DE102023105834A1 - Pole tube for a solenoid valve arrangement - Google Patents

Abstract

One-piece pole tube and method for producing a one-piece pole tube for use in a solenoid valve assembly, which has a substantially cylindrical body made of magnetic metal and defines an axis of rotation. The one-piece pole tube is divided in the axial direction into a pole section, a transition section and a tube section consisting of a blind bore in the pole tube. The inner end of the blind bore is formed by the transition section. An armature is accommodated in the tube section so as to be movable in the direction of the axis of rotation. The outer diameter of the cylindrical body in the transition section is radially set back to form a magnetic flux deflection groove, so that the metallic wall thickness in the transition section is less than in the tube section. According to the invention, the magnetic flux deflection groove is filled with cast or molded plastic material up to the outer diameter of the cylindrical body.

Description

The invention relates to a pole tube for a solenoid valve arrangement. The invention also relates to a solenoid valve arrangement with such a pole tube. In particular, the invention relates to pole tubes for solenoid valve arrangements that are used in the field of hydraulics or pneumatics, e.g. in fluidics as a drive for actuating hydraulic or pneumatic valves.

Solenoid valve assemblies in fluidics are usually modular in design and have an essentially cylindrical pole tube made of magnetic metal material, which accommodates a movable armature in a tube section that can be actuated by electromagnetic forces generated by a coil surrounding the pole tube. The armature is movable in the longitudinal direction of the cylinder together with a plunger that transmits the armature movement to the outside of the solenoid valve assembly.

Such a pole tube consists of a pole section and a tube section with a longitudinal blind hole. Between the pole section and the tube section there is a transition section at the inner end of the tube section, i.e. the transition section forms the medial part of the tube section. In a solenoid valve arrangement, the pole tube is surrounded by an electrical coil that can be acted upon by an electrical current to generate an electromagnetic field that builds up a magnetic flux along the pole tube to move a cylindrical armature in the pole tube from an initial position to an actuating position. The length of the armature is shorter than the length of the blind hole. In the initial position there is a gap between the armature and the bottom of the blind hole, i.e. at the beginning of the pole section. This gap is usually part of the transition area. At the distal end of the tube section the pole tube is closed by an end plug, often liquid-tight.

In order to create a discontinuity of the magnetic flux along the pole tube, i.e. that the magnetic field lines do not only run along the tube walls to and from the pole section, but across the middle of the transition section to and from the pole segment, i.e. at least partially through the tube section, a non-magnetic groove, e.g. an air gap in the form of a groove, is introduced into the outer surface of the pole tube in the transition section.

Since the transition region forms the medial end of the tube section, the transition region has a smaller tube wall thickness due to the outer groove, so that a discontinuity of the magnetic flux is achieved. The smaller the tube wall thickness in the transition region, the better/greater the deflection of the magnetic flux from the pole section of the core tube to the transition region. In order to compensate for the weakening effect of the groove in the transition region while maintaining the deflection of the magnetic flux to the transition region, a non-magnetic metal material is usually introduced into the transition region.

In the prior art, the transition region of a one-piece pole tube has a groove in the form of a circumferential groove into which a magnetically isolating non-magnetic metallic material is introduced, typically by build-up welding or brazing, to introduce a mechanically resistant non-magnetic material that maintains the deflection of the magnetic flux through the gap in the transition region. For this purpose, e.g. tin, copper or a tin and solder filler material is filled into the groove. In another prior art, a ring element made of a non-magnetic metallic material with a larger diameter than the pole tube is used, wherein the ring material is plastically deformed by milling or rolling into the groove of the transition section. As a result, when the coil is energized, a magnetic flux flows across the pole section and the transition section, whereby the armature is attracted to the pole section by the magnetic field and moves a plunger/actuator pin outwards or inwards in the axial direction of the core tube.

In parallel to the magnetic deflection, the non-magnetic metallic material introduced into the groove must fulfill a mechanically stabilizing function of the one-piece pole tube in the transition area, since the wall thickness of the pole tube in this area is reduced compared to the rest of the pole tube, especially in the tube area. Therefore, a non-magnetic metallic material is the means of choice for filling the gap, preferably up to the outer diameter of the pole tube. In the prior art, methods for filling the gap by welding, soldering, plastic deformation with or without heat input are known, which have the disadvantage that they are not only costly and pollute the environment due to their high energy consumption, but also do not overlay the non-magnetic metallic material in the transition area very precisely in order to ensure a smooth transition from the pole area to the tube area on the outer diameter and back. In order to achieve a constant outer diameter along the entire cylindrical surface of the pole tube, rework is usually required. Such a constant diameter is required to maximize the magnetic force exerted by the coil that pole tube of a solenoid valve device. For this purpose, as is known to those skilled in the art, the coil should fit as closely as possible to the pole tube, since any (air) gap between the inner cylindrical surface of the coil and the outer surface of the pole tube reduces the magnetic flux through the pole section and the armature.

Another weakness of the state of the art is that a process where metallic material is built up by welding or soldering is always accompanied by difficult handling, which leads to contamination and an unstable process that is difficult to automate. Therefore, a high proportion of manual intervention is often required to achieve an acceptable result, making the pole tube expensive. In addition, especially at high temperatures or high mechanical forces, to fill the groove in the transition area of a one-piece pole tube, the wall thickness in this area often cannot be selected to the minimum thickness required to achieve the greatest possible magnetic forces on the armature, since breakage of the pole tube must be avoided when refilling the groove in the transition area, assembling the armature, fastening the end cap (usually screwed or crimped) and/or assembling the solenoid valve device.

It is therefore the object of the present invention to provide a simple, safe, clean and cost-effective way of filling the magnetic flux deflection groove in the transition region of a one-piece pole tube, which is environmentally friendly and reduces the post-processing effort to a minimum in order to achieve a smooth surface with a constant diameter on the outer surface of the one-piece pole tube in order to minimize any gap between the pole tube according to the invention and a coil surrounding the pole tube in a solenoid valve arrangement. Furthermore, the pole tube according to the invention should be able to replace existing pole tubes in solenoid valve arrangements of the prior art.

The object of the present invention is achieved by a one-piece pole tube according to claim 1, wherein preferred embodiments are provided by the subclaims dependent on claim 1. A solenoid valve device is provided with such a one-piece pole tube. The object of the invention is further achieved by the claimed method, wherein preferred embodiments of the invention are disclosed by the corresponding subclaims.

A pole tube according to the invention, which can be used in solenoid valve devices, has a substantially cylindrical shape, consists of magnetic metal and defines a rotation axis of the pole tube. The pole tube is divided in the axial direction into a pole section, a transition section and a tube section which consists of a blind hole in the pole tube. The medial end of the blind hole is formed by the transition section. An armature is arranged in the tube section so as to be movable in the direction of the rotation axis. In the transition section, the outer diameter of the pole tube is radially set back so that a circular groove is formed, the wall thickness of which is less in the transition section than in the tube section. According to the invention, the groove is filled with cast or molded plastic up to the outer diameter of the tube section.

According to the invention, the tube section of the one-piece pole tube essentially has the shape of a blind hole along the axis of rotation. The inner or medial end of the blind hole, i.e. the bottom of the blind hole, is common to the pole section, which extends to the other distal end of the core tube. A further axial hole can be arranged in the pole section, which connects the blind hole in the transition section with the tube section and the distal end of the pole section in the pole tube. A plunger or actuating pin can be accommodated in this axial hole in order to transmit a movement of the armature in the transition section to the outside of the core tube. However, such a pin or plunger can also be attached to the other end of the armature and protrude outwards through an end cap that closes the blind hole at the distal end of the tube section. In this embodiment, the pole section does not have to have a central hole, which increases the magnetic flux in this area.

In the initial position of the armature, a gap is provided between the bottom of the blind hole and the armature. The axial length of this gap is typically in the transition area of the one-piece pole tube. This means that the transition section is the section in which the pole section merges into the tube section and in which the magnetic deflection groove is located and a gap is provided for the armature movement.

According to the invention, the armature is also made of a magnetic material in order to be magnetically attracted by the magnetic flux that flows through the pole section, the transition section and the tube section of the one-piece pole tube. The outer diameter of the armature fits into the diameter of the blind hole in the tube section so that the armature can move smoothly in the direction of the axis of rotation. The groove in the transition area of the one-piece core tube, which redirects the magnetic flux generated by a coil surrounding the one-piece pole tube from the pole tube via the transition region and the tube section, the armature can move in the direction of the transition region when the coil is excited. Depending on the polarity of the electrical connection of the coil, the magnetic flux passes from the pole section via the armature to the tube section or vice versa. In both cases, the armature is attracted by the magnetic flux in the direction of the pole section, so that the starting position of the armature in the tube section is selected so that it is away from the bottom of the blind bore in the tube section, i.e. the armature forms a gap with the pole section. The armature is held in this starting position by a spring force, whereby the spring does not have to be part of the one-piece pole tube according to the invention. Radially parallel to the gap between the armature and the pole section, the magnetic deflection groove is formed in the outer wall of the one-piece pole tube, which reduces the wall thickness of the tubular part of the one-piece pole tube in this area.

Since the magnetic flux deflection groove according to the invention is filled or overmolded with cast or molded plastic material, the magnetic flux can be deflected because plastic material is not magnetic. In the sense of the invention, there are a variety of ways to form the magnetic flux deflection groove, e.g. it is introduced when casting the one-piece pole tube or after casting by turning. One way to fill the magnetic flux deflection groove according to the invention with plastic is to place the one-piece pole tube in a mold having a hollow tubular cavity corresponding to the outer diameter of the pole tube and extending over the transition region, and to cast an enclosed one-piece pole tube with plastic in order to fill the magnetic flux deflection groove. This small annular cavity can be filled with molten plastic material in the liquid state, for example by casting or injection molding, the plastic material then being allowed to harden.

According to one embodiment of the invention, the plastic material used to fill the magnetic flux deflection groove can be a reinforced plastic material, e.g. reinforced with carbon or glass fibers. All types of plastic materials are suitable for selecting the plastic material with which the magnetic flux deflection groove can be filled, as long as they do not have magnetic properties. Both thermoplastics and thermosetting materials can be used. The person skilled in the art will find a variety of plastics that meet the mechanical requirements and give the transition area of a one-piece pole tube with a magnetic flux deflection groove in the transition area sufficient stability.

In a simple embodiment of the pole tube according to the invention, the magnetic flux deflection groove can have a substantially rectangular, conical or rounded cross-section, since these basic geometric shapes can be easily realized by turning the magnetic flux deflection groove into a commercially available cylindrical metal material. When designing the cross-section of the magnetic flux deflection groove, other conditions can also be taken into account, such as the best cross-sectional shape for deflecting the magnetic flux or the best cross-sectional shape for achieving high mechanical stability. In these investigations, the inventors of the present invention found that in a preferred embodiment, the cross-section of the magnetic flux deflection groove should have a relief-like cross-section. In order to achieve the highest possible mechanical strength, the magnetic flux deflection groove is filled with plastic according to the invention. Relief-like means that the bottom surface of the magnetic flux deflection groove is not flat, but has at least one hump, a rib or a projection in the radial direction, which increases the mechanical stability not only in the axial direction, but also the mechanical stability against bending forces. At the same time, the plastic material adjacent to the at least one bump, rib or projection allows the magnetic flux generated by a coil surrounding the one-piece pole tube to pass from the pole section through the transition region into the tube section. This does not reduce the magnetic force exerted on the armature because the influence of the bump, rib or projection on the deflected magnetic flux is minimal and the armature can move towards the transition section when the coil is energized.

Of course, the bottom surface can have more than one hump, e.g. two or three humps in parallel in the axial direction, where the radial height of the humps is less than the depth of the magnetic flux deflection groove. The number of parallel humps is limited by the axial extent of the magnetic flux deflection groove, since the axial extent is limited by the magnetic flux that can be generated/deflected via the magnetic flux deflection groove. If the magnetic flux deflection groove is too large in the axial direction, no or too little magnetic force can be generated via the single pole tube. A compromise must therefore be found between mechanical stability and the magnetic forces that can be generated.

A further improvement in mechanical stability can be achieved by cylindrical body is hardened after the formation of the magnetic flux deflection groove, e.g. by nitrocarburizing, which forms a composite and/or diffusion layer that connects/connects the metallic material of the cylindrical body of the pole tube. Such nitrocarburizing, similar to other hardening processes known to those skilled in the art, increases the surface hardness of the one-piece pole tube, ensures high wear resistance, excellent fatigue strength and does not deform the material structure.

In a further preferred embodiment of the invention, the magnetic flux deflection groove has side walls that are inclined with respect to the orthogonal direction to the axial direction of the one-piece pole tube. Such an inclination of the side walls enhances the deflection effect of the groove for the magnetic flux, since sharp corners that hinder the deflection of the magnetic flux are avoided. Since any inclination deviating from the orthogonal direction reduces the axial length of the magnetic flux deflection groove and the possibility of arranging bumps or ribs or channels on the bottom surface of the magnetic flux deflection groove, the angles of the two side walls can be chosen differently. In order to find the best inclination of the two side walls, simulation methods can be used. A first analysis by the inventors showed that the side wall surface closer to the pole section should have a greater inclination - a flatter angle with respect to the axial direction - than the side wall surface of the magnetic flux deflection groove facing the tube section. A first indication leads to angles in the range of 20° to 60°, which probably represent an optimum. In particular, 30° to 40°, and in particular 32° to 36° could represent an optimum. However, this theory still has to be verified by simulations and tests, since this result was achieved by arranging only one hump on the bottom surface of the magnetic flux deflection groove. Analogously, the side surfaces of the hump/rib can also be inclined relative to the perpendicular to the axial direction in order to find an optimal compromise between the best magnetic flux deflection and mechanical stability of the transition region of the one-piece pole tube according to the invention with a magnetic flux deflection groove filled with plastic.

As a result of the cross-sectional geometry of the magnetic flux deflection groove, an optimum can be found for achieving the highest possible magnetic force on the armature while at the same time ensuring sufficient mechanical stability. It is therefore preferable to carry out investigations and simulations for each individual geometric condition, in particular for different external and internal diameter ratios of the pipe section in relation to the pole section and the movement path length of the armature required for the use of a solenoid valve device according to the invention. In summary, it can be said that the magnetic flux deflection groove according to the invention can be realized deeper in the pipe section compared to the prior art, since the forces for pouring or injecting plastic material into the groove are lower than in the prior art methods. Furthermore, greater stability is achieved because the homogeneity of the plastic filled into the groove is increased by the fact that the plastic can be introduced in a molten or hardenable liquid state, so that complete filling without air inclusions and thus greater mechanical strength is achieved. According to the invention, a metallic wall thickness in the transition region of the pole tube can be achieved in a range between 40% and up to 10% or even zero with respect to the metallic wall thickness in the tube region.

In one embodiment of the invention, the pole tube can be manufactured in such a way that the metal material is completely interrupted in the transition region, i.e. that there is no continuity of the metal material in the axial direction, i.e. that in a short region the wall thickness of the metal material in the transition region can be zero. This can be achieved by making the blind hole in the cylindrical body of the one-piece pole tube after the plastic in the magnetic flux deflection groove has been overmolded and hardened. The diameter of the blind hole in the transition region can thus be selected to be large enough that the metal material is reduced to zero in short regions in the transition region within the magnetic flux deflection groove. In this embodiment, the plastic material connects the pole section to the tube section. To implement this embodiment, a precise investigation of the magnetic flux deflection groove geometry is required in order to achieve the required mechanical stability of the one-piece pole tube according to the invention. Here, for manufacturing reasons, it would be conceivable that a mold or die is used to fill the magnetic flux deflection groove with plastic material, which also serves as a carrier for drilling the blind hole and/or the tappet guide bore as well as for mounting the armature in the pole tube and closing the transition section with an end cap, e.g. by screwing or pressing. After the one-piece pole tube has been fully assembled, a coil or winding can be attached around the cylindrical body of the pole tube to give the solenoid valve device more mechanical stability. The person skilled in the art will recognize that this type of production is not limited to tube sections whose inner diameter is larger than the smallest Diameter of the magnetic flux deflection groove, since it is also applicable for all other embodiments.

In a further embodiment of the pole tube according to the invention, the blind hole in the tube section can first be made in a bar material, e.g. a standard bar material or a cylindrical bolt. The tube section can then be supported with a mandrel in order to make the magnetic flux deflection groove on the outer surface, e.g. by turning. In a next step, the magnetic flux deflection groove is filled with plastic. The assembly of the armature, the plunger and the end cap complete the one-piece pole tube according to the invention.

• 1 schematisch eine Ausführungsform eines einteiligen Polrohrs gemäß der Erfindung;
• 2 schematisch ein vergrößertes Detail der in 1 dargestellten Ausführungsform;
• 3 schematisch eine Ausführungsform einer erfindungsgemäßen Magnetventil-Anordnung in einer Ausgangsstellung;
• 4 schematisch eine Ausführungsform einer erfindungsgemäßen Magnetventil-Anordnung in einer betätigten Stellung;

In the following, the invention is explained in more detail using the embodiments shown in the attached figures for illustrative purposes only. It is understood that the embodiments shown in the figures do not limit the scope of the invention and merely represent possible embodiments and their manufacturing methods. The figures show:

• 1 schematically an embodiment of a one-piece pole tube according to the invention;
• 2 schematically an enlarged detail of the 1 illustrated embodiment;
• 3 schematically an embodiment of a solenoid valve arrangement according to the invention in an initial position;
• 4 schematically an embodiment of a solenoid valve arrangement according to the invention in an actuated position;

In the various in the 1 to 4 In the embodiments shown, parts, elements or sections with the same or equivalent function are provided with the same reference number for better readability and easier understanding.

1 shows schematically an embodiment of a one-piece pole tube 1 according to the invention with a substantially cylindrical body 2 which defines a rotation axis 9. A blind hole 8 is made in the cylindrical body 2 at a distal end of the cylindrical body 2. The area in which the blind hole 8 is made forms a tube section 7 of the one-piece pole tube 1 according to the invention. The tube section 7 is closed at its medial end by a base surface 6 which is part of a pole section 3. A pin guide bore 4 extends through the pole section 3 to accommodate a pin or plunger 37 for transmitting the movement of an anchor 35 which is arranged to be movable in the blind hole 8 in the direction of the rotation axis 9.

Adjacent to the bottom surface 6, a transition section 5 is formed on the side of the blind hole 8, in which the outer diameter of the cylindrical body 2 is set back and a magnetic flux deflection groove 20 is formed in the outer surface of the cylindrical body 2. According to the invention, the magnetic flux deflection groove 20 is filled with plastic material 10, which can be introduced into the magnetic flux deflection groove 20, for example by casting or injection molding or by overmolding. The plastic can be a homogeneous thermoplastic or thermosetting plastic or a reinforced plastic, e.g. reinforced with carbon or glass fibers. Since the magnetic flux deflection groove 20 fulfills the function of deflecting the magnetic flux by forming an air gap for the magnetic flux, the plastic 10 filled into the pole tube 20 ensures the required mechanical stability of the one-piece pole tube 1 according to the invention.

2 shows the magnetic flux deflection groove 20 of the embodiment of 1 in an enlarged view, wherein the magnetic flux deflection groove 20 is shown for explanation purposes only without the plastic material 10 to be introduced to complete the one-piece pole tube 1 according to the invention. It can be seen in detail that in this preferred embodiment of the invention the magnetic flux deflection groove 20 is designed in relief. This means that the bottom surface 26 of the magnetic flux deflection groove 20 is not flat or even, but has a type of relief. This relief is optimized to gently and effectively deflect the magnetic flux on its way through the transition section 5 from the pole section 3 to the tube section 7. For this purpose, the side walls 21 and 23 are inclined relative to a direction perpendicular to the axis of rotation 9 of the one-piece pole tube 1 according to the invention. In this embodiment of the invention, the side wall 21 adjacent to the pole section 3 has a flatter angle 22 with respect to the rotation axis 9 than the side wall 23 adjacent to the pipe section 7. In simulations according to the invention, a range of 20° to 60° for the angle 22 for the side wall 21 adjacent to the pole section 3 has proven to be expedient in order to find a compromise with the length of the bottom surface 26 of the magnetic flux deflection groove 20. For the other side wall 23, a range for the angle 24 of 30° to about 70° was found to be favorable.

The steeper the angles 22 and 24 are, the longer the horizontal surface, ie the bottom surface 26 of the magnetic flux deflection groove 20 can be and the more stiffening material can be introduced into it. In the 2 shown detail A a hump 25 is formed, which increases the mechanical stability of the transition section 5, in particular in the longitudinal direction and against bending forces. The expert recognizes a variety of other possibilities for increasing the mechanical rigidity of the magnetic flux deflection groove 20 according to the invention, which is filled with plastic material 10. The magnetic flux deflection groove 20 can have undercuts in the direction of the rotation axis 9, e.g. in the form of channels or the like. All of these modifications are compared to the in 2 The general form shown in detail A is covered by the invention.

As can be seen from detail A in 2 - at least for the person skilled in the art - the metallic wall thickness of the cylindrical body 2 of the one-piece pole tube 1 in the transition region 5 is much smaller than the wall thickness in the tube section 7. The smaller the metallic wall thickness in the transition section 5, the better the magnetic flux can be diverted from the pole section 3 to the tube section 7, and the higher the magnetic force that can be generated in the blind hole 8 to attract an armature 35 to the pole section 3. As already mentioned above, the metallic wall thickness in the transition section 5 can even be zero if the blind hole 8 in the tube section 7 is produced after the magnetic flux diversion groove 20 in the cylindrical body 2 has been formed and filled with plastic material 10. However, as can also be seen in detail A of 2 with a view to 1 As can be seen, the total wall thickness of the one-piece pole tube 1 in the transition section 5, ie the plastic wall thickness together with the metallic wall thickness is equal to the metallic wall thickness in the tube section 7, ie in the transition section 5 the wall thicknesses of the metallic material of the cylindrical body 2 and the thickness of the plastic are added together, or the entire thickness is formed only by the plastic 10.

In order to increase the mechanical strength of the magnetic flux deflection groove 20 filled with plastic 10, the cylindrical body 2 of the one-piece pole tube 1 can be hardened. The cylindrical body 2 is preferably hardened before the cylindrical body 2 is encapsulated with plastic, e.g. by nitrocarburizing at temperatures between 490 °C and 580 °C. After hardening, the plastic material can be filled into the magnetic flux deflection groove 20.

In the 3 and 4 an embodiment of a solenoid valve assembly 30 is shown, wherein an armature 35 is received in the blind bore 8 and arranged in the blind bore 8 such that a gap 39 is formed between the armature 35 and the bottom surface 6 of the blind bore 8. The blind bore 8 is closed by an end cap 34 which can be screwed or crimped, for example, onto the distal end of the pipe section 7. Typically, the end cap 34 is attached in a liquid-tight manner to the open end of the blind bore 8 in the pipe section 7. On the other side of the fitting 35, a plunger or pin 37 is attached to the armature 35 and can move with the armature 35, being guided by a pin guide bore 4 in the cylindrical body 2.

3 shows the solenoid valve assembly 30 in an initial or starting state when a coil 32 surrounding the cylindrical body 2 of the one-piece pole tube 1 is not energized, i.e. no magnetic force is generated that would attract the armature 35 to the bottom surface 6 of the blind hole 8, i.e. towards the pole section 3. Often the armature 35 is held/biased in this position by a spring force that acts, for example, on a tappet/pin 37 on the outside of the solenoid valve assembly 30 (not shown). In the position of the armature 35 in 3 Therefore, there is a gap 39 between the bottom surface 6 and the armature 35, the width of which is generally smaller than the width of the transition section 5, so that the magnetic attraction force generated by the deflected magnetic flux on the armature 35 is sufficient to move the armature 35 together with the plunger 37 in the direction of the pole section 3, ie the bottom surface 6 of the blind hole 8.

To generate this magnetic attraction force on the armature 35, the coil 32 can be supplied with a current. As is known to those skilled in the art, the magnetic attraction force on the armature 35 depends on a variety of factors, such as the level of the current, the distance of the armature 35 from the pole section 3, i.e. the width of the gap 39 between the armature 35 and the bottom surface 6 of the blind hole 8, the materials of the one-piece pole tube 1 and the armature 35. The magnitude of the magnetic attraction force also depends on the deflection shape or curve of the magnetic flux and the distance of the magnetic flux from the outer surface of the cylindrical body 2 of the one-piece pole tube 1, so the wall thickness in the pole tube should not be too great. To smooth the deflection curve of the magnetic flux, the magnetic flux deflection groove 20 according to the invention is designed with inclined side walls 21 and 23, so that the magnetic flux generated by the current-carrying coil 32 surrounding the one-piece pole tube 1 does not strike these side walls perpendicularly or sharp edges are formed. The depth of the magnetic flux deflection groove is also optimized so that a high magnetic flux is achieved through the blind hole diameter in the transition region 5.

4 shows the solenoid valve assembly 30 according to the invention in an actuated state in which the gap 39 is closed and the plunger/pin 37 is guided in a pin guide bore 4 which is pushed by the armature 35 to the other distal end of the one-piece pole tube 1 opposite the blind hole 8. By moving the plunger 37, the movement and the magnetic force of the armature 35 can be transmitted to the outside of the solenoid valve assembly 30, e.g. for actuating a control or flow valve or another valve used in fluid technology. As is known to those skilled in the art, the magnetic force on the armature 35 can be generated proportionally by applying a proportional current to the coil 32. The higher the current, the higher the magnetic force on the armature 35. In this way, and using a suitable spring that biases the armature 35 into the starting position, the magnitude of the movement of the armature 35 can also be controlled proportionally, since a spring produces a force that increases with the magnitude of the spring travel, e.g.

• Bereitstellen eines zylindrischen Körpers 2, z.B. durch Ablängen des zylindrischen Körpers 2 von einem magnetischem Metallwerkstoff und Erzeugen der Magnetflussumlenknut 20 im nächsten Schritt als Aussparung im Außendurchmesser des zylindrischen Körpers 2 im Übergangsbereich 5. Ausfüllen der Magnetflussumlenknut 20 mit Kunststoffmaterial 10 im nächsten Schritt durch Gießen, Formen, Spritzgießen oder Überspritzen. Anschließend wird die Sacklochbohrung 8 durch paralleles Abstützen des zylindrischen Körpers 2 an der Außenfläche des zylindrischen Körpers 2 realisiert. Nach der Fertigstellung der Außen- und Innenflächen des einteiligen Polrohrs 1 kann mit der Endmontage der Magnetventilbaugruppe 30 begonnen werden, z.B. durch Einsetzen des Ankers 35 in die Sacklochbohrung 8 und Verschließen der Sacklochbohrung 8 mit einer Endkappe 34, z.B. durch Verschrauben oder Verpressen. Schließlich kann die Spule 32 um den zylindrischen Körper 2 gelegt werden, die den Polabschnitt 3, den Übergangsabschnitt 5 und zumindest teilweise den Rohrabschnitt 7 abdeckt.

Basically, there are two methods for producing a one-piece pole tube 1 according to the invention, the first method comprising:

• Providing a cylindrical body 2, e.g. by cutting the cylindrical body 2 to length from a magnetic metal material and creating the magnetic flux deflection groove 20 in the next step as a recess in the outer diameter of the cylindrical body 2 in the transition region 5. Filling the magnetic flux deflection groove 20 with plastic material 10 in the next step by casting, molding, injection molding or overmolding. The blind hole 8 is then created by supporting the cylindrical body 2 in parallel on the outer surface of the cylindrical body 2. After the outer and inner surfaces of the one-piece pole tube 1 have been completed, final assembly of the solenoid valve assembly 30 can begin, e.g. by inserting the armature 35 into the blind hole 8 and closing the blind hole 8 with an end cap 34, e.g. by screwing or pressing. Finally, the coil 32 can be placed around the cylindrical body 2, covering the pole section 3, the transition section 5 and at least partially the tube section 7.

• Bereitstellen eines zylindrischen Körpers, z.B. durch Ablängen eines zylindrischen Körpers aus magnetischem Metallmaterial und Ausführen der Sacklochbohrung 8 in dem zylindrischen Körper 2 im nächsten Schritt. Anschließend wird im Übergangsbereich 5 die Magnetflussumlenknut 20 ausgeführt, indem der zylindrische Körper 2 z. B. mittels eines Dorns in der Sacklochbohrung 8 parallel abgestützt wird. Nach diesem Schritt wird die Magnetflussumlenknut 20 durch Gießen, Formen, Spritzgießen oder Umspritzen mit Kunststoff 10 vergossen. Nach der Fertigstellung der Außen- und Innenflächen des Polrohrs kann die Endmontage des einteiligen Polrohrs nach dem oben beschriebenen Verfahren erfolgen.

The other method according to the invention for producing a one-piece pole tube 1 comprises the following steps:

• Providing a cylindrical body, e.g. by cutting a cylindrical body made of magnetic metal material to length and making the blind hole 8 in the cylindrical body 2 in the next step. The magnetic flux deflection groove 20 is then made in the transition area 5 by supporting the cylindrical body 2 in parallel in the blind hole 8, e.g. by means of a mandrel. After this step, the magnetic flux deflection groove 20 is cast by casting, molding, injection molding or overmolding with plastic 10. After the outer and inner surfaces of the pole tube have been completed, the final assembly of the one-piece pole tube can be carried out using the method described above.

From the foregoing disclosure and the accompanying figures and claims, it will be apparent that the inventive one-piece pole tube 1 and the inventive solenoid valve assembly 30 offer many possibilities and advantages over the prior art. Those skilled in the art will further recognize that further modifications and changes can be made to the inventive one-piece pole tube 1 and the inventive solenoid valve assembly 30 without departing from the spirit of the present invention. Therefore, all such modifications and changes are within the scope of the claims and are covered thereby. It is further understood that the examples and embodiments described above are for illustrative purposes only and that various modifications, changes or combinations of embodiments in light thereof that would suggest to a person skilled in the relevant art are included within the spirit and scope of this application.

List of reference symbols

1

One-piece pole tube

2

Cylindrical body

3

Pole section

4

Pin guide hole

5

Transition area

6

Base area of the blind hole

7

Pipe section

8

Blind hole drilling

9

Rotation axis

10

Plastic

20

Magnetic flux deflection groove

21

First side wall

22

Angle first side wall

23

Second side wall

24

Angle second side wall

25

hump / rib

26

Bottom of the magnetic flux deflection groove

30

Solenoid valve assembly

32

Sink

34

End cap

35

anchor

37

Plunger/pin

39

gap

Claims (16)

One-piece pole tube (1) for use in a solenoid valve device (30), which has a substantially cylindrical body (2) made of magnetic metal material and defines an axis of rotation (9), wherein the one-piece pole tube (1) is axially divided into a pole section (3), a transition section (5) and a tube section (7) consisting of a blind hole (8) in the cylindrical body (2), the medial end of which is formed by the transition section (5), wherein an armature (35) is accommodated in the blind hole (8) so as to be movable in the direction of the axis of rotation (9), and the outer diameter of the cylindrical body (2) in the transition section (5) is radially reduced to form a magnetic flux deflection groove (20), so that the metallic wall thickness in the transition section (5) is less than that in the tube section (7), and the magnetic flux deflection groove (20) is filled by cast or molded plastic material (10) up to the outer diameter of the cylindrical body (2). Pole tube (1) after Claim 1 , wherein the plastic material (10) is a plastic material reinforced by glass or carbon fibers. Pole tube (1) according to one of the Claims 1 or 2 , wherein the groove (20) has a substantially conical cross-section. Pole tube (1) according to one of the Claims 1 until 3 , wherein the groove (20) has a relief-like cross-section. Pole tube (1) according to one of the Claims 1 until 4 , wherein the two side walls (21; 23) of the groove (20) have different angles (22; 24) with respect to the axis of rotation (9). Pole tube (1) according to one of the Claims 1 until 5 , wherein the bottom surface (26) of the groove (20) is not flat and has at least one hump/rib (25) running substantially perpendicular to the axis of rotation (9), the radial extent of which is smaller than the radial extent of the cylindrical body (2). Pole tube (1) according to one of the Claims 1 until 6 , wherein the metallic wall thickness of the pole tube (1) in the transition region (5) is less than 40% of the wall thickness in the tube region (7), preferably less than 30% of the wall thickness in the tube region (7), even more preferably less than 20% of the wall thickness in the tube region (7). Pole tube (1) according to one of the Claims 1 until 7 , wherein the blind hole (8) in the tube section (7) is connected to a pin guide hole (4) in the pole section (3), and the two holes have different diameters. Pole tube (1) according to one of the Claims 1 until 8 , wherein the cylindrical body (2) is hardened, preferably by nitrocarburizing. Solenoid valve device (30) in the pole tube (1) according to one of the preceding claims, wherein an armature (35) is guided so as to be movable in the axial direction in the blind hole (8) arranged in the tube section (7), and a coil (32) surrounds the one-piece pole tube (1) in the pole section (3), in the transition section (5) and in the tube section (7). Solenoid valve arrangement (30) with a pole tube according to Claim 10 in its dependence on Claim 8 , wherein a plunger (37) is arranged in a pin guide bore (4) in the pole section (3), which plunger is movable through the armature (35) in the blind bore (8) in the tube section (7). Method for producing a one-piece pole tube (1) according to one of the Claims 1 until 9 , comprising the steps of: - providing a rod section made of magnetic metal material; - producing the magnetic flux deflection groove (20) in the transition region (5); - filling the magnetic flux deflection groove (20) with plastic (10) by casting, molding or overmolding; - making the blind hole (8) by supporting the cylindrical body (2) on the outer surface; - finishing the outer and internal surfaces of the one-piece pole tube (1). Method for producing a one-piece pole tube (1) according to one of the Claims 1 until 9 , comprising the following steps: - providing a bar material made of magnetic metal; - producing the blind hole (8) in the cylindrical body (2); - producing the magnetic flux deflection groove (20) in the transition section (5) by supporting the cylindrical body (2) by means of a mandrel in the blind hole (8); - filling the magnetic flux deflection groove (20) with plastic material (10) by casting, moulding or overmolding; - finishing the outer and inner surfaces of the pole tube (1). Procedure according to Claim 12 or 13 , wherein the magnetic flux deflection groove (20) is produced by turning, rolling and/or grinding. Procedure according to one of the Claims 12 until 14 , comprising the further step of mounting an anchor (35) in the blind hole (8) in the pipe section (7) and closing the distal end of the blind hole (8) with an end cap (34) by means of screwing or crimping. Procedure according to one of the Claims 12 until 15 , comprising the further step of wrapping the one-piece pole tube (1) with a coil (32) at the pole section (3), the transition section (5) and the tube section (7).

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