阅读说明：本技术 剪叉车控制系统 (Cut fork truck control system ) 是由 姜洪 王震山 魏宏宇 张晓磊 柯稳 史浙安 于 2019-10-21 设计创作，主要内容包括：一种剪叉车控制系统。解决了现有的剪叉车功能单一,转向不可靠的问题。它包括主进油口、回油口、变副油口、转向油口、马达驱动口、第一换向阀、第二换向阀、第三换向阀和压力补偿器,所述的主进油口通过第一换向阀分别与变副油口、压力补偿器相连,所述压力补偿器控制腔选取压力补偿器出油口处的压力油并与压力补偿器弹簧腔相互配合控制压力补偿器的开口大小,所述压力补偿器出油口的压力油通过第三换向阀与马达驱动口相连通。本发明的有益效果是,通过压力补偿器能实现转向优先功能,特别是在行走动作和转向动作同时发生时,优先转向,且多余的油量才会用于其他动作,使得产品灵活性高,动作可靠。(A control system for a scissor fork truck. The problem of current cut fork truck function singleness, turn to insecure is solved. The hydraulic oil pressure compensator comprises a main oil inlet, an oil return port, a variable auxiliary oil port, a steering oil port, a motor driving port, a first reversing valve, a second reversing valve, a third reversing valve and a pressure compensator, wherein the main oil inlet is respectively connected with the variable auxiliary oil port and the pressure compensator through the first reversing valve, a control cavity of the pressure compensator selects pressure oil at an oil outlet of the pressure compensator and is matched with a spring cavity of the pressure compensator to control the opening size of the pressure compensator, and the pressure oil at the oil outlet of the pressure compensator is communicated with the motor driving port through the third reversing valve. The invention has the advantages that the pressure compensator can realize the steering priority function, especially when the walking action and the steering action occur simultaneously, the steering is prioritized, and the redundant oil quantity can be used for other actions, so that the product has high flexibility and reliable action.)

1. The control system of the forklift truck is characterized by comprising a main oil inlet (P), an oil return port (T), a variable auxiliary oil port (1), a steering oil port (2), a motor driving port (3), a first reversing valve (4), a second reversing valve (5), a third reversing valve (6) and a pressure compensator (7), wherein the main oil inlet is respectively connected with the variable auxiliary oil port and the pressure compensator through the first reversing valve, the second reversing valve is arranged between the pressure compensator and the steering oil port, a control cavity of the pressure compensator selects pressure oil at an oil outlet of the pressure compensator and is matched with a spring cavity of the pressure compensator to control the opening size of the pressure compensator, and the pressure oil at an oil outlet of the pressure compensator is communicated with the motor driving port through the third reversing valve.

2. The control system of claim 1, wherein the pressure oil at the pressure compensator oil outlet is in communication with the pressure compensator spring chamber via a second directional valve and cooperates with the pressure compensator control chamber to control the size of the pressure compensator opening.

3. A control system according to claim 2, characterised in that a first orifice (8) and a second orifice (9) are provided in the line between the second directional control valve and the pressure compensator spring chamber, the first orifice having a larger diameter than the second orifice.

4. A control system of a scissors forklift truck according to claim 3, characterized in that a first overflow valve (10) is arranged in a pipeline between the first throttle hole and the second throttle hole, and an oil outlet of the first overflow valve is communicated with an oil return port.

5. A control system for a scissors forklift according to claim 1, characterised in that a main overflow valve (11) is provided, said main overflow valve being located between the main inlet and the return.

6. A scissors fork truck control system as in claim 1, further comprising a balancing valve (12) disposed between the third reversing valve and the motor drive port, the balancing valve comprising a balancing excess flow valve (121), a balancing check valve (122) and a balancing orifice (123) disposed in parallel with each other.

7. A control system for a scissors forklift truck according to claim 1, wherein the motor driving ports are grouped into two groups, the two motor driving ports of each group are respectively connected with a walking motor, and a fourth direction changing valve (13) is arranged between the two groups of motor driving ports.

8. The control system of claim 7, wherein the fourth reversing valve has a first position in which the two sets of motor drive ports are arranged in parallel with one another and a second position in which the four reversing valves are arranged in series with one another.

9. The control system of the forklift truck according to claim 1, wherein pressure oil passing through the motor driving port is communicated with a back pressure check valve (14) and an oil supplementing check valve (15) through a third reversing valve, an oil outlet of the back pressure check valve is communicated with an oil return port, an oil outlet of the oil supplementing check valve is communicated with the motor driving port, and an oil drain hole (16) is arranged at the back pressure check valve in parallel.

10. The control system of claim 1, further comprising a brake port (17), and the pressure compensator and the third directional valve are provided with brake lines connected to the brake port.

Technical Field

The invention relates to a hydraulic control system, in particular to a control system of a scissor fork truck.

Background

The shearing forklift is used as a movable aerial work platform and is widely applied to airports, factories, construction sites, shipyards and the like. A scissor-type lifting platform is one of elevators, the working principle of the scissor-type lifting platform is similar to that of a scissor, and only manual driving is changed into oil cylinder driving, so that the scissor-type lifting platform and the working principle thereof can be formed. The scissor fork type lifting platform has a scissor fork mechanical structure, so that the lifting platform has higher stability, a wide operation platform and higher bearing capacity, the aerial work range is larger, and the scissor fork type lifting platform is suitable for simultaneous operation of multiple persons. It makes work efficiency higher, and the safety is more ensured. In a hydraulic lifting system of the scissor type hydraulic lifting platform in the prior art, an upper oil cylinder hydraulic oil path and a lower oil cylinder hydraulic oil path are generally arranged, a safety valve, a one-way throttle valve, an electromagnetic reversing valve and other hydraulic elements are generally arranged in the upper oil cylinder oil path, and a one-way throttle valve, an electromagnetic reversing valve and other hydraulic elements are also arranged in the lower oil cylinder oil path. Wherein: the safety valve plays a role in overload protection; the one-way throttle valve controls the quick rising and stable gliding of the output of the oil cylinder; the electromagnetic directional valve realizes the purpose of power-off self-locking. However, the lifting system of the scissor type hydraulic lifting platform in the prior art has the following problems: the scissor-fork type hydraulic lifting platform is compact in structure, and the hydraulic oil circuit of the upper oil cylinder and the hydraulic oil circuit of the lower oil cylinder are respectively provided with various hydraulic elements, so that the lifting system is huge in size, is not beneficial to arrangement of the hydraulic system on the lifting platform, or is increased in size, and is not suitable for being applied to narrow spaces; or the specification and the volume of hydraulic parts are reduced, so that all parameters of an oil way required by the lifting platform cannot meet the requirements. In addition, the existing hydraulic system of the forklift is single in function, only has a lifting function, and cannot realize a steering priority function, so that the forklift is troublesome to move and steer.

Disclosure of Invention

The invention provides a critical process valve for a power station, which aims to solve the problems that the existing forklift is single in function and unreliable in steering in the background technology.

The technical scheme of the invention is as follows: the utility model provides a scissor fork truck control system, includes main oil inlet, oil return opening, becomes vice hydraulic fluid port, turns to the hydraulic fluid port, motor drive mouth, first switching-over valve, second switching-over valve, third switching-over valve and pressure compensator, main oil inlet link to each other with becoming vice hydraulic fluid port, pressure compensator respectively through first switching-over valve, second switching-over valve locate pressure compensator and turn to between the hydraulic fluid port, pressure compensator control chamber selects the pressure oil of pressure compensator delivery port department and mutually supports the opening size of control pressure compensator with pressure compensator spring chamber, the pressure oil of pressure compensator oil-out is linked together through third switching-over valve and motor drive mouth.

As an improvement of the invention, the pressure oil at the oil outlet of the pressure compensator is communicated with the pressure compensator spring cavity through the second reversing valve and is matched with the pressure compensator control cavity to control the opening size of the pressure compensator.

As a further improvement of the invention, a first throttling hole and a second throttling hole are arranged in a pipeline between the second reversing valve and the pressure compensator spring cavity, and the diameter of the first throttling hole is larger than that of the second throttling hole.

As a further improvement of the invention, a first overflow valve is arranged in a pipeline between the first throttle hole and the second throttle hole, and an oil outlet of the first overflow valve is communicated with the oil return port.

As a further improvement of the invention, the oil return device is also provided with a main overflow valve which is arranged between the main oil inlet and the oil return port.

As a further improvement of the invention, a balance valve is also arranged and is arranged between the third reversing valve and the motor driving port, and the balance valve comprises a balance overflow valve, a balance check valve and a balance throttling hole which are arranged in parallel.

As a further improvement of the invention, two motor driving ports are arranged in two groups, two motor driving ports of each group are respectively connected with the walking motor, and a fourth reversing valve is arranged between the two motor driving ports.

As a further improvement of the present invention, the fourth direction valve has a first position where the two sets of motor driving ports are arranged in parallel with each other and a second position where the two sets of motor driving ports are connected in series after direction change.

As a further improvement of the invention, the pressure oil passing through the motor driving port is respectively communicated with the backpressure one-way valve and the oil supplementing one-way valve through a third reversing valve, the oil outlet of the backpressure one-way valve is communicated with the oil return port, the oil outlet of the oil supplementing one-way valve is communicated with the motor driving port, and the backpressure one-way valve is provided with an oil drainage hole in parallel.

As a further improvement of the invention, a brake interface is also arranged, and brake pipelines communicated with the brake interface are arranged on pipelines of the pressure compensator and the third reversing valve.

The invention has the advantages that the pressure compensator can realize the steering priority function, especially when the walking action and the steering action occur simultaneously, the steering is prioritized, and the redundant oil quantity can be used for other actions, so that the product has high flexibility and reliable action. The invention also has the advantages of simple structure, convenient assembly, reliable action, long service life and the like.

Drawings

Fig. 1 is a hydraulic original drawing of an embodiment of the present invention.

Fig. 2 is a schematic diagram of the balancing valve 12 of fig. 1.

In the figure, 1, a variable auxiliary oil port; 2. a steering oil port; 3. a motor drive port; 4. a first direction changing valve; 5. a second directional control valve; 6. a third directional control valve; 7. a pressure compensator; 8. a first orifice; 9. a second orifice; 10. a first overflow valve; 11. a main overflow valve; 12. a balancing valve; 121. a balanced overflow valve; 122. a balanced one-way valve; 123. a balance orifice; 13. a fourth directional control valve; 14. a back pressure check valve; 15. an oil-supplementing one-way valve; 16. an oil drainage hole; 17. a brake interface; p, a main oil inlet; t, an oil return port.

Detailed Description

The embodiments of the invention will be further described with reference to the accompanying drawings in which:

referring to fig. 1 and fig. 2, a forklift truck control system comprises a main oil inlet P, an oil return port T, a variable auxiliary oil port 1, a steering oil port 2, a motor driving port 3, a first reversing valve 4, a second reversing valve 5, a third reversing valve 6 and a pressure compensator 7, wherein the main oil inlet is connected with the variable auxiliary oil port and the pressure compensator respectively through the first reversing valve, the second reversing valve is arranged between the pressure compensator and the steering oil port, a pressure compensator control cavity selects pressure oil at an oil outlet of the pressure compensator and is matched with a pressure compensator spring cavity to control the opening size of the pressure compensator, and the pressure oil at an oil outlet of the pressure compensator is communicated with the motor driving port through the third reversing valve. The invention has the advantages that the pressure compensator can realize the steering priority function, especially when the walking action and the steering action occur simultaneously, the steering is prioritized, and the redundant oil quantity can be used for other actions, so that the product has high flexibility and reliable action. The invention also has the advantages of simple structure, convenient assembly, reliable action, long service life and the like. The hydraulic pressure compensator has a steering priority function, pressure oil of a main oil inlet is directly supplied to a motor driving port through the pressure compensator when the system needs steering operation, so that the traveling motor is driven to move, when the system needs steering operation, the pressure oil of the main oil inlet is supplied to a steering oil port through the second reversing valve, so that the system can steer reliably, meanwhile, the pressure oil enters a pressure compensator spring cavity through the second reversing valve, the pressure oil at an oil outlet of the pressure compensator simultaneously enters a pressure compensator control cavity, and the spring cavity and the control cavity of the pressure compensator are matched with each other to realize the opening size of a pressure compensator valve core. In the invention, the first reversing valve is a two-position four-way reversing valve, specifically, the first reversing valve is an electromagnetic reversing valve, and the steering and walking operation is usually not carried out when the auxiliary oil port acts. The second reversing valve is an electromagnetic reversing valve, and specifically, the second reversing valve is a three-position five-way reversing valve. The third reversing valve is an electromagnetic reversing valve, and specifically, the third reversing valve is a three-position four-way reversing valve. The fourth reversing valve is an electromagnetic reversing valve, and specifically, the fourth reversing valve is a two-position four-way reversing valve.

And the pressure oil at the oil outlet of the pressure compensator is communicated with the spring cavity of the pressure compensator through a second reversing valve and is matched with the control cavity of the pressure compensator to control the size of the opening of the pressure compensator. The structure ensures that the system can realize preferential steering oil supply and reasonably distribute oil simultaneously, so that the invention has reliable action.

And a first throttling hole 8 and a second throttling hole 9 are formed in a pipeline between the second reversing valve and the pressure compensator spring cavity, and the diameter of the first throttling hole is larger than that of the second throttling hole. Specifically, a first overflow valve 10 is arranged in a pipeline between the first throttle hole and the second throttle hole, and an oil outlet of the first overflow valve is communicated with an oil return port. The first throttling hole and the second throttling hole are arranged, so that pressure oil flowing into the pressure compensator is smoother, the impact is small, and the steering performance is not affected. The arrangement of the first overflow valve plays a role in overload protection, so that the steering pipeline is safer and more reliable. Specifically, a variable auxiliary overflow valve is also arranged in a pipeline of the variable auxiliary oil port, and the variable auxiliary overflow valve plays a role in performing high-pressure overflow on the variable auxiliary oil port and protecting an actuating mechanism or an element.

The invention is also provided with a main overflow valve 11 which is arranged between the main oil inlet and the oil return port. The main overflow valve plays a role in overload protection, so that the system is safer.

The invention is also provided with a balance valve 12 which is arranged between the third reversing valve and the motor driving port and comprises a balance overflow valve 121, a balance check valve 122 and a balance throttling hole 123 which are arranged in parallel. The balance valve is arranged to drive the walking motor at the motor driving outlet more stably. Specifically, when the motor driving port acts, oil is supplied through the balance check valve, the balance overflow valve plays a role in safety overflow and enables pressure of supplied pressure oil to be kept balanced, and the arrangement of the balance throttling hole enables pressure oil entering the motor driving port to be constant and small in impact.

The two motor driving ports are used as one group and are arranged in two groups, the two motor driving ports of each group are respectively connected with the walking motor, and a fourth reversing valve 13 is arranged between the two motor driving ports. Specifically, the fourth reversing valve is provided with a first position and a second position, wherein the first position enables the two groups of motor driving ports to be arranged in parallel, and the second position enables the two groups of motor driving ports to be connected in series after reversing. The switching of two sets of motor drive mouths realization series-parallel connection can be realized through the switching-over of fourth switching-over valve for the system walking is more reliable, and is more stable and energy utilization is higher.

The pressure oil passing through the motor driving port is respectively communicated with a backpressure one-way valve 14 and an oil supplementing one-way valve 15 through a third reversing valve, an oil outlet of the backpressure one-way valve is communicated with an oil return port, an oil outlet of the oil supplementing one-way valve is communicated with the motor driving port, and an oil drain hole 16 is formed in the backpressure one-way valve in parallel. The back pressure one-way valve and the oil drain hole are arranged to provide back pressure for the system, the reliable action of the system is realized, the oil supplementing one-way valve is arranged to be a walking motor for further oil supply, the structure is simple and reliable, and the energy consumption is reduced.

The invention is also provided with a brake interface 17, and the pipelines of the pressure compensator and the third reversing valve are provided with brake pipelines communicated with the brake interface. The arrangement of the brake interface makes the product safety higher.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

The skilled person should understand that: although the invention has been described in terms of the above specific embodiments, the inventive concept is not limited thereto and any modification applying the inventive concept is intended to be included within the scope of the patent claims.