DE102020206644A1 - Electromagnetic valve, in particular for slip-regulated motor vehicle brake systems - Google Patents

Abstract

The invention relates to an electromagnetic valve with a valve tappet (4) which is axially movably arranged in a valve housing (1) and is able to open or close a valve passage in the valve housing (1) which is formed in a valve seat (7), as well as with a for the electromagnetic actuation of the valve tappet (4) provided magnet armature (9) and a spring element (2) which is arranged such that the valve tappet (4) in the electromagnetically non-actuated basic position of the magnet armature (9) in a lifted from the valve seat (7) Position persists.
The invention provides that a bushing (11) is arranged between the valve tappet (4) and the valve housing (1) to adjust the remaining air gap (18) and is fixed in the valve housing (1) with a force fit.

Description

The invention relates to an electromagnetic valve, in particular for slip-regulated motor vehicle brake systems, according to the preamble of claim 1.

From the DE 10 2018 205 089 A1 An electromagnetic valve, which is switched open in the electromagnetically non-excited state, is already known, consisting of a magnet armature for actuating a valve tappet, which can be moved against the action of a return spring, in a tubular valve housing which has a pressure medium passage in a valve seat, which is closed when the magnet armature is excited by the valve tappet is.

However, the construction has the disadvantage that the adjustment of the remaining air gap between the magnet armature and the valve housing, which is designed as a magnet core, can only be done by moving the valve seat in the valve housing, so that the valve seat should be easily displaceable in the valve housing in order to be able to set the remaining air gap precisely. However, this has the disadvantage that high demands are placed on the production and monitoring of the necessary setting parameters in order to permanently position the valve seat in its end position after the remaining air gap has been set. Another disadvantage arises from the fact that the remaining air gap can only be set against the valve closing direction.

It is therefore now the object of the present invention to create an electromagnetic valve of the type mentioned at the beginning that does not have the aforementioned disadvantages. Furthermore, the solenoid valve should have the lowest possible switching noise.

According to the invention, these objects are achieved for a solenoid valve of the specified type by the features characterizing patent claim 1.

Further features and advantages of the invention are explained below with reference to the description of several exemplary embodiments with reference to drawings.

• 1 eine zweckmäßige Ausführungsform des Elektromagnetventils im Längsschnitt mit einer im Ventilgehäuse eingepressten Buchse zur Einstellung des Restluftspalts,
• 2 die Buchse in einer Perspektivansicht,
• 3-5 Varianten zur Ausgestaltung einer mit dem Ventilgehäuse verbundenen Blechhülse, die zur Aufnahme eines Ventilsitzes und eines Filterelements dient,
• 6-11 Montage- und Einstellschritte zur Herstellung des Elektromagnetventils.

Show it:

• 1 an expedient embodiment of the solenoid valve in longitudinal section with a bushing pressed into the valve housing for adjusting the remaining air gap,
• 2 the socket in a perspective view,
• 3-5 Variants for the design of a sheet metal sleeve connected to the valve housing, which serves to accommodate a valve seat and a filter element,
• 6-11 Assembly and adjustment steps for manufacturing the solenoid valve.

the 1 shows in a considerably enlarged view a solenoid valve, which is open in the electromagnetically non-excited state, in longitudinal section, which is preferably used for slip-controlled hydraulic motor vehicle brake systems.

The solenoid valve has one in a valve housing 1 axially movably arranged valve tappet 4th on, the one in the valve housing 1 able to open or close a valve passage which is located in a valve seat 7th is designed, as well as with one for electromagnetic actuation of the valve tappet 4th provided magnet armature 9 and a spring element 2 , which is arranged such that the valve lifter 4th in the electromagnetically non-actuated basic position of the armature 9 in one from the valve seat 7th lifted position remains.

The magnet armature is as shown in the illustration 9 inside an austenitic sheet metal sleeve 12th added that with the thick-walled, tubular valve housing 1 , the so-called. Central housing, is preferably welded, which ensures attachment in a valve receiving bore of a valve receiving body.

The sheet metal sleeve 12th is preferably made as a dome-shaped closed cap by deep drawing of thin sheet metal, while the contour of the tubular valve housing 1 is manufactured inexpensively by cold hammering or cold extrusion from a steel blank which has a ferritic material structure for the purpose of magnetic properties.

Both sides of the valve seat 7th opens into the below the valve housing, as shown in the illustration 1 arranged further sheet metal sleeve 13th one fluid passage each time 14th , 15th one, the one shown above the valve seat 7th as a punched hole on the side and below the valve seat 7th is designed as a vertical central bore.

In the illustrated, electromagnetically non-excited normal valve position remains due to the action of the spring element 2 the valve lifter 4th opposite the valve seat 7th in one the valve passage in the valve seat 7th releasing distance, so that an unimpeded hydraulic connection between the two sides of the valve seat 7th into the lower sheet metal sleeve 13th opening fluid passages 14th , 15th is guaranteed.

In contrast, the valve tappet closes 4th in the electromagnetically excited valve position, the valve passage in the valve seat 7th , whereby it is ensured that with the lowest possible impact speed of the valve tappet 4th the valve seat cannot be heard acoustically 7th contacted.

Therefore it is necessary to brake the valve tappet 4th an annular chamber acting as a damping chamber 10 provided, from which the pressure medium can escape exclusively throttled as soon as the valve tappet 4th into the annular chamber 10 Electromagnetically operated, immersed. The valve tappet is advantageous 4th made of a material that does not conduct magnetic flux, in particular made of a plastic, for which purpose polyetheretherketone (PEEK) is preferably used, the valve seat of which is used 7th facing, within a socket 11th arranged portion of the valve lifter 4th a paragraph 8th has, on which the spring element 2 supports. The spring element 2 is shown inside the annular chamber 10 as an integral part of the socket 11th between the paragraph 8th and one at the bottom of the socket 11th executed drilling stage 6th clamped.

By using a valve stem made of plastic 4th the valve seat 7th Manufacture particularly cost-effectively by deep drawing thin sheet metal (see the 1 , 3 , 5 until 11th ), which is hardened by gas nitriding if desired or required.

Furthermore, each goes from one of the 1 , 4th , 5 , 7th until 11th those for setting the remaining air gap 18th axially in the valve housing 1 sliding bush 11th immediately between the valve stem 4th and the valve housing 1 is arranged, which after the adjustment of the remaining air gap 18th force-fit in the valve housing 1 takes its final position. Details on mounting and adjusting the socket 11th are the 7th until 11th refer to.

the 1 and 2 show all the details of the construction of the socket 11th who have favourited a stepped hole 5 has, in which the valve stem 4th and the spring element 2 are recorded with radial play. The socket 11th points to her the valve seat 7th facing end of the drilling step 6th on to the one with the valve lifter 4th cooperating spring element 2 to be able to support. About the circumference of the socket 11th several longitudinal slots are distributed 3 provided to depend on the design of the longitudinal slots 3 the required press-in and displacement force within the valve housing 1 to be able to influence what the longitudinal slots are for 3 in sections via the frictional connection with the valve housing 1 standing length of the socket 11th extend. To an impairment of the magnetic force during the electromagnetic actuation of the magnet armature 9 To avoid this, the longitudinal slots run 3 in the direction of the valve symmetry axis and thus parallel to the magnetic field lines that can be generated from the excitation of a valve coil. Due to the chosen design of the longitudinal slots 3 there is unhindered volume compensation on both sides of the socket when the valve is switched 11th possible without the requirement in the area of the valve stem 4th Provide compensation grooves.

The socket 11th exists just like the valve housing 1 made of a material that conducts magnetic flux, so that the socket 11th takes over the function of the magnetic core or magnetic pole. Consequently, one points to the magnet armature 9 facing end of the socket 11th opposite the valve body 1 a supernatant 17th on, between the and the armature 9 the remaining air gap 18th is trained.

Between the paragraph 8th and the one on the socket 11th intended drilling stage 6th the hydraulically loaded annular chamber is located in each case 10 , from which, depending on the stroke movement of the valve tappet 4th in the direction of the valve seat 7th Pressure medium can be displaced in a throttled manner in order to enable a closing and opening movement of the digitally switching solenoid valve that is as quiet as possible.

Also show the 3 , 4th , 5 each the sheet metal sleeve 13th in some design variants, according to which in 3 the valve seat 7th by a cup-shaped, deep-drawn section of the sheet metal sleeve 13th is formed on the outer circumference with a groove 19th is provided, in which the cup-shaped filter element 16 clicks into place. In contrast, in 4th the valve seat 7th designed as a separate cartridge component that is inserted into the sheet metal case from below 13th is pressed in until it stops. Another design variant for the sheet metal sleeve 13th is the 5 can be seen, after which in the lower end area on both sides of the valve seat 7th the sheet metal sleeve 13th to accommodate the filter element 16 is folded.

Using the following 6th until 11th should be the assembly and adjustment of the remaining air gap 18th be clarified.

According to the 6th is first the lower sheet metal sleeve 13th with the valve body 1 non-positively, preferably by means of caulking the valve housing 1 attached. After that, according to the 7th the socket 11th from above in the direction of the sheet metal sleeve 13th in sections to a defined pre-setting dimension in the valve housing 1 pressed in. This happens due to the resilient properties of the longitudinal slots 3 with relatively little effort. the 8th shows the spring element in the next assembly step 2 and the valve lifter 4th from above into the socket 11th inserted to then according to the 9 in the next assembly step using a flat moving tool 20th that is both the face of the valve lifter 4th as well as the face of the socket 11th covered and the valve stem 4th depressed so that the top of the valve lifter 4th flat to the top of the socket 11th is aligned. After that, according to the 10 the socket 11th with the valve lifter 4th so deep into the valve body 1 depressed until the out of the socket 11th protruding valve lifters 4th the valve seat 7th contacted. This is the so-called zero position or the starting position for setting the remaining air gap 18th , according to which, according to the 11th after removing the move tool 20th only the socket 11th by the required amount of the remaining air gap 18th in the valve housing 1 is moved further, which is due to the through the longitudinal slots 3 favorable spring properties of the socket 11th particularly sensitive in the valve housing 1 happens. After that are the magnet armature 9 and the cap-shaped closed sheet metal sleeve 12th above the valve lifter 4th on the valve body 1 to be mounted, depending on the selected overlap or position of the sheet metal sleeve 12th on the valve body 1 the desired slide stroke is set. Finally the two filter elements 16 on the sheet metal sleeve 13th mounted to the one from the 1 known overall structure of the solenoid valve.

Thus, a low-noise solenoid valve is created with the aid of the details shown and described here, the remaining air gap of which 18th can be adjusted easily and precisely from the armature side by means of a suitable socket.

List of reference symbols

1

Valve body

2

Spring element

3

Longitudinal slot

4th

Valve lifters

5

Stepped bore

6th

Bore stage

7th

Valve seat

8th

unit volume

9

Magnet armature

10

Annular chamber

11

Rifle

12th

Sheet metal sleeve

13th

Sheet metal sleeve

14th

Fluid passage

15th

Fluid passage

16

Filter element

17th

Got over

18th

Residual air gap

19th

groove

20th

Move tool

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely 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 102018205089 A1 [0002]

Claims (10)

Electromagnetic valve, especially for slip-controlled motor vehicle brake systems, with a tubular valve housing that conducts the magnetic flux and in which a valve tappet is axially movably arranged, which is able to open or close a valve passage in a valve seat, and with a magnet armature provided for electromagnetic actuation of the valve tappet and a spring element which is arranged in such a way that the valve tappet in the electromagnetically non-actuated basic position of the magnet armature remains in a position lifted from the valve seat, characterized in that an axially displaceable bushing (11 ) is arranged, which is non-positively fixed in the valve housing (1). Solenoid valve according to Claim 1 , characterized in that the bush (11) has a stepped bore (5) in which the valve tappet (4) and the spring element (2) are received with radial play. Solenoid valve according to Claim 1 , characterized in that the bush (11) at its end facing the valve seat (7) has a bore step (6) on which the spring element (2) is supported. Solenoid valve according to one of the preceding claims, characterized in that the socket (11) has several longitudinal slots (3) distributed over its circumference, which extend in sections over the length of the socket (11) which is frictionally connected to the valve housing (1). Solenoid valve according to one of the preceding claims, characterized in that the bushing (11) is made from a material which conducts the magnetic flux. Solenoid valve according to Claim 1 , characterized in that one end of the bushing (11) facing the armature (9) has a protrusion (17) opposite the valve housing (1), a residual air gap (18) being formed between the protrusion (17) and the armature (9) is. Solenoid valve according to Claim 1 , characterized in that the valve tappet (4) is made in one piece from a plastic, in particular from PEEK, whose tappet section facing the valve seat (7) and arranged inside the bushing (1) has a shoulder (8) on which the spring element rests (2) is supported. Solenoid valve according to Claim 7 , characterized in that a hydraulically actuated annular chamber (10) is formed between the shoulder (8) and a bore step (6) provided on the bushing (11), from which, depending on the stroke movement of the valve tappet (4) in the direction of the valve seat ( 7) Pressure medium can be displaced in a throttled manner. Solenoid valve according to Claim 1 , characterized in that the valve housing (1) is made from a preferably cold-formed, tubular steel blank, the diametrical pipe ends of which have sheet-metal sleeves (12, 13), preferably made in a deep-drawing process, in which the magnet armature (9) and the valve seat (7) are arranged diametrically are. Solenoid valve according to Claim 9 , characterized in that the sheet metal sleeve (13) having the valve seat (7) is pot-shaped, in the pot bottom of which there is a first fluid passage (14) produced by the deep-drawing process, and that in the sleeve jacket a further fluid passage (15) produced by the stamping or stamping process ) is provided which, like the first fluid passage (14), is each surrounded by a filter element (16).

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