High-frequency-response low-power-consumption pneumatic proportional valve

Abstract

The application discloses a high-frequency-response low-power-consumption aerodynamic proportional valve. The application is composed of a torque motor and an aerodynamic rotary valve; the torque motor comprises a permanent magnet, a magnetic conducting yoke, an upper armature, a lower armature, an upper framework, a framework column, a lower framework, an exciting coil, a coil framework, a spring support, a spring plate and a load spring. The torque motor in the application adopts a single-coil structure and the axis of the exciting coil coincides with the rotating axis of the armature, and the coil is placed between the upper and lower armatures, so that the structure is simple and compact and the miniaturization of the torque motor is easy to realize. The torque motor in the application has two upper and lower armatures, and the two upper and lower armatures have four armature arms, so that eight air gaps can be formed. The eight air gaps are paired, and under the excitation of the control coil, four pairs of parallel magnetic circuits are formed; under the same power consumption and size, the torque motor with two pairs of parallel magnetic circuits has greater output torque, so that the same output torque can be realized with lower power consumption and smaller size.

Description

Technical Field

[0001] This invention relates to the field of valve body design technology, specifically a high-frequency response, low-power rotary pneumatic proportional directional valve. Background Technology

[0002] Proportional valves are crucial control components in fluid systems, and their performance directly impacts the system's control accuracy and speed. Traditional pneumatic proportional valves mostly employ a proportional electromagnet with a seated valve structure. However, due to the large translational inertia of the proportional electromagnet, the response speed is often slow, and the frequency response is not high. Furthermore, since the magnetic field is entirely generated by the coil, power consumption is also relatively high. A torque motor combined with a rotary valve, on the other hand, can fully utilize the advantage of the small rotational inertia of the moving parts, thereby improving the response speed.

[0003] However, traditional torque motors are not compact enough. The control coil axis points along the length of the armature and is divided into two parts, requiring space at the armature arm for the coil. This makes it difficult to further reduce the moment of inertia and hinders further improvements in frequency response. Furthermore, traditional torque motors often have relatively low output torque. To meet the requirements of control valves, they tend to be larger in size and consume more power. With pneumatic valves constantly decreasing in size and power consumption while improving frequency response, traditional torque motors are no longer sufficient to meet the performance requirements of direct-drive pneumatic proportional valves. Summary of the Invention

[0004] The present invention aims to propose a torque motor with a simple and compact structure, low moment of inertia, large output torque, driven by a single coil, and a high-frequency response, low-power pneumatic proportional valve directly driven by the torque motor.

[0005] This invention consists of two parts: a torque motor and a pneumatic rotary valve.

[0006] The torque motor has a single-coil structure, including a permanent magnet, a magnetic yoke, an upper armature, a lower armature, an upper frame, a frame column, a lower frame, an excitation coil, a coil frame, a spring support, a spring plate, and a load spring.

[0007] The upper and lower skeletons are each provided with blind holes, and the two ends of the skeleton column are inserted into the blind holes of the upper and lower skeletons respectively; the excitation coil is wound on the coil skeleton, and the through hole in the middle of the coil skeleton passes through the skeleton column and is sandwiched between the upper and lower skeletons.

[0008] The upper armature includes an armature arm and a central magnetic post. The magnetic post passes through a through hole in the middle of the frame post, and the armature arm is disposed in a groove in the upper frame. The lower armature is disposed in a groove in the lower frame and is interference-fitted with the lower end of the magnetic post of the upper armature. The lower end of the magnetic post is connected to the lower frame through a first bearing.

[0009] Four magnetic yokes are attached around the excitation coil. Each magnetic yoke is fan-shaped, and its two perpendicular sides are in close contact with the outer walls of the upper and lower frame grooves, respectively. Four permanent magnets are sandwiched between the four magnetic yokes. The armature arms of the upper armature and the armature arms of the lower armature are vertically staggered, forming eight working air gaps with the four magnetic yokes.

[0010] The spring support is installed on the upper end face of the upper frame. The spring support is equipped with a second bearing to support the upper end of the magnetic column. The spring plate has a semi-circular through hole in the middle, which cooperates with the semi-circular shaft at the upper end of the magnetic column and is fixed by a stop screw.

[0011] The four load springs are placed around the spring plate. The initial angle of the armature is adjusted by adjusting the compression of the load springs at both ends of the spring plate.

[0012] The pneumatic rotary valve includes a valve body, valve sleeve, valve core, wedge block, pneumatic valve connector, and pneumatic joint.

[0013] The valve body and valve sleeve are fitted with an interference fit, the valve core and valve sleeve are sealed with a gap, and are connected by a bearing assembly.

[0014] The valve core has a semi-circular through hole and a threaded blind hole in the middle. A wedge block is set in the blind hole of the valve core, and the flat side of the wedge block is in close contact with the flat side of the semi-circular through hole of the valve core, and the inclined side of the wedge block is in close contact with the inclined surface of the lower end of the magnetic column. The transmission between the torque motor and the valve core is realized through the inclined and flat sides of the wedge block.

[0015] The flow channel on the valve body is aligned and fits with the flow channel on the air valve connector. The threaded end of the pneumatic connector is screwed into the four threaded holes of the air valve connector, and the quick-connect end is connected to the pneumatic system to be controlled.

[0016] The present invention has the following beneficial effects:

[0017] The torque motor in this invention adopts a single-coil structure with the axis of the excitation coil coinciding with the axis of rotation of the armature. The coil is placed between the upper and lower armatures, resulting in a simple and compact structure that facilitates the miniaturization of the torque motor.

[0018] The torque motor arm of this invention does not require space for placing the coil, which can save the radial dimension of the arm and reduce the moment of inertia, making it easier to achieve high frequency response.

[0019] The torque motor of this invention has two armatures, upper and lower, with a total of four armature arms, forming eight air gaps. The eight air gaps are paired up in two pairs, forming four pairs of parallel magnetic circuits under the excitation of the control coil. With the same power consumption and size, compared with a traditional torque motor with one armature, the torque motor with two pairs of parallel magnetic circuits has a larger output torque, and thus can achieve the same output torque with lower power consumption and smaller size.

[0020] The proportional directional valve features a rotary valve structure, which is compact, easily reduces inertia, and achieves high response speed. No eccentric mechanism is needed between the torque motor and the rotary valve, further simplifying the structure. The entire proportional directional valve's moving parts are rotary joints, supported by bearings, resulting in less hysteresis in the valve's output characteristics. Attached Figure Description

[0021] Figure 1 These are the three views of the present invention.

[0022] Figure 2 This is a quarter-section view of the present invention.

[0023] Figure 3 This is a quarter-section view and a side view of the novel single-coil torque motor of the present invention, with the housing removed.

[0024] Figure 4 This is the invention Figure 1 Cross-sectional views along the AA and BB directions.

[0025] Figure 5 This is a quarter-section view of the upper and lower frames of the novel single-coil torque motor of the present invention.

[0026] Figure 6 This invention relates to the structure of the armature on a novel single-coil torque motor.

[0027] Figure 7 This invention relates to the structure of a novel single-coil torque motor chuck.

[0028] Figure 8 This is an exploded schematic diagram of the novel single-coil torque motor of the present invention.

[0029] Figure 9 This is an exploded schematic diagram of the rotary valve part of the present invention.

[0030] Figure 10 This invention relates to the transmission method between the torque motor and the valve core.

[0031] Figure 11 This is a schematic diagram of the magnetic circuit generated by the permanent magnet of the novel single-coil torque motor of the present invention.

[0032] Figure 12This is a schematic diagram of the magnetic circuit generated by the excitation coil of the novel single-coil torque motor of the present invention.

[0033] Figure 13 This is a schematic diagram of the working principle of the rotary pneumatic proportional directional valve rotary valve part of the present invention. Detailed Implementation

[0034] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, this application provides a rotary pneumatic proportional directional valve, which is divided into two parts: a torque motor and a pneumatic rotary valve. The torque motor is a novel single-coil structure, including a permanent magnet 10, a magnetic yoke 9, an upper armature 6, a lower armature 7, an upper frame 1, a frame column 3, a lower frame 2, an excitation coil 4, a coil frame 5, a first bearing 8, a second bearing 12, a spring support 11, a spring plate 13, a load spring 15, a stop screw 14, an adjusting plate 16, an adjusting screw 17, and a housing 18.

[0036] The upper and lower bobbins each have blind holes, and the two ends of the bobbin posts are inserted into the blind holes of the upper and lower bobbins respectively. The coil is wound on the coil bobbin, and the through hole in the middle of the coil bobbin passes through the bobbin post and is sandwiched between the upper and lower bobbins.

[0037] In one embodiment, the skeleton column is provided with sealing grooves near both ends for placing sealing rings.

[0038] like Figure 6 As shown, the upper armature has a T-shaped structure, consisting of an armature arm 601 and a central magnetic post 602. The magnetic post passes through a through hole in the middle of the frame post, while the armature arm is placed in a groove in the upper frame. The lower armature has a similar structure to the armature arm of the upper armature. It is placed in a groove in the lower frame and is interference-fitted to the lower end of the magnetic post of the upper armature. The lower end of the magnetic post is connected and supported to the lower frame via a first bearing.

[0039] like Figure 8 As shown, the magnetic yoke is fan-shaped, with four magnetic yokes attached to the perimeter of the excitation coil. Two perpendicular sides are in close contact with the outer walls of the grooves in the upper and lower frame, respectively. Four permanent magnets are clamped between the four magnetic yokes. A spring support is mounted on the upper end face of the upper frame, and a second bearing is installed on the spring support to support the upper end of the upper armature magnetic column. A semi-circular through hole is opened in the middle of the spring plate, which mates with the semi-circular hole at the upper end of the upper armature magnetic column, and is fixed with a locking screw. Four springs are placed around the spring plate, and the compression of the springs at both ends of the spring plate is adjusted by adjusting the adjusting plate and adjusting screw, thereby adjusting the initial rotation angle of the armature.

[0040] In one embodiment, the spring support is installed on the upper end face of the upper frame and has a square straight opening for positioning. At the same time, a sealing groove is also opened on the upper end face of the upper frame to place a sealing ring to achieve a seal between the upper frame and the spring support.

[0041] The entire assembly of the torque motor is housed within the housing, and the seal between the housing and the torque motor is achieved through a sealing ring mounted on the side of the spring support. The housing and upper frame have lead-out holes and slots, from which the excitation coil wires are led out.

[0042] like Figure 2 , Figure 9 and Figure 10 As shown, the pneumatic rotary valve includes a valve body 19, a valve sleeve 20, a valve core 21, a third bearing 22, a fourth bearing 23, a wedge block 24, a support spring 25, a set screw 26, an end cap 27, a valve connector 28, and a pneumatic joint 29. The valve body and valve sleeve are press-fitted, while the valve core and valve sleeve are sealed with a clearance seal and connected by the third and fourth bearings. The valve core has a semi-circular through hole and a threaded blind hole in the center. The wedge block is inserted into the blind hole of the valve core, with its flat side against the flat side of the semi-circular through hole and its inclined side against the inclined side of the lower end of the armature magnetic column of the torque motor. The lower frame of the torque motor is positioned against the valve sleeve by a locating pin. The transmission between the torque motor and the valve core is achieved through the inclined and flat sides of the wedge block. A spring is placed in the blind hole of the valve core, and a set screw is screwed in to hold the wedge block in place. Considering the machinability of the magnetic yoke, it can be divided into two identical types: upper magnetic yoke 901 and lower magnetic yoke 902, such as... Figure 7 As shown.

[0043] An end cap is installed at the lower end of the valve body. The end cap has a sealing groove on the side of its boss. The boss, while abutting against the third bearing at the lower end of the valve core, also works with the valve body to create a seal. The flow channel on the valve body aligns perfectly with the flow channel on the air valve connector, is sealed by a sealing ring, and is tightened with screws. The threaded end of the pneumatic connector is screwed into the four threaded holes of the air valve connector, and the quick-connect end is connected to the pneumatic system to be controlled.

[0044] In one embodiment, a sealing groove is also provided on the lower end face of the lower frame. The sealing ring in the sealing groove is pressed together by the bolt connection between the outer shell and the valve body to achieve sealing.

[0045] As a preferred embodiment, in one embodiment, the upper armature and lower armature of the torque motor are arranged vertically and alternately, forming a total of 8 working air gaps with the four magnetic chucks.

[0046] As a preferred embodiment, the four permanent magnets of the torque motor in one embodiment are made of neodymium iron boron material and are arranged such that the polarity of two adjacent permanent magnets is the same on the adjacent side.

[0047] As a preferred embodiment, the upper armature, lower armature, and magnetic yoke of the torque motor in one embodiment are made of magnetically conductive material DT4C.

[0048] As a preferred embodiment, the pneumatic rotary valve body is made of plastic with low stiffness, while the valve sleeve is made of stainless steel with high stiffness.

[0049] In this invention, the novel single-coil torque motor has a magnetic circuit different from that of a traditional torque motor. The magnetic flux generated by the coil rises upward along the upper armature's magnetic guide post. Upon reaching the upper end of the guide post, it splits into two branches that travel along the two armature arms. When the magnetic flux of these branches reaches the end of the armature arm, it splits into two branches again, passing through the two sides of the armature arm and entering the magnetic guide yokes on both sides. Subsequently, the four magnetic paths from both ends of the upper armature arm enter the lower armature from the four sides of the lower armature arm along the four magnetic guide yokes, and finally return to the upper armature's magnetic guide post along the lower armature, thus forming a closed loop. Figure 12 As shown.

[0050] The adjacent end faces of two adjacent permanent magnets, having the same magnetic poles, generate magnetic flux that passes through the magnetically conductive yoke, flowing upwards and downwards through the working air gaps on both sides of the armature arm, returning to their respective opposite poles. Figure 11 As shown. Therefore, the magnetic flux generated by the excitation coil in the working air gaps on both sides of the armature arm is in opposite directions, while the magnetic flux generated by the permanent magnet is in the same direction. Thus, the magnetic flux generated by the coil and the magnetic flux generated by the permanent magnet are superimposed on one side of the working air gap and cancel each other out on the other side, creating a magnetic flux difference. This causes the end of the armature arm to experience an electromagnetic force pointing towards the side with the greater magnetic flux. Under the action of the same direction of electromagnetic force on all four armature arms, an electromagnetic torque is generated that causes the armature to rotate in the specified direction.

[0051] Because of the aforementioned magnetic circuit design, the excitation coil axis does not need to be arranged along the length of the armature arm. The armature arm can be placed at the upper and lower ends of the excitation coil, thus achieving the coincidence of the coil axis and the shaft axis, making the overall structure more compact. Simultaneously, two armatures can be set, increasing the output torque. Furthermore, the vertically staggered arrangement of the upper and lower armatures, along with the arrangement of the permanent magnets in this invention, ensures that the electromagnetic forces of the four armature arms of the torque motor based on the magnetic circuit point in the same direction. This allows the torque motor to output torque, supporting the feasibility of the aforementioned magnetic circuit scheme.

[0052] The working principle of the rotary pneumatic proportional directional valve of the present invention is as follows:

[0053] When the excitation coil is not energized, the armature is in the middle position of the working air gap under the action of the spring mechanism, the valve core is in the neutral position, ports P and T are closed, and there is no gas flow at ports A and B. The structure of the spring mechanism is as follows: Figure 4 As shown in view AA. At this time, the torque motor conductor only contains the bias magnetic flux generated by the permanent magnet, and the magnetic circuit is as follows. Figure 11 As shown. When a positive current is applied to the excitation coil, a control magnetic flux appears in the magnetic conductive parts of the torque motor, such as... Figure 12 As shown, the control flux and bias flux combine at the working air gap to form a total flux, generating an electromagnetic force that drives the upper and lower armatures to rotate counterclockwise. Because the new single-coil torque motor has eight working air gaps (I, II, III, IV, V, VI, VII, VIII), it has a larger output torque than traditional torque motors under the same current. Driven by the wedge block, spring, and set screw, the valve core also rotates, eventually balancing the electromagnetic torque with the load torque of the spring mechanism, placing the valve core at... Figure 13 In the operating state ①, the air valve's P port is connected to the A port, and its B port is connected to the T port. High-pressure gas enters the air valve through the P port, exits through the A port, and enters the controlled pneumatic system, driving the pneumatic actuator. The gas then flows out of the actuator's outlet, enters the air valve through the B port, and finally exits through the T port, returning to the air chamber or being discharged into the atmosphere. The flow rate through the working ports A and B can be adjusted by regulating the current of the input torque motor, thereby regulating the movement speed of the pneumatic actuator.

[0054] When a reverse current is applied to the excitation coil, a reverse control flux will be generated in the torque motor, which will combine with the flux of the permanent magnet to form a total flux, generating a reverse driving torque that drives the armature to move clockwise, thereby driving the valve core to be in a state of... Figure 13 In the operating state of step ②, the inlet gas enters through port P, exits the gas valve through port B, and drives the pneumatic actuator back to its original state. Then, the gas flows out of the actuator's outlet, enters the gas valve through port A, and finally exits the gas valve through port T, returning to the gas chamber or being discharged into the atmosphere. Similarly, the flow rate can be adjusted by regulating the current.

[0055] In summary, this invention innovates the structure and magnetic circuit of the torque motor, improving its compactness and output torque. By directly driving the rotary valve with the torque motor, it eliminates the need for an eccentric mechanism, resulting in a simpler structure and achieving miniaturization and low power consumption in pneumatic proportional directional valves. Compared to the spool valve structure commonly used in traditional directional valves, the rotary valve is internally simple and compact, operates by rotation, has low inertia, and easily achieves rapid response characteristics.

[0056] Finally, it should be noted that the above-described embodiments are merely specific examples of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this invention should be considered within the scope of protection of this invention.

Claims

1. A high-frequency response, low-power pneumatic proportional valve, characterized in that: It consists of two parts: a torque motor and a pneumatic rotary valve; The torque motor is a single-coil structure, including a permanent magnet, a magnetic yoke, an upper armature, a lower armature, an upper frame, a frame column, a lower frame, an excitation coil, a coil frame, a spring support, a spring plate, and a load spring; The upper and lower frames are each provided with blind holes, and the two ends of the frame column are inserted into the blind holes of the upper and lower frames respectively; the excitation coil is wound on the coil frame, and the through hole in the middle of the coil frame passes through the frame column and is sandwiched between the upper and lower frames. The upper armature includes an armature arm and a central magnetic post. The magnetic post passes through a through hole in the middle of the frame post, and the armature arm is disposed in a groove in the upper frame. The lower armature is disposed in a groove in the lower frame and is interference-fitted with the lower end of the magnetic post of the upper armature. The lower end of the magnetic post is connected to the lower frame through a first bearing. Four magnetic yokes are attached around the excitation coil. Each magnetic yoke is fan-shaped, and its two perpendicular sides are in close contact with the outer walls of the upper and lower frame grooves, respectively. Four permanent magnets are sandwiched between the four magnetic yokes. The armature arms of the upper armature and the armature arms of the lower armature are vertically staggered, forming eight working air gaps with the four magnetic yokes. The spring support is installed on the upper end face of the upper frame. The spring support is equipped with a second bearing to support the upper end of the magnetic column. The spring plate has a semi-circular through hole in the middle, which cooperates with the semi-circular shaft at the upper end of the magnetic column and is fixed by a stop screw. The four load springs are placed around the spring plate. The initial angle of the armature is adjusted by adjusting the compression of the load springs at both ends of the spring plate. The pneumatic rotary valve includes a valve body, a valve sleeve, a valve core, a wedge block, a pneumatic valve connector, and a pneumatic joint. The valve body and valve sleeve are fitted with an interference fit, the valve core and valve sleeve are sealed with a gap, and are connected by a bearing assembly; The valve core has a semi-circular through hole and a threaded blind hole in the middle. A wedge block is set in the blind hole of the valve core, and the flat side of the wedge block is in close contact with the flat side of the semi-circular through hole of the valve core, and the inclined side of the wedge block is in close contact with the inclined surface of the lower end of the magnetic column. The transmission between the torque motor and the valve core is realized through the inclined and flat sides of the wedge block. The flow channel on the valve body is aligned and fits with the flow channel on the air valve connector. The threaded end of the pneumatic connector is screwed into the four threaded holes of the air valve connector, and the quick-connect end is connected to the pneumatic system to be controlled.

2. The high-frequency response, low-power pneumatic proportional valve according to claim 1, characterized in that: It also includes an adjustment plate and adjustment screws, which are used to adjust the compression of the load springs at both ends of the spring plate.

3. The high-frequency response, low-power pneumatic proportional valve according to claim 1, characterized in that: The lower frame and the valve sleeve are positioned by a locating pin.

4. A high-frequency response, low-power pneumatic proportional valve according to any one of claims 1 to 3, characterized in that: The four permanent magnets are made of neodymium iron boron material and are arranged such that the polarity of two adjacent permanent magnets is the same on the adjacent side.

5. A high-frequency response, low-power pneumatic proportional valve according to claim 4, characterized in that: The upper armature, lower armature, and magnetic yoke are made of magnetically conductive material DT4C.

6. The high-frequency response, low-power pneumatic proportional valve according to claim 1, characterized in that: A support spring and a set screw are also provided in the blind hole of the valve core to hold the wedge block in place.

7. A high-frequency response, low-power pneumatic proportional valve according to claim 1, characterized in that: An end cap is installed at the lower end of the valve body. The side of the boss on the end cap has a sealing groove. While the boss is pressing against the lower end bearing of the valve core, it also works with the valve body to achieve a sealing function.

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