EP1064485A1

EP1064485A1 - Magnet armature

Info

Publication number: EP1064485A1
Application number: EP99910869A
Authority: EP
Inventors: Jacob Michiel Van Houte
Original assignee: Helvoet BV
Current assignee: Helvoet Rubber and Plastic Technologies BV
Priority date: 1998-03-24
Filing date: 1999-03-17
Publication date: 2001-01-03
Also published as: AU2963299A; WO1999049251A1; NL1009009C2

Abstract

Magnet armature (7) comprising an armature body (8) made from magnetic or magnetizable material, which armature comprises a passage with one or two open ends (10), an assembly of sealing means being accommodated in the passage (9), which assembly of sealing means, in the case of one open end, comprises a displaceable sealing element (12), spring means (14) and a reinforcement component (15), the displaceable sealing element (12) being held under prestress by the spring means (14), and with the intervention of the reinforcement component (15), against a stop (19) in the passage, in the vicinity of the open end (10) of the passage (9), while in the case of two open ends a sealing element which is fixed or can also be displaced under prestress is present in the other end. The assembly of sealing means is introduced into the passage (9) as an assembly of sealing means which forms a single unit with components which are coupled together at least during assembly of the magnet armature (7).

Description

Short title: Magnet armature

The present invention relates firstly to a magnet armature, at least comprising an armόture body made from magnetic or magnetizable material, which armature body comprises a passage with one open end, an assembly of sealing means being accommodated in the passage, which assembly of sealing means comprises at least one displaceable sealing element, spring means and a reinforcement component, the displaceable sealing element being held under prestress by the spring means, and with the intervention of the reinforcement component, against a stop in the passage, in the vicinity of the open end of the passage.

A magnet armature of this nature is generally known and is used as a closure member in an electromagnetically actuated shut-off valve. Possible applications are for braking systems, such as ABS (.-Antilock Brake Systems) and vehicle suspension systems.

Magnet armatures of this nature, and in particular the components of the assembly of sealing means present therein have relatively small dimensions. The sealing element can be displaced under prestress in the passage, so that when an armature of this nature is used to close a feed or discharge port in a shut-off valve, the closure force is determined not by the electromagnetic force but by the spring stress of the spring means.

The presence of every component in the armature is highly important for the armature to function correctly.

During assembly of a magnet armature of this nature, hitherto the relevant components of the assembly of sealing means have been placed in the passage in succession, specifically in the order spring means, then the reinforcement component and finally the sealing element. Often, the spring means used is a coil spring, the reinforcement component used is a metal sleeve which is pushed over the spring, and the sealing element used is a small rubber disc. Then, the assembly is enclosed in the passage under stress from the spring. To enclose it, it is possible, for example, to flange over the end slightly, or to use rivets, or to add an annular cap. In use, the sealing element can be moved slightly into the passage counter to the prestress applied by the spring. This displacement therefore has a self-restoring character. In practice, the level of reliability which industry requires with regard to the presence of the relevant components of the assembly of sealing means in the armature has been constantly increasing. In practice, it is virtually impossible to give a guarantee that all the components are present, since after assembly of an armature such matters can no longer be checked. For the reasons mentioned above, it is substantially impossible to automate the assembly of magnet armatures, so that in practice assembly very often represents a laborious and therefore very expensive process.

The object of the present invention is to provide a solution to the above problem, and, to that end, is characterized in that the assembly of sealing means is introduced into the passage as an assembly of sealing means which forms a single unit with components which are coupled together at least during assembly of the magnet armature.

By coupling the components of the assembly of sealing means together in advance, the assembly can be introduced as a single unit and, before being introduced, can be suitably checked for the presence of all the components. This ensures a virtually 100% level of reliability with regard to the presence of all the components .

It should be noted that the closed end of the passage may also comprise a sealing element which is fixedly attached in the opening of the said end and may interact with the spring means, if appropriate also with the intervention of an additional reinforcement component. The invention furthermore provides a magnet armature, at least comprising an armature body made from magnetic or magnetizable material, which armature body comprises a passage with two open ends, an assembly of sealing means being accommodated in the passage, which assembly of sealing means comprises at least a first displaceable sealing element, a second sealing element, spring means and two reinforcement components, the displaceable sealing element being held under prestress by the spring means, and with the intervention of a first reinforcement component, against a stop in the passage, in the vicinity of one open end of the passage, while the other sealing element is present in the other end of the passage, which sealing element, with the intervention of a second reinforcement component, likewise interacts with the spring means. According to the invention, this magnet armature is characterized in that the assembly of sealing means is introduced into the passage as an assembly of sealing means which forms a single unit with components which are coupled together at least during assembly of the magnet armature.

In practice, the second sealing element may be designed in various ways. For example, this sealing element may be a fixed sealing element which is attached in such a manner that it cannot move. This second sealing element may also be a sealing element which can be displaced under prestress from the spring means, in a corresponding manner to the first sealing element, and which likewise bears under prestress against a stop in the passage, in the vicinity of the relevant end of this passage. The components of the assembly of sealing means can be coupled together, at least prior to assembly, in various ways. Consideration may be given to adhesive bonding, welding, etc. However, a mechanical coupling is preferred. It is particularly preferable for the spring means to comprise a coil spring, for the sealing elements to comprise a disc-like sealing element with a central projection, which projection is able to form a snap-action connection to the relevant end of the coil spring. To this end, the central projection may, for example, comprise a surrounding thickened section.

The spring means may also be coupled to the sealing element with the intervention of the reinforcement component. In other words, the spring means may likewise be connected to the reinforcement component, which in turn is connected to the sealing element . All this will be explained in more detail later in the description of the figures .

There is no need for the coupling between the components of the assembly of sealing means to persist after this assembly has been introduced into the passage in the armature. In certain cases, it could be preferable for the components to be able to move with respect to one another after they have been introduced into this passage. The reinforcement components advantageously comprise a reinforcement ring which is accommodated between the relevant sealing elements and the spring means.

In practice, sealing elements are often made from rubber-like materials. If there is no reinforcement component present, a metal coil spring will abrade ("eat into") the element. Apart from coil springs, it is, of course, also conceivable to use other spring means. Examples of suitable rubber-like materials for the sealing elements are thermoplastic materials, rubbers such as NBR, HNBR and FKM.

According to the invention, the components of the assembly of sealing means can easily be fitted during its production by snapping them together.

A reinforcement ring can be placed over a projection of a sealing element, after which the sealing element can be connected to a coil spring by means of a snap-action connection.

In a particular embodiment, the reinforcement components form a single unit with the sealing elements. In this case, consideration may be given, for example, to a plastic reinforcement component which is formed around the projection of a disc-like sealing element, for example by injection-moulding or the like.

The invention furthermore provides an assembly of sealing means which is obviously intended for a magnet armature with one open end and an assembly of sealing means which is obviously intended for a magnet armature with a passage with two open ends.

Furthermore, the invention provides a sealing element which is obviously intended for an assembly of sealing means according to the invention.

Moreover, the invention provides a method for assembling a magnet armature according to the invention, which method is characterized in that an assembly of sealing means according to the invention is introduced as a single unit into the passage in the armature and is enclosed therein, while stressing the spring means.

Here too, the assembly of sealing means again relates to an assembly of sealing means for an armature with a passage with one or two open ends.

Finally, the invention provides an electromagnetic shut-off valve which comprises a magnet armature according to the invention. The invention will be explained in more detail below with reference to the appended drawing, in which:

- Fig. 1 shows a diagrammatic view of an electromagnetic shut-off valve with a magnet armature;

- Fig. 2 shows a cross section through a magnet armature with a passage with two open ends;

- Fig. 3 shows a cross section through a magnet armature with a passage with one open end;

- Fig. 4 shows a cross section through an amended embodiment of a magnet armature according to the invention which comprises two open ends;

- Fig. 5 shows a cross section through an assembly of sealing means according to the invention for a magnet armature with a passage with two open ends ; and - Fig. 6 shows a cross section through another embodiment of the assembly of sealing means according to the invention for a magnet armature with a passage with two open ends . In Fig. 1, 1 denotes an electromagnetic shut-off valve which comprises a feed duct 2 and two discharge ducts 3 and 4. 5 denotes an electromagnetic coil, and 6 denotes a magnet armature. As will be explained below, the magnet armature comprises a sealing element which can be displaced under prestress and in Fig. 1 is shown on the top side, and a sealing element which is clamped in a fixed position and in Fig. 1 is shown on the bottom side. A coil spring which is used to hold the top, displaceable sealing element under prestress is present between the sealing elements. In the position shown in the figure, the discharge duct 3 is closed and the discharge duct 4 is open. Therefore, fluid can flow via duct 2 into duct 4. When the electromagnetic coil 5 is energized, the armature 6 will be moved downwards and the discharge 4 will be closed off while the discharge 3 is opened. It will be clear that numerous variant applications for magnet armatures of this nature will be evident to the average person skilled in the art.

Fig. 2 shows a magnet armature 7 according to the invention, comprising an armature body 8 in which there is a passage 9 with two open ends 10 and 11. Two sealing elements, namely a displaceable sealing element 12 and a fixedly attached sealing element 13, are present in the passage, together with a coil spring 14 which, with the intervention of a small metal cover cap 15, interacts with the displaceable sealing element 12 and, with the intervention of a small metal disc 16, interacts with the fixedly attached sealing element 13.

The sealing element 13 is accommodated between a flanged collar 17 and a shoulder 18 in the wall of the passage 9.

The sealing element 12 bears with slight prestress against an inwardly directed collar 19 and, in use, can be moved slightly into the passage, counter to the stress of the spring 14. According to the invention, the components of the assembly of sealing means, comprising the sealing element 12, the small cover cap 15, the spring 14, the small metal disc 16 and the sealing element 13 , were coupled together at least while being introduced into the passage 9. The assembly was introduced into the passage 9 as a single unit, via the underside, in the direction indicated by the arrow, after which the spring 14 was stressed and the rim 17 was flanged over, in order to enclose the assembly and to fixedly attach the sealing element 13. It will be clear that a significant advantage of the invention is that the entire assembly of sealing means can be checked in advance for the presence of all the components, after which this assembly can be introduced into the passage 9 as a single unit . This increases the reliability with regard to the presence of the relevant components very considerably.

Fig. 3 shows an embodiment of an armature according to the invention in which the passage 9 comprises only one open end 10. In this case, the assembly of sealing means comprises the spring 14, the small cover cap 15 and the displaceable sealing element 12. In this embodiment, the assembly of sealing means is introduced from the top side, in the direction of the arrow indicated, after which a closure cap 20 holds the unit in place in the passage 9. Fig. 4 shows an altered embodiment of the magnet armature 7 in accordance with Fig. 2, with two open ends, displaceable sealing elements 12, 31 being accommodated under prestress from the spring 14 in both ends . The displaceable sealing element 31 is situated in the end 11 and, as its reinforcement element, likewise comprises a small metal cover cap 32. As in Fig. 3, a rim 33 is flanged over in order to hold the bottom sealing element 31 in the passage 9. The way in which the relevant components of the assembly of sealing means according to the invention are coupled together during assembly is not highly critical, although a very advantageous embodiment of this assembly method is shown in Fig. 5. In Fig. 5, the assembly of sealing means is diagrammatically denoted by 21. This advantageous embodiment comprises a sealing element 22, a reinforcement ring 23, a spring 24, a second reinforcement ring 25 and a second sealing element 26. It will be clear that this embodiment of the assembly of sealing means is intended for an armature in accordance with Fig. 2. By omitting the sealing element 26 and the reinforcement ring 25, the unit can be made suitable for an armature in accordance with Fig. 3, but also for an armature in accordance with Fig. 2 in which the sealing element 13 and the small reinforcement plate 16 are introduced separately and do not form part of the assembly of sealing means, in other words in the case where the closed end of the passage 9 is formed by a fixed sealing element.

The sealing elements 22 and 26 comprise a central projection 27 and 28 respectively, which comprises a surrounding thickened section 29 and 30 respectively, which is able to form a snap-action connection with the spring 24.

The reinforcement rings 23 and 25 can be designed as a single unit with the relevant sealing elements 22 and 26, for example by injection-moulding them together, or they may be separate components. The reinforcement ring 23 comprises a skirt 34 which, during use, serves to ensure that when the sealing element 22 moves it is always positioned correctly with respect to the spring 14. Preferably, in the assembly of sealing means 21 according to the invention, in the case where there are two displaceable sealing elements present, as in Fig. 4, both reinforcement components comprise a ring corresponding to the ring 23 shown in Fig. 5.

In particular, the reinforcement rings 23 and 25 comprise metal rings . By pushing these rings over the projections 27 and 28 respectively, and then snapping the projections into the ends of the spring 24, an assembly of sealing means according to the invention as shown in Fig. 4 is obtained.

In this assembly of sealing means, all the components are coupled together, so that the presence of the components in this assembly can easily be checked before it is fitted into a passage in an armature.

Fig. 6 shows yet another embodiment of an assembly of sealing means according to the invention which comprises two sealing elements 35, 36 which are each provided with a central projection 37 and 38, respectively. The projections 37, 38 are provided with assembly ribs 39 which are used to attach the relevant reinforcement component. In this embodiment, a reinforcement component in the form of a plastic ring 40 is present on the sealing element 35, which ring is provided with a flange 41 and assembly ribs 42. The flange 41 is used to support the spring 24 and the assembly ribs 42 serve to provide a slightly clamped connection between the spring 24 and the ring 40.

The sealing element 36 comprises a steel support sleeve 43 as its reinforcement component, which sleeve comprises a through-opening 44 which interacts in a clamping manner with the assembly ribs 39 of the projection 38.

Furthermore, the support sleeve 43 comprises a number of protrusions 45 which are distributed around the circumference, are directed inwards, are formed by bending and are used to attach the spring 24. The assembly of sealing means in accordance with

Fig. 6 can be fitted in the same way as the assembly of sealing means in accordance with Fig. 5, by firstly pushing the relevant reinforcement components onto the central projections of the relevant sealing elements and then coupling these assemblies together by coupling them to the spring.

Claims

1. Magnet armature (7), at least comprising an armature body (8) made from magnetic or magnetizable material, which armature body (8) comprises a passage with one open end (10) , an assembly of sealing means (21) being accommodated in the passage (9) , which assembly of sealing means (21) comprises at least one displaceable sealing element (12; 22; 36), spring means (14; 24) and a reinforcement component (15; 23; 43), the displaceable sealing element (12; 22; 36) being held under prestress by the spring means (14; 24), and with the intervention of the reinforcement component (15; 23; 43), against a stop (19; 20) in the passage, in the vicinity of the open end (10) of the passage (9) , characterized in that the assembly of sealing means (21) is introduced into the passage (9) as an assembly of sealing means (21) which forms a single unit with components which are coupled together at least during assembly of the magnet armature (7) .

2. Magnet armature (7), at least comprising an armature body (8) made from magnetic or magnetizable material, which armature body (8) comprises a passage (9) with two open ends (10, 11), an assembly of sealing means (21) being accommodated in the passage (9) , which assembly of sealing means (21) comprises at least a first displaceable sealing element (12; 22; 36), a second sealing element (13; 26; 31; 35), spring means (14; 24) and two reinforcement components (15, 16; 23, 25; 32; 40), the displaceable sealing element (12; 22; 36) being held under prestress by the spring means (14; 24), and with the intervention of a first reinforcement component (15; 23; 43) , against a stop (19; 20) in the passage (9) , in the vicinity of one open end (10) of the passage (9) , while the other sealing element (13; 26; 31; 35) is present in the other end (11) of the passage (1) , which sealing element (13; 26; 31; 35), with the intervention of a second reinforcement component (16; 25; 32; 40), likewise interacts with the spring means (14; 24), characterized in that the assembly of sealing means (21) is introduced into the passage (9) as an assembly of sealing means (21) which forms a single unit with components which are coupled together at least during assembly of the magnet armature (7) .

3. Magnet armature according to claim 1 or 2 , characterized in that the spring means comprise a coil spring (24) , and in that the sealing elements comprise a disc-like sealing element (22, 26) with a central projection (27, 28) , which projection (27, 28) is able to form a snap-action connection with the relevant end of the coil spring (24) .

4. Magnet armature according to one or more of claims 1-3, characterized in that the reinforcement components comprise a reinforcement ring (23, 25; 40, 43) which is accommodated between the relevant sealing element (22, 26; 35, 36) and the spring means (24) .

5. Magnet armature according to one or more of the preceding claims, characterized in that the reinforcement components (15, 16, 32; 23, 25; 40, 43) form a single unit with the sealing element (12, 13, 31; 22, 26, 35, 36).

6. Assembly of sealing means which is obviously intended for a magnet armature according to one or more of claims 1, 3-5.

7. Assembly of sealing means which is obviously intended for a magnet armature according to one or more of claims 2-5.

8. Sealing element which is obviously intended for an assembly of sealing means according to claim 7 or 8.

9. Method for assembling a magnet armature according to one or more of claims 1-5, characterized in that an assembly of sealing means (21) according to claim 6 or 7 is introduced as a single unit into a passage (9) in the armature (7) and is enclosed therein, under stress from the spring means (14; 24) .

10. Electromagnetic shut-off valve (1) comprising a magnet armature (7) according to one or more of claims 1-5.