WO2006015790A1 - Solenoid valve - Google Patents

Abstract

The invention relates to a solenoid valve comprising a prestressed armature (4), which is surrounded by a pressure tube (16) comprising a solenoid (62). According to the invention, the pressure tube consists of an electrically non-conductive material.

Description

 description

magnetic valve

The invention relates to a solenoid valve according to the preamble of patent claim 1.

Such solenoid valves are used for controlling or regulating pressure medium flows. They have an armature biased in an armature space, which executes a stroke when energized a coil, so that a pressure medium connection is opened or closed. The armature space is bounded radially by a pressure tube which is surrounded by the coil.

Known pressure pipes consist of a magnetizable and a non-magnetizable section. With the aid of the non-magnetizable section, a magnetic separation in the pressure tube is achieved, through which the magnetic flux is directed via the armature.

A disadvantage of these known solutions is that by the magnetizable portion of the pressure tube, a mutual induction is caused in the same, resulting in a sluggish response of the armature.

The object of the present invention is to provide a magnetic valve in which no mutual induction occurs in the pressure pipe and which is easy to produce in terms of manufacturing technology.

This object is achieved by a solenoid valve having the features of claim 1.

According to the invention, the pressure tube consists of an electrically nonconductive material. By the electric non-conductive material, the formation of a Gegenin¬ production is prevented in the pressure tube. This results in a faster field structure and thus an improved dynamic response of the solenoid valve.

Advantageously, the pressure tube is produced in an injection molding of a fiber-reinforced plastic.

In one embodiment, the pressure tube between an armature space cover and a valve body housing is pressed. The pressure or the distance of the Ankerraum¬ lid to the valve body housing can be defined by at least one spacer outside the pressure tube over which the magnetic circuit is closed. Preferably, a plurality of spacers in the form of a metal tube are used, which are distributed around the pressure tube at regular intervals, wherein suitable fastening means such as screws are guided in the longitudinal direction through the metal tubes, such as screws for clamping the pressure tube. However, the spacer may also be formed as a metal sleeve enclosing the pressure tube, or by a U-shaped bracket, through whose legs the pressure tube extends.

In one embodiment, the pressure tube has conical end sections for the purpose of permitting a defined dense pressing. To improve the dense pressing ring seals can be provided, on which the pressure tube is supported.

In another embodiment, the ring seals are formed integrally on the end sections of the pressure tube. This has the advantage that the number of parts reduced and the assembly of the solenoid valve is much easier. They can as ring seals formed end portions may be formed of a different material than the remaining body portions of the pressure tube.

In a further embodiment, the pressure tube simultaneously serves as a coil carrier. In this case, the coil is wound around two opposite radial walls of the pressure tube. Thus, can be dispensed with a usual coil carrier, whereby the assembly is further simplified.

Advantageously, the radial walls are formed integrally with the pressure tube, wherein on a radial wall, a foldable tab may be provided for covering the wound coil.

In one embodiment, a fixed valve body emerges in the basic position in sections in the armature and forms together with this the valve seat. The valve body may be formed of a magnetizable material and terminate at a distance to a, a working gap (24) limiting anchor end face.

Other embodiments are the subject of further subclaims.

In the following, preferred embodiments of the invention will be explained in more detail with reference to schematic representations. Show it

FIG. 1 shows a longitudinal section through a first embodiment of the solenoid valve according to the invention,

FIG. 2 shows a longitudinal section through a second embodiment of the solenoid valve according to the invention; and

3 shows an enlarged longitudinal section through a development of a pressure tube according to the invention. Figure 1 shows a first preferred embodiment of the solenoid valve 2 according to the invention with an armature 4, which is biased by a spring 6 against a ^' fixed in this Ausfüh¬ insurance form valve body 8 in its Grund¬ position. In this basic position, a pressure medium connection between a front-side working port A and a radial working port B is interrupted.

The armature 4 is slidably disposed in an armature space 10 which is bounded by an armature space cover 12 and a valve body housing 14 in the axial direction and by a pressure pipe 16 according to the invention in the radial direction. A protruding into the armature space 10 body portion of the armature 4 is set back radially, whereby a shoulder 18 is formed on which engages a free end of the spring 6. The other free end of the spring 6 engages around an axial projection 20 of the AnkerraumdeckeIs 12 and is supported on an armature space cover shoulder 22 from. In the basic position of the armature 4, an axial working gap 24 is formed on the end face between the armature 4 and the projection, which defines a maximum stroke of the armature 4.

In the armature 4, an axial through-bore 26 is formed, into which the valve body 8 is immersed with an extension 50.

The valve body 8 is fixed in an axial bore 28 of the valve body housing 14 and forms the valve seat 32 together with the armature 4. The axial bore 28 communicates with the front-side working port A and is radially expanded in the direction of the valve seat 32, so that a valve seat space 36 is formed. In this valve seat space 36 opens a bore star 38, which communicates with the radial working port B. The valve body 8 is tapered ra¬ dial in the direction of the armature 4, so that an oblique seat 34 is formed, against which the armature 4 is biased with a body edge 40 in its normal position. The seat 34 merges into a cylindrical body portion 42 of the valve body 8, which dips into the through hole 26 of the armature 4. The outer diameter of Körperab¬ section 42 is selected so that an annular gap 44 between the body portion 42 and a gegenüberlie¬ ing inner wall portion of the through hole 26 is formed.

In the body portion 42, a transverse bore 46 is provided, which represents a cross-connection for the annular gap 44. In this transverse bore 46 opens a Längsboh¬ tion 48 of the valve body 8, which is open to the axial bore 28. Thus, pressure medium can flow from the working port A via the axial bore 28, the longitudinal bore 48, the transverse bore 46, the annular gap 44, the valve seat space 36 and the bore star 38 to the working port B and vice versa when the armature abhebobe¬ from the seat 34.

The extension 50 adjoins the body section 42. This is radially expanded relative to the body portion 42 and formed cylindrical. The outer diameter of the extension 50 corresponds essentially to the inner diameter of the through-bore 26, so that guidance of the armature 4 via the extension 50 can take place during the stroke. The length of the extension 50 is selected in accordance with FIG. 1 in the case of a non-magnetizable valve body 8 in such a way that, in the basic position of the armature 4, it terminates flush with the end face. However, if the valve body 8 is made of a magnetizable material (FIG. 2), the extension 50 is shortened such that it ends at a distance from the axial working gap 24. This distance causes the field lines to be directed via the armature 4 and not via the valve body 8.

The pressure tube 16 is made of a non-magnetizable material to prevent counterinduction. Preferably, it is manufactured by means of an injection molding process and consists of a fiber-reinforced plastic. It dives with its end sections 56, 58 in

Circumferential grooves 52, 54 of the AnkerraumdeckeIs 12 and the valve body housing 14 a. For sealing the armature space 10, the end sections 56, 58 are formed as ring seals (not shown), via which the pressure pipe 16 is sealed to the armature space cover 12 and the valve body housing 14. It is conceivable that the end portions 58, 60 are formed of a different plastic than the other body portions in order to achieve a particularly high density. The inner diameter of the pressure tube 16 is selected such that a radial gap 60 is formed between opposing circumferential surfaces of the pressure tube 16 and the armature 4.

The end sections 56, 58 can also be of conical design or additional ring seals can be inserted into the circumferential grooves 52, 54 for sealing purposes.

Furthermore, it is conceivable that the pressure tube 16 made of another electrically non-conductive material than plastic, such as ceramic

The pressure tube 16 is encompassed by a coil 62 on an outer peripheral surface section 82. The outer peripheral surface portion 82 extends between two radial walls 64, 66 which define a winding space for the coil 62 in the axial direction. Thus, the pressure tube 16 serves as a coil carrier at the same time. The radial walls 64, 66 are advantageously formed integrally with the pressure tube 16.

The coil 62 is surrounded by a plurality of spacers 68, 70 for pressing in the pressure tube 16 between the armature space cover 12 and the valve body housing 14. The spacers 68, 70 are spaced apart from one another in the circumferential direction and engage an armature space cover flange 72 and a valve body housing flange 74. According to FIG. 1, they are designed as tubes, through which screws 76, 78 extend in the longitudinal direction, by means of which the armature space cover 12 and the valve body housing 14 can be braced against one another. Thus, over the length of the spacers 68, 70, the pressure of the pressure tube 16 between the armature space cover 12 and the valve body housing 14 is determined. To close the magnetic circuit when the coil 62 is energized, the tubes are metallic, i. magnetizable.

Alternatively, however, it is also conceivable, instead of metal tube-like spacers 68, 70, to use a preferably slotted metal sleeve (not shown) as a spacer.

When the coil 62 is energized, a magnetic magnetic field is built up, by means of which the armature 4 is displaced axially from its seated surface 34 in the direction of the projection 20 (upward in FIG. 1). The solenoid valve 2 is open and between the working ports A and B a Druck¬ medium connection is made. By the solution according to the invention is no mutual induction in the pressure tube 16 generates, so that the armature 4 has a high dynamics auf¬.

The embodiment of the solenoid valve 2 according to the invention shown in FIG. 2 essentially corresponds to the above-described embodiment according to FIG. 1. The only differences are the magnetizable material of the valve body 8 and the short version of the extension 50 connected thereto. To repeat To avoid this, reference is made to the above explanations.

Figure 3 is an enlarged longitudinal section of a further development of the pressure tube 16 according to the invention, in which a coil 62 between two radial walls 64, 66 covered by a tab 30 and thus protected from dirt and damage. Advantageously, the tab 30 is formed integrally with one of the radial walls 64, wherein it is umklapp¬ over a film hinge 80 bar.

Disclosed is a solenoid valve with a prestressed armature which is surrounded by a pressure tube with a coil, wherein the pressure tube consists of an electrically non-conductive material.

LIST OF REFERENCE NUMBERS

magnetic valve

anchor

feather

Valve body 0 Anchor space 2 Anchor space cover 4 Valve body housing 6 Pressure tube 8 Shoulder 0 Projection 2 Anchor space cover shoulder 4 Working gap 6 Through hole 8 Axial bore 0 Tab 2 Valve seat 4 Seat 6 Valve seat 8 Bore star 0 Body edge 2 Body section 4 Annular gap 6 Transverse bore 8 Longitudinal bore 0 Extension 2 Circumferential groove 4 Circumferential groove 6 End section 8 End section 0 Radial gap 2 Coil 4 Radial wall 6 Radial wall 68 spacers

70 spacers

72 Anchor space cover flange

74 Valve body housing flange

76 screw

78 screw

80 film hinge

82 outer circumferential surface portion

Claims

claims 1. Solenoid valve with a prestressed armature (4) in an armature space (10) which is bounded by a coil (62) surrounded by a pressure pipe (16), wherein when energizing the coil (62) of the armature (4) ei¬ NEN stroke executes, so that a pressure medium connection between working ports (A, B) can be opened or closed, characterized in that the pressure tube (16) consists of an electrically non-conductive material. 2. Solenoid valve according to claim 1, wherein the pressure tube (16) is pressed between an armature space Dekekel (12) and a valve body housing (14). 3. Solenoid valve according to claim 2, wherein the armature space cover (12) and the valve body housing (14) via at least one magnetizable spacer (68, 70) outside the pressure tube (16) from each other beab¬ are stood. 4. Solenoid valve according to claim 3, wherein a plurality of spacers (68, 70) are provided, are guided by the axial fastening means for connecting the Ankerraum¬ lid (12) with the valve body housing (14). 5. Solenoid valve according to claim 3, wherein the Abstandshal¬ ter (68, 70) is a metal sleeve which surrounds the coil (62). 6. Solenoid valve according to one of the preceding claims, wherein for sealing the armature space (10) Endab- sections of the pressure tube (16) aus¬ are formed as ring seals. 7. Solenoid valve according to claim 6, wherein the end portions of a different material than the remaining Körperab¬ sections of the pressure tube (16) are formed. 8. Solenoid valve according to one of claims 1 to 5, wherein the pressure tube (16) is frontally conical. 9. Solenoid valve according to one of the preceding claims, wherein the pressure tube (16) is designed as a coil carrier. 10. A solenoid valve according to claim 9, wherein the coil (62) between two spaced apart radial walls (64, 66) is wound around the pressure tube (16), which are formed integrally with the pressure tube (16). 11. Solenoid valve according to claim 10, wherein integrally with a radial wall (64) a tab (30) for rückseiti¬ conditions covering the coil (62) is arranged. 12. Solenoid valve according to one of the preceding claims, wherein the pressure tube (16) is made of a fiber-reinforced plastic. 13. Solenoid valve according to one of the preceding claims, wherein the pressure tube (16) is executed as an injection molded body. 14. Solenoid valve according to one of the preceding claims, wherein in the basic position a fixed valve body (8) in sections immersed in the armature (4) and forms with this the valve seat (32). 15. Solenoid valve according to claim 14, wherein the valve body (8) is formed from a magnetizable material and ends at a distance to a working gap (24) be¬ bordering anchor end face.