is suitable for hydraulic systems with different requirements. Time relay A11 and time relay B12 are set at the power supply of the electromagnetic coil at both ends of the jacking link, which are connected to the electromagnetic coil through an electrical circuit. The time relay A11 and the time relay B12 are connected to the electromagnetic coil through an electrical circuit. Relay B12 can set the oil supply time according to the actual oil supply of the hydraulic pump 9. Its main function is to control the power-off timing of the electromagnet assembly 2, thereby controlling the opening frequency of the valve body 1, extending the service life of the valve body 1, avoiding high-pressure shock when the hydraulic cylinder reaches the maximum stroke, and improving the stability of the hydraulic jacking system. For example, when the hydraulic cylinder is approaching the maximum stroke, the power-off of the electromagnet assembly 2 is accurately controlled by the time relay A11 and the time relay B12, so that the oil circuit is switched in time or the valve body 1 is opened in time to avoid the high-pressure shock caused by the continuous action of the hydraulic cylinder. It is like setting a precise "timer" for the operation of the hydraulic system, so that each action link can be connected in order at the right time to ensure the stable and safe operation of the system.

[0025] Example 2 like Figures 1 to 7 As shown in the figure, when the valve stem 6 of each joint is in the middle position, the A port, B port, P port, T1 port and T2 port are not connected, the oil cylinders of the jacking joint, the lock pin joint Ⅰ and Ⅱ oil circuits all have the pressure-maintaining function, and the hydraulic oil supplied by the hydraulic pump 9 directly returns to the oil tank through the unloading flow channel 1 and the flow channel 2, so as to achieve the purpose of energy saving. When the electromagnet on the left side of the jacking joint is energized, the electromagnet push rod pushes the valve stem 6 to move right, the unloading flow channel 1 and the flow channel 2 are closed, and the high-pressure oil output by the hydraulic pump 9 enters the A1 port through the P port. At this time, port B1 is connected with port T2, and the high-pressure oil at port A1 enters the rodless chamber of the jacking cylinder through the two-way hydraulic lock, pushing the tower crane sleeve frame and boom to a certain height. When the electromagnet on the right side of the jacking link is energized, the valve stem 6 is pushed to the left position, and the unloading circuit is still closed. High-pressure oil enters port B1. At this time, port A1 is connected with port T1, and the hydraulic oil flowing out of port B1 enters the rod chamber of the jacking cylinder through the two-way hydraulic lock. The cylinder retracts, driving the lower frame of the jacking mechanism to rise to a certain height.

[0026] like Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, after the electromagnets at both ends of the jacking link lose power, its valve stem 6 returns to the middle position, and the hydraulic oil flowing out from the jacking link flow channel 1 and flow channel 2 enters the lock pin link I after a part of the flow is separated through the small hole of the diverter screw 8 in the liquid flow channel. The electromagnet power gain and loss situation and the hydraulic oil flow direction control process of the lock pin link I are the same as those of the jacking link. The difference is that the throttling screw 7 is installed at the oil outlet and return port of the lock pin link respectively, and the two-way hydraulic lock is not installed in the lock pin link. Its working process will not be described here. Similarly, when the jacking link and the lock pin link I are both in the middle position, the hydraulic oil enters the lock pin link II, and the action of the lock pin link II is exactly the same as that of the lock pin link I.

[0027] In this electrically controlled multi-way reversing valve, the oil outlets A2, B2, A3, and B3 of the lock pin links Ⅰ and Ⅱ are all provided with throttling screws 7, and the holes of the throttling screws 7 are respectively connected in parallel with the screw holes of the diverter screws 8. The flow area of ​​the screw holes can be changed by replacing the screws to control the flow rates entering the oil outlets A2, B2, A3, and B3 of the lock pin links, thereby controlling the movement speed of the lock pin link cylinder.

[0028] When the valve stem 6 of a certain link is in the left or right position, after the extension length of the oil cylinder reaches the maximum length, the hydraulic system pressure quickly rises to the opening pressure of the valve body 1, the valve body 1 opens, and the high-pressure oil flows back to the oil tank through the valve body 1, limiting the maximum pressure of the hydraulic system. Until all the valve stems 6 of each link return to the middle position, the hydraulic system is unloaded.

[0029] The various links of the multi-way valve are designed to be connected in series. The valve stem 6 of the subsequent link can only be activated when the valve stem 6 of the previous link is in the middle position. That is, when the valve stem 6 of the subsequent link needs to supply oil to the hydraulic cylinder, the valve stems 6 of the previous links must be in the middle position. This multi-way valve has an oil circuit interlocking function.

[0030] like Figure 6 As shown, referring to the schematic diagram of the tower crane jacking hydraulic system, time relays A11 and B12 are set at the power supply of the electromagnetic coils at both ends of the jacking connection. When the oil cylinder extends or retracts a sufficient stroke but has not reached the maximum stroke, the electromagnet is de-energized under the control of the time relay, and the valve stem 6 returns to the middle position and the oil supply is stopped. The opening frequency of the valve body 1 can be further controlled to extend the service life of the valve body 1. At the same time, the high-pressure shock generated when the hydraulic cylinder reaches the maximum stroke is avoided, and the stability of the hydraulic jacking system is improved. The time relays A11 and B12 can set the oil supply time according to the actual oil supply of the hydraulic pump 9.

[0031] like Figure 7 As shown, this electrically controlled multi-way directional control valve can be made into a single-unit, or a dual-unit, triple-unit, quadruple-unit, etc. The control mode of this electrically controlled multi-way directional control valve can also be changed to hydraulic control or manual control, which is suitable for hydraulic systems with different requirements.

[0032] Working principle: The electrically controlled multi-way reversing valve used in the tower crane jacking hydraulic system is first placed at the position where the tower crane jacking hydraulic system needs to use it, and then, according to the specific jacking or lowering operation requirements, the power-on and power-off states of the corresponding electromagnets are controlled. For example, during the jacking operation, the electromagnet on the left side of the jacking link is energized first, and the valve stem 6 is pushed to move to realize the oil inlet of the rodless chamber of the jacking cylinder, and the sleeve and the arm rise. When it is necessary to stop or change the action, the electromagnet is de-energized according to the set control logic (such as time relay control or other sensor signals, etc.), and the valve stem 6 returns to the middle position or switches to the other side position. During the whole process, various components work together, such as the valve body 1 opens to relieve pressure when the pressure is too high, and the throttling screw 7 and the diverter screw 8 control the flow, so as to ensure the stable and efficient operation of the hydraulic system and realize the automation, safety and reliability of the tower crane jacking operation.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system, characterized in that: include: A valve body (1), wherein the valve body (1) is provided with independent unloading oil passages, and the oil passages are connected in series; A valve stem (6), wherein the valve stem (6) is located in the middle position of each valve hole of the valve body (1), the oil inlet and outlet ports are completely closed when the valve stem (6) is in the middle position, and a throttling groove is formed on the valve stem (6). A spring (4), wherein the spring (4) is fixedly arranged on both sides of the valve stem (6); Spring seats (5), the spring seats (5) being fixedly arranged on both sides of the valve stem (6); An electromagnet assembly (2), the electromagnet assembly (2) being fixedly arranged on both sides of the valve stem (6), and the electromagnet assembly (2) having a manual reset function; A throttling screw (7), wherein the throttling screw (7) is fixedly arranged on the valve body (1); A flow-dividing screw (8), the flow-dividing screw (8) being fixedly arranged on the valve body (1); A safety relief valve assembly (3), wherein the safety relief valve assembly (3) is used to limit the maximum pressure of a hydraulic system.

2. The electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system according to claim 1, characterized in that: A hydraulic pump (9), wherein the hydraulic pump (9) is mounted on the valve body (1); When each valve rod (6) is in the middle position, the unloading oil passage allows the hydraulic oil supplied by the hydraulic pump (9) to return directly to the oil tank, thereby realizing the middle position unloading function.

3. The electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system according to claim 2 is characterized in that: When the valve stem (6) of the first link is in the middle position, the valve stem (6) of the second link can be actuated to realize the oil circuit interlocking function. The electric control multi-way reversing valve can be made into different link numbers such as 1 link, 2 links, 3 links, 4 links, etc. according to the needs.

4. The electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system according to claim 3 is characterized in that: When the valve stem (6) is in the middle position, the oil inlet and outlet ports are completely closed, so that the oil cylinders of the jacking link, the locking pin link I and II oil circuits have a pressure-maintaining function.

5. The electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system according to claim 4 is characterized in that: The throttling groove designed on the valve stem (6) is used to reduce the impact of starting and closing the oil cylinder.

6. The electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system according to claim 5, characterized in that: The throttling screw (7) and the flow dividing screw (8) enable the oil inlet and outlet ports and the oil circuit to have throttling and flow dividing functions, and the movement speed of the locking pin-linked oil cylinder can be controlled by changing the flow area of ​​the screw hole by replacing the screw.

7. The electrically controlled multi-way reversing valve for a tower crane lifting hydraulic system according to claim 6, characterized in that: A time relay A (11) and a time relay B (12) are provided at the power supply locations of the electromagnetic coils at both ends of the jacking connection, and are used to control the timing of powering off the electromagnetic iron assembly (2), so as to control the frequency of opening the valve body (1), extend the service life of the valve body (1), avoid high-pressure shock when the hydraulic cylinder reaches the maximum stroke, and improve the stability of the hydraulic jacking system. The time relay A (11) and the time relay B (12) can set the oil supply time according to the actual oil supply of the hydraulic pump (9), and the control mode of the electronically controlled multi-way reversing valve can be changed to hydraulic control or manual control, and is suitable for hydraulic systems with different requirements.

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