CN108506257B - A device and method for debugging the trajectory of the jet axis of a three-way jet tube servo valve - Google Patents

Abstract

The invention relates to a device and a method for adjusting the trajectory of the jet axis of a three-way jet tube servo valve. The device comprises a valve body, a jet receiver arranged in the jet region on the valve body, and a jet receiver which is arranged opposite the jet region and whose displacement is controlled by a torque motor. The jet nozzle and the pressure sensor connected to the jet nozzle through the detection hole. Compared with the prior art, the invention has the advantages of simple detection method, high accuracy, high efficiency and high reliability.

Description

A device and method for debugging the trajectory of the jet axis of a three-way jet tube servo valve

technical field

The invention relates to the technical field of jet tube servo valves, in particular to a device and method for adjusting the trajectory of a jet axis of a three-way jet tube servo valve.

Background technique

The jet tube servo valve first appeared during the Second World War. The German Askania Company first invented the jet tube servo valve. Jet pipe valves have been widely used in hydraulic systems of civil and military aerospace equipment due to their fail-safe functions. In 1957, R. Atchley invented a two-stage jet tube servo valve on the basis of the principle of Askania (reference patent document: R.D.Atchley.Servo-mechanism: US2884907A[P].1957-8-30). Gerald C. Zoller (Reference patent document: Gerald C. Zoller. Variable gain jet pipe servo vavle: US3589238A [P]. 1969-2-24) in the fixed position between the nozzle and the receiving hole in the pre-stage of the jet pipe servo valve A movable annular jet guide cavity is installed, and the purpose of adjusting the recovery pressure is achieved by changing the relative position between the guide cavity, the nozzle and the receiving hole. In 1971, Clyde E. Cobb (reference patent document: Clyde E Cobb, Charles Ejones. Adjustable receiver port construction for jet pipe servovavle: US3584638A[P]. 1971-6-15) and others invented a jet pipe servo with adjustable receiving holes The two receiving holes in the pre-stage of the valve are directly arranged on the main valve core, and the positions of the two receiving holes relative to the nozzle can be adjusted by radial adjustment of the main valve core, so as to adjust the recovery pressure of the receiving holes. In 1987, Richard D.Bartholomew (reference patent document: Richard D.Bartholomew.Optical feedback loop system for a hydraulicservovalve:US4660589A[P].1986-3-3) used electromagnetic positioner to replace traditional hydraulic and electronic control positioner, This feedback method is more precise than mechanical feedback. Among the various methods of adjusting the recovery pressure of the receiving hole, the core is to adjust the relative position of the nozzle and the receiving hole, so that the movement trajectory of the nozzle driven by the torque motor changes, so that the flow of the nozzle jet flowing into the receiving hole changes, and then To achieve the purpose of regulating recovery pressure. Due to the complex working environment of the servo valve, it is easily affected by various factors during the working process, resulting in the deviation of the nozzle position, and then the change of the trajectory of the jet axis, and the influence of this change is often unfavorable. Therefore, it is necessary to propose a method that can adjust the trajectory of the jet axis according to people's wishes.

Because the three-way jet tube servo valve works in a closed space, its jet axis trajectory cannot be directly detected. At present, most of the methods for adjusting the trajectory of the jet axis are based on experience, intuition, hand feeling, etc. These methods lack professionalism and are not intuitive.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device and method for adjusting the trajectory of the jet axis of a three-way jet tube servo valve in order to overcome the above-mentioned defects in the prior art.

The object of the present invention can be realized through the following technical solutions:

A three-way jet tube servo valve jet axis trajectory debugging device, the device comprises a valve body, a jet receiver arranged in a jet region on the valve body, a jet nozzle arranged directly opposite the jet region and controlled by a torque motor for displacement, and a detection The orifice is connected to the pressure sensor of the jet nozzle.

Preferably, the jet receiver is in the shape of an inverted cylindrical table, the lower part is fixed in the jet region, the upper part is arranged opposite the jet nozzle, and the upper end face is respectively provided with a jet receiving hole, an upper pressure detection hole and a lower pressure detection hole, so The jet receiving hole communicates with the receiving long hole in the valve body, and the upper pressure detecting hole and the lower pressure detecting hole are respectively connected with the pressure difference sensor through the right detecting long hole and the left detecting long hole.

Preferably, the jet flow receiving hole is a straight hole perpendicular to the upper end face of the jet flow receiver, the upper pressure detection hole and the lower pressure detection hole are both inclined holes, and are symmetrically arranged in a spatial figure-eight shape, in order to prevent pressure The detection hole interferes with the jet receiving hole, and the included angle between the axis of the jet receiving hole and the axis of the upper pressure detection hole and the lower pressure detection hole is 15°-35°, preferably 30°.

Preferably, the vertical line connecting the circle centers of the upper pressure detection hole and the lower pressure detection hole passes through the circle center of the jet receiving hole.

Preferably, the radius R' of the upper pressure detection hole and the lower pressure detection hole is half of the radius R of the jet receiving hole.

Preferably, the center-to-center distance between the upper pressure detection hole and the lower pressure detection hole is R'+0.02mm.

A debugging method includes the following steps:

1) Connect the pressure difference sensor on both sides of the valve body, place the jet nozzle at the initial position, turn on the driving torque motor, and make the jet nozzle complete the movement process from the initial position to the end point under the action of the torque motor;

2) During the movement of the jet nozzle, obtain the pressure difference value of the pressure detection holes on both sides, and judge whether the trajectory of the jet axis meets the requirements according to the pressure difference;

3) When the trajectory of the jet axis meets the requirements, that is, it is coincident with or parallel to the x-axis and the distance is the set expected value, remove the pressure difference sensor, use the sealing screw to seal the detection slot, and complete the debugging of the jet axis trajectory;

4) When the trajectory of the jet axis does not meet the requirements, re-adjust the nozzle installation position and return to step 1).

In the described step 2):

When the difference between the pressure values of the pressure sensors on both sides is constant to zero, the trajectory of the jet axis coincides with the x-axis, and it is determined that the requirements are met;

When the pressure value of the pressure sensors on both sides is not zero and the pressure difference is a constant non-zero value, the jet axis trajectory is parallel to the x-axis, and the distance is a certain value, and it is determined that the requirements are met;

When the difference between the pressure values of the pressure sensors on both sides changes irregularly, the trajectory of the jet axis is not parallel to the x-axis, and it is determined that it does not meet the requirements.

The x-axis is the vertical line connecting the centers of the upper pressure detection holes and the lower pressure detection holes.

The centers of the upper pressure detection hole and the lower pressure detection hole are both located in the annular region formed by the turbulent flow region in the initial jet state and the isokinetic core region in the initial jet state.

Compared with the prior art, the present invention has the following advantages:

1. The present invention uses a pressure difference sensor to record the pressure difference between the two pressure detection holes, and the measurement process is more convenient.

2. The present invention can judge the trajectory of the jet axis of the three-way jet servo valve according to the detected pressure difference, which is more intuitive and more reliable than traditional judgment methods such as experience, intuition and hand feeling.

3. The detection sensitivity is high and the accuracy is good. In order to adapt to the jet flow servo valve, the jet receiver of the present invention has a jet flow receiving hole in the center, which effectively avoids more position restrictions when opening two pressure detection holes. , resulting in limited receiving flow and low sensitivity, while there is only one jet receiving hole in the three-way servo valve, so the positions of the two pressure detection holes can be set more freely, and the detection sensitivity is higher.

4. The detection method is simple and efficient.

Description of drawings

FIG. 1 is a schematic structural diagram of a jet tube type electro-hydraulic servo pressure reducing valve according to an embodiment of the present invention.

FIG. 2 is a geometrical relationship diagram of a free-nozzle jet flow field according to an embodiment of the present invention.

FIG. 3 is a schematic plan view of a receiver according to an embodiment of the present invention.

FIG. 4 is a three-dimensional schematic diagram of a receiver according to an embodiment of the present invention.

Figure 5 shows four different cases of jet axis trajectory in an embodiment of the present invention.

Fig. 6 is the pressure change trend corresponding to the pressure detection hole under four different situations in the embodiment of the present invention, wherein, Fig. (6a) is the pressure change trend corresponding to the pressure detection hole in the case of a, Fig. (6b) is b Figure (6c) shows the pressure change trend corresponding to the pressure detection hole in the case of c, and Figure (6d) shows the pressure change trend corresponding to the pressure detection hole in the case of d.

Figure 7 shows the pressure difference changes corresponding to the upper and lower pressure detection holes under four different situations in the embodiment of the present invention, wherein Figure (7a) is the pressure difference changes corresponding to the upper and lower pressure detection holes in the case of a, Figure (7b) Figure (7c) is the pressure difference corresponding to the upper and lower pressure detection holes in the case of c, Figure (7d) is the pressure corresponding to the upper and lower pressure detection holes in the case of d. poor change.

Description of marks in the figure:

1. Valve body, 2. Valve core, 3. Spring, 4. Differential pressure sensor, 5. Right detection slot, 5', Left detection slot, 6. Pilot return port, 7. Jet receiving hole, 8 , the upper pressure detection hole, 8', the lower pressure detection hole, 9, the turbulent flow area in the initial jet state, 10, the isokinetic core area in the initial jet state, 11, the isokinetic core area at the end point of the jet beam movement, 12. Turbulent flow area at the end of the jet beam movement, 13, Torque motor, 14, Flexible oil supply pipe, 15, Jet nozzle, 16, Jet receiver, 17, Receiving slot, P, oil supply port, C, Control oil port, T, oil return port, O, coordinate origin, O ₁ , the center of the section circle of the constant velocity core area in the initial jet state, P ₁ , the section circle center of the upper pressure detection hole, P ₂ , the section circle of the lower pressure detection hole Circle center, Δ, valve opening.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example

As shown in Figure 1, the jet tube type electro-hydraulic servo pressure reducing valve of the present invention is composed of a valve body 1, a valve core 2, a spring 3, a torque motor 13, a flexible oil supply pipe 14, a jet nozzle 15, and a jet receiver 16. , the jet receiving hole 7 on the jet receiver 16 is connected to the right cavity of the valve core. When the input control current of the jet tube servo pressure reducing valve is zero, the torque motor 13 does not act, as shown in Figure 3, at this time, the projection on the jet The turbulent region of the jet stream on the receiver 13 is the section circle 9, the isokinetic core region is the section circle 10, the center of the circle is O ₁ , and the section circle 9 of the turbulent region is tangent to the outer circle of the jet receiving hole 7, and the receiving hole 7 The energy received is zero, and the spool is in the right position under the action of the left spring. After applying the control current, driven by the torque motor 13, the jet nozzle 15 is shifted to the left, the jet energy received by the receiving hole 7 on the jet receiver 16 gradually increases, and the pressure generated at the right end of the valve core gradually increases. Since the left end of the valve core is subjected to the force of the spring, when the pressure in the receiving hole is greater than the elastic force of the spring, the valve core 2 moves to the left end, the valve opening Δ increases, and a part of the pressure oil entering from the oil supply port P passes through the opened valve. The port is connected to the control oil port C, and finally enters the left side of the spool 2, which plays a feedback role and avoids the problem of excessive instantaneous displacement of the spool 2. When the pressure at both ends of the valve core 2 is equal to form a new force balance, the valve core is stable in a certain working position. At this time, the offset amount of the main spool 2 is proportional to the control current. The jet tube 15 can move as far as it is directly above the jet receiving hole 7. At this time, the turbulent region of the jet beam projected on the jet receiver 16 is the cross-section circle 12, and the isokinetic core region is the cross-section circle 11. At this moment, the jet beam is turbulent. The center of the flow area cross-sectional circle 12 coincides with the center of the jet receiving hole 7, which is the coordinate origin O, which is the end point of the jet axis trajectory. At this time, the energy received by the jet tube receiving hole 7 reaches the maximum value.

As shown in Fig. 2, the jet oil is injected into the static fluid of the same kind through the jet nozzle 15. Before the jet comes into contact with the surface of the receiving hole, it is considered that the jet is not affected by the impact surface, so it is equivalent to injecting into a static infinite space. The fluid is a freely submerged turbulent jet, and its beam is shown by the dotted line in the figure, including a constant velocity core region and a turbulent flow region, where the jet velocity in the constant velocity core region is v ₀ , and the jet velocity in the turbulent flow region is v. In this example, the diameters of the jet nozzle 15 and the receiving hole 7 are both D=2R, and the distance between the outlet of the nozzle 15 and the plane of the receiver 16 is generally L≈(1-1.4)D. According to the precise numerical description of the pressure distribution in the jet category of incompressible turbulent flow proposed by Zalmanzon and Semikova, when the jet jet angle α=14°, the constant velocity core zone angle γ=11°26', the length of the constant velocity core zone is 5D. In this embodiment, the distance between the jet nozzle 15 and the plane of the jet receiver is L=1.2D, which is obtained from the geometric relationship in the figure:

Isokinetic core region beam diameter

Shear laminar beam diameter

As shown in FIG. 3 , the two pressure detection holes 8 and 8' on the jet receiver are located on both sides of the jet reception hole respectively, and the center of the jet reception hole 7 is located in the middle of the center line P1P2 between the two pressure detection holes 8 and 8'. On the vertical line, R is the radius of the jet receiving hole, and is the radius of the pressure detection hole. During installation, adjust the position of the jet nozzle 15 back and forth in the direction of the vertical line in P1P2 as required, so that the pressure difference and its changes at the detection holes 8 and 8' are as expected. When the jet axis is required to coincide with the x-axis, the pressure difference detected at the upper and lower detection holes 8 and 8' should be constant zero; when the jet axis is required to be parallel to the x-axis and separated by a certain value, the upper and lower detection holes 8, 8' The pressure difference at 8' shall be a non-zero value within a certain interval. When it is detected that the pressure difference at the two detection holes varies irregularly, it means that the trajectory of the jet axis is not parallel to the x-axis, which is generally judged to be unsatisfactory, and the position of the jet nozzle 15 needs to be adjusted continuously. The upper and lower detection holes 8 and 8' are symmetrically opened on both sides of the jet receiving hole 7. Assuming that the coordinates of the upper detection hole 8 in the figure are (x, y), in order to ensure that the detection hole can be maximal during the swing of the jet tube In order to receive the maximum energy of the jet tube, the detection hole is set close to the initial jet and as far as possible in its isokinetic core area. Then, from the graphical geometric relationship, we can get

The detection hole is set close to the initial jet to ensure the recognition of the receiving pressure of the detection hole. In order to make the jet tube move to the end position, there is still a certain detection pressure, and the two detection holes 8 and 8' are not connected to the jet receiving hole. 7 Interference occurs, then according to the geometric relationship shown in the figure:

At the same time, in order to ensure that the detection hole 8 can increase its output pressure as much as possible when the position is fixed, the detection holes 8 and 8' should receive as many jets as possible from the isokinetic core area and the shear layer. Therefore, the detection holes should be located as far as possible. For the area between circle 9 and circle 10, the radius range can be obtained from the geometric relationship shown in the figure:

Take the detection hole radius R'=0.5R. According to the existing processing technology, the physical distance between two adjacent processing holes can be guaranteed to reach millimeter-level accuracy. In this example, the physical distance between the lower edge of the detection hole 8 and the upper edge of the detection hole 8' is 0.02mm , that is, the distance between the lower edge of the detection hole 8 and the upper edge of the detection hole 8' from the x-axis is both 0.01 mm. The y-coordinate value of the detection hole 9 is determined, y=0.5R+0.01. According to the above known conditions, inequality (2) can be transformed into:

最终得到两检测小孔8、8’的坐标分别为(1.6R,0.5R+0.01)、(1.6R,-0.5R-0.01)。两检测小孔8、8’关于x轴对称。Taking into account the constraints of inequalities (1), (2) and (3), in this example we take

Finally, the coordinates of the two detection holes 8 and 8' are respectively (1.6R, 0.5R+0.01) and (1.6R, -0.5R-0.01). The two detection holes 8, 8' are symmetrical about the x-axis.

As shown in FIG. 4 , the two pressure detection holes 8 and 8 ′ on the jet receiver 16 are symmetrically distributed with respect to the jet receiver hole 7 and are arranged in a figure-eight shape in space. Interference, the included angle between the axes of the two pressure detection holes 8, 8' and the axis of the jet receiving hole 7 ranges from 15° to 35°. In this example, the included angle is preferably 30°. The distance between the centers of the two detection holes is R+0.02 (mm), the radius of the detection hole is R'=0.5R, and the radius of the jet receiving hole is R. The jet receiver 16 is in the shape of an upside-down boss, and its tail is provided with two symmetrical longitudinal sections. During the process that the torque motor is driven by the current to drive the nozzle to move, the pressure difference between the two detection holes 8 and 8' is recorded. When the pressure difference is constant at zero, it means that the trajectory of the jet axis coincides with the x-axis; when it appears in a section, the pressure difference is constant to a non-zero value, indicating that the trajectory of the jet axis is parallel to the x-axis, and the distance is a certain value; When the pressure difference varies irregularly, it means that the jet axis is not parallel to the x-axis. Generally, it is judged that this situation is unsatisfactory. It is necessary to fine-tune the position of the jet nozzle 15 so that it is as perpendicular to the y-axis as possible and crosses the x-axis. on the plane, so as to ensure that the trajectory of the jet axis reaches the ideal situation.

As shown in FIG. 5 , a, b, c, and d respectively correspond to four typical jet trajectories during the movement of the jet nozzle 15 driven by the torque motor. Among them, a is the case where the jet axis trajectory coincides with the x-axis, b is the case where it is parallel to the x-axis and at a certain distance, and c and d are the cases where the two different jet axis trajectories are not parallel to the x-axis. Among these four different jet axis trajectories, a and b are the jet axis trajectories that meet the requirements, and c and d are the jet axis trajectories that do not meet the requirements.

FIG. 6 is the pressure change trend corresponding to the pressure detection hole under four different conditions of a, b, c, and d in the embodiment of the present invention. As mentioned above, a is the case where the trajectory of the jet axis coincides with the x-axis. In this case, the pressure detection holes 8 and 8' have a completely consistent pressure change trend. b is the case where it is parallel to the x-axis and is separated by a certain distance, and the pressure values of the two detection holes have a similar change trend when neither of them is zero. In the two cases of c and d, the pressure values measured by the two detection pressure holes 8 and 8' change irregularly.

Fig. 7 is the variation of the pressure difference between the pressure detection holes 8 and 8' under four different conditions of a, b, c, and d in the embodiment of the present invention. As mentioned above, a is the case where the trajectory of the jet axis coincides with the x-axis, and in this case, the pressure difference detected at the two pressure detection holes is always zero. b is the case where it is parallel to the x-axis and is separated by a certain distance, and when the pressure values of the two detection holes are not zero, the difference is a certain value. In the two cases of c and d, the pressure difference between the two pressure detection holes changes irregularly.

The above description of the embodiments is for the convenience of those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made to the present invention by those skilled in the art according to the disclosure of the present invention should all fall within the protection scope of the present invention.

Claims (1)

1. A three-way jet pipe servo valve jet axis track debugging device is characterized by comprising a valve body (1), a jet receiver (16) arranged on a jet area on the valve body (1), a jet nozzle (15) which is just opposite to the jet area and controls displacement through a torque motor (13), and a pressure sensor connected with the jet nozzle (15) through a detection hole, wherein the jet receiver (16) is in an inverted circular truncated cone shape, the lower part of the jet receiver is fixed in the jet area, the upper part of the jet receiver is opposite to the jet nozzle (15), the upper end surface of the jet receiver is respectively provided with a jet receiving hole (7), an upper pressure detection hole (8) and a lower pressure detection hole (8 '), the jet receiving hole (7) is communicated with a receiving long hole (17) arranged in the valve body, the upper pressure detection hole (8) and the lower pressure detection hole (8 ') are respectively connected with a pressure difference sensor (4) through a right detection long hole (5) and a left detection long hole (5 '), the jet flow receiving hole (7) is a straight hole perpendicular to the upper end face of the jet flow receiver (16), the upper pressure detection hole (8) and the lower pressure detection hole (8 ') are inclined holes and are arranged symmetrically in a splayed manner, an included angle between the axis of the jet flow receiving hole (7) and the axis of the upper pressure detection hole (8) and the axis of the lower pressure detection hole (8') is 15-35 degrees, a perpendicular bisector of a line connecting the circle centers of the upper pressure detection hole (8) and the lower pressure detection hole (8 ') passes through the circle center of the jet flow receiving hole (7), the radius R' of the upper pressure detection hole (8) and the radius R 'of the lower pressure detection hole (8') are half of the radius R of the jet flow receiving hole (7), and the distance between the circle centers of the upper pressure detection hole (8) and the lower pressure detection hole (8 ') is R' +0.02 mm;

the debugging method of the three-way jet pipe servo valve jet axis track debugging device comprises the following steps:

1) connecting pressure difference sensors on two sides of the valve body, placing the jet nozzle at an initial position, starting a driving torque motor, and enabling the jet nozzle to finish a moving process from the initial position to a final point under the action of the torque motor;

2) in the moving process of the jet flow nozzle, the pressure difference value of the pressure detection holes on the two sides is obtained, and whether the track of the jet flow axis meets the requirement or not is judged according to the pressure difference, and the method specifically comprises the following steps:

when the difference between the pressure values of the pressure sensors on the two sides is constant to zero, the jet axis track is superposed with the x axis, and the judgment is that the jet axis track meets the requirement;

when the pressure values of the pressure sensors on the two sides are not zero and the pressure difference is constant to be a non-zero value, the axial track of the jet flow is parallel to the x axis, and the distance is a certain value, so that the requirement is met;

when the difference between the pressure values of the pressure sensors on the two sides changes irregularly, the trajectory of the jet axis is not parallel to the x axis, and the jet axis is judged to be not in accordance with the requirement;

the x axis is a perpendicular bisector of a connecting line of circle centers of the upper pressure detection hole and the lower pressure detection hole, and the circle centers of the upper pressure detection hole and the lower pressure detection hole are both positioned in an annular region formed by a turbulent flow region in an initial jet flow state and a constant speed core region in the initial jet flow state;

3) when the jet flow axis track meets the requirement, namely the jet flow axis track is overlapped with or parallel to the x axis and has a set expected value at a distance, the pressure difference value sensor is disassembled, the detection long hole is sealed by using a sealing screw, and the debugging of the jet flow axis track is completed;

4) and when the jet axis trajectory does not meet the requirement, readjusting the installation position of the nozzle, and returning to the step 1).

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