The blow molding machine hydraulic control system
Technical field
The present invention relates to blow molding machine, relate in particular to a kind of blow molding machine hydraulic control system.
Background technology
The hydraulic system of blow molding machine is used single pump hydraulic circuit mostly, minority is also arranged with big or small double pump hydraulic circuit, but its control mode is different, below briefly describes:
Referring to Fig. 1, be existing middle-size and small-size blow molding machine single pump hydraulic system schematic diagram commonly used.All executive components of this system (comprise folding mould oil cylinder 11, mould shifting oil cylinder 12, blow decorations by cylinder 13, lift die head oil cylinder 14 and lifting platform motor 15 etc.) pressure adjust by pilot proportional overflow valve (scaling signal by PLC Programmable Logic Controller output comes controlled pressure) 5.According to the action feature of blow molding machine, some action (such as locked mode time action) needs very high pressure, but does not need the too many oil mass of using; Because what this system adopted is single constant displacement pump fuel feeding, the discharge capacity of oil pump 2 outputs is fixed; Because the power consumption of the high more motor 3 of system pressure is just big more; Need be seldom and under the exigent situation of pressure at executive component with oil mass; The oil that oil pump 2 is discharged can only under high pressure flow back to fuel tank 16 through pilot proportional overflow valve 5, and this will cause oily temperature rise, and power loss is very big.
Referring to Fig. 2, be the big or small pump hydraulic system schematic diagram of the existing middle-size and small-size blow molding machine use of minority.This system makes certain improvements to the said system of Fig. 1; Duplex pump wherein is set; Between itself and the executive component corresponding check valve 19,20 is set; Like this: needing very high pressure but do not need to choose with two actions (promptly come back action and locked mode move) of oil mass too much next, come fuel feeding with little pump 2.2 separately then, its pressure is controlled by direct-acting overflow valve 17,18 respectively that (both can only be with manually adjusting pressure; Wherein direct-acting overflow valve 17 is controlled the pressure of locked mode separately, and direct-acting overflow valve 18 is the pressure of control new line separately); Other executive component then by big pump 2.1 fuel feeding, then controlled by pilot proportional overflow valve 5 by its pressure.There has been certain improvement in this system to the described system of Fig. 1, but the rough sledding that exists in the said system of Fig. 1 still can occur by several executive components of big pump 2.1 fuel feeding, still has the big problem of power loss, and energy-saving effect is obvious inadequately; Moreover in order to satisfy the speed of part executive component, the discharge capacity of big pump 2.1 will be selected very greatly, is unfavorable for reducing production costs exactly.
Summary of the invention
In view of this, the not foot phenomenon to existing in above analysis chart 1, the said existing hydraulic system of Fig. 2 the object of the present invention is to provide a kind of blow molding machine hydraulic control system, so that effectively reduce the system power loss.
For solving above technical problem; Technical scheme provided by the invention is: a kind of blow molding machine hydraulic control system; Comprise the hydraulic actuator group; By the control of separately solenoid directional control valve, wherein hydraulic circuit is provided with a big pump and a little pump to each Hydraulic Elements in the said hydraulic actuator group respectively, the oil-in of said big pump and the oil-in of said little pump and connect after be connected to fuel tank; The oil-out of said big pump behind check valve with the oil-out of said little pump and connect; Be connected to the corresponding oil-in of each hydraulic actuator in the said hydraulic actuator group afterwards; So that system when carrying out the high-pressure low-flow action by the independent fuel feeding of said little pump, system when carrying out the low pressure and mass flow action by said big pump and the common fuel feeding of said little pump.
More excellent ground, said big pump is controlled by the electromagnetic type overflow valve.
More excellent ground, said little pump is controlled by the pilot proportional overflow valve.
More excellent ground, said big pump and said little pump are electric motor driven duplex pump.
More excellent ground, the Hydraulic Elements in the said hydraulic actuator group comprise folding mould oil cylinder, mould shifting oil cylinder, blow needle oil cylinder, lift die head oil cylinder and lifting platform motor.
More excellent ground, said fuel tank is provided with oil cleaner screen before at the oil-in of said big pump and the oil-in of said little pump.
More excellent ground is provided with cooler between the corresponding oil-out of each hydraulic actuator and the said fuel tank in the said hydraulic actuator group.
More excellent ground comprises controller, and said controller is electrically connected each magnetic valve, so that carry out corresponding actions according to each magnetic valve of pre-set programs control.
Compared with prior art; Blow molding machine hydraulic control system of the present invention is provided with big pump and little pump; Wherein big pump often is in unloading condition, just be incorporated into system when having only the big flow of needs to move and give system's fuel feeding with little pump, so motor can select very for a short time; Help reducing power loss, finally reach the purpose of economize on electricity.Simultaneously because when big flow action be by big pump and little pump together to system's fuel feeding, thereby big pump delivery need not select very greatly, this helps reducing cost.
Description of drawings
Fig. 1 is a kind of sketch map of existing blow molding machine hydraulic control system;
Fig. 2 is the sketch map of another kind of existing blow molding machine hydraulic control system;
Fig. 3 is the sketch map of blow molding machine hydraulic control system of the present invention.
Among Fig. 1~Fig. 3, relevant Reference numeral is:
1, oil cleaner screen; 2, oil pump, 2.1, big pump, 2.2, little pump; 3, motor; 4, cooler; 5, pilot proportional overflow valve, 6, solenoid directional control valve; 7, solenoid directional control valve; 8, solenoid directional control valve; 9, solenoid directional control valve; 10, solenoid directional control valve; 11, folding mould oil cylinder; 12, mould shifting oil cylinder; 13, blow needle oil cylinder; 14, lift the die head oil cylinder; 15, lifting platform motor; 16, fuel tank; 17, direct-acting overflow valve; 18, direct-acting overflow valve; 19, check valve; 20, check valve; 21, one-way valve; 22, electromagnetic type overflow valve.
The specific embodiment
Core of the present invention is, big pump and little pump are set in hydraulic control circuit, wherein system when carrying out the high-pressure low-flow action by the independent fuel feeding of little pump, system when carrying out the low pressure and mass flow action by big pump and the common fuel feeding of little pump.
In order to make those skilled in the art understand technical scheme of the present invention better, the present invention is done further detailed description below in conjunction with accompanying drawing and specific embodiment.
Referring to Fig. 3, be the schematic diagram of the big or small pump blow molding machine hydraulic control system after improving through the present invention.Be provided with the hydraulic actuator group in this system, comprise folding mould oil cylinder 11, mould shifting oil cylinder 12, blow decorations by cylinder 13, lift die head oil cylinder 14, lifting platform motor 15 etc., they are respectively by 6,7,8,9,10 controls of the solenoid directional control valve of correspondence.And in hydraulic circuit, be provided with by the electromagnetic type overflow valve 22 big pumps 2.1 of control with by the little pump 2.2 of pilot proportional overflow valve 5 controls; Both constitute the duplex pump that is driven by motor 3; Wherein: the oil-in of big pump 2.1 and the oil-in of little pump 2.2 and connect after be connected to fuel tank 16, this fuel tank 16 was provided with oil cleaner screen 1 before the oil-in of the oil-in of big pump 2.1 and little pump 2.2; The oil-out of big pump 2.1 is through check valve 21 after and the oil-out of little pump 2.2 and connecing; Be connected to the corresponding oil-in of each hydraulic actuator in the hydraulic actuator group afterwards; And be provided with cooler 4 between the corresponding oil-out of these hydraulic actuators and the fuel tank 16, make hydraulic oil lower the temperature; In addition; Also comprise Programmable Logic Controller (PLC; Scheme not shown), this controller is electrically connected each magnetic valve, can control each magnetic valve according to pre-set programs thus and carry out corresponding actions; So that system when carrying out the high-pressure low-flow action by little pump 2.2 independent fuel feeding, system when carrying out the low pressure and mass flow action by big pump 2.1 and little pump 2.2 common fuel feeding.
Directly give system's fuel feeding by little pump 2.2 in the present embodiment, big pump 2.1 is controlled fuel feeding by electromagnetic type overflow valve 22, and the pressure of system is adjusted by pilot proportional overflow valve 5, and its course of work is following:
When carrying out high pressure, low discharge action, system is by little pump 2.2 fuel feeding, and the oil that this moment, big pump 2.1 was discharged is controlled by electromagnetic type overflow valve 22; Because of electromagnetic type overflow valve 22 is open in usual; Electromagnetic type overflow valve 7 must not when the PLC programmable controller program was written as the low discharge action; The oil that therefore big pump 2.1 is discharged is through electromagnetic type overflow valve 22 direct oil sump tanks 16; This moment, big pump 2.1 was unloaded basically, only motor 3 was produced very little load.
When carrying out the low pressure and mass flow action; Electromagnetic type overflow valve 22 when the PLC director demon is written as the action of big flow; Electromagnetic type overflow valve 22 just closed the loop of big pump 2.1 oil-outs after electric to fuel tank 16; The a end pressure of check valve 21 raises (greater than the b end pressure), thereby pushes check valve 21 open, makes big pump 2.1 be incorporated in the system and is system's fuel feeding with little pump 2.2.
Big pump 2.1 in the hydraulic control system shown in Figure 3 often is in unloading condition, have only just to be incorporated into system when needing big flow action and to give system's fuel feeding with little pump 2.2, so motor 3 can select very for a short time, thereby reduce the purpose that power loss reaches economize on electricity; Simultaneously, when big flow action, be by big pump 21 and little pump 2.2 together to system's fuel feeding, it is very big that the discharge capacity of therefore big pump 21 also need not be selected, this helps reducing cost; In addition, also easily, flexibly, the program that only needs to revise Programmable Logic Controller (PLC) is just passable when increasing or reducing large and small flow action in this system, need not change the hardware of hydraulic system.
Can know that by above analysis blow molding machine hydraulic control system of the present invention has reduced the model of motor, oil pump, effectively reduces cost, also help energy-conservationly that it is easy to use, flexible, thereby have market prospects preferably.
Only be preferred implementation of the present invention below, should be pointed out that above-mentioned preferred implementation should not be regarded as limitation of the present invention, protection scope of the present invention should be as the criterion with claim institute restricted portion.For those skilled in the art, do not breaking away from the spirit and scope of the present invention, can also make some improvement and retouching, these improvement and retouching also should be regarded as protection scope of the present invention.