阅读说明：本技术 一种消除主阀滞环的比例换向阀 (Proportional reversing valve for eliminating hysteresis loop of main valve ) 是由 杨敬 岳路宏 权龙� 于 2021-09-30 设计创作，主要内容包括：本发明公开了一种消除滞环的比例换向阀,属于机械领域,它包括主阀芯、滚珠丝杠、伺服电机、通电线圈、先导油腔二位二通比例换向阀、先导油腔压力传感器、进油口压力传感器、主阀弹簧、压力补偿器、堵头,先导阀芯置于主阀芯的大环形槽中；先导油腔二位二通比例换向阀连通主阀先导油腔,伺服电机与减速器直连,减速器与所述滚珠丝杠左侧直连,先导油腔压力传感器安装于主阀弹簧腔,导线电源固定于阀体,通电线圈从导线电源引出并穿过主阀芯的导线孔缠绕于主阀芯中间凹槽。本发明解决了比例换向阀主阀芯在运动过程产生的滞环、冲击和控制精度低的问题。(The invention discloses a proportional reversing valve for eliminating hysteresis, which belongs to the field of machinery and comprises a main valve core, a ball screw, a servo motor, an electrified coil, a pilot oil cavity two-position two-way proportional reversing valve, a pilot oil cavity pressure sensor, an oil inlet pressure sensor, a main valve spring, a pressure compensator and a plug, wherein the pilot valve core is arranged in a large annular groove of the main valve core; the pilot oil cavity two-position two-way proportional reversing valve is communicated with a main valve pilot oil cavity, the servo motor is directly connected with the speed reducer, the speed reducer is directly connected with the left side of the ball screw, the pilot oil cavity pressure sensor is installed in a main valve spring cavity, the lead power supply is fixed on the valve body, and the electrified coil is led out from the lead power supply and penetrates through a lead hole of the main valve core to be wound on a middle groove of the main valve core. The invention solves the problems of hysteresis, impact and low control precision of the main valve core of the proportional reversing valve in the motion process.)

1. A proportional reversing valve for eliminating hysteresis of a main valve is characterized in that: the hydraulic control valve comprises a main valve core (3), a ball screw (4), a servo motor (12), a right electrified coil (6), a left electrified coil (8), a left pilot oil cavity two-position two-way proportional reversing valve (9), a right pilot oil cavity two-position two-way proportional reversing valve (2), a left pilot oil cavity pressure sensor (14), a right pilot oil cavity pressure sensor (20), an oil inlet pressure sensor (5), a main valve left spring (10), a main valve right spring (1), a pressure compensator (18), a left plug (16), a right plug (19), reducers (11) with two reduction ratios, a left lead power supply (13), a right lead power supply (21), a pilot valve core (7), a valve body (17) and a main valve core displacement sensor (15);

the main valve core (3) is provided with an end face through hole j communicated with a pilot oil cavity, the middle shaft diameter of the main valve core (3) is provided with a main valve core large annular groove f and a main valve core small annular groove d, four inclined holes e uniformly distributed on the circumference of the middle shaft diameter of the main valve core (3) are communicated with the main valve core large annular groove f and the main valve core small annular groove d, and hydraulic oil of a port P can be communicated with the pilot oil cavities on two sides through the inclined holes e and the end face through hole j; the large circular groove f of the main valve core can prevent uneven pressure of pressure oil introduced by four inclined holes e uniformly distributed on the circumference of the diameter of the middle shaft of the main valve core (3); two sides of the pilot valve core (7) are respectively provided with a chamfer, and the pilot valve core (7) is arranged in the large circular groove f of the main valve core; two end faces of the pilot valve core (7) are provided with chamfers to form a variable liquid resistance together with the large circular groove f of the main valve core; the chamfer surfaces at the two sides of the pilot valve core (7) and the large circular groove f of the main valve core with the middle shaft diameter form a positive opening; the left-position pilot oil cavity two-position two-way proportional reversing valve (9) is communicated with a main valve left-position pilot oil cavity, and the right-position pilot oil cavity two-position two-way proportional reversing valve (2) is communicated with a main valve right-position pilot oil cavity; the variable liquid resistance formed by the pilot valve core (7) and the large circular groove f of the main valve core, the left pilot oil cavity pressure sensor (14) and the right pilot oil cavity pressure sensor (20) respectively form two groups of hydraulic half bridges; the speed reducer (11) with two speed reduction ratios and the servo motor (12) are arranged on the left side outside the valve body; the ball screw (4) extends out of the valve body from the left pilot oil cavity; the servo motor (12) is directly connected with the speed reducers (11) with the two speed reduction ratios, and the speed reducers (11) with the two speed reduction ratios are directly connected with the left side of the ball screw (4); the pilot valve core (7) is a permanent magnet; the left position lead power supply (13) is fixed on the left end face of the valve body (17), and the right position lead power supply (21) is fixed on the right end face of the valve body (17); the left electrified coil (8) is led out from a left lead power supply (13), penetrates through a lead hole b of the main valve core (3) and is wound on a left groove c in the middle shaft diameter of the main valve core; the right electrified coil (6) is led out from a right lead power supply (21), penetrates through a lead hole h of the main valve core (3) and is wound in a groove g on the right side of the middle shaft diameter of the main valve core; the oil inlet pressure sensor (5) is installed at the port P of the oil inlet; a pressure sensor hole a is formed in the spring cavity on the left side of the main valve, and a pressure sensor hole i is formed in the spring cavity on the right side of the main valve; the left pilot oil cavity pressure sensor (14) is arranged at a main valve spring cavity a; and the right pilot oil cavity pressure sensor (19) is arranged at a main valve spring cavity i.

2. The system of claim 1, wherein the servo system further comprises: chamfer angles on two sides of the pilot valve core (7) and a large circular groove f of the main valve core form an adjustable liquid resistance, and the servo motor (12) and the ball screw (4) adjust the position of a nut to change the liquid resistance and prevent the throttling port from being completely closed; a left pilot oil cavity two-position two-way proportional reversing valve (9) and a right pilot oil cavity two-position two-way proportional reversing valve (2) are also arranged at the oil return position and are also adjustable liquid resistances; the hydraulic half-bridge and the hydraulic half-bridge can form a type a hydraulic half-bridge and a type b hydraulic half-bridge; the pressure of hydraulic oil of a P port entering the pilot oil cavity through four inclined holes e uniformly distributed on the circumference of the diameter of the middle shaft of the main valve core (3) is changed by adjusting the left pilot oil cavity two-position two-way proportional reversing valve (9) and the right pilot oil cavity two-position two-way proportional reversing valve (2).

3. The system of claim 2, wherein the servo system comprises: the pilot oil cavity is communicated with the main valve core end surface through hole j; the P port is guided to the pilot oil cavity through the hydraulic oil behind the pilot valve core (7), and the pressure is used for offsetting the friction force between the main valve core (3) and the valve body (17).

4. The system of claim 1, wherein the servo system further comprises: after determining that the positions of the main valve core (3) and the pilot valve core (7) are close, the main valve core displacement sensor (15) is electrified with the coil to generate magnetic force so as to further realize accurate centering of the main valve core (3) and the pilot valve core (7).

5. The system of claim 1, wherein the servo system further comprises: the pressure of a pilot oil cavity obtained by the left pilot oil cavity pressure sensor (14) and the right pilot oil cavity pressure sensor (20) and the displacement of the main valve element obtained by the main valve element displacement sensor (15) can adjust the back pressure valve, so that the main valve element has the same dynamic characteristics under different load working conditions; pressure exists in the pilot oil cavities on the two sides in the zero position, so that the natural frequency and the dynamic response of the system are improved; the valve core dynamic adjustment characteristic adapting to load change is provided.

Technical Field

The invention relates to a hysteresis eliminating mechanical-hydraulic servo system.

Background

A flow distribution multi-way valve (ludv system) independent of load pressure is used for a hydraulic system of a small excavator, a pressure compensation valve is arranged behind a main valve, and post-valve compensation is carried out on system pressure. When a plurality of actuators are operated simultaneously, the pressure of the actuator with the smaller pressure is compensated by the pressure of the actuator with the highest pressure, and the differential pressure of each actuator is kept constant at any time, so that proportional distribution of the flow rates of the plurality of actuators can be realized. However, because friction exists between the main valve core and the valve body, the main valve core cannot reach an accurate position, and the opening degree of the valve port is controlled inaccurately.

Disclosure of Invention

The invention provides a proportional reversing valve for eliminating a hysteresis loop of a main valve, aims to eliminate a mechanical-hydraulic servo system of the hysteresis loop caused by friction force and solves the problems of hysteresis loop generated by the friction force between a valve core and a valve body and low control precision.

The technical scheme of the invention is as follows: the hydraulic control valve mainly comprises a main valve core, a ball screw, a servo motor, a right electrified coil, a left pilot oil cavity two-position two-way proportional reversing valve, a right pilot oil cavity two-position two-way proportional reversing valve, a left pilot oil cavity pressure sensor, a right pilot oil cavity pressure sensor, an oil inlet pressure sensor, a main valve left spring, a main valve right spring, a pressure compensator, a left plug, a right plug, reducers with two reduction ratios, a left lead power supply, a right lead power supply, a pilot valve core, a valve body and a main valve core displacement sensor.

Further, the main valve core is provided with an end surface through hole j communicated with the pilot oil cavity. The diameter of the middle shaft of the main valve core is provided with a main valve core large annular groove f and a main valve core small annular groove d, and four inclined holes e which are uniformly distributed on the circumference of the diameter of the middle shaft of the main valve core are communicated with the main valve core large annular groove f and the main valve core small annular groove d, so that hydraulic oil of a port P can be communicated with pilot oil cavities at two sides through the inclined holes e and the end face through hole j. The small annular groove d of the main valve core can prevent uneven pressure of pressure oil introduced by four inclined holes e uniformly distributed on the circumference. And chamfering is respectively carried out on two sides of the pilot valve core, and the pilot valve core is arranged in the large annular groove f. The two end faces of the pilot valve core are provided with chamfers to form a variable liquid resistance together with the large annular groove f of the main valve core. So that the chamfer surfaces at the two sides of the pilot valve core and the large annular groove f form a positive opening. The pilot oil cavity two-position two-way proportional reversing valve is communicated with a pilot oil cavity of a main valve. The variable liquid resistance formed by the pilot valve core and the large annular groove f of the main valve core and the two-position two-way proportional reversing valve of the left pilot oil chamber and the two-position two-way proportional reversing valve of the right pilot oil chamber respectively form an a-type hydraulic half bridge and a b-type hydraulic half bridge.

Furthermore, the speed reducer and the servo motor are arranged on the left side outside the valve body. The ball screw extends out of the valve body from the left pilot oil cavity. The servo motor is directly connected with the speed reducer, and the speed reducer is directly connected with the left side of the ball screw. The lead screw nut is a permanent magnet. The electrified coil is wound in grooves c and g on two sides of the central axis diameter of the main valve core. The lead power supply is fixed on two end faces of the main valve core, and leads are led out from the power supplies on two sides of the main valve core and respectively pass through the lead holes b and h of the main valve core to be connected with the electrified coil. The oil inlet pressure sensor is installed at an oil inlet P port, a hole a is formed in a left spring cavity of the main valve, a hole i is formed in a right spring cavity of the main valve, the left pilot oil cavity pressure sensor is installed in the spring cavity a of the main valve, and the right pilot oil cavity pressure sensor is installed in the spring cavity i of the main valve.

Furthermore, the chamfers on the two sides of the pilot valve core and the annular groove f on the middle shaft section form an adjustable liquid resistance, and the servo motor and the ball screw adjust the position of the nut to change the liquid resistance and prevent the throttling port from being completely closed. The oil return position is also provided with a pilot oil cavity two-position two-way proportional reversing valve which is also an adjustable hydraulic resistance. The adjustable hydraulic resistance formed by the chamfers on the two sides of the screw nut and the annular groove f of the middle shaft section and the adjustable hydraulic resistance of the two-position two-way proportional reversing valve of the pilot oil cavity form a hydraulic half bridge. The pressure of the hydraulic oil at the port P after entering the pilot oil cavity through the annular groove f can be changed by adjusting the opening degree of the valve port of the two-position two-way proportional reversing valve at the oil return position.

Further, the pilot oil cavity is communicated with a through hole j on the end face of the main valve core. The P port is guided to the pilot oil cavity through the hydraulic oil behind the pilot valve core, and the pressure is used for counteracting the friction force between the main valve core and the valve body. Two groups of electrified coils are respectively wound in the grooves c and g at two sides of the middle shaft diameter. The pilot spool is a permanent magnet. After the energizing coil is electrified, magnetic force is generated, and the main valve core and the lead screw nut are further accurately centered.

Furthermore, the pressure of a pilot oil cavity obtained by a pilot oil cavity pressure sensor and the displacement of the main valve element obtained by a main valve element displacement sensor can adjust the back pressure valve, so that the main valve element has the same dynamic characteristics under different load working conditions. And in zero position, the pilot oil cavities on two sides have pressure, so that the natural frequency and the dynamic response of the system are improved.

The invention has the following beneficial effects:

(1) the invention compensates the friction force between the main valve core and the valve body through the mechanical-hydraulic servo system, realizes the cancellation of the problem of hysteresis in the motion process of the main valve core, improves the position control precision of the valve core due to the adoption of a high-precision mechanical structure,

(2) no overshoot, good dynamic property, controllability and good stability.

Drawings

Fig. 1 is a schematic diagram of the present invention.

In the figure: 1-main valve left spring, 2-right pilot oil cavity two-position two-way proportional reversing valve, 3-main valve core, 4-ball screw, 5-oil inlet pressure sensor, 6-right electrified coil, 7-pilot valve core, 8-left electrified coil, 9-left pilot oil cavity two-position two-way proportional reversing valve, 10-main valve left spring, 11-reducer with two reduction ratios, 12-servo motor, 13-left lead power supply, 14-left pilot oil cavity pressure sensor, 15-main valve core displacement sensor, 16-left plug, 17-valve body, 18-pressure compensator, 19-right plug, 20-right pilot oil cavity pressure sensor, 21-right lead power supply, a-left pressure sensor hole, b-a left wire guide hole, c-a left groove of the middle shaft diameter of the main valve core, d-a small annular groove of the main valve core, e-an oblique hole, f-a large annular groove of the main valve core, g-a right groove of the middle shaft diameter of the main valve core, h-a right wire guide hole, i-a right pressure sensor hole and j-a through hole of the end face of the main valve core.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

Referring to fig. 1, the hydraulic control valve comprises a main valve core 3, a ball screw 4, a servo motor 12, a right electrified coil 6, a left electrified coil 8, a left pilot oil cavity two-position two-way proportional reversing valve 9, a right pilot oil cavity two-position two-way proportional reversing valve 2, a left pilot oil cavity pressure sensor 14, a right pilot oil cavity pressure sensor 20, an oil inlet pressure sensor 5, a main valve right spring 1, a main valve left spring 10, a pressure compensator 17, a left plug 15, a right plug 18, a speed reducer 11 with two speed reduction ratios, a left lead power supply 13, a right lead power supply 21, a pilot valve core 7, a valve body 16 and a main valve core displacement sensor 15.

The main valve core 3 is provided with a main valve core end surface through hole j communicated with the pilot oil cavity. A main valve core large annular groove f and a main valve core small annular groove d are arranged in the middle shaft diameter of the main valve core 3, four inclined holes e evenly distributed on the circumference of the middle shaft diameter of the main valve core 3 are communicated with the main valve core small annular groove d in the middle shaft diameter of the main valve core 3, and hydraulic oil of a port P can be communicated with pilot oil chambers on two sides through the inclined holes e and a main valve core end face through hole j. The small annular groove d of the main valve core can prevent uneven pressure oil introduced by four inclined holes e uniformly distributed on the circumference. And chamfering is respectively performed on two sides of the pilot valve core 7, and the pilot valve core 7 is placed in the large circular groove f of the main valve core. The two end faces of the pilot valve core 7 are provided with chamfers to form a variable liquid resistance together with the large circular groove f of the main valve core. The chamfer surfaces at the two sides of the pilot valve core 7 and the large circular groove f of the main valve core form a positive opening. The left-position pilot oil cavity two-position two-way proportional reversing valve 9 is communicated with a main valve left-side pilot oil cavity and the right-position pilot oil cavity two-position two-way proportional reversing valve 2 is communicated with a main valve right-side pilot oil cavity. The variable liquid resistance formed by the pilot valve core 7 and the large annular groove f of the main valve core and the two-position two-way proportional reversing valve 9 of the left pilot oil cavity and the two-position two-way proportional reversing valve 2 of the right pilot oil cavity form two groups of hydraulic half bridges respectively.

The speed reducer 11 with two speed reduction ratios and the servo motor 12 are arranged on the left side outside the valve body. The ball screw 4 extends out of the valve body from the left pilot oil cavity. The servo motor 12 is directly connected with the speed reducers 11 with the two speed reduction ratios, and the speed reducers 11 with the two speed reduction ratios are directly connected with the left side of the ball screw 4. The pilot valve core 7 is a permanent magnet. The right position electrified coil 6 and the left position electrified coil 8 are wound in grooves c and g on two sides of the middle shaft diameter of the main valve core 3. The left lead power supply 13 and the right lead power supply 21 are fixed on two end faces of the main valve core 3, leads are respectively led out from the left lead power supply 13 and the right lead power supply 21, respectively penetrate through a left lead hole b and a right lead hole h of the main valve core 3, and are connected with the left electrified coil 8 and the right electrified coil 6. The oil inlet pressure sensor 5 is installed at the port P of the oil inlet, a left pressure sensor hole a and a right pressure sensor hole i are formed in a left spring cavity of the main valve, and the pilot oil cavity pressure sensors 14 and 20 are installed at the spring cavities a and i of the main valve.

The chamfers on the two sides of the pilot valve core 7 and the large circular groove f of the main valve core form an adjustable liquid resistance, and the servo motor 12 and the ball screw 4 adjust the position of a nut to change the liquid resistance and prevent the throttling port from being completely closed. The oil return position is also provided with a pilot oil cavity two-position two-way proportional reversing valve 2 and a pilot oil cavity 9 which are also adjustable liquid resistors, and the two valves form a hydraulic half bridge. The pressure of the hydraulic oil at the port P after entering the pilot oil cavity through the annular groove c can be changed by adjusting the two-position two-way proportional reversing valves 2 and 9 at the oil return position.

The pilot oil cavity is communicated with a through hole j on the end face of the main valve core. The port P leads the hydraulic oil after passing through the pilot spool 7 to the pilot oil chamber, and the frictional force between the main spool 3 and the valve body 17 is cancelled by the pressure. The right position energizing coil 6 and the left position energizing coil 8 are respectively wound in the left groove c of the diameter of the middle shaft of the main valve core and the right groove g of the diameter of the middle shaft of the main valve core. The pilot poppet 7 is a permanent magnet. After the energizing coil is electrified, magnetic force is generated to further enable the main valve element 3 and the pilot valve element 7 to be accurately centered.

The first-arriving oil cavity pressure obtained by the left pilot oil cavity pressure sensor 14 and the right pilot oil cavity pressure sensor 20 and the main valve core displacement obtained by the main valve core displacement sensor 15 can be used for the left pilot oil cavity two-position two-way proportional reversing valve 9 and the right pilot oil cavity two-position two-way proportional reversing valve 2, so that the main valve cores have the same dynamic characteristics under different load working conditions. And in zero position, the pilot oil cavities on two sides have pressure, so that the natural frequency and the dynamic response of the system are improved.

Eliminating the working principle and characteristics of a hysteresis loop mechanical-hydraulic servo system: the servo motor is used as an electric-mechanical converter to drive the screw rod to rotate, and the nut moves linearly, so that pressure oil at the port P enters the pilot oil cavity through the small main valve core annular groove d and the large main valve core annular groove f of the main valve core 3 and the through hole j on the end face of the main valve core 3. And then the oil returns to the oil tank through the pilot oil cavity, the left pilot oil cavity two-position two-way proportional reversing valve 9 and the right pilot oil cavity two-position two-way proportional reversing valve 2 respectively. The pilot oil cavity two-position two-way proportional reversing valve 9 and the right pilot oil cavity two-position two-way proportional reversing valve 2 respectively form two variable liquid resistors with the middle shaft diameter annular groove d, and the two pilot oil cavity two-position two-way proportional reversing valves are also variable liquid resistors and respectively form a hydraulic half bridge. Therefore, the pressure of the pilot oil cavity can be changed by adjusting the opening degrees of the valve ports of the pilot oil cavity two-position two-way proportional reversing valve 9 and the right pilot oil cavity two-position two-way proportional reversing valve 2, so that the friction force between the main valve core and the valve body is counteracted, and the hysteresis is eliminated.