HK1152738B - Balanced solenoid valve - Google Patents

Description

Balanced solenoid valve

Cross Reference to Related Applications

This application claims priority from U.S. patent application No.12/141419 filed on 18/6/2008; U.S. patent application No.12/141419 is a partial continuation of U.S. patent application No.11/784,106 filed on 5/4/2007. The disclosures of the above applications are incorporated herein by reference.

Technical Field

The present invention relates to solenoid operated valves for isolating and controlling pressurized fluid flow.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Solenoid operated valves are known which provide control of a fluid (e.g. pressurized air) for operating additional equipment (e.g. sorters, packaging machines, food processors, etc.). To maintain the solenoid operated valve in the closed position, biasing members such as springs are known.

It is also known, for example, in U.S. patent 4,598,736 to chord that the inlet pressure of the pressurized fluid can be balanced within the valve to reduce the force required by the solenoid assembly to move the valve member between the closed and open positions. However, known designs have several drawbacks. The valve member is typically assembled from multiple parts, which increases the cost of the valve. Known designs also provide separate resilient valve elements that can be widely spaced apart from one another to provide valve-open and valve-close seals. The total displacement or stroke of the valve member is typically not adjustable. Balancing the valve member to allow free sliding movement of the valve member typically requires multiple flow passages, which also increases valve cost and complexity. Furthermore, known valve designs do not provide for axial adjustment of the spacing between seating surfaces and thus are not suitable for controlling seating integrity in the event of wear of the elastomeric sealing material. Known valves also lack the ability to prevent system fluid from contacting the coil of the solenoid assembly. Moisture and dust as contaminants in the fluid can thus enter the solenoid assembly, which can result in valve sticking, reduced valve power, or delayed operating times.

Disclosure of Invention

According to various embodiments of the pressure balanced solenoid operated valve of the present invention, the pressure balanced solenoid operated valve includes a solenoid can. A valve body is connected to the solenoid can. A pole piece (pole piece) connected to the solenoid can is operable to transfer magnetic flux. A homogenous valve member/armature is slidably disposed in the valve body and is movable from a valve closed position to a valve open position in the presence of a magnetic flux.

According to other embodiments, a solenoid operated valve assembly includes a solenoid can having a built-in coil. A valve body is connected to the solenoid can. The valve body has a first valve seat. A pole piece connected to the solenoid can transfer magnetic flux generated by the coil. An axially adjustable retainer is threaded to the valve body. An end of the retainer defines a second valve seat. Axial movement of the retainer axially positions the second valve seat relative to the first valve seat. A homogenous valve member/armature slidably disposed in the valve body is movable in the presence of a magnetic flux from a valve closed position in which the resilient valve element is in contact with the first valve seat to a valve open position in which the resilient valve element is in contact with the second valve seat.

According to a further embodiment, a pressure balanced solenoid operated valve assembly includes a solenoid can having a built-in coil. A valve body is releasably connected to the solenoid housing. The valve body has an inlet port and a first valve seat. An axially adjustable retainer is threaded to the valve body and has an end defining a second valve seat. A homogenous valve member/armature is slidably disposed in the valve body and is movable between a valve closed position and a valve open position in the presence of a magnetic flux generated by the coil. The first surface area of the valve member/armature is in fluid communication with pressurized fluid through the inlet port. The second surface area of the valve member/armature is in fluid communication with the pressurized fluid when in the valve closed position. The first surface area is substantially equal to the second surface area, wherein in the valve closed position, pressurized fluid acts equally on the first and second surface areas, thereby defining a pressure equilibrium condition.

According to further embodiments, a solenoid operated valve assembly includes a solenoid can. A valve body is connected to the solenoid can. A pole piece connected to the solenoid is operable to transfer magnetic flux. A homogenous valve member/armature slidably disposed in the valve body is movable from a valve closed position to a valve open position by a pulling force of the magnetic flux operable to pull the valve member/armature toward the pole piece.

According to additional embodiments, a solenoid operated valve assembly includes a solenoid can having a built-in coil. A valve body is connected to the solenoid can. An axially adjustable retainer is threaded to the valve body. A pole piece is connected to the solenoid can and is operable to transfer magnetic flux generated by the coil. A homogenous valve member/armature slidably disposed in the axially adjustable retainer is operably drawn toward the pole piece between a valve closed position and a valve open position by magnetic flux generated by the coil. A sealing member disposed between the valve member/armature and the axially adjustable retainer is operable to form a fluid seal between the valve member/armature and the axially adjustable retainer to prevent pressurized fluid within the valve body from contacting the coil in either of the valve open and closed positions.

According to other embodiments, a bushing portion is engageable with the solenoid can and has a predetermined length adapted to provide a non-zero clearance gap between the pole piece and the valve member/armature in either an energized or de-energized position of the valve member/armature.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a cross-sectional side view of a 3-way pressure balanced solenoid operated valve of the present invention in a de-energized position;

FIG. 2 is a cross-sectional side view of the valve of FIG. 1 in an energized position;

FIG. 3 is a cross-sectional side view showing region 3 of FIG. 1;

FIG. 4 is a cross-sectional side view of another pressure balanced solenoid operated valve modified from FIG. 1 with the addition of a fluid seal to prevent fluid from entering the solenoid assembly;

FIG. 5 is a cross-sectional side view of the valve of FIG. 4 in a valve open position, further showing the valve attached to a valve body block;

FIG. 6 is a cross-sectional side view of a two-way pressure balanced solenoid operated valve on the inlet side of the present invention;

FIG. 7 is a side view of another embodiment of a two-way pressure balanced solenoid operated valve on the inlet side of the present invention;

FIG. 8 is a perspective view of a manifold assembly having a plurality of the two-way pressure balancing valves of FIG. 7 in communication with a plurality of flow distribution devices;

FIG. 9 is a cross-sectional side view of a two-way pressure balanced solenoid operated valve on the inlet side of the present invention modified from the valve of FIG. 6;

FIG. 10 is a cross-sectional side view showing region 10 of FIG. 9;

FIG. 11 is a cross-sectional side view of a variation 2-way pressure balanced solenoid operated valve of the present invention in a de-energized position; and

FIG. 12 is a cross-sectional side view of the valve of FIG. 11 shown in an energized position.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

Referring generally to FIG. 1, the valve assembly 10 of the present invention includes a valve body 12, the valve body 12 being releasably connected to a solenoid can 14 using a threaded connection 16. Combined valve member/armature 18 is slidable in either a valve closing direction "A" or a valve opening direction "B". Valve member/armature 18 is fabricated as a homogenous or unitary combination of valve member and armature in a single element. In various embodiments, valve member/armature 18 is made of a magnetic material, such as steel, stainless steel, or the like.

A coil 22 comprising wire in the form of a plurality of windings is disposed within the solenoid can 14. An adjustable pole piece 24 is disposed within the coil 22 and is connected to the solenoid can 14 using a threaded connection 26. Adjustable pole piece 24 transfers magnetic flux from energized coil 22 to "pull" valve member/armature 18 from the valve closed position to the valve open position. A biasing member 28 (e.g., a coil spring) within valve body 12 provides a biasing force to continuously bias valve member/armature 18 in a valve closing direction "a". In the valve closed position shown, a clearance gap 30 is provided between valve member/armature 18 and adjustable pole piece 24. When the biasing member 28 biases the valve member/armature 18 in the valve closing direction "a", a gap 30 is formed. Gap 30 is adjustable by rotating adjustable pole piece 24 using threaded connection 26 to axially move adjustable pole piece 24 in either a valve opening direction "a" or a valve closing direction "B". Gap 30 defines the total valve member/armature 18 axial displacement between the valve closed (de-energized) and valve open (energized) positions plus an over-stroke. Spacing 30 also provides for adjustable axial displacement to compensate for wear of the valve member and/or valve seat. The spacing 30 can be adjusted throughout the life of the valve assembly to maintain a consistent response time of the valve. Decreasing spacing 30 will decrease the time it takes to open the valve, i.e., the valve opening time, and conversely, increasing spacing 30 will increase the valve opening time. The spacing 30 is initially set to achieve optimum performance for a particular application.

A first end of biasing member 28 is disposed within a member cavity 32 formed at an end 34 of valve member/armature 18. A second end of the biasing member 28 is retained within a pole piece cavity 36 formed in a pole piece end 38 of the adjustable pole piece 24. Solenoid bushing 40 is disposed between coil 22 and valve member/armature 18. Valve member/armature 18 is slidably disposed within a bushing bore 42 of solenoid bushing 40. The material of solenoid bushing 40 may be provided by a magnetic material, such as steel or stainless steel, and provides a snug fit for valve member/armature 18. An electrical connector member 44, which can include one or more wires, is connected to the coil 22 and extends outwardly from the coil 22. The electrical connector member 44 provides electrical power from a power source (not shown) to energize the coil 22. Solenoid can 14, valve member/armature 18, coil 22, adjustable pole piece 24, solenoid bushing 40, and electrical connector member 44 together define a solenoid assembly.

Pressure equalization passage 46 extending throughout the length of valve member/armature 18 is oriented longitudinally and substantially coaxially with a corresponding passage 48 formed through adjustable pole piece 24. Pressure equalization passage 46 and passage 48 together provide a flow path for fluid (e.g., air) that is displaced as valve member/armature 18 slides within valve body 12. The pressure equalization passage 46 is also capable of conducting fluid (e.g., air) that may be present due to seal leakage.

The valve body 12 includes an inlet port 50, the inlet port 50 being in fluid communication with an inlet passage 52, the inlet passage 52 in turn being connected to a plenum chamber 54. The inlet passage 52 can have the same or a larger diameter than the inlet port 50, or it can be smaller, as shown. The inlet passage 52 may also be in the form of a slot, or be arranged in other geometric shapes, including but not limited to rectangular, oval, etc. Fluid in plenum 54 is provided from a source of pressurized fluid (e.g., air) (not shown). When valve assembly 10 is in the valve closed position, pressurized fluid is retained within volume booster 54 by a seal 56 disposed in a piston 58, piston 58 defining an end of valve member/armature 18. The piston 58 is slidably received within a cylindrical bore 60 of the valve body 12. When the valve element 62 engages a first valve seat 64 of the valve body 12, the end of the plenum 54 opposite the seal 56 is sealed. The first valve seat 64 may define a pointed, beveled, or radiused surface. Valve element 62 may be formed or machined from the same material as valve member/armature 18 or may be made of a resilient material, such as a rubber or elastomeric material, that is attached to valve member/armature 18, for example, by bonding, over-molding, non-tight sealing, or other known processes. Valve member/armature 18 can be made of any material that can be affected by the magnetic flux created through adjustable pole piece 24 when coil 22 is energized.

The valve body 12 also includes a cylinder port 66 in fluid communication with a cylinder port passage 68. An exhaust port 70 is also provided in the valve body 12 in fluid communication with an exhaust port passage 72. The cylinder port passage 68 is in fluid communication with the cylinder port chamber 74. In various embodiments, the cylinder port chamber 74 is formed as a circumferential cavity within the valve body 12. The exhaust port passage 72 is in fluid communication with an exhaust port chamber 76. In various embodiments, discharge port chamber 76 is formed as a circumferential recess or cavity in valve member/armature 18 that is disposed proximate discharge port 70 in any operative position of valve member/armature 18.

When the valve assembly 10 is in the valve closed position, fluid within the discharge port chamber 76 is discharged through the discharge port chamber 78, the discharge port chamber 78 being in fluid communication with the discharge port 70 via the discharge port passage 72. According to various embodiments, the discharge port cavity 78 is formed as a circumferential groove disposed within an adjustable retainer 80, the adjustable retainer 80 being disposed proximate the discharge port passage 72. After insertion of valve member/armature 18, adjustable retainer 80 is connected to valve body 12 using threaded connection 82 to enable axial adjustment parallel to valve longitudinal axis 20 by rotating adjustable retainer 80. By axially moving the adjustable retainer 80, the distance between the adjustable retainer 80 and the valve element 62 in the valve closed position may be increased or decreased and set to an optimal or desired position. The adjustment also determines the flow rate of the valve. First and second O-rings 84, 86 are used to form a fluid seal between the adjustable retainer 80 and the inner wall of the valve body 12. First and second O-rings 84, 86 straddle exhaust port cavity 78, exhaust port passage 72, and exhaust port 70 and form a fluid seal that prevents fluid from passing through exhaust port 70 or through the coil 22 cross-section when the valve member/armature is in the valve open position.

The valve body 12 also includes a plurality of body seals, which in the illustrated example are provided as rubber or elastomeric O-rings, but may be other types of seals suitable for acting around the periphery of the valve body 12. These seals include a first body seal 88, a second body seal 90, a third body seal 92, and a fourth body seal 94. The first, second, third and fourth body seals 88, 90, 92, 94 are partially received within seal cavities or circumferential grooves formed in the valve body 12 and are intended to sealingly mate with a valve body block (e.g., the body block shown and described with reference to FIG. 5). In various embodiments, therefore, the valve body 12 with the first, second, third and fourth body seals 88-94 defines a cartridge assembly that is slidably received in and removable from the respective body blocks.

The valve closed position shown in fig. 1 is defined by engagement of a first side 95 of valve element 62 with first valve seat 64. Pressurized fluid provided through inlet port 50 is thereby retained in pressurized chamber 54. In the valve closed position, fluid pressure in cylinder port 66 is directed through exhaust port 70 by a path including cylinder port chamber 74, exhaust port chamber 76, exhaust port cavity 78 and exhaust port passage 72. In the valve closed position, coil 22 is de-energized, allowing the biasing force provided by biasing member 28 to bias valve member/armature 18 in a valve closing direction "A", which seats valve element 62 against first valve seat 64. As previously mentioned, clearance gap 30 provided between first end 34 of valve member/armature 18 and a pole piece end 38 of adjustable pole piece 24 is adjustable and can be made smaller or larger by rotating adjustable pole piece 24 using threaded connection 26 to increase or decrease clearance gap 30. Increasing or decreasing the spacing 30 can increase or decrease the opening and closing times, respectively, of the valve assembly 10. The clearance gap 30 can also be maintained during the life of the valve assembly 10, for example, to allow for compressive positioning or wear of the valve element 62.

Axial adjustment of adjustable pole piece 24 operably controls a dimension "X" of a clearance gap 30 formed between adjustable pole piece 24 and valve member/armature 18 when valve member/armature 18 is in the valve closed position. Clearance gap 30 is also equal to the total travel distance of valve member/armature 18, determined by the distance between the two opposing valve seats, which affects the operating time of valve assembly 10. According to various embodiments, the spacing 30 can be about 0.005 inches (0.13 millimeters). Access to adjustable pole piece 24 is provided through an open end of valve assembly 10 so that adjustable pole piece 24 can be rotated to axially adjust its position to control the stroke or over-stroke of the solenoid assembly even when coil 22 of the valve is energized. Thereby providing in situ adjustment of the valve assembly 10. The field adjustment also optimizes valve switching forces, provides wear compensation, and can be used to keep response times consistent throughout the life of the valve.

Referring now to FIG. 2, when coil 22 is energized, a magnetic field or flux defining a pulling force is generated through adjustable pole piece 24 that magnetically pulls or draws valve member/armature 18 in the valve opening direction "B" against the biasing force of biasing member 28. A second valve seat 96 is defined at an end of the adjustable retainer 80. The valve open position is defined when a first side 95 of valve element 62 moves away from first valve seat 64 and an opposing second side 97 of valve element 62 contacts second valve seat 96. The valve open position also occurs when clearance gap 30' is reduced but not allowed to reach a zero value, which will allow valve member/armature 18 to contact adjustable pole piece 24. Contact between valve member/armature 18 and adjustable pole piece 24 is undesirable because there may not be full sealing contact between valve member/armature 18 and adjustable pole piece 24, and because repeated contact may result in rattling of metal parts and increased noise. Thus, eliminating contact will increase the operating life of the valve assembly 10 by eliminating metal wear.

The second valve seat 96 may define a pointed, beveled, or rounded end of the adjustable retainer 80, with the adjustable retainer 80 disposed proximate the valve element 62. The first valve seat 64 may also define a sharp corner, a beveled surface, or a rounded shape. As previously described, the position of the adjustable retainer 80 and, thus, the second valve seat 96 is longitudinally adjustable by rotating the adjustable retainer 80 using the threaded connection 82. By adjusting the axial position of the adjustable retainer 80, and thus the second valve seat 96, the total distance "Y" between the first and second valve seats 64, 96 may be adjusted. This adjustment allows for adjustment of the compression positioning and wear of the valve element 62 as well as the valve opening and closing times.

When the coil 22 is in the energized condition, the valve assembly 10 will remain in the valve open position shown in FIG. 2. In the valve open position, fluid (e.g., pressurized air) provided within pressurization chamber 54 through inlet port 50 is exhausted to a fluid operated component or device (not shown) via cylinder port chamber 74, cylinder port passage 68, and cylinder port 66. Thus, flow through the valve assembly 10 flows in an inflow direction "C" through the inlet port 50 and out of the cylindrical port 66 in an outflow direction "D".

When the valve element 62 is in contact with the second valve seat 96, the exhaust port 70 is isolated. In addition to the drain path provided by drain port 70, in the valve open position, fluid within valve assembly 10 may also drain through a passage 98 defined between valve member/armature 18 and a bushing sleeve 100 of solenoid bushing 40. Fluid escaping through passageway 98 will exit valve body 12 and valve assembly 10 through threaded connection 26 and may contact coil 22. These paths are isolated in the valve closed position. Because the pressure differential between the fluid within discharge port chamber 76 and discharge port 70 is expected to be significantly less than the pressure differential between discharge port chamber 76 (via passage 98) and threaded connection 26, fluid will generally be discharged through discharge port 70 in the valve closed position. When coil 22 is de-energized, biasing member 28 will return valve member/armature 18 to the valve closed position shown in FIG. 1.

Referring now to fig. 2 and 3, when valve member/armature 18 is in either the valve closed position (fig. 3) or the valve open position (fig. 2), a "pressure balanced" condition exists due to the geometry provided at the opposite end of pressurized chamber 54. As particularly shown in fig. 3, when valve element 62 is in contact with first valve seat 64, a first surface area "E" of piston end wall 102 is substantially equal to a second surface area "F" of the corresponding fluid exposed portion of valve element 62. Thus, the fluid pressure "P" acting on the first surface area "E₁"substantially equal to the fluid pressure" P acting on the second surface area "F₂". Due to pressure "P₁"substantially equal to pressure" P₂", and thus at the inlet port 50Does not act to move valve member/armature 18 from the valve closed position. The pressure balanced condition allows the biasing force provided by biasing member 28 (not shown in this figure) to be the only force used to maintain valve member/armature 18 in the valve closed position. When coil 22 is subsequently energized, the static force affecting valve member/armature 18 is ignored, so that the input force required to move valve member/armature 18 from the valve closed position to the valve open position need only be greater than the biasing force of biasing member 28. This reduces the energy required to move valve member/armature 18, thereby reducing the opening time of valve assembly 10. Even if valve element 62 wears over time due to use, second surface area "F" is substantially unchanged, thus maintaining a pressure balanced condition across valve member/armature 18. The distance "Z" defined between the corner of the second valve seat 96 of the adjustable retainer 80 and the second face 103 of the valve element 62 is shown. The distance "Z" is adjustable by axial movement of the adjustable retainer 80. When the valve is in the valve open position (fig. 2), a pressure balanced condition also occurs when fluid flow through cylinder port 66 ceases, due to the substantially equal opposing valve seat surface areas. These regions of pressure equilibrium also allow the valve response time to be consistent in the event of any change in fluid pressure.

Returning to fig. 2, when valve assembly 10 is in the valve open position, after a volume of fluid has passed from inlet port 50 through cylinder port 66, the fluid pressure at inlet port 50 is substantially equal to the fluid pressure at cylinder port 66, cylinder port 66 being used to operate downstream equipment. In the valve open position, a "pressure balanced" condition generally exists due to the angular shape of the opposing sides of the valve element 62. At the point of contact between valve element 62 and second valve seat 96, the fluid pressure acting on opposite sides of valve element 62 is approximately equal. When the coil 22 is subsequently de-energized, the biasing force of the biasing element 28 need only overcome the minimum fluid pressure to initiate movement of the valve member/armature 18 in the valve closing direction "A" from the valve closed position back to the valve closed position shown in FIG. 1.

Referring now to fig. 4, valve assembly 104 is modified from valve assembly 10 to add a fluid seal. Valve member/armature 106 is modified from valve member/armature 18 by the addition of a sealing member 108 (e.g., an O-ring), sealing member 108 being disposed within a sealing groove 110 formed in valve member/armature 106. Sealing member 108 provides a fluid seal between valve member/armature 106 and an orifice face 112 of adjustable retainer 80. The remaining components of valve assembly 104 are substantially unchanged from valve assembly 10.

By adding a sealing member 108 to valve assembly 104, passage 98 is isolated under any operating conditions of valve assembly 104. Depending on the type of fluid being controlled by the valve assembly 104, the use of the sealing member 108 may be selected, for example, when the fluid is not readily filtered to remove contaminants such as dust or moisture, or when the fluid is corrosive with respect to the material of the valve assembly 10, including the coil 22. The use of the sealing member 108 prevents the damaging effects of unfiltered or corrosive fluids from reaching the coil 22 area of the valve assembly 104. When valve element 114 of valve member/armature 106 is in contact with a valve seat in either the valve closed position or the valve open position, and for any position therebetween, sealing member 108 isolates passage 98 from the flow path of threaded connection 26. The addition of the sealing member 108 also provides the ability to use the valve assembly 104 as a normally-off valve, a normally-open valve, as a selector, or as a flow diverter assembly. The inlet port may also be reconfigured as any of the ports involved and the valve assembly 104 may also be used with a connected vacuum system.

Referring now to FIG. 5, an exemplary installation of valve assembly 104 in body block 116 is shown. The valve assembly 10 (not shown) would be similarly installed. Body block 116 is an example of any type of configuration for a receiving member of valve assembly 104. Body piece 116 may include a plurality of fluid ports defining fluid communication paths for each of inlet port 50, cylinder port 60, and exhaust port 70. These fluid ports include a first fluid port 118 in fluid communication with each inlet port 50, a second fluid port 120 in fluid communication with each cylinder port 66, and a third fluid port 122 in fluid communication with each exhaust port 70. First, second, and third fluid ports 118, 120, and 122 may be adapted to receive a connector 124, such as a threaded, welded, swaged, or other similar connector. Each connector 124, in turn, is connected to a fluid line 126, which fluid line 126 may provide, for example, a source of pressurized fluid to inlet port 50, provide a flow path to exhaust fluid from valve assembly 104 to a pressure operated device, or to direct fluid from exhaust port 70 to the environment.

In the example shown in FIG. 5, valve member/armature 106 is disposed in a valve open position, thereby providing a path of fluid communication between inlet port 50 and cylinder port 66. In this condition, fluid at the inlet port 50 will pass through the valve assembly 104 and be discharged through the cylinder port 66. The body seals (e.g., first, second, third, and fourth body seals 88-94) allow valve assembly 104 to be releasably inserted as a cartridge into body block 116. This allows valve assembly 104 to be disassembled for maintenance, such as replacing any of the various seals or adjusting adjustable retainer 80.

Referring now to FIG. 6, a two-way valve assembly 128 of the present invention includes a valve body 130 releasably connected to a solenoid can 132 using a threaded connector 134. A valve member/armature 136 is slidably disposed in the valve body 130 for sliding movement in a valve longitudinal axis 138. Similar to valve member/armature 18, valve member/armature 136 is movable in each of a valve closing direction "A" and a valve opening direction "B".

A coil 140 is disposed in the solenoid housing 132. An axially adjustable pole piece 142, similar to adjustable pole piece 24, is connected to solenoid can 132 using a threaded connection 144. A biasing member 146 (e.g., a coil spring) similar to biasing member 28 is disposed between a flange portion 148 of valve member/armature 136 and a solenoid bushing 150. Biasing member 146 biases valve member/armature 136 in a valve closing direction "A" to define a clearance gap 151 between valve member/armature 136 and adjustable pole piece 142 when valve member/armature 136 is in a valve closed position. Gap 151 is similar in function and adjustment to gap 30 provided for valve assembly 10.

Valve member/armature 136 is slidably disposed within a bushing sleeve 152 of solenoid bushing 150. A passage 154 similar to passage 98 is formed between bushing sleeve 152 and valve member/armature 136. A pressure equalization passage 156, functionally similar to equalization passage 46, is also provided in valve member/armature 136.

The valve body 130 includes an inlet port 158, the inlet port 158 being disposed at an angle α relative to the valve longitudinal axis 138. According to various embodiments, the angle α is about 45 degrees, but may vary at the discretion of the manufacturer. The inlet port 158 is in fluid communication with a plenum 160. Fluid in plenum 160 is retained by a seal 162 (e.g., an O-ring), seal 162 being retained circumferentially around a piston 164 of valve member/armature 136. The seal 162 contacts the cylindrical bore 166 of the valve body 130 to form a pressure fluid boundary at one end of the plenum 160. When a valve element 168, similar to valve element 62, contacts a valve seat 170 of valve body 130, an opposite end of plenum 160 is formed. The pressure balance condition of the valve assembly 10 is replicated by the configuration of the two-way valve assembly 128.

The valve body 130 also includes a cylinder port 172, the cylinder port 172 being in fluid communication with a cylinder port chamber 176 using a cylinder port passage 174. Fluid pressure in inlet port 158 is generally isolated from cylinder port chamber 176, and thus cylinder port 172, by virtue of valve element 168 contacting valve seat 170 in the valve closed position. A sealing member (not shown), such as sealing member 108 shown and described with reference to FIG. 4, may also be added to valve member/armature 136 to prevent pressurized fluid from passing through passage 154 and threaded connection 144. The sealing member may be disposed in flange portion 148 or between valve member/armature 136 and bushing sleeve 152.

The valve body 130 differs from the valve body 12 in the geometry of the position of the valve body 130 adjacent the piston 134. A first body seal 178, such as an elastomeric O-ring, is disposed in a groove or recess formed in an end face 180 of the valve body 130. The end face 180 is oriented substantially perpendicular to the valve longitudinal axis 138. The second and third body seals 182, 184 are each disposed in respective grooves formed in a side 186 of the valve body 130. An angularly oriented face 188 is formed between the end face 180 and the side face 186. The angled face 188 is generally perpendicular to a central axis 189 of the inlet port 158.

The two-way valve assembly 128 operates similarly to each of the valve assemblies 10 and 104. When coil 140 is de-energized, the biasing force of biasing member 146 urges valve member/armature 136 toward the valve closed position. When coil 140 is energized, the magnetic flux induced through adjustable pole piece 142 pulls or pulls valve member/armature 136 toward adjustable pole piece 142 until clearance gap 151 decreases to substantially zero. In the design of two-way valve assembly 128, contact between valve member/armature 136 and adjustable pole piece 142 is contemplated. If desired, additional items, such as elastomeric bushings or spacers (not shown), may be provided between valve member/armature 136 and adjustable pole piece 142 to reduce contact forces and associated noise. When valve member/armature 136 moves in the valve opening direction "B", valve element 168 withdraws from valve seat 170, allowing fluid in pressurized chamber 160 to vent via cylinder port chamber 176, cylinder port passage 174, and through cylinder port 172. The use of flanged portion 148 of valve member/armature 136 allows biasing member 146 to be disposed outside of valve member/armature 136, thereby eliminating the need for member cavity 32 and pole piece cavity 36 of valve assembly 10.

Referring now to fig. 7, a two-way valve assembly 190 is modified from the two-way valve assembly 128 by the addition of a plurality of external body threads 192, the external body threads 192 extending radially outward from a solenoid housing 193. Threads 192 allow valve assembly 190 to positively engage internal threads of a manifold (e.g., manifold block 198, which will be better described with reference to fig. 8). To assist in rotating valve assembly 190 during threading engagement, solenoid can 193 is provided with a pair of opposing wrench flats 194 (only one wrench flat is visible in this view). A fastener, such as a wrench, may engage wrench flats 194 to apply additional torque during assembly. Further, a slotted end may be provided in the adjustable pole piece 195 for engagement by a different installation tool, such as a screwdriver.

Referring now to fig. 8, as a space and cost saving measure, multiple valve assemblies of the present invention may be commonly connected to a manifold to operate multiple components from the valve assemblies. In the exemplary embodiment, a plurality of valve assemblies 190 are threaded into separate threaded receiving apertures of manifold block 196. The valve assemblies 190 may be arranged in generally parallel rows (represented by first and second rows 198, 200). A group of valve assemblies 190, illustrated by exemplary group 202, may be commonly connected to one or more flow distribution devices 204. In the present configuration, the group 202 includes eight valve assemblies 190 commonly connected to a flow distribution device 204 through internal flow passages (not shown) of the manifold block 196 and device mounting block 206. Additional sets of valve assemblies 190 may then be connected to each of the flow distribution devices 204 ', 204 ", and 204'". The number of valve assemblies and flow distribution devices is not limited by the exemplary configuration shown and may vary at the discretion of the manufacturer. Grouping the plurality of valve assemblies also facilitates forming electrical connections for the valve assemblies, as a wiring harness (not shown) may be used to electrically energize the plurality of valve assemblies.

Referring now to fig. 9, another embodiment of a two-way pressure balanced valve assembly 208 is modified from two-way valve assembly 128. Thus only the modified part will be discussed further. The two-way pressure balanced valve assembly 208 includes a valve body 210 having a homogenous valve member/armature 212 slidably disposed therein. The valve body 210 is threaded to the solenoid housing 214. The solenoid can 214 has an adjustable pole piece 216 similar to the adjustable pole piece 142, the adjustable pole piece 216 being threaded onto the solenoid can 214. Valve member/armature 212 and adjustable pole piece 216 are modified to include a resilient member 218, such as a coil spring, disposed in a member cavity 220 and a pole piece cavity 222, respectively. Resilient member 218 biases valve member/armature 212 in a direction "H" that tends to close valve assembly 208.

Valve member/armature 212 is modified from valve member/armature 136 to include a radial flange portion 224, with radial flange portion 224 including an outer surface 226 slidably received in a receiving cavity 228 of raised body portion 230. A seal 232 (e.g., an O-ring) disposed within a seal groove 234 of the radial flange portion 224 provides a fluid-boundary seal to prevent fluid from escaping past the radial flange portion 224 and contacting a coil 236. Valve member/armature 212 further includes a valve element 238, valve element 238 being integrally connected to valve member/armature 212 within a radial pocket 240 of valve member/armature 212, thereby being modified from valve elements 62 and 168, as will be described in greater detail with reference to FIG. 10. Valve element 238 contacts valve seat 242, which is similar to valve seat 170. To load valve member/armature 212 into valve body 210 in direction "H", valve element 238 is adapted to be deflectable in direction "G" to allow valve element 238 to deflect when disposed through receiving cavity 228 of raised body portion 230.

Referring now to fig. 10, the valve seat 242 and the inner surface 243 defined by the receiving cavity 228 each have substantially the same diameter "J". Thus, the end wall 244 of the radial flange portion 224 defines a surface area "K" that is substantially equal to a surface area "L" of a piston 245 (similar to the piston 164) received in the piston cavity 246. Surface area "K" is also substantially equal to surface area "M" of the portion of valve element 238 exposed to fluid pressure in the illustrated valve closed condition. Surface regions "L" and "M" are functionally similar to first and second surface regions "E" and "F" shown in fig. 3. When coil 236 (shown in FIG. 9) is energized, valve member/armature 212 moves to a valve open position (not shown) and fluid pressures acting on surface areas "L" and "K" are equalized.

Valve element 238 is modified from valve elements 62 and 168 by omitting any portion of radially outwardly extending valve member/armature 212 that is partially received within valve elements 62 and 168. In contrast, valve element 238 is received in radial pocket 240, which allows the portion of valve element 238 that freely extends radially away from valve member/armature 212 to deflect or bend. To further assist in the deflection of valve element 238 when valve member/armature 212 is loaded, surface 247 of valve element 238 is oriented at angle β relative to axis 248, which axis 248 is oriented substantially perpendicular to longitudinal axis 250 of valve assembly 208. According to various embodiments, the angle β may range from about 20 degrees to about 60 degrees. However, this range of angles is not limiting, and the angle β may be larger or smaller at the discretion of the manufacturer.

The coils 22, 140 of the valve assembly of the present invention are shown herein as being generally circular or tubular in shape. The shape is not intended to limit the present invention. Additional coil shapes, such as rectangular, or non-circular (e.g., oval), or a variety of other geometries, may also be used. By changing the geometry of the coil, the coil wattage or valve operating speed can be varied by changing the design and number of windings that define the active area of the coil. The remaining operational features of the valve assembly of the present invention may be maintained with a variety of the described coil geometries. The shapes of the solenoid can (14, 132, 193, 214) and adjustable pole piece (24, 142, 195, 216) can also be modified to correspond to the geometry of the coil. For example, a generally rectangular solenoid can 193 can eliminate the need for wrench flats 194 of the valve assembly 190 shown in FIG. 7.

Although a cartridge-type valve body (12, 130, 190, 210) is shown herein, the valve body may have other configurations, such as, but not limited to, a straight-line or manifold body style. A valve stroke, defined as the axial displacement of the valve member/armature (18, 106) from the valve closed position to the valve open position, is predetermined by the axial position of the adjustable retainer (80). The solenoid stroke produced by the solenoid assembly is predetermined by the axial position of the adjustable pole piece (24, 142, 195, 216). The valve assembly of the present invention is also not limited to two-way and three-way designs, but may be a 4-way or more valve.

Referring to FIG. 11, in accordance with an additional embodiment of the present invention, a 2-way valve assembly 252 includes a valve body 276 having a valve member/armature 254 slidably disposed therein. Valve member/armature 254 is fabricated as a homogenous or unitary combination of valve member and armature in a single element. In various embodiments, valve member/armature 254 is made from a magnetic material, such as steel, stainless steel, or the like. First end 256 of valve member/armature 254 is slidably disposed within a bushing sleeve 257 of a solenoid bushing 258. A pressure equalization passage 259 is also provided in valve member/armature 254. Axially adjustable pole piece 260 is threaded into solenoid can 262 and is thus axially adjustable relative to solenoid can 262 and valve member/armature 254. Coil 263 disposed in solenoid housing 262 is operable when energized to slide valve member/armature 254 from the de-energized position shown to the right as shown in FIG. 11 using a magnetic field acting through first end 256 of valve member/armature 254. Pressure equalization passage 264 is also disposed in pole piece 260 in axial alignment with pressure equalization passage 259. Biasing member 266, which is in contact with both solenoid bushing 258 and valve member/armature 254, normally biases valve member/armature 254 toward the de-energized position shown when coil 263 is de-energized.

Bushing portion 268 of valve body 276 (e.g., made from metal such as brass) is threaded into solenoid housing 262 using threads 270 and provides a sliding seal for valve member/armature 254. The bushing portion 268 may also be adapted to retain the solenoid bushing 258. Bushing portion 268 defines a first valve seal when contacted by an overmolded elastomeric valve element 272 provided with valve member/armature 254. A second valve seal is formed by contact between the valve element 272 and a valve seat 274 provided by a valve body 276. In the de-energized position of valve member/armature 254 shown, a first width W exists between end face 280 of valve member/armature 254 and face 282 of pole piece 260₁Spacing 278.

Referring to fig. 12 and again to fig. 11, valve assembly 252 is shown with valve member/armature 254 moved to an energized position due to energizing coil 263. The magnetic field generated by coil 263 overcomes the biasing force of biasing member 266, causing valve member/armature 254 to move in the sliding direction "U". In the energized position, clearance gap 278' is reduced from clearance gap 278, however, end face 280 of valve member/armature 254 is not allowed to contact face 282 of pole piece 260. Gap 278' is defined to have a width W₂Minimum value of, width W₂Less than width W₁But always greater than zero, to prevent physical contact between the end face 280 of the valve member/armature 254 and the face 282 of the pole piece 260. Physical contact between end face 280 of valve member/armature 254 and face 282 of pole piece 260 is prevented to eliminate the possibility of physical wear between these two surfaces and the noise that may accompany this contact.

By initially predetermining the length "V" of the liner portion 268 and threadingly adjusting the pole piece 264 using the threads 290 of the pole piece 264, the width W of the gap 278₂Remaining greater than zero, the pole piece 264 is threadably received by corresponding threads 292 of the solenoid can 262 as desired. At the free end of bushing portion 268 when valve assembly 252 is energizedA seat surface 284 formed on 286 is adapted to receive a surface 288 of valve element 272. Because valve element 272 is a resilient material, some over-travel of valve member/armature 254 in the sliding direction "U" may occur after seat surface 284 begins to contact seat surface 284. Thus, the length "V" of the bushing portion 268 is initially predetermined to allow for this over travel and to allow for normal wear of the valve element 272 in use. The position of pole piece 260 can also be adjusted as needed toward or away from valve member/armature 254 to redefine width W₂. Width W by axial adjustment in direction "X₂Will be such that the width W₂To a minimum value above gap 278', for example, to allow wear of valve element 272 and/or to adjust the strength of the magnetic field through pole piece 260. As noted in the previously discussed embodiments, the valve assembly 252 of fig. 11 and 12 is also not limited to a two-way or three-way design, but may be a 4-way or more valve, having a cartridge-type valve body and a straight or manifold body style.

The pressure balanced solenoid operated valve of the present invention has several benefits. By controlling the geometry at the opposite end of the pumping chamber, a pressure balanced condition is created between the piston of the valve member/armature and the resilient valve element seated against the valve seat. The pressure balanced condition allows the valve member/armature to be held in the valve closed position solely by the force of the biasing member. To move the valve member/armature to the valve open position, the magnetic flux generated by the coil need only overcome the biasing force of the biasing member. Due in part to the pressure balanced design of the valve assembly of the present invention, valve operating times of less than 0.0004 seconds may be achieved, and valve operating frequencies of greater than 2200 cycles per second may also be achieved. According to various embodiments, the axially adjustable retainer allows for axial adjustment in the range of about 0.002 inches (0.05 millimeters) to 0.025 inches (0.635 millimeters). By providing an axially adjustable pole piece independent of the axially adjustable second valve seat provided by the retainer, the overall solenoid stroke of the valve can be maintained or adjusted throughout its life. Access to the adjustable pole piece is provided through the open end of the valve assembly so that the pole piece can be axially adjusted over the life of the valve to control the stroke or over-stroke of the solenoid assembly even when the valve is energized. An external seal provided on the valve body allows the valve body to be inserted into a valve body block or similar structure or removed from an installed position as a cartridge assembly.

Claims (14)

1. A solenoid operated valve assembly comprising:

a solenoid can;

a valve body connected to the solenoid can;

a pole piece connected to the solenoid can, the pole piece operable to transfer magnetic flux;

a homogenous valve member/armature slidably disposed in the valve body and movable from a valve closed position to a valve open position in the presence of the magnetic flux;

a bushing portion engageable with said solenoid housing, said bushing portion having a predetermined length adapted to provide a non-zero clearance distance between a pole piece and said valve member/armature in an energized or de-energized position of said valve member/armature;

a solenoid bushing retained within the solenoid can by the bushing portion, the solenoid bushing having a bushing sleeve within which the valve member/armature is received and in slidable contact therewith;

a coil received in the solenoid can, the coil when energized adapted to provide the magnetic flux to the pole piece to cause the valve member/armature to move from the de-energized position toward the pole piece to an energized position; and

a valve element having a first side adapted to contact the bushing portion in the energized position of the valve member/armature.

2. The solenoid operated valve assembly of claim 1, wherein the valve element is a resilient material allowing compression of the valve element and over-travel of the valve member/armature when the valve element is in contact with the bushing portion, wherein the clearance distance allows the over-travel without allowing contact between the valve member/armature and the pole piece.

3. The solenoid operated valve assembly of claim 1, wherein the pole piece includes a plurality of threads adapted to be threadedly received in the solenoid can to allow axial adjustment of the pole piece, wherein axial adjustment of the pole piece is operable such that a clearance distance between the pole piece and the valve member/armature increases at least above a minimum value in the energized or de-energized position of the valve member/armature.

4. The solenoid operated valve assembly of claim 1, wherein the bushing portion includes a seating surface formed proximate the free end.

5. A solenoid operated valve assembly comprising:

a solenoid can;

a valve body connected to the solenoid can, the valve body having a valve seat;

a pole piece threadedly connected to the solenoid can, the pole piece operable to transfer magnetic flux;

a valve member/armature slidably disposed in the valve body and movable from a valve closed position to a valve open position in the presence of the magnetic flux, the valve member/armature having an elastomeric valve element;

a solenoid bushing in direct contact with the solenoid housing and slidably receiving the valve member/armature;

a bushing portion in direct contact with the solenoid bushing, the bushing portion having a predetermined length adapted to create a non-zero width clearance gap between the pole piece and the valve member/armature in an energized or de-energized position of the valve member/armature to prevent contact between the valve member/armature and the pole piece; and

a biasing member disposed in said valve body between and in direct contact with said solenoid bushing and said valve member/armature, said biasing member continuously biasing said valve member/armature away from said pole piece and toward said valve closed position, wherein said valve element is in contact with said valve seat.

6. The solenoid operated valve assembly of claim 5, wherein the valve member/armature includes a first pressure equalization passage extending through an overall length of the valve member/armature.

7. The solenoid operated valve assembly of claim 6, further comprising a second pressure equalization passage extending through the pole piece and axially aligned with the first pressure equalization passage.

8. The solenoid operated valve assembly of claim 5, wherein the valve element of the valve member/armature comprises an overmolded elastomer.

9. The solenoid operated valve assembly of claim 5, wherein the pole piece includes a plurality of threads adapted to be threadably received in the solenoid can to allow the pole piece to be axially adjustable relative to the valve member/armature, wherein axial adjustment of the pole piece is operable to at least increase a clearance distance between the pole piece and the valve member/armature in the energized or de-energized position of the valve member/armature.

10. The solenoid operated valve assembly of claim 9, wherein axial adjustment of the pole piece is operable to move the pole piece closer to the valve member/armature to initially set the clearance gap to a minimum value between the pole piece and the valve member/armature defined in the energized position of the valve member/armature.

11. A solenoid operated valve assembly comprising:

a solenoid can having a coil;

a valve body connected to the solenoid can;

a pole piece connected to the solenoid can, the pole piece operable to transfer magnetic flux;

a valve member/armature formed as an integral combination of a valve member coupled to an armature, the valve member/armature slidably disposed in the valve body and movable from a valve closed position to a valve open position in the presence of the magnetic flux; and

a solenoid bushing received within the solenoid can, the solenoid bushing having a length that forms a non-zero clearance distance between the pole piece and the valve member/armature in an energized or de-energized position of the valve member/armature; and

a biasing member in contact with both the solenoid bushing and valve member/armature, the biasing member normally biasing the valve member/armature to the de-energized position when the coil is de-energized.

12. The solenoid operated valve assembly of claim 11, wherein the first end of the valve member/armature is slidably disposed in a bushing sleeve of the solenoid bushing.

13. The solenoid operated valve assembly of claim 11, wherein the valve member/armature is made of a magnetic material.

14. The solenoid operated valve assembly of claim 11, wherein the valve member/armature includes an elastomeric valve element overmolded onto the valve member.