WO2011087938A2

WO2011087938A2 - Solenoid with plastic sleeve using a series of metal components as bearing surfaces

Info

Publication number: WO2011087938A2
Application number: PCT/US2011/020185
Authority: WO
Inventors: Kenneth W. Morgan, Jr.; Dennis R. Que
Original assignee: Borgwarner Inc.
Priority date: 2010-01-15
Filing date: 2011-01-05
Publication date: 2011-07-21
Also published as: WO2011087938A3

Abstract

A hydraulic housing for a solenoid valve is provided having a polymeric housing body with at least three control volumes intersected by a central bore with at least two of said control volumes being intersected by a radial passage. At least three axially spaced annular metallic bearing members are provided with at least two annular metallic bearing members providing control volume boundaries. The bearing members are permanently affixed within the polymeric body and have concentric inner diameters for receipt of a spool valve. The inner diameters of the bearing members are machined after the bearing members are affixed within the polymeric body.

Description

SOLENOID WITH PLASTIC SLEEVE USING A SERIES OF METAL COMPONENTS AS BEARING SURFACES

FIELD OF THE INVENTION

The present invention relates to housing for solenoid valves and methods of manufacture thereof.

BACKGROUND OF THE INVENTION

Generally speaking, land vehicles require a powertrain consisting of three basic components. These components include a power plant (such as an internal combustion engine), a power transmission, and wheels. The power transmission component is typically referred to simply as the "transmission." Engine torque and speed are converted in the transmission in accordance with the tractive-power demand of the vehicle. Presently, there are two typical transmissions widely available for use in conventional motor vehicles. The first and oldest type is the manually operated transmission. These transmissions include a foot-operated start-up or launch clutch that engages and disengages the driveline with the power plant and a gearshift lever to selectively change the gear ratios within the transmission. When driving a vehicle having a manual transmission, the driver must coordinate the operation of the clutch pedal, the gearshift lever, and the accelerator pedal to achieve a smooth and efficient shift from one gear to the next. The structure of a manual transmission is simple and robust and provides good fuel economy by having a direct power connection from the engine to the final drive wheels of the vehicle. Additionally, since the operator is given complete control over the timing of the shifts, the operator is able to dynamically adjust the shifting process so that the vehicle can be driven most efficiently. One disadvantage of the manual transmission is that there is an interruption in the drive connection during gear shifting. This results in losses in efficiency. In addition, there is a great deal of physical interaction required on the part of the operator to shift gears in a vehicle that employs a manual transmission.

The second and newer choice for the transmission of power in a conventional motor vehicle is an automatic transmission. Automatic transmissions offer ease of operation. The driver of a vehicle having an automatic transmission is not required to use both hands, one for the steering wheel and one for the gearshift, and both feet, one for the clutch and one for the accelerator and brake pedal in order to safely operate the vehicle. In addition, an automatic transmission provides greater convenience in stop and go situations, because the driver is not concerned about continuously shifting gears to adjust to the ever-changing speed of traffic.

Automatic transmissions require a large number of hydraulic valves to control various actuators for friction packs throughout the transmission and for the controls of various hydro kinetic devices such as torque converters. Initially, most automatic transmissions use hydraulic logic circuits to control these devices. During a time period of the late 1980's and early 1990's many automatic transmissions were converted to electronic control rather than hydraulic control. The conversion to electronic control automatic transmissions brought forth a requirement for a plurality of electric solenoid actuated valves. Most of the aforementioned solenoid valves have a solenoid portion which includes an armature which is actuated by an encircling electric coil. The actuator is connected with or abuts a plunger which penetrates into a hydraulic housing portion of the valve which is connected with the solenoid portion of the valve. The housing portion, sometimes referred to as the hydraulic sleeve, is typically manufactured from metal. Some prior solenoid valve housings have been assembled from polymeric material such as plastic; however, in many instances, due to the environment of operation of the valve, it has been found that polymeric or plastic valve housings are not preferable. It is desirable to provide a solenoid valve housing which can be utilized in a highly demanding environment which at the same time keeping the housing weight as low as possible and allowing the housing to have a complex design without extensive expensive machining. SUMMARY OF THE INVENTION

To make manifest the above noted and other manifold desires, a revelation of the present invention is brought forth.

In a preferred embodiment, the present invention brings forth the freedom provided by a hydraulic housing for solenoid valve which has a polymeric housing body having at least three control valves intersected by a central bore. At least two of the control valves are intersected by a radial passage connecting the central bore with an outer perimeter of a hydraulic body. At least three axially spaced annular metallic bearing members are provided. At least two of these bearing members provide a control volume boundary. The annular metallic bearing members are permanently affixed within the polymeric body and have their concentric inner diameters for receipt of a spool valve. The inner diameter of the axially spaced metallic bearing members is machined after they have been affixed within the polymeric body. Additionally, the present invention provides a method of manufacture of the hydraulic housing afore described.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a sectional view of a preferred embodiment solenoid valve hydraulic housing according to the present invention;

Figure 2 is a partial sectional view of an alternate preferred embodiment of the present invention; and

Figure 3 is a partial sectional view of yet another alternate preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Referring to Figure 1 , a hydraulic housing body 7 for a solenoid hydraulic valve is provided. The hydraulic housing 7 has a housing body 8 (sometimes referred to as the sleeve) is fabricated from a suitable polymeric material such as a thermoplastic or thermoset molding compound. The housing body 8 has at least three control volumes provided as shown with a lower first control volume 10, a mid-level or second control volume 20 and an upper or third control volume 30. In the example shown, the housing body 7 has an extreme upper control volume 40. The control volumes 10, 20, 30 and 40 are intersected by an axial multi-diameter central bore 12. The central bore 12 has a first diameter 14 and a second diameter 16. Separating the first diameter 14 from the second diameter 16 is a first step 18. The central bore 12 also has a third diameter 22. Separating the third diameter 22 from the second diameter 16 is a second step 24. The central bore 12 has a fourth diameter 26. Separating the fourth diameter 26 from the third diameter 22 is a third step 28.

Control volume 20 is intersected by a radial passage 32 that connects the second control volume with a periphery of the housing body 8. Control volume 30 is radially intersected by a radial passage 34 that connects the second control volume 30 with the periphery of the housing body 7. The housing body 7 has a first annular groove 36 for placement of an O-ring sealing the housing body 7 with respect to an outer housing (not shown) that the housing body 8 is placed in to. The housing body 7 also has an annular groove 38 for receipt of another O-ring (not shown). The O-ring placed within annular groove 38 will typically seal the periphery of the housing body 7 from fluid in the second control volume 20 being exposed to fluid in the third control volume 30 along the periphery of the housing body 7.

Shown for illustrative purposes only is a complete or partial portion of a valve spool 42. The valve spool 42 has a generally axial passage 44 intersecting with a radial cross-passage 46. Spool valve passages 44 and 46 allow for fluid communication between the first control volume 10 and alternatively second control volume 20 or third control volume 30. Additionally, spool valve 42 can have a top end 48 which can have a connected or abutting relationship with an armature (not shown) of a solenoid valve. Often, the spool valve 42 will have annular groove adjacent its top end (not shown) to allow a lower portion of a periphery of the spool valve 42 to be sealed as contrasted with its upper end 48. A lower end 50 of the housing body 8 has an enlarged interior diameter 52 to allow for insertion of a plug or for connection with a passage to either seal off the control volume 10 or connect control volume 10 with a hydraulic passage external to the housing body 8.

The hydraulic housing 7 has three permanently affixed annular metallic bearing members. A first annular metallic bearing member 60 is provided. Above the first annular metallic bearing member is a second annular metallic annular bearing member 62. Position above the second annular metallic bearing member 62 is a third annular metallic bearing member 64. The first annular metallic bearing member has a lower end 66 which is placed upon the first step 18. The second annular metallic bearing member 64 has a lower end 68 which is placed upon the second step 24. The third annular metallic bearing member 64 has a lower end 70 which is placed upon the third step 28. The first annular metallic bearing member 60 provides a border between the first control volume 10 and the second control volume 20. The second annular metallic bearing member 62 functions to provide a control volume boundary for the third control volume 30 and the second control volume 20. The first annular metallic bearing member 60 has an inner diameter 74 for receipt of the spool valve 48. The clearance between an outer diameter 76 and the first annular metallic bearing member 60 is exaggerated for illustrative purposes. In a similar fashion, the second annular metallic bearing member 62 has an inner diameter 78 (with an exaggerated illustrative clearance) for receipt of the outer diameter 76 of the spool valve. Additionally, the third annular metallic bearing member 64 has an inner diameter 80 for receipt of the outer diameter of the spool valve 48 and again the clearance between the two is exaggerated for illustrative purposes. Inner diameter 80 is a multi- diameter inner diameter having an enlarged portion 82. Typically, the inner diameter 74, 78 and 80 will be of a common diameter but need not be so. The outer diameters of the annular metallic bearing members 64, 62 and 60 are progressively smaller and are generally coincident with the inner diameters 26, 22 and 16 of the polymeric housing body 7.

Typically, the material utilized for fabrication of the annular metallic bearing members 60, 62 and 64 will be a metal such as low carbon steel, stainless steel, aluminum or copper, brass or alloys thereof. To ensure that the inner diameters 74, 78 and 80 are concentric, they will typically be machined after installation within the polymeric housing body 8.

There are several methods of manufacturing the hydraulic housing 7 according to the present invention. In one method, the polymeric housing body 8 is first molded and the annular metallic bearing members 60, 62 and 64 are pressed into position. In another method of manufacture, the annular metallic bearing members 60, 62 and 64 are heated before their placement or pressing in within the polymeric housing body 8. This heating can be by short placement within in an oven or can be done ultrasonically. In another method of manufacture, the annular metallic bearing member 60, 62 and 64 are placed within a mold and the polymeric housing body 8 is molded about the bearing member while at the same time retaining the same annular metallic bearing member upon contraction as the molten material for the polymeric housing body 8 solidifies. In all of the techniques here to fore mentioned, final machining will occur after the affixation of the annular metallic bearing member 60, 62 and 64 within the polymeric housing body 8. Whenever a molding operation is desired, it is typically desirable with the coefficient of thermal expansion of the plastic and annular metallic bearing members be as close as possible to provide for proper retention throughout a wide operating temperature range of the solenoid valve. It is also desirable that during the process of fixation that the plastic of the polymeric housing body be (shrink "molded") at a significantly higher temperature than that of the annular bearing members so that as the plastic cools, it will shrink around the annular metallic bearing members and achieve proper retention therewith. Referring to Figure 2, a partial sectional view of an alternate embodiment annular metallic bearing member 166 is shown having an annular continuous spring cantilevered spring 168 with a tip making sealing contact with an annular groove 170 made in the polymeric body. An upper end 172 of the bearing member may make contact with an undercut of the polymeric body to increase the sealing capacity. Spring 168 aids in retaining the bearing member 166 in position if the plastic of the polymeric body though thermal expansion radially extends away from the bearing member. Figure 3 illustrates an embodiment 207 wherein the annular spring 268 is integral with the bearing member 266.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims

CLAIMS What is claimed is:

1. A method of manufacturing a hydraulic housing for a solenoid hydraulic valve comprising:

providing a polymeric housing body having at least first, second and third control volumes intersected by a generally central axial bore;

affixing within said polymeric body central axial bore at least three axially spaced apart annular metallic bearing members, at least two of said annular metallic bearing members defining borders for said control volumes;

concentrically machining inner diameters of said annular metallic bearing members to provide for axial movement of a spool valve;

providing intersecting radial passages in said polymeric body to intersect at least two of said control volumes of said polymeric control body and to connect said control volumes of said polymeric housing bodies with an outer periphery of said polymeric housing bodies.

2. A method as described in claim 1 wherein said polymeric body is molded around said annular metallic bearing members and upon contraction of said polymeric body retains said annular metallic bearing members.

3. A method as described in claim 1 wherein said annular metallic bearing members are heated and then pressed into position within said polymeric housing body.

4. A method as described in claim 3 wherein said bearing members are ultrasonically heated.

5. A hydraulic housing for a solenoid valve comprising:

a polymeric housing body, said body having at least three control volumes intersected by a central bore at least two of said control volumes being intersected by a radial passage connecting said central bore with an outer perimeter of said polymeric body; and at least three axially spaced annular metallic bearing members, at least two of said annular metallic bearing members providing a control volume boundary, said annular metallic bearing members being permanently affixed within said polymeric body and having concentric inner diameters for receipt of a spool valve, said inner diameters being machined after said annular metallic bearing members are affixed within said polymeric body.

6. A hydraulic housing as described in claim 5 wherein said annular metallic bearing members have a common inner diameter.

7. A hydraulic housing as described in claim 5 wherein at least one of said bearing members has multiple inner diameters.

8. A hydraulic body as described in claim 5 wherein at least one of said annular metallic bearing members is positioned on a stop of said polymeric housing body.

9. A housing body as described in claim 8 wherein all of said annular metallic bearing members are positioned on a stop wherein said stops are progressively sized axially within said polymeric housing body.

10. A housing body as described in claim 5 wherein said annular metallic bearing members have multiple outer diameters.

11. A housing body as described in claim 5 wherein at least one of said annular metallic bearing members has a radial spring fit with said polymeric housing body.

12. A housing body as described in claim 11 wherein said annular metallic bearing members has an integral radial spring.