CN2244627Y

CN2244627Y - Variable controlling mechanism for digital hydraulic pump

Info

Publication number: CN2244627Y
Application number: CN 95244124
Authority: CN
Inventors: 徐大地; 张友世
Original assignee: KEMAN ELECTRICAL CO SHANGHAI
Current assignee: KEMAN ELECTRICAL CO SHANGHAI
Priority date: 1995-06-05
Filing date: 1995-06-05
Publication date: 1997-01-08
Anticipated expiration: 2005-06-05

Abstract

The utility model relates to a variable control mechanism for a digital hydraulic pump comprising a wet type stepper motor, a valve core, a valve sleeve, a sloping plate, a plunger piston, a pump body, a feedback device and a control unit, and is characterized in that the valve core is an upright cylinder, the centre of the valve core is provided with an axial passage, which is communicated with an oil reservoir, and the top of the valve core is connected with the stepper motor. The lower end of the valve sleeve is provided with a multi-path oil inlet passage, and a ring groove, which is arranged on the outer wall of the valve sleeve, forms an oil drainage passage with a plunger piston wall. The upper and the lower ends of the valve sleeve are provided with sealing rings, which are fixed in the plunger piston, and serve as amplifiers for power. One side of the pump is provided with the feedback device and the control unit, which is composed of a computer or a program controller and a driving plate for the stepper motor. The digital hydraulic pump can work correctly within range of low pressure and high pressure (0.1Mpa - 31.5MPa).

Description

The Variable Control mechanism of numeral oil hydraulic pump

The utility model relates to digital oil hydraulic pump, is a kind of stroking mechanism that can be realized Digital Control by computer chip, software, stepper motor.

Traditional shaft orientation plunger variable pump, the mode of controlled variable mechanism can be manual, machinery, hydraulic pressure or electric.Also there are some to use single-chip microcomputer, stepper motor to remove the stroking mechanism of control pump in recent years, for example Chinese 1991 2 phases of " hydraulic industry " magazine, 47 pages of " from the voltage-controlled standards; the single-chip microcomputer regulating system of axial piston pump stroking mechanism " published and model utility " stroking mechanism of the Digital axial piston pump " patent No. 91215039.4, they have all stated rotating band movable wire bar, feed screw nut with stepper motor, make stroking mechanism do axial displacement, to regulate the pivot angle of swash plate, change pump delivery.Just the former has continued to use traditional general servo variable mechanism, and the latter is a kind of stroking mechanism of otherwise designed.Deficiency is in the rated pressure value that does not all reach 31.5MPa in them.Secondly, the former speed of response is slow, and the variable that the latter can't realize ideal exists out of control and disadvantage low precision.

The purpose of this utility model provides a kind of Variable Control mechanism of digital oil hydraulic pump.Can both proper functioning in the rating value scope of high-pressure hydraulic pump, by computer program and feedback means or other electromechanical transducer can be in very wide pressure, range of flow rapidly, accurate control, form a perfect digital pump.

In order to achieve the above object, the utility model has been done improvement to traditional stroking mechanism, mainly comprise the wet type stepper motor, spool, valve pocket, swash plate, plunger, the pump housing, feedback means, control unit, be characterized in that spool is the cylindrical body of always uniting, the center has axial passage and annular groove oil pocket a, b, c communicates, the top is provided with and screw mandrel, the annular groove that the feed screw nut is connected, the valve pocket lower end is provided with exact figures road oil input channel and oil inlet hole, be provided with the draining hole at upper position, on the outer wall between oil inlet hole and the draining hole, be provided with concave ring groove and plunger wall and constitute the draining road, communicate with the radial hole on the plunger, on, following two ends are provided with seal ring, and are fixed on the amplifier that becomes power in the plunger; Be provided with a feedback means in the pump housing one side, this device becomes corresponding electrical signal by potentiometer or other electromechanical transducer with angular transition, detects for control unit, and stroking mechanism is done simple, accurate open loop control.

The utility model has the advantages that:

1, spool, valve pocket can be selected less stepper motor for use, and not making any changes directly to drive spool work.

2, digital oil hydraulic pump can (0.1MPa～31.5MPa), flow can be regulated in the maximum output scope and correctly works from zero to high pressure in low pressure.

Description of drawings:

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is spool of the present utility model, valve pocket structure enlarged view.

The utility model is described in further detail in conjunction with the accompanying drawings, but it must be noted that present embodiment is for illustrative purposes only rather than to restriction of the present utility model.

The Variable Control mechanism of the utility model numeral oil hydraulic pump is made up of wet type stepper motor 1, spool 4, valve pocket 5, swash plate 6, plunger 7, the pump housing 8, feedback means 9, control unit 12.

Spool 4 is the cylindrical body of always uniting, and the center has axial passage 14 and communicates with annular groove oil pocket a, b, C, and the top is provided with the annular groove that is connected with screw mandrel 2, feed screw nut 3.

Valve pocket 5 lower ends are provided with several roads oil input channel 15 and oil inlet hole 18, be provided with draining hole 21 at upper position, on the outer wall between oil inlet hole 18 and the draining hole 21, be provided with concave ring groove and plunger wall and constitute draining road 20, communicate with the radial hole 19 on the plunger 7, upper/lower terminal is provided with seal ring 13,16, and is fixed on the amplifier that becomes power in the plunger 7.

Working procedure, the high pressure oil in the pump housing 8 is directed to the B chamber, keeps high pressure in B chamber and the oil duct 17.When moving on the spool 4, open in draining hole 21, and the oil in A chamber flows back to the pump housing 8 inner chambers through oil pocket a to flow through draining hole 21, draining road 20, radial hole 19 of oil pocket b, become apiezon oil, at this moment, the B chamber is a high pressure, plunger 7 rises, and till draining hole 21 was closed, plunger 7 stopped to rise.When spool 4 moves down, oil inlet hole 18 is opened, the high pressure oil in B chamber enters the A chamber through oil input channel 15, oil inlet hole 18 to oil pocket c and a, A, and B two cavity oil pressure equates, and be high pressure, but the area of A chamber plunger is bigger than the area of B chamber plunger, and A chamber thrust is big, and plunger 7 moves down, heavily be closed up to oil inlet hole 18, plunger 7 stops to move down.Like this, with the very little movable valve plug 4 of trying hard to recommend, plunger 7 is promptly movable, and the power that output is very big drives swash plate 6 simultaneously, overcomes Variable Control moment, changes the tilt angle of swash plate 6, has changed the flow of pump.

The method of control spool adopts wet type stepper motor 1, directly by connecting shaft screw mandrel 2, feed screw nut 3, makes angle of swing be converted into axial displacement, drives spool 4 and moves, and wet type stepper motor 1 rotates certain step number and is equivalent to the certain axial displacement of spool 4.

Control unit 12 is to be made of computer or programming controller and step motor drive plate.The control unit 12 certain pulse of flow output as required, drive stepping motor is moved corresponding step number.

Feedback means 9 is signal feed back unit, utilize the scale on the plunger pump to indicate interior lever displacement to draw, this setting position is corresponding one by one with the swash plate 6 angles variation in the pump housing, promptly the output flow with pump is corresponding one by one, this device becomes corresponding electrical signal by potentiometer or other electromechanical transducer with angular transition, detect for control unit 12, stroking mechanism is done simple accurate open loop control.If mix flow transducer 10 or pressure transducer 11 for control unit 12, this hydraulic system just becomes closed loop control.

Claims

1, the Variable Control mechanism of one sharp digital oil hydraulic pump, comprise the wet type stepper motor, spool, valve pocket, swash plate, plunger, the pump housing, feedback means, control unit, it is characterized in that, spool is the cylindrical body of always uniting, the center has axial passage and annular groove oil pocket a, b, c communicates, the top is provided with and screw mandrel, the annular groove that the feed screw nut is connected, the valve pocket lower end is provided with several roads oil input channel and oil inlet hole, be provided with the draining hole at upper position, on the outer wall between oil inlet hole and the draining hole, be provided with concave ring groove and plunger wall and constitute the draining road, communicate with radial hole on the plunger, on, following two ends are provided with seal ring, and are fixed on the amplifier that becomes power in the plunger.

2, the Variable Control mechanism of digital oil hydraulic pump according to claim 1 is characterized in that the pump housing one side is provided with a feedback means, and this device becomes corresponding electrical signal by potentiometer or other electromechanical transducer with angular transition, detects for control unit.