阅读说明：本技术 用于避免机械应力的滑阀的控制系统 (Control system for a slide valve for avoiding mechanical stresses ) 是由 D.佩特罗内拉 A.鲍鲁斯 于 2020-03-13 设计创作，主要内容包括：一种流体压力控制的滑阀将由迫使阀芯轴的凸台磨损或粘附到支撑阀芯轴的圆柱形桶的内部面向表面的压力板的倾斜定向引起的磨损或粘附最小化。永磁体安装在压力板上。由铁磁材料构成的圆头形成在阀芯轴的端部上并且配置成被磁性地吸引到永磁体。当压力板和磁体相对于阀芯轴的轴线倾斜时,在阀芯轴的圆头上产生的磁吸引力矢量保持与阀芯轴的轴线同轴。(A fluid pressure controlled spool valve minimizes wear or adhesion caused by the angular orientation of a pressure plate forcing the boss of the spool shaft to wear or adhere to the inner facing surface of the cylindrical barrel supporting the spool shaft. The permanent magnet is mounted on a pressure plate. A rounded head composed of ferromagnetic material is formed on an end of the spool shaft and is configured to be magnetically attracted to the permanent magnet. When the pressure plate and magnet are tilted relative to the axis of the spool shaft, the magnetic attraction force vector generated on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft.)

1. A slide valve control system comprising:

a housing including a first chamber for receiving a control fluid and a second chamber for supporting a spool shaft having an axis, the spool shaft configured to move along the axis;

a flexible membrane separating the first chamber and the second chamber configured to form a flexible barrier to a control fluid in the first chamber;

a pressure plate in the second chamber against which the flexible membrane presses in response to pressure changes of the control fluid;

a permanent magnet mounted on the pressure plate in the second chamber; and

a rounded head formed on an end of the spool shaft and constructed of a ferromagnetic material configured to be magnetically attracted to the permanent magnet;

wherein a magnetic attraction force vector generated by the permanent magnet on the rounded head of the spool shaft remains coaxial with the shaft axis when the pressure plate and magnet are tilted relative to the spool shaft axis.

2. The spool valve control system of claim 1, wherein an attractive force vector generated on the rounded head of the spool shaft remains coaxial with the shaft axis when the pressure of the control fluid is reduced in the first chamber.

3. The spool valve control system of claim 1, wherein a force vector generated on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft when the pressure of the control fluid increases in the first chamber, urging the magnet toward the rounded head of the spool shaft.

4. The spool valve control system of claim 1, wherein the round head formed on the end of the spool shaft is comprised of an alloy of iron, cobalt, or nickel.

5. The spool valve control system of claim 1, wherein the permanent magnet is comprised of an alloy of neodymium, iron, and boron.

6. The spool valve control system of claim 1, wherein the composition of the material for the magnet and the composition of the material for the round head maximize their hardness and resistance to wear or adhesion due to their surface contact as the pressure of the control fluid increases in the first chamber.

7. The spool valve control system of claim 1, wherein the rounded head is contoured to have a hemispherical surface to minimize any component of force transverse to the axis of the spool shaft as the surface of the magnet pushes against the rounded head surface of the spool shaft.

8. The sliding valve control system of claim 1, wherein wear or sticking caused by the angular orientation of the pressure plate that forces the boss of the spool shaft to cause wear of the inner facing surface of the cylindrical barrel that supports the spool shaft in the housing is minimized.

9. A slide valve control system in a slide valve including a flexible membrane separating a control fluid chamber and an internal chamber, and a pressure plate in the internal chamber against which the flexible membrane presses in response to a pressure change of a control fluid in the control fluid chamber, the slide valve control system comprising:

a permanent magnet mounted on a pressure plate in the inner chamber; and

a rounded head formed on an end of the valve plug shaft in the interior chamber, the rounded head constructed of a ferromagnetic material configured to be magnetically attracted to the permanent magnet;

wherein a magnetic attraction force vector generated by the permanent magnet on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft when the pressure plate and the magnet are tilted relative to the axis of the spool shaft.

10. The spool valve control system of claim 9, wherein an attractive force vector generated on the rounded head of the spool shaft remains coaxial with the shaft axis when the pressure of the control fluid is reduced in the first chamber.

11. The spool valve control system of claim 9, wherein a force vector generated on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft when the pressure of the control fluid increases in the first chamber, urging the magnet toward the rounded head of the spool shaft.

12. The spool valve control system of claim 9, wherein the round head formed on the end of the spool shaft is comprised of an alloy of iron, cobalt, or nickel.

13. The spool valve control system of claim 9, wherein the permanent magnet is comprised of an alloy of neodymium, iron, and boron.

14. The spool valve control system of claim 9, wherein the composition of the material for the magnet and the composition of the material for the round head maximize their hardness and resistance to wear or adhesion due to their surface contact as the pressure of the control fluid increases in the first chamber.

15. The spool valve control system of claim 9, wherein the rounded head is contoured to have a hemispherical surface to minimize any component of force transverse to the axis of the spool shaft as the surface of the magnet pushes against the rounded head surface of the spool shaft.

16. The slide valve control system of claim 9, wherein wear or sticking caused by the angular orientation of the pressure plate that forces the boss of the spool shaft to cause wear of the inner facing surface of the cylindrical barrel that supports the spool shaft in the housing is minimized.

Technical Field

The disclosed invention relates to spool valves.

Background

Spool valves are used to control the direction of fluid flow in various applications such as automotive power steering and inkjet printing. The spool valve includes a plunger-like spool shaft that slides within a cylindrical barrel that is ported on the side of the barrel. The blockage of the ports is provided by bosses (lands) or full diameter portions on the spool shaft separated by narrower portions which provide for interconnection through the ports of the cylindrical barrel. Seals are located between the ports and at the outer end of the cylindrical barrel beyond the outermost port. The sliding action of the spool shaft may be controlled by an electromechanical solenoid or by pneumatic or hydraulic pressure.

In pneumatic or hydraulic control, a control fluid pressure signal is introduced into a control fluid chamber of a valve housing, which is separated from a second chamber by a flexible membrane. A pressure plate located in the second chamber abuts the flexible membrane and is mechanically connected to one end of the spool shaft. A coil spring located in the second chamber maintains a spring force on a pressure plate directed toward the flexible membrane. As the control fluid pressure signal increases in the control fluid chamber, the flexible membrane expands into the second chamber, compressing and moving the pressure plate into the second chamber, thereby sliding the spool shaft toward the open position. Alternatively, as the control fluid pressure signal decreases in the control fluid chamber, the flexible membrane retracts from the second chamber, pulling the pressure plate, which in turn pulls the mechanical connection with the spool shaft, thereby sliding the spool shaft toward the closed position.

A problem with pneumatically or hydraulically controlled spool valves is that the pressure plate and its mechanical connection to the spool shaft may tilt relative to the axis of the cylindrical barrel as the flexible membrane expands and retracts due to changes in the control fluid pressure signal. The angular orientation of the pressure plate and its mechanical connection may cause the boss or full diameter portion on the spool shaft to wear or stick to the inner facing surface of the cylindrical barrel, resulting in eventual leakage of working fluid around the boss, thereby limiting the useful life of the spool valve.

What is needed is a design for a pneumatically or hydraulically controlled spool valve that minimizes wear or sticking caused by the angular orientation of the pressure plate and its mechanical connection.

Disclosure of Invention

In accordance with an exemplary embodiment of the present invention, a pneumatically or hydraulically controlled spool valve minimizes wear or sticking caused by the angular orientation of the pressure plate that forces the boss of the spool shaft to wear or stick to the inner facing surface of the cylindrical barrel that supports the spool shaft. The permanent magnet is mounted on a pressure plate in the interior chamber. The rounded head formed on the end of the valve plug shaft is constructed of a ferromagnetic material and is configured to be magnetically attracted to the permanent magnet. According to the present invention, when the pressure plate and the magnet are tilted with respect to the axis of the spool shaft, the magnetic attraction force vector generated on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft. When the pressure of the control fluid is reduced, the attractive force vector generated on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft to minimize wear or sticking in the barrel of the spool valve caused by the angular orientation of the pressure plate. When the pressure of the pilot fluid is increasing, pushing the magnet toward the rounded end of the poppet shaft, the force vector generated on the rounded end of the poppet shaft remains coaxial with the axis of the poppet shaft.

Drawings

FIG. 1 is an example system diagram illustrating a control system for a spool valve that receives a control fluid pressure signal to regulate a spool shaft of the spool valve to direct working fluid from a supply system through an output port of the spool valve to a double-acting hydraulic actuator, according to an embodiment of the invention.

Fig. 2 is a side cross-sectional view of a control system for a spool valve with the spool shaft positioned to flow working fluid out of the Y2 port, where the working fluid at the Y1 output port is at zero pressure and the working fluid at the Y2 output port is at supply port pressure. The figure shows a permanent magnet mounted on a pressure plate in the inner chamber and a rounded head formed on the end of the spool shaft that is configured to be magnetically attracted to the permanent magnet. According to the present invention, if the pressure plate is inclined relative to the axis of the spool shaft, the magnetic attraction force vector generated on the rounded head of the spool shaft remains coaxial with the axis of the spool shaft to minimize wear or sticking in the barrel of the spool valve.

FIG. 3 is a side cross-sectional view of a control system for the spool valve of FIG. 2 with a control fluid pressure signal increased to adjust the spool shaft of the spool valve to be at the intersection where the working fluid has equal pressure at the Y1 port and the Y2 port in accordance with an embodiment of the present invention.

Fig. 4 is a side cross-sectional view of a control system for the spool valve of fig. 3 with a further increase in the control fluid pressure signal to adjust the spool shaft of the spool valve to a position where the working fluid at the output port of Y2 is at zero pressure and the working fluid at the output port of Y1 is at the supply port pressure, in accordance with an embodiment of the present invention.

Fig. 5A shows a pressure plate oriented perpendicular to the shaft axis and the resulting magnetic attraction force vector on the rounded head of the spool shaft remains coaxial with the shaft axis to minimize wear or sticking in the barrel of the spool valve in accordance with an embodiment of the present invention.

Fig. 5B shows the pressure plate oriented to tilt upward relative to the shaft axis and the resulting magnetic attraction force vector on the rounded head of the spool shaft remains coaxial with the shaft axis to minimize wear or sticking in the barrel of the spool valve in accordance with an embodiment of the present invention.

Fig. 5C shows a pressure plate oriented downward relative to the shaft axis and the resulting magnetic attraction force vector on the rounded head of the spool shaft remains coaxial with the shaft axis to minimize wear or sticking in the barrel of the spool valve, according to an embodiment of the present invention.

FIG. 6 is a three-dimensional side cross-sectional view of a control system for a spool valve showing the discharge ports E1 and E2 for the spool valve.

Fig. 7 is a three-dimensional side view of the spool valve showing the control fluid pressure signal port, working fluid input ports Y1 and Y2, the working fluid supply port, and the working fluid drain port for the spool valve.

Detailed Description

Fig. 1 is an example system diagram illustrating a control system for a spool valve 100 that receives a control fluid pressure signal 105 introduced at a control input port 120 into a control fluid chamber 122 of a valve housing 102, the control fluid chamber 122 being separated from an internal second chamber by a flexible membrane. When the pressure of the control fluid 105 changes in the first chamber 122, the spool shaft 125 slides within the cylindrical barrel of the housing 102, thereby interconnecting or blocking the ports Y1 and Y2, the supply port S, and the drain port that opens in the side of the cylindrical barrel. The blockage of the ports is provided by bosses or full diameter portions on the spool shaft 125 separated by narrower portions that provide for interconnection through the ports of the cylindrical barrel. Seals are located between the ports and at the outer end of the cylindrical barrel beyond the outermost discharge port. The sliding action of the spool shaft 125 is controlled by a pneumatic or hydraulic control fluid pressure signal 105.

As the control fluid pressure signal 105 increases in the control fluid chamber 122, the flexible membrane expands into the second chamber, compressing and moving the pressure plate into the second chamber, sliding the spool shaft 125 to connect port Y2 to supply port S and Y1 to drain port. Working fluid from the supply system 104 flows through the interconnected supply port S and port Y2 to the port 108 of the double acting hydraulic actuator 106, pushing the piston 112 in a downward direction as shown in the figure. Working fluid returning from port 110 of double acting hydraulic actuator 106 is supplied through interconnected port Y1 and the exhaust port of spool valve 100.

Fig. 2 is a side cross-sectional view of a control system for spool valve 100. The spool shaft 125 is positioned in the control fluid chamber 122 by the control fluid pressure signal 105 to connect the supply port S to the Y2 port and the Y1 port to the drain port E1. The working fluid at the Y1 output port is at zero pressure and the working fluid at the Y2 output port is at the pressure of the supply port S. The figure shows a permanent magnet 130 mounted on the pressure plate 128 in the inner second chamber 124 and a rounded head 132 formed on the end of the spool shaft 125 that is configured to be magnetically attracted to the permanent magnet 130. According to the present invention, if the pressure plate 128 is tilted relative to the axis of the poppet shaft 125, the magnetic attraction force vector generated on the rounded head 132 of the poppet shaft 125 remains coaxial with the axis of the poppet shaft 125 to minimize wear or sticking in the cylindrical barrel of the spool valve 100.

The rounded head 132 formed on the end of the valve plug shaft 125 may be constructed of a ferromagnetic material, such as an alloy of iron, cobalt, or nickel. The permanent magnet 130 may be composed of an alloy of neodymium, iron, and boron. The rounded head 132 is configured to be magnetically attracted to the permanent magnet 130. According to the present invention, when the pressure plate 128 and magnet 130 are tilted relative to the axis of the poppet shaft 125, the magnetic attraction force vector generated on the rounded head 132 of the poppet shaft 125 remains coaxial with the axis of the poppet shaft 125. As the pressure of the control fluid 105 decreases in the control fluid chamber 122, the attractive force vector generated on the rounded head 132 of the spool shaft 125 remains coaxial with the axis of the spool shaft 125 to minimize wear or sticking in the cylindrical barrel of the spool valve 100 caused by the angular orientation of the pressure plate 128.

Further, as the pressure of the control fluid 105 increases in the control fluid chamber 122, pushing the surface of the magnet 130 against the surface of the rounded head 132 of the spool shaft 125, the force vector generated on the rounded head 132 of the spool shaft 125 remains coaxial with the axis of the spool shaft 125 to minimize wear or sticking in the cylindrical barrel of the spool valve 100 caused by the angular orientation of the pressure plate 128. As the pressure of control fluid 105 increases in control fluid chamber 122, the composition of the material for magnet 130 and the composition of the material for rounded head 132 may be selected to maximize their hardness and resistance to wear or adhesion due to their contact surfaces. The contour of the rounded head 132 may have a hemispherical surface to minimize any component of force transverse to the axis of the poppet shaft 125 as the surface of the magnet 130 pushes against the surface of the rounded head 132 of the poppet shaft 125.

This figure shows a coil spring 140 located in the inner second chamber 124, which is held against the spring force of the pressure plate 128 directed towards the flexible membrane 126. The figure shows a bushing 142 positioned around the poppet shaft 125 to support the poppet shaft in the cylindrical barrel of the housing 102. The figure shows the seal 144 between the ports Y1, Y2, S, E1 and E2 between the liner 142 and the cylindrical barrel of the housing 102.

Fig. 3 is a side cross-sectional view of a control system for the spool valve 100 of fig. 2 with the control fluid pressure signal 105 increased to adjust the spool shaft 125 of the spool valve 100 to be at the intersection where the working fluid has equal pressure at the Y1 port and the Y2 port in accordance with an embodiment of the present invention.

Fig. 4 is a side cross-sectional view of a control system for the spool valve 100 of fig. 3 with the control fluid pressure signal 105 further increased to adjust the spool shaft 125 of the spool valve 100 to a position where the working fluid at the output port of Y2 is at zero pressure and the working fluid at the output port of Y1 is at the supply port S pressure, in accordance with an embodiment of the present invention.

Fig. 5A shows the pressure plate 128 oriented perpendicular to the shaft axis 127 and the resulting magnetic attraction force vector 134 on the round head 132 of the spool shaft 125 remains coaxial with the shaft axis 127 to minimize wear or sticking in the cylindrical barrel of the spool valve 100, in accordance with an embodiment of the present invention.

Fig. 5B shows the pressure plate 128 oriented to tilt upward relative to the shaft axis 127, and the resulting magnetic attraction force vector 134 on the round head 132 of the poppet shaft 125 remains coaxial with the shaft axis 127 to minimize wear or sticking in the cylindrical barrel of the spool valve 100, in accordance with an embodiment of the present invention.

Fig. 5C shows the pressure plate 128 oriented to slope downward relative to the shaft axis 127, and the resulting magnetic attraction force vector 134 on the rounded head 132 of the poppet shaft 125 remains coaxial with the shaft axis 127 to minimize wear or sticking in the cylindrical barrel of the spool valve 100, in accordance with an embodiment of the present invention.

Fig. 6 is a three-dimensional side cross-sectional view of the control system for the spool valve 100, showing the discharge ports E1 and E2 for the spool valve 100. The figure shows a permanent magnet 130 mounted on the pressure plate 128 in the inner second chamber 124 and a rounded head 132 formed on the end of the spool shaft 125 that is configured to be magnetically attracted to the permanent magnet 130.

Fig. 7 is a three-dimensional side view of the spool valve showing the control fluid pressure signal port 120, the working fluid ports Y1 and Y2, the working fluid supply port S, and the working fluid drain ports E1 and E2 for the spool valve 100.

Although specific example embodiments of the invention have been disclosed, it will be understood by those skilled in the art that changes in the details described for specific example embodiments may be made without departing from the spirit and scope of the invention.