DE102018131782A1 - Actuator for a solenoid valve, in particular a swivel motor adjuster for a camshaft of an internal combustion engine - Google Patents

Abstract

The invention relates to an actuator for a solenoid valve of a swivel motor adjuster, with a housing (16) which comprises at least one pole tube (12) and a pole core (46), which are arranged and encompassed by at least one coil (14) generating a magnetic field. and with an actuating plunger (38) which is arranged on an armature (40) of the actuator (10), the armature (40) in an armature space (42) formed by the pole tube (12) and pole core (46) in the axial direction a longitudinal axis (68) of the actuator (10) is designed to be displaceable, and with a cover element (70) which is designed to be closable in the armature space (42), the cover element (70) comprising at least one end element (20) which supports the actuating plunger (38 ) is designed such that it can be accommodated in storage, and an end cover (30) is constructed in a comprehensive manner eht.

Description

The invention relates to an actuator for a solenoid valve, in particular a swivel motor adjuster for a camshaft of an internal combustion engine, according to the preamble of patent claim 1.

Actuators, especially for solenoid valves of swivel motor adjusters, are known. Swivel motor adjusters are used to adjust camshafts of internal combustion engines.

An actuator for a solenoid valve, in particular a swivel motor adjuster for a camshaft of an internal combustion engine, is known from the published patent application DE 10 2015 102 066 A1 known. The actuator comprises an electromagnet with a cylindrical, hollow magnetic body, which has a yoke, a pole core with an armature counterpart influencing the characteristic curve and a housing, as well as a cylindrical armature with guide rod and armature piston and a cylindrical coil comprising the armature, the armature being displaceably arranged relative to the pole core is. The actuator additionally has a magnetic iron disc, which is received in a bearing bush for mounting and guiding the guide rod. The iron disk serves to reinforce a magnetic field which is brought about with the aid of the coil and the magnetic elements of the actuator.

In order to bring about a further strengthened magnetic field, this iron disk would have to be made larger, so that the actuator as a whole would require more installation space. Furthermore, the iron disk itself and its mounting on the bearing bush are provided with costs which are preferably to be saved. In other words, it is the object of the present invention to provide an improved actuator for a solenoid valve, in particular a swivel motor adjuster for a camshaft of an internal combustion engine, which can be designed to produce an enlarged magnetic field and / or to reduce costs with the same installation space requirement.

The object is achieved according to the invention by an actuator for a solenoid valve, in particular a swivel motor adjuster for a camshaft of an internal combustion engine, with the features of patent claim 1. Advantageous refinements with expedient and non-trivial developments of the invention are specified in the respective subclaims.

The actuator according to the invention for a solenoid valve of a swivel motor adjuster has a housing which comprises at least one pole tube and a pole core, which are arranged comprising at least one coil generating a magnetic field, and an actuating plunger which is arranged on an armature of the actuator. The armature is designed to be displaceable in the axial direction along a longitudinal axis of the actuator in an armature space formed by the pole tube and pole core. Furthermore, the actuator has a cover element, which is designed to be closable in the armature space, the cover element being constructed to comprise at least one end element, which is designed to accommodate the actuating plunger, and an end cover. According to the invention, the closure element is formed from a material which consists of a plastic having metal particles.

Actuators according to the prior art have a pole core insert which is formed in addition to the pole core in order to bring about a magnetic flux of the magnetic field which is sufficient to move the actuating plunger. This pole core insert is usually arranged on the terminating element and is preferably molded around it. In other words, since the pole core insert is made of magnetic material, in contrast to the end element made of a non-magnetic material, it constitutes a further component in addition to the end element.

Since, according to the invention, the terminating element is made of a material that consists of a plastic with metal particles, the magnetic flux of the magnetic field can be brought about with the terminating element and an additional additional component, which is usually an annular pole core insert, is omitted. This means that the advantage of the invention is to be seen in that the pole core insert designed to produce a necessary magnetic field is replaced by the metal particles in the plastic material.

Another advantage can be seen in the fact that shape and position tolerances can be maintained significantly improved due to the reduction in components. This means that if there are two components, both can each have corresponding tolerances, which can cancel each other out but can also add up. If there is only one component left, the tolerances are much easier to maintain.

The material can preferably be designed as plastic granules with enclosed ferritic metal particles, these granules preferably being suitable for injection molding, so that the end element can be produced in an inexpensive injection molding process.

In a further embodiment, the end cover is formed from a material which is made from a plastic having metal particles. This means that the end cover can also advantageously be used to form the magnetic field. As a result, for example, other magnetic elements which are designed to serve the magnetic flux in the actuator can be kept smaller or the magnetic flux and / or the magnetic field can be increased.

In a further advantageous embodiment, the cover element is formed in one piece, comprising at least the end element and the end cover. In other words, this means that the cover element, which is originally made at least from the components end element and end cover, is now realized in a single component. The advantage can be seen particularly in the fact that shape and bearing tolerances can be maintained in a significantly improved manner.

A reduction in wear on the actuating plunger, which is subject to wear due to its axial movement in the closing element, can be achieved with the aid of wear-reducing material which is attached to a surface of the closing element opposite the actuating plunger. Basically, there is no increase in wear due to the inventive design of the end element, but this can be reduced with the measure described. In particular, if the end element or the cover element in the form of a single component is produced by the injection molding process, the wear-reducing material can also be sprayed on inexpensively.

At this point it should be mentioned that a bearing bush formed in the end element for low-friction mounting of the actuating plunger can also advantageously be omitted, since the end element serves to mount the actuating plunger.

In order to reliably prevent the armature from sticking to the end element, it is proposed to provide the end element with a non-magnetic disk on its end face formed opposite the armature.

In a further embodiment of the actuator according to the invention, the end cover or the cover element are fastened to the housing with the aid of ultrasonic welding. Ultrasonic welding offers numerous advantages. Ultrasonic welding only requires a fraction of the energy required for other thermal welding processes. Another advantage is that three-dimensional seams can be realized with short welding cycles. Eliminating post-processing of existing weld seams is also advantageous. And ultrasonic welding is environmentally friendly because no adhesives are required.

Inexpensive and complex shapes and geometries of the end element or the end cover or the cover element are possible through the production of the components using an injection molding process.

Basically, it can be advantageous and regardless of whether only individual components of the cover element such as the end element or the end cover or the cover element are made in one piece from the plastic material comprising metal particles, by increasing the wall thicknesses of the corresponding components, and thus by increasing the material, an increase in the magnetic field and thus an increase in the magnetic flux can be brought about.

• 1 in einem Längsschnitt einen Aktuator gemäß dem Stand der Technik,
• 2 in einem Längsschnitt ein Abdeckelement des Aktuators gem. 1,
• 3 in einem Längsschnitt ein Abdeckelement eines erfindungsgemäßen Aktuators in einem ersten Ausführungsbeispiel, und
• 4 in einem Längsschnitt das Abdeckelement des erfindungsgemäßen Aktuators in einem zweiten Ausführungsbeispiel.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawings. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the combination indicated in each case, but also in other combinations or on their own, without the scope of Leaving invention. Identical reference symbols are assigned to identical or functionally identical elements. For reasons of clarity, it is possible that the elements are not provided with their reference symbols in all the figures, but without losing their assignment. Show it:

• 1 in a longitudinal section an actuator according to the prior art,
• 2nd in a longitudinal section a cover element of the actuator acc. 1 ,
• 3rd in a longitudinal section a cover element of an actuator according to the invention in a first embodiment, and
• 4th in a longitudinal section the cover element of the actuator according to the invention in a second embodiment.

1 shows an actuator in a longitudinal section 10th , which is designed according to the prior art. The actuator 10th , especially for a solenoid valve of a swivel motor adjuster is suitable includes a pole tube 12 , the inside of a cylindrical coil that generates a magnetic field 14 is arranged, as well as a housing 16 which is the actuator 10th is encompassing. The housing 16 is manufactured using a plastic injection molding process, so that the housing can be made in a cost-effective manner 16 to manufacture and at the same time different components of a pole yoke 18th in the injection molding process, which ensure the closed magnetic flux.

The actuator also includes 10th a finishing element 20th , which has a first receiving opening 22 of the housing 16 completes. The final element 20th forms together with a pole core insert 24th , which has a central second receiving opening 26 has, and an end cover 30th a preassembled unit in the form of a cover element 70 of the actuator 10th .

The end cover 30th is, for example, by means of ultrasonic welding, preferably so-called ultrasonic riveting on the housing 16 attached. For this, the housing shows 16 a so-called ultrasound geometry in the form of several projections 32 on through holes 34 of the end cover 30th protrude through. The tabs 32 are melt-deformed by the ultrasonic riveting, so that the end cover 30th securely on the case 16 is attached. 4

The end cover 30th has a central opening 36 in which a bearing bush 28 of the actuator 10th for storing a movable actuating plunger 38 of the actuator 10th is arranged. The bearing bush 28 is in one piece with the end element 20th educated. The bearing bush could also 28 and the final element 20th also be manufactured independently of one another and joined in a joining process.

The end element is expedient 20th manufactured with a plastic injection molding process and the end cover 30th and the pole core insert 24th are provided as inserts, which are used in the manufacture of the end element 20th inserted in the injection mold and in the area of their receiving openings 22 , 26 of the material of the end element 20th be encapsulated. This creates a permanent seal on the end element 20th against the pole core insert 24th and the end cover 30th given.

The actuating plunger 38 is on an anchor 40 arranged, which within one of at least the pole tube 12 and one in the direction of a longitudinal axis 68 of the actuator 10th the pole tube 12 following pole core 46 included anchor room 42 in the axial direction along the longitudinal axis 68 of the actuator 10th is slidable. The anchor 40 is in a non-magnetic sleeve 44 from the pole tube 12 and the pole core 46 is included, stored.

As in 1 can be seen, the sleeve extends 44 to one of the end covers 30th closed end of the anchor space 42 and points one to the whole of the anchor 40 traversable working area on the inside diameter so that it can be guided over its entire length. It also ensures that the anchor 40 cannot tilt, resulting in high magnetic radial forces on the armature 40 and thus a high friction compared to the pole tube 12 would lead.

The sealing of the sleeve 44 against the possibly penetrating fluid from the adjacent solenoid valve is carried out by means of an annular sealing element 48 which is between a covenant 50 the sleeve 44 and the housing 16 is arranged and on the end cover 30th and part of the Poljoch 18th fits tightly.

According to an embodiment, not shown, the pole tube 12 and the pole core 46 be made in one piece. The sleeve 44 can be omitted in this case and the anchor 40 is designed to be displaceable in the axial direction in a known manner.

The bearing bush 28 points at their anchor 40 trained trained side a stop 52 on what a stop the anchor 40 serves in its axial movement. Such a firm stop holds the face of the armature 40 at a certain distance from the disk-shaped pole core insert 24th and thus prevents the anchor from sticking 40 with the face of the anchor 40 on the pole core insert 24th . Sticking would change the behavior of the anchor 40 change and for the operation of the anchor 40 necessary magnetic forces significantly affect the overall dynamic behavior of the actuator 10th would be changed. Therefore, such an attack 52 the dynamic behavior and energy consumption of an actuator as an anti-adhesive disc 10th , which is operated with magnetic forces.

The actuating plunger 38 is in a central third receiving opening 54 of the anchor 40 pressed in. If the actuating plunger 38 made of a different material than the anchor 40 is a cheap solution to the connection of the two components.

The Poljoch 18th , which can be formed from several plates and / or tubes, encloses the coil 14 on their outsides, causing the coil 14 is surrounded as completely as possible by magnetic material, since inside the coil 14 the Pole tube 12 is trained. This will remove the coil 14 generated magnetic flux as cheaply as possible on the volume range in which the armature 40 can move, focused.

For pressure equalization between a front and a back of the anchor 40 has the substantially cylindrical actuating plunger 38 Flattening in the press-in area 56 , which are, for example, milled or flipped, in order to equalize the volume or pressure between the front and the back of the armature 40 to represent. The exemplary embodiment shown has, by way of example, four flats distributed around the circumference 56 on.

The bearing bush could also be used to bring about pressure equalization 28 Recesses between the anchor space 42 and an outside space 58 of the actuator 10th exhibit. The pressure equalization provides a volume equalization of the enclosed hydraulic fluid or the enclosed air between the armature space 42 and the outside space 58 of the actuator 10th for sure. Such pressure equalization is both in dry operation, i.e. air-filled armature space 42 , also when operating with hydraulic fluid in the armature space 42 significant.

The actuating plunger 38 which is used to transmit a force of the actuator 10th is formed on a piston of the solenoid valve, not shown, has a ball 60 at his from the anchor 40 end facing away from. The bullet 60 can in a recording room 62 of the actuating plunger 38 , in which it is movably mounted, rotate. The recording room 62 is from a wall 64 of the actuating plunger 38 partially enclosed and due to the movement of the ball, this can wear the wall 64 and / or the ball 60 to lead.

The cover element 70 of the actuator 10th according to the prior art is in 2nd shown enlarged. The pole core insert 24th which with the end cover 30th captive with the end element 20th is formed from a magnetic, in particular ferritic material. It is extrusion-coated with non-magnetic material, in particular plastic, in an injection molding process, the end element 20th is trained. The end cover 30th , which is designed according to the prior art as a sheet metal plate, is preferably extrusion-coated at the same time. The final element 20th is in one piece with the bearing bush 28 executed and thus takes over the function of a slide bearing of the actuating plunger 38 .

The cover element 70 of an actuator according to the invention 10th is according to a first embodiment 3rd educated. The pole core insert 24th is in one piece with the end element 20th executed. In other words, that means the final element 20th and the pole core insert 24th are made in the form of a single component and from the same material. The material corresponds to a plastic which has metal particles, in particular ferritic metal particles. The magnetic field is thus formed with the aid of the terminating element 20th . In other words, the pole core insert 24th is substituted with the help of the metal particles. Depending on the number and size of the metal particles, a larger or less strong magnetic flux can be generated.

The also in one piece with the end element 20th trained bearing bush 28 Due to the plastic-containing material, it still has very good storage properties for mounting the actuating plunger 38 which is subjected to nitriding to reduce wear. In an embodiment not shown in detail, a wear-reducing layer is on one, the actuating plunger, to further reduce wear 38 opposite surface 66 of the final element 20th , thus on the surface 66 the second receiving opening 26 , sprayed on. The actuating plunger could also 38 even partially on his anchor 40 end facing away from being nitrided and / or the wear-reducing layer only partially onto the surface 66 be sprayed on.

In an exemplary embodiment, not shown, the end element 20th at its the anchor 40 opposite end face 72 a non-metallic washer, causing the anchor to stick 40 on the end element 20th is safely avoided.

In a second embodiment of the actuator according to the invention 10th is the cover element 70 comprehensively the final element 20th , which the pole core insert 24th substituted covers, and the end cover 30th formed in one piece, consisting of a material, the above-mentioned metal particle plastic, as in 4th is shown. Of course, the bearing bush 28 , as one piece with the end element 20th executed, also integrated. The sealing element can also be advantageous 48 with the help of the cover element 70 which the end cover 30th has integrated, held in its known position.

The one-piece cover element preferably has 70 of the second exemplary embodiment also has a shape suitable for ultrasonic welding.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102015102066 A1 [0003]

Claims (8)

Actuator for a solenoid valve, in particular a swivel motor adjuster for a camshaft of an internal combustion engine, with a housing (16) which comprises at least one pole tube (12) and a pole core (46) which comprises at least one coil (14) generating a magnetic field are arranged, and with an actuating plunger (38) which is arranged on an armature (40) of the actuator (10), the armature (40) in an armature space (42) formed by the pole tube (12) and pole core (46) in is displaceable in the axial direction along a longitudinal axis (68) of the actuator (10), and with a cover element (70) which is designed to be closable in the armature space (42), the cover element (70) having at least one end element (20) which the Actuating plunger (38) is designed such that it can be accommodated in a bearing, and an end cover (30) is constructed comprehensively, characterized in that the end element (20) is formed from a material which consists of a metal particle plastic. Actuator after Claim 1 , characterized in that the plastic is in the form of a plastic granulate with enclosed metal particles. Actuator after Claim 1 or 2nd , characterized in that the end cover (30) is formed from a material which is made from a plastic material having metal particles, the material in particular corresponding to the material of the end element (20). Actuator according to one of the preceding claims, characterized in that the cover element (70) is formed in one piece, comprising at least the end element (20) and the end cover (30). Actuator according to one of the preceding claims, characterized in that a surface (66) of the closure element (20) opposite the actuating plunger (38) is formed with a wear-reducing material. Actuator according to one of the preceding claims, characterized in that the end element (20) has a non-magnetic disk on its end face (72) which is formed opposite the armature (40). Actuator according to one of the preceding claims, characterized in that the cover element (70) or the end cover (30) is fastened to the housing with the aid of an ultrasonic welding. Actuator according to one of the preceding claims, characterized in that the end element (20) and / or the end cover (30) and / or the cover element (70) is produced by means of an injection molding process.

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