A kind of testing machine electro-hydraulic loading control structureTechnical field：
The utility model is related to a kind of electro-hydraulic add load control, more particularly to a kind of testing machine electro-hydraulic loading controlStructure.
Background technology：
Currently, traditional Loading Control has electro-hydraulic proportional valve Loading Control and AC servo Loading Control.
Electro-hydraulic proportional valve Loading Control is to drive oil pump full power operation with motor, is used as by overflow regulating system pressurePower source, the pressure then exported by ratio valve regulation or flow, as shown in Figure 2.The response of its Loading Control is fast, but unloads(backhaul) control is then undesirable.Whole system is complicated, and of high cost, contamination resistance is undesirable, maintenance and maintenance difficult, eitherNo in working condition, the oil pump systems calorific value of full-speed operation is larger, causes the loss of overflow valve overflow energy big, cost of freezingIt is high.
AC servo Loading Control is to drive servopump as power source using AC servo motor, by changing rotational speed regulationThe pressure or flow of output.Whole system cost is not high, safeguards and easy to maintenance；Its power consumption changes with output power to a certain extentBecome, when standby mode is low in energy consumption, calorific value is smaller, and energy loss is small.But the structure constraint is in the technology of AC servo motor,It can not be applied to large-power occasions, and its unloading (backhaul) control is then undesirable.
Utility model content：
The utility model provides a kind of testing machine electro-hydraulic loading control structure, this is reasonable in design, novel, systemMake at low cost, operation energy consumption is low, safeguards simple, conveniently, effectively increases contamination resistance, efficiently solve high-power applications andUnloading (backhaul) controls undesirable problem and solves problems of the prior art suitable for being widely used to promote.
Used technical solution is the utility model to solve above-mentioned technical problem：
The oil outlet of a kind of testing machine electro-hydraulic loading control structure, including fuel tank, the fuel tank connects an oil filterOil inlet end, the oil outlet end of oil filter is connected with the hydraulic pump that a variable-frequency motor is driven by shaft coupling, the oil outlet end of hydraulic pumpIt is connected with a high-pressure filter, the pipeline between high-pressure filter and hydraulic pump is equipped with a check valve；The high-pressure filterOil outlet end be connected with the P mouths of a three position four-way directional control valve, the A mouths of three position four-way directional control valve connect output cylinder, 3-position 4-wayThe T mouths of reversal valve connect fuel tank by oil return line；Connect on pipeline between the high-pressure filter and three position four-way directional control valveIt is connected to an oil return component branch, the oil inlet of the tail end connection fuel tank of oil return component branch, oil return component branch road is equipped with a sectionValve is flowed, throttle valve both ends are parallel with a pressure safety valve by pipeline.
The fuel tank is equipped with oil thermometer and content gauge.
Pipeline between the high-pressure filter and three position four-way directional control valve is equipped with a pressure gauge.
The output cylinder has gap oil return branch, the tail end of gap oil return branch to connect fuel tank by piping connection.
Using the above structure, this is reasonable in design, novel for the utility model, is replaced using throttle valve and pressure safety valveOverflow valve effectively prevents the big disadvantage of overflow valve energy consumption, and the system heat generation amount is small, effectively reduces refrigeration cost, is manufactured intoThis is low, and operation energy consumption is low, and connection structure is simple, safeguards simply, conveniently, contamination resistance is effectively increased, using alternating current asynchronousMotor efficiently solves the problems, such as that high-power applications and unloading (backhaul) control are undesirable, suitable for being widely used to promote.
Description of the drawings：
Fig. 1 is the oil circuit connection figure of the utility model.
Fig. 2 is the oil circuit connection figure of the prior art.
In figure, 1 fuel tank, 2 oil filters, 3 variable-frequency motors, 4 shaft couplings, 5 hydraulic pumps, 6 high-pressure filters, 7 check valves, 8 threePosition and four-way reversing valve, 9 output cylinders, 10 throttle valves, 11 pressure safety valves, 12 oil thermometers, 13 content gauges, 14 pressure gauges.
Specific implementation mode：
In order to clarify the technical characteristics of the invention, below by specific implementation mode, and its attached drawing is combined, to this realityIt is described in detail with novel.
As shown in fig. 1, a kind of testing machine electro-hydraulic loading control structure, including fuel tank 1, the fuel tank 1 it is fuel-displacedThe oil inlet end of mouth one oil filter 2 of connection, the oil outlet end of oil filter 2 are connected with the hydraulic pressure that a variable-frequency motor 3 is driven by shaft coupling 4Pump 5, the oil outlet end of hydraulic pump 5 is connected with a high-pressure filter 6, and the pipeline between high-pressure filter 6 and hydraulic pump 5 is equipped with oneCheck valve 7；The oil outlet end of the high-pressure filter 6 is connected with the P mouths of a three position four-way directional control valve 8, three position four-way directional control valve 8A mouthfuls of connection output cylinders 9, the T mouths of three position four-way directional control valve 8 connect fuel tank 1 by oil return line；The high-pressure filter 6 withAn oil return component branch is connected on pipeline between three position four-way directional control valve 8, the tail end connection fuel tank 1 of oil return component branchOil inlet, oil return component branch road are equipped with a throttle valve 10, and 10 both ends of throttle valve are parallel with a pressure safety valve 11 by pipeline.
In order to real-time, the accurate height for understanding oily temperature and liquid level in fuel tank 1, the fuel tank 1 is equipped with oil temperatureMeter 12 and content gauge 13.
In order to real-time, the accurate pressure for understanding output hydraulic pressure, the high-pressure filter 6 and three position four-way directional control valve 8Between pipeline be equipped with a pressure gauge 14.
The output cylinder 9 has gap oil return branch, the tail end of gap oil return branch to connect fuel tank 1 by piping connection.
Using the testing machine electro-hydraulic loading control structure of the utility model, in use, variable-frequency motor 3 passes through shaft coupling4 drive hydraulic pump 5 to work, and hydraulic pump 5 extracts the oil in fuel tank 1, pass sequentially through high-pressure filter 6 and 3-position 4-way commutationValve 8 enters in output cylinder 9, and output fuel tank 9 will make corresponding action, 11 He of pressure safety valve of oil return component branchThrottle valve 10 can ensure that a small amount of oil flows back into fuel tank 1, increase output cylinder 9 and act cushion effect, be effectively ensured defeatedGo out the service life of oil cylinder 9, when output cylinder 9 returns, three position four-way directional control valve 8 is moved on left position, 9 the inside of output cylinderOil can be flowed back by A mouthfuls and T mouthfuls in fuel tank 1.
This is simple in structure, easy to implement, and contamination resistance is stronger, at low cost.Only need variable-frequency motor 3, hydraulic pump 5, threePosition and four-way reversing valve 8, throttle valve 10 and pressure safety valve 11, without proportioning valve, contamination resistance is stronger；Energy conservation and environmental protection,Noise is low；Without the overflow fever of overflow valve, without traffic flow, no flowed friction fever, hydraulic pump 5 when executive component is staticMost of time is the slow-speed of revolution or dead state, and system heat generation amount is generally 20% of traditional approach or so, and fuel tank 1 can be than passingUniting, fuel tank 1 is small, and oil changing interval can also extend, and the hydraulic oil of consumption generally only has 50% or so of traditional approach, power savingsIt is prominent；Applied widely suitable for the occasion of any power, control accuracy is high；The output power of servo motor is usually 0.1-10kW, and 0.75~1000kW of power of variable-frequency motor 3.Throttle valve 10 makes sub-fraction traffic flow oil return box, suitably increasesWhen executive component is operated at full capacity, corresponding motor speed, increases adjustable range, and unit speed is made to change corresponding smallerPressure flow change, improve degree of regulation；Failure rate is low, and system does not flog a dead horse, and oil temperature is not easy to increase, in oil piping systemIt is larger to reduce failure without negative pressure, extend the service life of Hydraulic Elements.
Above-mentioned specific implementation mode cannot function as the limitation to scope of protection of the utility model, for the skill of the artFor art personnel, any alternate modification or transformation made to the utility model embodiment all fall within the guarantor of the utility modelIt protects in range.
Place is not described in detail for the utility model, is the known technology of those skilled in the art of the present technique.