Type: Hydraulic Control Valve Structure: Monoblock, Sectional
Nominal Flow: 20 Liters To 200 Liters Max Pressure: 250 Bar, 350 Bar
Lever: 1 - 12 Temperature Range: -40 °C ~ 80 °C
High Light: Sectional hydraulic control valve, Monoblock hydraulic control valve, 200 liters Hydraulic Control Valve
Classification, function and correct selection of hydraulic control valve
Hydraulic control valve:
Hydraulic control valve is used to control the liquid pressure, flow and direction in the hydraulic drive system or hydraulic control system.
Among them, pressure control valve is called pressure control valve, flow control valve is called flow control valve, control on, off and flow direction is called direction control valve.
A complete hydraulic system consists of 4 parts:
Energy part (hydraulic pump and prime mover collectively),
Control control part (direction control valve, pressure control valve, flow control valve and other types of hydraulic control valves),
Actuators (hydraulic cylinders, hydraulic motors and oscillating hydraulic motors) and
Auxiliary parts (accumulator, oil tank, filter, pressure gauge, switch and pipe fitting, etc.)
Functions of hydraulic control valve:
The function of hydraulic control valve in hydraulic system is to control the flow direction, pressure and flow of oil in the hydraulic system
So that the actuator and its driving mechanism to obtain the required direction of motion, thrust (torque) and motion speed (rotational speed).
Any hydraulic system, no matter how simple, can not lack of hydraulic valves;The same process of hydraulic mechanical equipment, through the use of different combinations of hydraulic valves, can constitute a completely different oil structure of a variety of hydraulic systems.
Therefore, the hydraulic valve is the most variety and specifications in the hydraulic technology, the most widely used, the most active part (components);Whether a newly designed or running hydraulic system can run normally according to the established requirements depends largely on the performance of various hydraulic Chambers used and whether the parameter matching is reasonable.
The correct selection of hydraulic control valve:
For any hydraulic system, the correct selection of hydraulic control valve, will make the hydraulic system design reasonable, excellent performance, easy installation, easy maintenance, and ensure the normal operation of the system important conditions.The following from several aspects to describe how to choose a reasonable hydraulic valve.
1.General principles of selection
First, according to the functional requirements of the system, determine the type of hydraulic control valve.Try to choose a standard series of generic products.According to the actual installation situation, choose different connection mode, such as pipe or plate connection.Then, select the rated pressure of the hydraulic valve according to the maximum working pressure designed by the system, and select the flow specification of the hydraulic valve according to the maximum flow through the hydraulic valve.If the overflow valve should be selected according to the maximum flow of hydraulic pump;Flow valve should be selected according to the loop control flow range, its minimum stable flow should be less than the required minimum stable flow speed range.
2.Selection of installation mode of hydraulic control valve
The installation mode of hydraulic control valve has a decisive influence on the structure form of hydraulic device, so it is necessary to choose the appropriate installation mode according to the specific situation.Generally speaking, in the selection of hydraulic control valve installation, should be based on the selection of hydraulic control valve specifications, the complexity of the system and layout characteristics to determine.The installation methods described above have their own characteristics.Threaded connection, suitable for simple system, fewer components, more spacious installation position.Plate type connection, suitable for the system is more complex, the number of components, the installation position is relatively compact occasions.The connecting plate can be drilled to communicate the oil circuit, and multiple hydraulic components can be installed on the connecting plate, which can reduce the connecting pipe between hydraulic control valves, reduce leakage points, and make the installation and maintenance more convenient.Flanged joint type is generally used for large diameter valves.
3.Selection of hydraulic control valve rated pressure
The rated pressure of the hydraulic control valve is the basic performance parameter of the hydraulic valve, indicating the pressure capacity of the hydraulic valve, which refers to the nominal pressure of the hydraulic valve under the rated working state.The choice of hydraulic valve rated pressure, should be based on the hydraulic system design of the working pressure to choose the corresponding pressure level of hydraulic control valve.In general, the rated pressure value indicated on the hydraulic valve should be greater than the working pressure of the system.
4.Hydraulic control valve flow specification selection
The rated flow rate of hydraulic control valve is the nominal flow rate that hydraulic valve passes under rated working condition.The actual operating flow of the hydraulic control valve is related to the connection mode of the oil circuit in the system: the flow rate of the series circuit is equal to that of the parallel circuit, while the flow rate of the parallel circuit is equal to the sum of the flow rates of each oil circuit.Select the flow specification of hydraulic control valve, if the rated flow of the control valve and the system flow rate is close to, is obviously the most economical.If the choice of the rated flow of the control valve is less than the working flow, it is easy to cause hydraulic clamping and hydraulic power, and may have a bad effect on the working quality of the valve.In addition, can not simply according to the rated output flow of the hydraulic pump to choose the flow of the valve, because for a hydraulic system, each circuit through the flow is not likely to be the same.Therefore, in the selection, should consider the hydraulic control valve loop may through the maximum flow.
5.Choice of control mode of hydraulic control valve
Hydraulic control valve control mode has a variety of, is generally based on the control of the system needs and electrical system configuration ability to choose.For hydraulic system with low automation requirement, small size or infrequent adjustment, manual control mode can be selected.For the hydraulic system with higher automation requirements or control performance requirements, electric and hydraulic can be selected.
Choose hydraulic control valve, should meet the requirements of the premise, as far as possible to choose the cost and lower cost of the hydraulic valve, in order to improve the economic indicators of the main engine.For example, for the speed stability requirements of the system is not high, should choose throttle valve and do not choose speed control valve.In addition, in the selection of hydraulic control valve, do not blindly choose a cheaper valve, to consider the reliability of its work and working life, that is, consider the comprehensive cost.At the same time, the convenience and rapidity of maintenance should also be considered so as not to affect production.
The specific selection of hydraulic control valve:
1.Direction control valve selection
Should be based on the requirements of the system to choose the direction of the valve type, such as the requirement that oil flow can only flow in one direction, not reverse flow, should be used one-way valve;If the actuator is required to complete the working cycle of one step forward, one step backward and one stop, the three-position reversing valve should be selected.If only two working conditions are completed, namely feed and return, two reversing valves should be used to connect or close the oil circuit;If the executive component to complete the "fast forward a work into a fast back a stop" working cycle or reciprocating frequent motion, usually should choose a reversing valve to change the direction of oil flow.Direction valve can also be selected according to the working state of the system and the characteristics of the valve.
For example, the mass of moving parts is small, the reversing precision requirements are not high, flow is less than 63 L/min, should choose the electromagnetic reversing valve, because the valve reversing impact is large, so only allow small flow, not suitable for large flow through;If the moving part has a large mass and a wide range of velocity variation, and the commutation is required to be stable. If the flow rate is 63 L/rain, electro-hydraulic commutation valve with stable direction and no impact should be selected.If there is a locking loop in the system, the liquid control check valve with good sealing performance should be selected, rather than the poor sealing reversing valve.
2.Selection of pressure control valve
The pressure control valve is to control the pressure of the hydraulic system, so it should be selected according to the working state of the hydraulic system, the pressure requirements and the function of the control valve in the system.
For example, in the quantitative pump throttling speed regulation system, the motion speed of the actuator depends on the throttle valve control;In order to maintain the basic constant working pressure of the pump, the overflow valve should be used to stabilize the overflow;In order to prevent system overload, a relief valve can be connected in parallel at the pump outlet to protect the safety of the pump and the whole system.If there is a pressure reducing loop in the system, the pressure of the high pressure loop must be reduced to low pressure by using the pressure reducing valve;If the system USES the pressure control of the sequential action of each component, the sequence valve should be used to adjust the pressure of the sequence valve as the required pressure value, so as to control the sequence of action of the components. Pressure relays can also be used to convert the liquid pressure into electrical signals to control the sequential action of each component.If the actuator is required to move steadily, the backpressure valve should be set on the circuit to form a certain oil return resistance, which can greatly improve the motion stability of the actuator.Overflow valve, sequence valve, one-way valve and throttle valve can be used as a backpressure valve
3.Flow control valve selection
According to the working state of the hydraulic system and the characteristics of flow control valve to choose flow control valve, to control the speed of the actuator.For example, the actuator requires stable speed, and do not produce crawling, should choose the speed control valve, in the selection of the specification of the speed control valve, should pay attention to the minimum stable flow of the speed control valve, should meet the minimum speed of the actuator, that is to say, the minimum stable flow of the speed control valve should be less than the minimum flow required by the actuator;If the flow stability requirements are particularly high, or used in the case of trace feed, should choose temperature compensation type speed regulating valve.
In short, the choice of the hydraulic valve is correct or not, the success or failure of the system has a great relationship.As a hydraulic designer, we should have a comprehensive understanding of the production of hydraulic valves at home and abroad, especially the performance of various hydraulic valves, replacement and replacement of old and new products.Also often to use the site to understand the working condition of the hydraulic valve, only in this way, in order to achieve the correct selection of hydraulic valve and reasonable.
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- válvula de controle hidráulico
- componentes hidráulicos
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