CN108716489B - Power stage structure of electro-hydraulic pressure servo valve - Google Patents
Power stage structure of electro-hydraulic pressure servo valve Download PDFInfo
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- CN108716489B CN108716489B CN201810890162.5A CN201810890162A CN108716489B CN 108716489 B CN108716489 B CN 108716489B CN 201810890162 A CN201810890162 A CN 201810890162A CN 108716489 B CN108716489 B CN 108716489B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/023—Excess flow valves, e.g. for locking cylinders in case of hose burst
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/08—Servomotor systems incorporating electrically operated control means
Abstract
The utility model provides an electricity liquid pressure servo valve power level structure, the valve barrel is installed in the valve body, the case is installed in the valve barrel, the end cap dress is at the both ends of valve barrel, two joint slide bars set up respectively at the both ends of case, the bulb of joint slide bar one end sets up in case terminal surface hole, the bulb of the other end sets up in the end cap hole, the bulb of joint slide bar one end cooperates with case terminal surface hole and cuts apart the case into feedback chamber and control chamber, two joint slide bars constitute two sets of independent slide valve pairs with case terminal surface hole and end cap hole. The invention adopts a power stage slide valve structure with two groups of independent matching pairs to replace the existing layer-by-layer matching structure, thereby reducing the part matching links and greatly reducing the processing difficulty.
Description
Technical Field
The invention relates to a power stage structure of an electro-hydraulic pressure servo valve.
Background
The electro-hydraulic pressure servo valve is widely applied to a hydraulic servo system with higher pressure control precision requirement, and the control on the pressure precision is incomparable with the control on the pressure precision of a common proportional pressure valve, so that the electro-hydraulic pressure servo valve has irreplaceable effect in certain fields.
The electro-hydraulic pressure servo valve can output unilateral pressure and bilateral pressure according to the number of pressure cavities for controlling output. The unilateral pressure output is similar to a proportional pressure reducing valve, and the bilateral pressure output can accurately control the pressure difference of the first output cavity and the second output cavity.
The electro-hydraulic pressure servo valve can be divided into three structural forms of electric pressure feedback, spraying and blocking reaction moment feedback and valve core reaction pressure feedback according to a feedback mode. The performance of the electro-hydraulic pressure servo valve is closely related to a slide valve level structure and a feedback mode, and the pressure feedback is realized by adopting a pressure sensor to detect the pressure and feeding the pressure back to an input end to form closed-loop control; the spraying baffle reaction torque feedback is to lead the pressure acting on the output cavity to the feedback nozzle, and the reaction force of the feedback nozzle to the motor is balanced with the action force of the control nozzle to the motor to form feedback control; the valve core reaction pressure feedback divides the valve core into two groups of cavities, namely a control cavity and a feedback cavity, the control cavity is connected with the front stage of the valve body, the feedback cavity is connected with the output cavity, the valve core opening is controlled by the control cavity after the pressure of the front stage is changed, so that the pressure of the output cavity is changed, the feedback cavity timely feeds back the pressure of the output cavity and acts on the feedback end surface of the valve core, and the force balance of the feedback cavity and the control cavity forms closed-loop control.
The electric feedback structure of the pressure sensor is adopted, the control precision is high, but the cost is high, the space structure is large, and the electric feedback structure is limited on a system with relatively severe environment or compact space structure. The electro-hydraulic pressure servo valve for reverse torque feedback of the spraying and blocking adopts the feedback nozzle pressure feedback in the output cavity, so that the servo valve has poor anti-pollution capability and is not suitable for occasions with general oil source cleanliness. The valve core has compact structure and strong pollution resistance due to the reaction pressure feedback, as shown in figure 1, the conventional structural form is that the valve core 2 is made into a step mode and is matched and ground with an embedded end cover, the valve core is divided into a feedback cavity 5 and a control cavity 9, the valve core needs to be simultaneously matched and ground with the inner holes of a valve sleeve 1 and an embedded end cover 6, the outer circle 4 of the end cover needs to be matched and ground with the inner hole 10 of the valve sleeve, the valve core, the valve sleeve and the embedded end cover need to be comprehensively matched layer by layer, the precision requirement is high, and the processing efficiency is very low. Generally, the electrohydraulic pressure servo valve has high manufacturing cost and poor pollution resistance, so that the application of the electrohydraulic pressure servo valve in most general fields is limited.
Disclosure of Invention
The invention provides a power stage structure of an electro-hydraulic pressure servo valve, which adopts two groups of independent power stage slide valve structures of line contact matching pairs to replace the existing cylindrical surface matching structure needing layer-by-layer matching grinding, reduces the part matching links and greatly reduces the processing difficulty.
In order to achieve the above object, the present invention provides a power stage structure of an electro-hydraulic pressure servo valve, comprising:
the valve body is provided with a first preposed stage hole and a second preposed stage hole;
a valve housing mounted within the valve body;
the valve core is arranged in the valve sleeve, the valve core can move in the valve sleeve, and small oil through holes are formed in the two ends of the valve core;
the valve sleeve sealing rings are arranged between the valve sleeve and the valve body, the valve sleeve sealing rings divide the valve sleeve into a high-pressure cavity, a low-pressure cavity, a first output cavity, a second output cavity, a first control cavity and a second control cavity, the high-pressure cavity is used for inputting oil, the low-pressure cavity is used for outputting oil return, the first output cavity is communicated with a first feedback cavity of the valve core through an oil through small hole in the valve core, the second output cavity is communicated with a second feedback cavity of the valve core through the oil through small hole in the valve core, the first control cavity is connected with a first preposed stage hole, and the second control cavity is connected with a second preposed stage hole;
the two plugs are arranged at the two ends of the valve sleeve and used for limiting the movement of the valve core; a plurality of plug sealing rings are arranged between the plug and the valve sleeve;
the two joint slide bars are respectively arranged at two ends of the valve core, the ball head at one end of the joint slide bar is arranged in the inner hole of the end face of the valve core, the ball head at the other end of the joint slide bar is arranged in the inner hole of the plug, the ball head at one end of the joint slide bar is matched with the inner hole of the end face of the valve core to divide the valve core into a feedback cavity and a control cavity, and the two joint slide bars, the inner hole of the end face of the valve core.
The ball head, the inner hole of the end face of the valve core and the inner hole of the plug are in clearance fit, and the ball head of the joint slide rod, the inner hole of the end face of the valve core and the inner hole of the plug are in clearance fit in the movement process of the valve core.
The valve core is provided with a plurality of throttling edges, the valve sleeve is provided with a plurality of throttling square holes, the throttling edges and the throttling square holes form throttling openings, and each throttling opening is communicated with the high-pressure cavity or the low-pressure cavity and used for controlling flow.
The two ends of the valve body are fixed through end covers and screw assemblies.
The invention has the following advantages:
1. the joint slide rod, the inner hole of the end face of the valve core and the inner hole of the plug form two independent slide valve pairs, the joint slide rod and the plug can be selected and matched according to the size of the inner hole of the end face of the valve core, and the joint slide rod is a standard component and is convenient to select and match;
2. the valve core, the valve sleeve and the plug do not need to be ground and matched layer by layer, a large number of single-matched processing links are reduced, the processing difficulty is greatly reduced, and the power level can be produced in batch.
Drawings
Fig. 1 is a schematic structural diagram of an electro-hydraulic pressure servo valve in the background art.
FIG. 2 is a structural section view of a power stage structure of an electro-hydraulic pressure servo valve provided by the invention.
Fig. 3 is a schematic view of the slide valve pair.
Detailed Description
The preferred embodiment of the present invention will be described in detail below with reference to fig. 2 to 3.
The electro-hydraulic pressure servo valve has the advantages that the defects of high manufacturing cost and low processing efficiency of the electro-hydraulic pressure servo valve are overcome, and the characteristics of strong pollution resistance, compact structure and high reliability are met, so that the electro-hydraulic pressure servo valve has a wider application space, and a good power level design scheme is required.
As shown in fig. 2, the present invention provides a power stage structure of an electro-hydraulic pressure servo valve, comprising:
a valve body 19 provided with a first prestage hole 16 and a second prestage hole 21;
a valve housing 1 mounted within the valve body 19;
the valve core 17 is arranged in the valve sleeve 1, the valve core 17 can move in the valve sleeve 1, and small oil through holes 20 are formed in the two ends of the valve core 17;
the valve sleeve sealing rings 13 are arranged between the valve sleeve 1 and the valve body 19, the valve sleeve sealing rings 13 divide the valve sleeve 1 into a high-pressure cavity 32, a low-pressure cavity 30, a first output cavity 31, a second output cavity 29, a first control cavity 14 and a second control cavity 23, the high-pressure cavity 32 is used for oil inlet input, the low-pressure cavity 30 is used for oil return output, the first output cavity 31 is communicated with the first feedback cavity 15 of the valve core through an oil through small hole 20 on the valve core 17, the second output cavity 29 is communicated with the second feedback cavity 22 of the valve core through the oil through small hole 20 on the valve core 17, the first control cavity 14 is connected with the first prestage hole 16, and the second control cavity 23 is connected with the second prestage hole 21;
two plugs 25 installed at both ends of the valve housing 1 for limiting the movement of the valve core 17; a plurality of plug sealing rings 33 are arranged between the plug 25 and the valve sleeve 1;
two joint slide bars 26 respectively arranged at two ends of the valve core 17, as shown in fig. 3, a ball head 35 at one end of the joint slide bar 26 is arranged in a valve core end surface inner hole 34, a ball head 35 at the other end is arranged in a plug inner hole 36, the ball head 35, the valve core end surface inner hole 34 and the plug inner hole 36 are in clearance fit, two joint slide bars 26, the valve core end surface inner hole 34 and the plug inner hole 36 form two groups of independent slide valve pairs, the ball head 35 of the joint slide bar 26, the valve core end surface inner hole 34 and the plug inner hole 36 are in clearance fit in the motion process of the valve core 17, and the valve core 17 is divided into a feedback cavity (inner cavity) and a control cavity (outer cavity) after the ball head 35 at one end.
The valve core 17 is provided with a larger diameter part and a smaller diameter part, four throttling edges 28 are formed on the end surface between the larger diameter part and the smaller diameter part, the valve sleeve 1 is provided with four throttling square holes 27, the high pressure cavity 32 and the low pressure cavity 30 are respectively communicated with the throttling square holes 27, the throttling edges 28 and the throttling square holes 27 form a throttling opening, and the throttling opening can be completely shielded, partially shielded or completely opened along with the left and right movement of the valve core 17, so that the flow of oil inlet and outlet can be controlled, and the output pressure can be controlled.
Further, both ends of the valve body 19 are fixed by the end cap 24 and the screw assembly 12.
The working principle of the power stage structure of the electro-hydraulic pressure servo valve provided by the invention is as follows:
the middle groove of the valve core 17 is connected with a feedback rod 18 of a motor, the first control cavity 14 is connected with a motor part prestage through a first prestage hole 16, the second control cavity 23 is connected with the motor part prestage through a second prestage hole 21, the first output cavity 31 and the second output cavity 29 are connected with an external actuator (such as a hydraulic cylinder or a hydraulic motor), the first output cavity 31 is communicated with the first feedback cavity 15 of the valve core through an oil through small hole 20 on the valve core 17, the second output cavity 29 is communicated with the second feedback cavity 22 of the valve core through the oil through small hole 20 on the valve core 17, and the pressure of the feedback cavity and the control cavity at the outer end of the valve core are balanced to form pressure feedback. In the initial position, because the motor of the electro-hydraulic pressure servo valve does not work, the pressure from the first prestage hole 16 to the first control cavity 14 on the outer end face of the valve core is equal to the pressure from the second prestage hole 21 to the second control cavity 23, and the valve core 17 is located in the middle position of the valve sleeve 1. When the electro-hydraulic pressure servo valve motor works (current signals are input), pressure difference is generated between the first control cavity 14 and the second control cavity 23, the pressure difference is in proportion to the input current signals, the valve core 17 is pushed to move by the pressure difference, throttling openings formed by four throttling edges 28 of the valve core and a throttling square hole 27 of the valve sleeve are opened, and pressure difference is generated between the first output cavity 31 and the second output cavity 29. Meanwhile, the differential pressure generated by the first output chamber 31 and the second output chamber 29 is fed back to the first feedback chamber 15 and the second feedback chamber 22 at both ends of the spool through the oil through small hole 20 inside the spool 17, and the acting force generated by the spool inner chamber (the first feedback chamber 15 and the second feedback chamber 22) is opposite to the spool acting force generated by the spool outer chamber (the first control chamber 14 and the second control chamber 23) and equal in magnitude, so the spool 17 is in a balanced state.
The invention has the following advantages:
1. the joint slide rod, the inner hole of the end face of the valve core and the inner hole of the plug form two independent slide valve pairs, the joint slide rod and the plug can be selected and matched according to the size of the inner hole of the end face of the valve core, and the joint slide rod is a standard component and is convenient to select and match;
2. the valve core, the valve sleeve and the plug do not need to be ground and matched layer by layer, a large number of single-matched processing links are reduced, the processing difficulty is greatly reduced, and the power level can be produced in batch.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.
Claims (4)
1. An electro-hydraulic pressure servo valve power stage structure, comprising:
a valve body (19) provided with a first prestage hole (16) and a second prestage hole (21);
a valve housing (1) mounted within the valve body (19);
the valve core (17) is arranged in the valve sleeve (1), the valve core (17) can move in the valve sleeve (1), and small oil through holes (20) are formed in the two ends of the valve core (17);
the valve sleeve sealing rings (13) are arranged between the valve sleeve (1) and the valve body (19), the valve sleeve sealing rings (13) divide the valve sleeve (1) into a high-pressure cavity (32), a low-pressure cavity (30), a first output cavity (31), a second output cavity (29), a first control cavity (14) and a second control cavity (23), the high-pressure cavity (32) is used for oil inlet input, the low-pressure cavity (30) is used for oil return output, the first output cavity (31) is communicated with a first feedback cavity (15) of the valve core through an oil through small hole (20) in the valve core (17), the second output cavity (29) is communicated with a second feedback cavity (22) of the valve core through the oil through small hole (20) in the valve core (17), the first control cavity (14) is connected with a first preposed stage hole (16), and the second control cavity (23) is connected with a second preposed stage hole (21);
two plugs (25) which are arranged at two ends of the valve sleeve (1) and used for limiting the movement of the valve core (17); a plurality of plug sealing rings (33) are arranged between the plug (25) and the valve sleeve (1);
the two joint sliding rods (26) are respectively arranged at two ends of the valve core (17), a ball head (35) at one end of each joint sliding rod (26) is arranged in an inner hole (34) in the end face of the valve core, a ball head (35) at the other end of each joint sliding rod (26) is arranged in an inner hole (36) in the end face of the plug, the ball head (35) at one end of each joint sliding rod (26) is matched with the inner hole (34) in the end face of the valve core to divide the valve core (17) into a feedback cavity and a control cavity, and the two joint sliding rods (26), the inner hole (34) in the end face of.
2. The power stage structure of the electro-hydraulic pressure servo valve as claimed in claim 1, wherein the ball head (35) is in clearance fit with both the valve core end face inner hole (34) and the plug inner hole (36), and the ball head (35) of the joint slide rod (26) is in clearance fit with both the valve core end face inner hole (34) and the plug inner hole (36) in the movement process of the valve core (17).
3. The power stage structure of an electrohydraulic pressure servo valve according to claim 1, characterized in that the valve core (17) is provided with a plurality of throttling edges (28), the valve sleeve (1) is provided with a plurality of throttling square holes (27), the throttling edges (28) and the throttling square holes (27) form throttling ports, and each throttling port is communicated with the high-pressure chamber (32) or the low-pressure chamber (30) and is used for controlling the flow.
4. Electro-hydraulic pressure servo valve power stage structure according to claim 1, characterized in that the valve body (19) is fixed at both ends by means of an end cap (24) and a screw assembly (12).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810890162.5A CN108716489B (en) | 2018-08-07 | 2018-08-07 | Power stage structure of electro-hydraulic pressure servo valve |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810890162.5A CN108716489B (en) | 2018-08-07 | 2018-08-07 | Power stage structure of electro-hydraulic pressure servo valve |
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| Publication Number | Publication Date |
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| CN108716489A CN108716489A (en) | 2018-10-30 |
| CN108716489B true CN108716489B (en) | 2020-04-10 |
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| CN201810890162.5A Active CN108716489B (en) | 2018-08-07 | 2018-08-07 | Power stage structure of electro-hydraulic pressure servo valve |
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| EP3901501A1 (en) | 2020-04-26 | 2021-10-27 | Hamilton Sundstrand Corporation | Servo valve |
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