CN213540937U - Oil cylinder valve unit for overhead working truck, lifting hydraulic system and overhead working truck - Google Patents

Abstract

The utility model relates to an overhead working truck, in particular to an oil cylinder valve unit for an overhead working truck, which comprises an oil cylinder valve first port, an oil cylinder valve second port, an emergency lowering oil circuit and an electric control lifting oil circuit; the emergency oil releasing way is provided with a sequence valve and a first throttling structure, a control port of the sequence valve is communicated with a first port of the oil cylinder valve, and when the pressure of the first port of the oil cylinder valve can overcome the spring force of the sequence valve, the first port of the oil cylinder valve is communicated with a second port of the oil cylinder valve through the sequence valve; the electric control lifting oil way is provided with an electric control lifting reversing valve, the second port of the oil cylinder valve can be in one-way conduction to the first port when the electric control lifting oil way is in a one-way conduction state, and the first port and the second port of the oil cylinder valve can be in two-way conduction when the electric control lifting oil way is in a two-way conduction state. The utility model discloses still relate to a lift hydraulic system and high altitude construction car. The utility model discloses a hydro-cylinder valve unit, when the oil pressure of the first port of hydro-cylinder valve changed, the case of sequence valve was difficult for resonating, and hydro-cylinder valve unit can not produce and whistle.

Description

Oil cylinder valve unit for overhead working truck, lifting hydraulic system and overhead working truck

Technical Field

The utility model relates to an aerial working car specifically relates to an oil cylinder valve unit for aerial working car. Furthermore, the utility model discloses still relate to a hydraulic system that lifts of high altitude construction car.

Background

The high-altitude operation vehicle is lifting equipment for high-altitude operation, and is widely applied to installation, maintenance and ascending operation in the industries of transportation, wharfs, airport ports, large-scale industrial and mining enterprises and the like.

In the prior art, a lifting hydraulic system of a common scissor-type aerial work vehicle adopts a cylinder valve as shown in fig. 1, and controls a first lifting cylinder 11a and a second lifting cylinder 21a to extend and retract so as to control the lifting of an aerial work platform. When the electromagnetic directional valve 3a is electrified, the hydraulic pump conveys hydraulic oil to the first lifting oil cylinder 11a and the second lifting oil cylinder 21a, and the working platform rises; after the working platform rises to the set height, the electromagnetic directional valve 3a is controlled to be powered off and switched to the direction, and the first lifting oil cylinder 11a and the second lifting oil cylinder 21a are in a locking state because the first electromagnetic valve 12a and the second electromagnetic valve 22a have a one-way stopping function, so that the working platform is stabilized at the set height. Under normal conditions, if the operation platform needs to be lowered, the first electromagnetic valve 12a and the second electromagnetic valve 22a are powered on and switched, and hydraulic oil leaks back to the oil tank from the first lifting oil cylinder 11a and the second lifting oil cylinder 21 a. When an electric appliance fault occurs, for example, the electric quantity of the whole vehicle is exhausted or an electric appliance control system fails, the first electromagnetic valve 12a can be manually controlled to change the direction, so that the first lifting oil cylinder 11a is communicated with the oil tank, the gravity of the operation platform is transferred to the second lifting oil cylinder 21a, the overflow valve 24a is forced to be opened, the second lifting oil cylinder 21a is communicated with the oil tank, and the operation platform is lowered.

The hydraulic system described above, however, has the following drawbacks:

1. in the electrically controlled lowering process of the operation platform, the lowering speed of the first lifting oil cylinder 11a is controlled by the first damping hole 13a, and the lowering speed of the second lifting oil cylinder 21a is controlled by the second damping hole 23a and the overflow valve 24a, so that the lowering speed of the operation platform is increased along with the increase of the load, and the light load is slow and the heavy load is fast; moreover, in order to avoid that the lowering speed of the operation platform is too high under the full load condition or too low under the light load condition, different lowering damp needs to be set for different vehicle types, so that the cylinder valve cannot be unified, and errors are easily caused in the product assembly process;

2. when the working platform is manually lowered, the acting force of the scissor bracket on the first lifting oil cylinder 11a and the second lifting oil cylinder 21a changes constantly, and the supporting pressure of the second lifting oil cylinder 21a is formed by the overflow valve 24a and the second damping hole 23a, so that in order to establish pressure balanced with the acting force of the scissor bracket, the position of a valve core of the overflow valve changes constantly, the flow area of hydraulic oil passing through the valve core changes constantly, the flow of hydraulic oil passing through the valve core also changes constantly, when the hydraulic oil passes through the second damping hole 23a connected in series behind the overflow valve 24a, the pressure at the oil inlet of the second damping hole 23a changes constantly, the pressure acting on a spring cavity of the overflow valve 24a changes constantly, and finally the pressure of the system fluctuates circularly, valve core resonance is easy to form, and the working platform shakes slightly and the overflow valve 24a squeals abnormally.

In view of the above, a new cylinder valve unit for an aerial work vehicle needs to be designed.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that the first aspect will be solved provides an automobile-used hydro-cylinder valve unit of high altitude construction, when the oil pressure of the first port of hydro-cylinder valve changes, the order valve case is difficult for producing the vibration, and the difficult production of hydro-cylinder valve unit is squealing.

The utility model discloses the technical problem that the second aspect will be solved provides a hydraulic system lifts of high altitude construction car, and this hydraulic system lifts has the emergent function of transferring operation platform to transfer the difficult vibration that produces of in-process operation platform, hydraulic system is difficult for producing and is squeeed.

The utility model discloses the technical problem that the third aspect will be solved provides an aerial working car, and this aerial working car has the emergent function of transferring operation platform, and transfers the difficult vibration that produces of in-process operation platform, and hydraulic system is difficult for producing to whistle.

In order to solve the technical problem, a first aspect of the present invention provides an oil cylinder valve unit for an aerial work vehicle, including a first port of an oil cylinder valve and a second port of the oil cylinder valve, wherein an emergency lowering oil circuit and an electric control lifting oil circuit are arranged between the first port of the oil cylinder valve and the second port of the oil cylinder valve; the emergency oil releasing way is provided with a sequence valve and a first throttling structure, a control port of the sequence valve is communicated with a first port of the cylinder valve, and when the pressure of the first port of the cylinder valve can overcome the spring force of the sequence valve, the first port of the cylinder valve is communicated with a second port of the cylinder valve through the sequence valve; the electric control lifting oil way is provided with an electric control lifting reversing valve, when the electric control lifting reversing valve is in a one-way conduction state, hydraulic oil can flow from the second port of the oil cylinder valve to the first port of the oil cylinder valve in a one-way mode, and when the electric control lifting reversing valve is in a two-way conduction state, the second port of the oil cylinder valve and the first port of the oil cylinder valve can be conducted in a two-way mode.

Preferably, the electric control lifting oil circuit is further provided with a lifting flow speed regulating valve to regulate the flow of the hydraulic oil flowing from the first port of the cylinder valve to the second port of the cylinder valve, the lifting flow speed regulating valve comprises a second throttling structure and lifting one-way valves connected in parallel to two ends of the second throttling structure, the second throttling structure is arranged on an oil section between the electric control lifting reversing valve and the second port of the cylinder valve of the electric control lifting oil circuit, and a forward oil port of the lifting one-way valve is connected to the second port of the cylinder valve to enable one-way conduction of the hydraulic oil input from the second port of the cylinder valve.

Further preferably, the first throttling structure is a damping plug or a speed regulating valve, and the second throttling structure is a damping hole or a speed regulating valve.

Preferably, the emergency lowering oil way and the electric control lifting oil way are provided with oil cylinder valve pressure measuring ports.

The second aspect of the utility model provides a hydraulic lifting system for high-altitude operation vehicle, which comprises a double-control cylinder valve unit and a cylinder valve unit for high-altitude operation vehicle according to any one of the technical schemes of the first aspect, wherein the double-control cylinder valve unit comprises a double-control lifting oil path with a first port of a double-control cylinder valve and a second port of the double-control cylinder valve, the double-control lifting oil path is provided with a double-control reversing valve, the double-control reversing valve is in a one-way conduction state and can enable hydraulic oil to flow from the second port of the double-control cylinder valve to the first port of the double-control cylinder valve in a one-way manner, the double-control reversing valve is in a two-way conduction state and can enable the second port of the double-control cylinder valve and the first port of the double-control cylinder valve to be in two-way conduction, the first port of the cylinder valve and the first port of the cylinder valve are respectively correspondingly connected with rodless cavities of the, and the second port of the double-control oil cylinder valve and the second port of the oil cylinder valve are connected with a hydraulic pump and an oil tank through a main reversing valve, so that the rodless cavities of the first lifting oil cylinder and the second lifting oil cylinder can be subjected to oil inlet or oil drainage through the reversing of the main reversing valve.

Preferably, a double-control lifting flow speed regulating valve is further arranged on the double-control lifting oil path, the double-control lifting flow speed regulating valve can regulate the flow of hydraulic oil flowing from the first port of the double-control oil cylinder valve to the second port of the double-control oil cylinder valve, the double-control lifting flow speed regulating valve comprises a double-control oil path throttling structure and double-control lifting one-way valves connected in parallel to two ends of the double-control oil path throttling structure, the double-control oil path throttling structure is arranged on an oil path between the double-control lifting reversing valve and the second port of the double-control oil cylinder valve, and a forward oil port of the double-control lifting one-way valve is connected to the second port of the double-control oil cylinder valve so as to unidirectionally conduct the hydraulic oil conveyed by the second port of the.

Further preferably, the double-control oil way throttling structure is a damping plug or a speed regulating valve.

Specifically, the double-control reversing valve is an electromagnetic reversing valve capable of being manually reversed.

Preferably, a pressure measuring port of the double-control cylinder valve is arranged on the double-control lifting oil way.

Specifically, the main directional control valve is an electromagnetic directional control valve.

The utility model discloses the third aspect provides an aerial working platform, including any technical scheme of second aspect aerial working platform lift hydraulic system.

The utility model discloses a basic technical scheme's automobile-used hydro-cylinder valve unit of high altitude construction has following technological effect:

1. the emergency lowering oil way and the electric control lifting oil way are arranged, when the first port of the cylinder valve cannot be communicated with the second port of the cylinder valve due to the fact that the electric control lifting oil way cannot work, the first port and the second port of the cylinder valve can be communicated through the emergency lowering oil way, and working reliability of a cylinder valve unit is improved;

2. the sequence valve is basically in a fully-opened state, the pressure difference between an oil inlet and an oil outlet of the sequence valve is small, and the flow of the emergency oil discharging way is basically controlled by the first throttling structure, so that when the oil pressure of the first port of the oil cylinder valve changes, a valve core of the sequence valve is not easy to resonate, and a hydraulic system cannot generate squeal.

Further advantages of the invention, as well as the technical effects of preferred embodiments, will be further explained in the following detailed description.

Drawings

FIG. 1 is a hydraulic schematic of a lift hydraulic system of a prior art aerial lift truck;

FIG. 2 is a hydraulic schematic diagram of an embodiment of a cylinder valve unit for an aerial lift truck according to the present invention;

fig. 3 is a hydraulic schematic diagram of an embodiment of a lifting hydraulic system of the aerial work platform of the present invention.

Reference numerals

11 cylinder valve first port 12 cylinder valve second port

13 cylinder valve pressure measurement port 14 double control cylinder valve first port

15 second port of double control cylinder valve 16 pressure measuring port of double control cylinder valve

21 emergency lowering oil way 22 electric control lifting oil way

23 double-control lifting oil way

31 sequence valve 32 first throttling structure

33 electric control lifting reversing valve 34 second throttling structure

35 lifting one-way valve and 36 double-control reversing valve

37 double-control oil way throttling structure 38 double-control lifting one-way valve

41 first lift cylinder 42 second lift cylinder

43 main reversing valve 44 hydraulic pump

45 oil tank

Detailed Description

The following describes in detail embodiments of the present invention with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "disposed" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; the two elements may be connected directly or indirectly through intervening media, or may be connected through one another or in any combination thereof. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 2, the utility model provides an oil cylinder valve unit for high altitude construction vehicle, including oil cylinder valve first port 11 and oil cylinder valve second port 12, be equipped with emergent oil circuit 21 and the automatically controlled oil circuit that goes up and down 22 between oil cylinder valve first port 11 and oil cylinder valve second port 12; the emergency lower oil discharge path 21 is provided with a sequence valve 31 and a first throttling structure 32, a control port of the sequence valve 31 is communicated with the first port 11 of the cylinder valve, when the pressure of the first port 11 of the cylinder valve can overcome the spring force of the sequence valve 31, the first port 11 of the cylinder valve is communicated with the second port 12 of the cylinder valve through the sequence valve 31, and as is common, a spring cavity of the sequence valve 31 can be connected with the second port 12 of the cylinder valve through an oil path and can also be connected with an external oil tank; the electric control lifting oil way 22 is provided with an electric control lifting reversing valve 33, when the electric control lifting reversing valve 33 is in a one-way conduction state, hydraulic oil can flow from the second port 12 of the cylinder valve to the first port 11 of the cylinder valve in a one-way mode, and when the electric control lifting reversing valve 33 is in a two-way conduction state, the second port 12 of the cylinder valve and the first port 11 of the cylinder valve can be in two-way conduction. It can be understood that the "port" in the present invention can be a point on the oil path, and also can be an entity oil port formed after the cylinder valve unit is packaged into the valve body. The utility model discloses an oil cylinder valve unit for high altitude construction vehicle of basic technical scheme has emergent oil circuit 21 and automatically controlled lift oil circuit 22 of transferring, when automatically controlled lift oil circuit 22 can't work and cause oil cylinder valve first port 11 and oil cylinder valve second port 12 to be unable to communicate, can transfer oil circuit 21 to communicate oil cylinder valve first port 11 and oil cylinder valve second port 12 through meeting an urgent need, realize the emergent function of transferring of operation platform, has promoted safety, the reliability of oil cylinder valve unit work; moreover, when the pressure of the first port 11 of the cylinder valve overcomes the spring force of the sequence valve 31 and the valve core of the sequence valve 31 is reversed, the sequence valve 31 is basically in a full-open state, the pressure difference between the oil inlet and the oil outlet of the sequence valve is small, and the flow of the emergency discharging oil path 21 is basically controlled by the first throttling structure, so that when the oil pressure of the first port 11 of the cylinder valve changes, the valve core of the sequence valve 31 is not easy to generate resonance, and the hydraulic system is not easy to generate squeal.

Preferably, referring to fig. 2, the electrically controlled lift oil path 22 is further provided with a lift flow rate control valve for adjusting the flow rate of the hydraulic oil flowing from the cylinder valve first port 11 to the cylinder valve second port 12. The lifting flow speed regulating valve comprises a second throttling structure 34 and lifting one-way valves 35 connected in parallel to two ends of the second throttling structure 34, the second throttling structure 34 is arranged on an oil path section between the electric control lifting reversing valve 33 and the second port 12 of the cylinder valve, a forward oil port of the lifting one-way valve 35 is connected to the second port 12 of the cylinder valve so as to be capable of conducting hydraulic oil input from the second port 12 of the cylinder valve in a one-way mode, specifically, the forward oil port of the lifting one-way valve 35 can be directly connected with the second port 12 of the cylinder valve, and a connection point can also be arranged at any point on the oil path section between the second port 12 of the cylinder valve and the second throttling structure 34. When the second port 12 of the oil cylinder valve is an oil inlet, the electrically controlled lifting reversing valve 33 is controlled to be in a one-way conduction state, hydraulic oil enters from the second port 12 of the oil cylinder valve and flows to the first port 11 of the oil cylinder valve through the lifting one-way valve 35 and the electrically controlled lifting reversing valve 33 in sequence, and the hydraulic oil in the electrically controlled lifting oil way 22 can be effectively prevented from flowing back; when the first port 11 of the cylinder valve is an oil inlet, the electrically controlled lifting reversing valve 33 is controlled to be in a two-way conduction state, hydraulic oil enters from the first port 11 of the cylinder valve and flows to the first port 11 of the cylinder valve through the electrically controlled lifting reversing valve 33 and the second throttling structure 34 in sequence, and the second throttling structure 34 can effectively control the flow of the hydraulic oil in the electrically controlled lifting oil way 22, so that the flow passing through the second throttling structure 34 is basically in a set value.

Specifically, the first throttling structure 32 and the second throttling structure 34 are both damping elements, specifically, may be damping plugs or speed regulating valves, etc., so as to limit the flow of hydraulic oil in the emergency lowering oil path 21 and the electrically controlled lifting oil path 22. Preferably, the first throttling structure 32 and/or the second throttling structure 34 adopt speed regulating valves, and the influence of pressure fluctuation of the first port 11 of the cylinder valve on the flow of the hydraulic oil in the oil path can be further reduced or eliminated on the basis of limiting the flow of the hydraulic oil in the oil path, so that the flow of the hydraulic oil passing through the speed regulating valves is basically stabilized at a set value.

Preferably, referring to fig. 2, a cylinder valve pressure measuring port 13 is arranged on the emergency lowering oil path 21 and the electrically controlled lifting oil path 22, and specifically, the cylinder valve pressure measuring port 13 may be respectively arranged on the emergency lowering oil path 21 and the electrically controlled lifting oil path 22, or may be communicated with the cylinder valve first port 11, so as to measure the pressure of the emergency lowering oil path 21 and the electrically controlled lifting oil path 22.

The utility model also provides a hydraulic lifting system for high-altitude operation vehicle, refer to fig. 3, including the double-control cylinder valve unit and the cylinder valve unit for high-altitude operation vehicle of any one of the technical schemes of the first aspect, the double-control cylinder valve unit includes the double-control lifting oil circuit 23 having the first port 14 of the double-control cylinder valve and the second port 15 of the double-control cylinder valve, the double-control lifting oil circuit 23 is provided with the double-control direction-changing valve 36, the double-control direction-changing valve 36 can make the hydraulic oil flow from the second port 15 of the double-control cylinder valve to the first port 14 of the double-control cylinder valve in one-way conduction state, the double-control direction-changing valve 36 can make the second port 15 of the double-control cylinder valve and the first port 14 of the double-control cylinder valve in two-way conduction state, the first port 14 of the double-control cylinder valve and the first port 11 of the cylinder valve are respectively and correspondingly connected with the rodless cavities of the first lifting cylinder 41, the double control cylinder valve second port 15 and the cylinder valve second port 12 are connected to the hydraulic pump 44 and the oil tank 45 through a main directional control valve 43, so that the rodless chambers of the first lift cylinder 41 and the second lift cylinder 42 can be filled with oil or drained of oil by reversing the main directional control valve 43, wherein the main directional control valve 43 is preferably a solenoid directional control valve, or it may be a hydraulic control or manual directional control valve.

Preferably, the dual-control lifting oil path 23 is further provided with a dual-control lifting flow speed regulating valve, the dual-control lifting flow speed regulating valve can control the flow of the hydraulic oil flowing from the first port 14 of the dual-control oil cylinder valve to the second port 15 of the dual-control oil cylinder valve, the dual-control lifting flow speed regulating valve comprises a dual-control oil path throttling structure 37 and a dual-control lifting check valve 38 connected in parallel to two ends of the dual-control oil path throttling structure 37, the dual-control oil path throttling structure 37 is arranged on the oil path between the dual-control reversing valve 36 and the second port 15 of the dual-control oil cylinder valve, and a forward oil port of the dual-control lifting check valve 38 is connected to the second port 15 of the dual-control oil cylinder valve so as to conduct the.

Specifically, the dual-control oil path throttling structure 37 is a damping element, which may be a damping plug or a speed regulating valve, etc., to limit the flow of the hydraulic oil in the dual-control lift oil path 23. It should be noted that if the first throttling structure 32 and/or the second throttling structure 34 employ a speed regulating valve, the dual-control oil-way throttling structure 37 may employ a damping plug with a simple structure, so that on one hand, the cost is saved, and the lowering speed of the work platform can be controlled by the speed regulating valve in the oil cylinder valve unit, on the other hand, if the dual-control lifting oil way 23 also employs a speed regulating valve, the parameters of each speed regulating valve need to be finely adjusted, and it is avoided that when the work platform descends, the push rods of the first lifting oil cylinder 41 and the second lifting oil cylinder 42 cannot be synchronously extended and retracted due to unequal flow rates of hydraulic oil passing through each speed regulating valve. Similarly, if the dual-control lifting oil path 23 is provided with a speed control valve, the cylinder valve unit does not need to be provided with a speed control valve.

Specifically, the double control directional valve 36 is an electromagnetic directional valve capable of being manually switched. When the lifting hydraulic system is powered off or fails, an operator can manually switch the position of the valve core of the double-control reversing valve 36, so that the emergency lowering function of the operation platform is realized.

Preferably, referring to fig. 3, a pressure measuring port 16 of the dual-control cylinder valve is disposed on the dual-control lifting oil path 23, so as to measure the pressure of the dual-control lifting oil path 23 and ensure the safety of the dual-control cylinder valve.

In order to help those skilled in the art to understand the technical idea of the present invention more deeply, the operation principle process of the lifting hydraulic system of the present invention is described below by taking the preferred structure shown in fig. 3 as an example.

The electric control lifting reversing valve 33, the double-control reversing valve 36 and the main reversing valve 43 are all electromagnetic reversing valves and are electrically connected with a controller, and the positions of valve cores of the reversing valves can be conveniently switched by the controller. The first throttling arrangement 32 and the second throttling arrangement 34 each employ a speed valve. When the operation platform is lifted, the hydraulic pump 44 delivers the hydraulic oil in the oil tank 45 to the second port 12 of the cylinder valve and the second port 15 of the double control cylinder valve, the double control directional valve 36 is in a one-way communication state in the double control cylinder valve unit, the hydraulic oil sequentially passes through the double control lifting one-way valve 38 and the double control directional valve 36 to enter the rodless cavity of the first lifting cylinder 41, the electric control lifting directional valve 33 is in a one-way communication state in the cylinder valve unit, and the hydraulic oil sequentially passes through the lifting one-way valve 35 and the electric control lifting directional valve 33 to enter the rodless cavity of the second lifting cylinder 42, so that the push rods of the first lifting cylinder 41 and the second lifting cylinder 42 extend out, thereby realizing the lifting of the operation platform. When the working platform is lifted to the right position, the main reversing valve 43 is controlled to reverse, the hydraulic pump 44, the second port 15 of the double-control oil cylinder valve and the second port 12 of the oil cylinder valve are communicated with the oil tank 45, and the first lifting oil cylinder 41 and the second lifting oil cylinder 42 are in a locking state and the working platform is static because the electric control lifting reversing valve 33 and the double-control reversing valve 36 are in a one-way conduction state. It should be noted that when the work platform is lifted and the work platform is stationary, the pressure at the first port 11 of the cylinder valve cannot overcome the spring force of the sequence valve 31, and therefore the emergency release line 21 is not opened. When an electric control system of the lifting hydraulic system can normally operate, the operation platform is lowered through electric control, the controller controls the electric control lifting reversing valve 33 and the double-control reversing valve 36 to reverse, so that the electric control lifting reversing valve 33 and the double-control reversing valve 36 are in a two-way conduction state, in the double-control oil cylinder valve unit, hydraulic oil in a rodless cavity of the first lifting oil cylinder 41 sequentially flows back to the oil tank 45 through the double-control reversing valve 36, the damping plug and the main reversing valve 43 under the action of load, in the oil cylinder valve unit, hydraulic oil in a rodless cavity of the second lifting oil cylinder 42 sequentially flows back to the oil tank 45 through the electric control lifting reversing valve 33, the speed regulating valve and the main reversing valve 43 under the action of load, and push rods of the first lifting oil cylinder 41 and the second lifting oil cylinder 42 retract, so that the operation platform is lowered. When the lifting hydraulic system is exhausted or the electrical control system fails, the operation platform needs to be manually lowered to be electrically controlled, an operator manually switches the valve core position of the double-control reversing valve 36 to enable the double-control reversing valve 36 to be in a two-way conduction state, the rodless cavity of the first lifting oil cylinder 41 is communicated with the oil tank 45, the pressure of the first port 14 of the double-control oil cylinder valve gradually drops, at the moment, most of the gravity of the operation platform is transferred to the second lifting oil cylinder 42 to enable the pressure of the first port 11 of the oil cylinder valve to rise, when the pressure of the first port 11 of the oil cylinder valve can overcome the spring force of the sequence valve 31, the sequence valve 31 is reversed, the rodless cavity of the second lifting oil cylinder 42 is communicated with the oil tank 45, and therefore, the push rods of the first lifting oil cylinder 41 and the second lifting oil cylinder 42 retract, and therefore the.

The utility model discloses preferred embodiment's lift hydraulic system has following advantage: in the lowering process of the operation platform, the lowering speeds of the first lifting oil cylinder 41 and the second lifting oil cylinder 42 are controlled by a speed regulating valve, so that the lowering speed of the operation platform cannot change along with the load, and the problems that the lowering speed of the operation platform is too high under the full load condition and the lowering speed is too low under the light load condition are effectively solved; moreover, in the prior art, different vehicle types can bear different loads, and different lowering damping is often required to be set in order to avoid the problem of slow lowering under light load and fast lowering under heavy load, and the lifting hydraulic system of the utility model is provided with the speed regulating valve, so that the cylinder valve units of different vehicle types and the lifting hydraulic system thereof can be unified, and the product assembly process is not easy to make mistakes; in addition, in the manual lowering process of the working platform, the sequence valve 31 is basically in a fully-opened state, the pressure difference between an oil inlet and an oil outlet of the sequence valve is small, and the flow of the emergency lowering oil circuit 21 is basically controlled by the speed regulating valve, so that when the pressure of the first port 11 of the cylinder valve continuously changes along with the load, a valve core of the sequence valve 33 is not easy to resonate, and the hydraulic system cannot generate squeal.

The utility model discloses an aerial working car, including the hydraulic system that lifts of the aerial working car of any one in the above-mentioned technical scheme, adopted the whole technical scheme of all embodiments of the hydraulic system that lifts of above-mentioned aerial working car, consequently have all beneficial effects that the technical scheme of above-mentioned embodiment brought at least.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the details of the above embodiments, and the technical concept of the present invention can be within the scope of the present invention to perform various simple modifications to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and in order to avoid unnecessary repetition, the present invention does not need to describe any combination of the features.

In addition, various embodiments of the present invention can be combined arbitrarily, and the disclosed content should be regarded as the present invention as long as it does not violate the idea of the present invention.

Claims (11)

1. An oil cylinder valve unit for an overhead working truck is characterized by comprising an oil cylinder valve first port (11) and an oil cylinder valve second port (12), wherein an emergency lowering oil way (21) and an electric control lifting oil way (22) are arranged between the oil cylinder valve first port (11) and the oil cylinder valve second port (12);

a sequence valve (31) and a first throttling structure (32) are arranged on the emergency lowering oil circuit (21), a control port of the sequence valve (31) is communicated with the first port (11) of the cylinder valve, and when the pressure of the first port (11) of the cylinder valve can overcome the spring force of the sequence valve (31), the first port (11) of the cylinder valve is communicated with the second port (12) of the cylinder valve through the sequence valve (31);

the hydraulic control lifting oil way is characterized in that an electric control lifting reversing valve (33) is arranged on the electric control lifting oil way (22), when the electric control lifting reversing valve (33) is in a one-way conduction state, hydraulic oil can flow from the second port (12) of the cylinder valve to the first port (11) of the cylinder valve in a one-way mode, and when the electric control lifting reversing valve (33) is in a two-way conduction state, the second port (12) of the cylinder valve and the first port (11) of the cylinder valve can be conducted in two directions.

2. The cylinder valve unit for the aerial work platform as claimed in claim 1, wherein the electrically controlled lifting oil path (22) is further provided with a lifting flow rate regulating valve to regulate the flow rate of the hydraulic oil flowing from the first port (11) of the cylinder valve to the second port (12) of the cylinder valve, the lifting flow rate regulating valve comprises a second throttling structure (34) and a lifting check valve (35) connected in parallel to two ends of the second throttling structure (34), the second throttling structure (34) is provided on an oil path between the electrically controlled lifting reversing valve (33) of the electrically controlled lifting oil path (22) and the second port (12) of the cylinder valve, and a forward oil port of the lifting check valve (35) is connected to the second port (12) of the cylinder valve to enable one-way communication of the hydraulic oil input from the second port (12) of the cylinder valve.

3. The cylinder valve unit for aerial lift trucks of claim 2, wherein the first throttling structure (32) is a damping plug or a speed valve and the second throttling structure (34) is a damping plug or a speed valve.

4. The cylinder valve unit for the aerial lift truck as claimed in claim 1, wherein a cylinder valve pressure measuring port (13) is provided on the emergency lowering oil path (21) and the electrically controlled lifting oil path (22).

5. A hydraulic lifting system for an aerial lift truck, comprising a double control cylinder valve unit and a cylinder valve unit for an aerial lift truck according to any one of claims 1 to 4,

the double-control oil cylinder valve unit comprises a double-control lifting oil circuit (23) with a first port (14) of the double-control oil cylinder valve and a second port (15) of the double-control oil cylinder valve, a double-control reversing valve (36) is arranged on the double-control lifting oil circuit (23), when the double-control reversing valve (36) is in a one-way conduction state, hydraulic oil can flow from the second port (15) of the double-control oil cylinder valve to the first port (14) of the double-control oil cylinder valve in a one-way mode, when the double-control reversing valve (36) is in a two-way conduction state, the second port (15) of the double-control oil cylinder valve and the first port (14) of the double-control oil cylinder valve can be conducted,

the double-control oil cylinder valve first port (14) and the oil cylinder valve first port (11) are correspondingly connected with rodless cavities of a first lifting oil cylinder (41) and a second lifting oil cylinder (42) respectively, the double-control oil cylinder valve second port (15) and the oil cylinder valve second port (12) are connected with a hydraulic pump (44) and an oil tank (45) through a main reversing valve (43), and oil can be fed or drained through the rodless cavities of the first lifting oil cylinder (41) and the second lifting oil cylinder (42) through the reversing of the main reversing valve (43).

6. The hydraulic lift system of an aerial lift truck as defined in claim 5, the double-control lifting oil way (23) is also provided with a double-control lifting flow speed regulating valve which can regulate the flow of the hydraulic oil flowing from the first port (14) of the double-control cylinder valve to the second port (15) of the double-control cylinder valve, the double-control lifting flow speed regulating valve comprises a double-control oil way throttling structure (37) and double-control lifting one-way valves (38) which are connected in parallel at two ends of the double-control oil way throttling structure (37), the double-control oil path throttling structure (37) is arranged on an oil path between the double-control reversing valve (36) and the second port (15) of the double-control oil cylinder valve, a forward oil port of the double-control lifting one-way valve (38) is connected with the second port (15) of the double-control cylinder valve, so as to conduct the hydraulic oil delivered by the second port (15) of the double-control cylinder valve in a single direction.

7. The hydraulic lifting system of the aerial lift truck as claimed in claim 6, wherein the double-control oil-way throttling structure (37) is a damping plug or a speed regulating valve.

8. The hydraulic lifting system of an aerial lift truck as claimed in claim 5, wherein the double control directional control valve (36) is a manually switchable solenoid directional control valve.

9. The hydraulic lifting system of the aerial lift truck as claimed in claim 5, wherein the double-control lifting oil path (23) is provided with a double-control cylinder valve pressure measuring port (16).

10. The hydraulic lifting system of an aerial lift truck as claimed in claim 5, characterized in that the main directional control valve (43) is a solenoid directional control valve.

11. An aerial lift truck comprising the lift hydraulic system of an aerial lift truck as defined in any one of claims 5 to 10.

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