阅读说明：本技术 电磁调压阀 (Electromagnetic pressure regulating valve ) 是由 马努埃尔·布劳恩 维克多·昂鲁 艾克·尼尔斯·文策尔 于 2019-07-30 设计创作，主要内容包括：本发明涉及一种电磁调压阀,其具有电磁调整器(12),所述电磁调整器用于定位在调节器壳体(14)中在所述调节器壳体的容纳开口(16)中轴向可移动地容纳的活塞(20),其中,所述调压阀(10)的多个接口(P,A,T)借助活塞可穿流地打开和/或闭合,并且其中,所述活塞在其构造为与所述电磁调整器相背的端面(42)上具有销钉(44),其中,在所述销钉与活塞之间可以形成相对运动,并且其中,在调节器壳体内构造为与所述活塞相背的销钉的面(90)设置为与止挡部(48)对置。根据本发明,为了阻挡销钉向止挡部方向的移动,弹簧加载地构造所述销钉,其中,被构造成引起弹簧加载的预张紧元件(64)设计为接合在所述销钉上。(The invention relates to an electromagnetic pressure regulating valve having an electromagnetic actuator (12) for positioning a piston (20) which is axially displaceably received in a receiving opening (16) of a regulator housing (14) in a regulator housing, wherein a plurality of connections (P, A, T) of the pressure regulating valve (10) are opened and/or closed by means of the piston in a flow-through manner, and wherein the piston has a pin (44) on its end face (42) which is formed opposite the electromagnetic actuator, wherein a relative movement can be produced between the pin and the piston, and wherein a face (90) of the pin which is formed opposite the piston in the regulator housing is arranged opposite a stop (48). According to the invention, the pin is designed to be spring-loaded in order to block a movement of the pin in the direction of the stop, wherein a pretensioning element (64) designed to cause the spring-loading is designed to engage on the pin.)

1. Electromagnetic pressure regulating valve having an electromagnetic regulator (12) for positioning a piston (20) axially displaceably received in a receiving opening (16) of a regulator housing (14) in a regulator housing (14), wherein a plurality of connections (P, A, T) of the pressure regulating valve (10) are openably and/or closably passable by means of the piston (20), and wherein the piston (20) has a pin (44) on its end face (42) which is configured opposite the electromagnetic regulator (12), wherein a relative movement is able to be produced between the pin (44) and the piston (20), and wherein a face (90) of the pin (44) which is configured opposite the piston (20) in the regulator housing (14) is arranged opposite a stop (48),

it is characterized in that the preparation method is characterized in that,

in order to block a movement of the pin (44) in the direction of the stop (48), the pin (44) is designed to be spring-loaded, wherein a pretensioning element (64) designed to cause a spring-loading is designed to engage on the pin (44).

2. The electromagnetic pressure regulating valve according to claim 1,

it is characterized in that the preparation method is characterized in that,

the pretensioning element (64) is designed to be supported on the piston (20) and the pin (44).

3. The electromagnetic pressure regulating valve according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the pretensioning element (64) is configured to comprise a pin (44).

4. The electromagnetic pressure regulating valve according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the pin (44) has at least one Diameter (DS) and a further Diameter (DK), wherein the Diameter (DS) is smaller than the further Diameter (DK), wherein the further Diameter (DK) belongs to a pin head (88) or a pin socket (92) on which the pretensioning element (64) is configured to bear.

5. The electromagnetic pressure regulating valve according to claim 4,

it is characterized in that the preparation method is characterized in that,

the pin head (88) is designed to rest against the stop (48).

6. The electromagnetic pressure regulating valve according to claim 5,

it is characterized in that the preparation method is characterized in that,

the abutment is in the form of a point or line contact.

7. The electromagnetic pressure regulating valve according to any one of claims 4 to 6,

it is characterized in that the preparation method is characterized in that,

the pin head (88) is designed in a spherical, convex or convex manner facing the stop (48).

8. The electromagnetic pressure regulating valve according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the pin (44) has a single Diameter (DS) and is designed to be supported with a pin end face (45) on the stop (48) and with a further pin end face (91) on the pretensioning element (64), wherein the pretensioning element (64) is designed to be positioned between the piston (20) and the pin (44).

9. The electromagnetic pressure regulating valve according to claim 8,

it is characterized in that the preparation method is characterized in that,

the stop (48) has a spherical, convex or convexly designed projection (89) for supporting the pin (44).

10. The electromagnetic pressure regulating valve according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the pin (44) and/or the stop (48) are made of a synthetic material.

11. The electromagnetic pressure regulating valve according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

a variable volume (V2) is formed between the stop (48) and the end face (42) of the piston (20) which is designed to face the stop (48), wherein a relief opening (70) which can be traversed by the variable volume (V2) is designed in the regulator housing (14).

12. The electromagnetic pressure regulating valve according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the stop (48) has a through-opening (70).

13. The electromagnetic pressure regulating valve according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the relief opening (70) formed in the regulator housing (14) is positioned according to the installation position of the electromagnetic pressure regulating valve (10).

14. The electromagnetic pressure regulating valve according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the stop (48) is configured in the form of a cover closing the first receiving opening (16).

15. The electromagnetic pressure regulating valve according to claim 14,

it is characterized in that the preparation method is characterized in that,

the cover (48) has a chamfer (76) on the outer circumference on its element end face (80) which is configured to face the pin (44).

16. The electromagnetic pressure regulating valve according to claim 14 or 15,

it is characterized in that the preparation method is characterized in that,

the cover (48) is fixed to the actuator housing (14) by means of at least one clamping element (54).

17. The electromagnetic pressure regulating valve according to any one of claims 14 to 16,

it is characterized in that the preparation method is characterized in that,

an element end face (82) of the cover (48) which is formed opposite the piston (20) is rounded.

Technical Field

The present invention relates to an electromagnetic pressure regulating valve according to the preamble of claim 1.

Background

Electromagnetic pressure regulating valves are known. Electromagnetic pressure control valves are used, for example, for the hydraulic control of clutches of automatic transmissions of motor vehicles. The pressure regulating valve has an axially movable piston in a regulator housing, which is provided for opening and/or closing a plurality of connections. The piston is moved axially by means of an electromagnetic adjuster. In order to bring about an adaptation of the actuating force of the electromagnetic actuating device, the pressure control valve has a pin, also referred to as a pin, at the end of the piston which is designed opposite the electromagnetic actuating device, said pin being received in a receiving opening of the piston. The pin is located on a wall of the regulator housing opposite the piston end, which wall is designed as a stop for the pin, upon and during movement of the piston, a relative movement between the piston and the pin being obtained. An electromagnetic pressure regulating valve of this type is known from two publications DE10241449a1 and EP1762765a 2.

The volume formed between the pin and the receiving opening is changed by the axial movement of the piston, as a result of which a damping of the movement of the piston can be brought about, since the volume is already at least partially filled with hydraulic fluid. Thus, a force balance can be formed on the piston. However, during operation of the pressure regulator, there are various load states, for example pressure oscillations in the interfaces, which lead to the pin lifting off the wall during the passage and the subsequent piston movement.

Vibrations from the system alone can also adversely affect a stationary pressure regulating valve, causing the pin to lift from the wall.

Problematically, the pin is subject to strong acceleration and impacts against the wall. In addition to the wall being damaged by, for example, a rupture, the above-mentioned impact in the wall inserted into the regulator housing can lead to a breakdown of the wall and thus to a failure of the pressure regulating valve.

Disclosure of Invention

It is therefore the object of the present invention to provide an improved electromagnetic pressure regulating valve, in the operation of which the aforementioned disadvantages are eliminated.

According to the invention, this object is achieved by a pressure regulating valve having the features of claim 1. Advantageous embodiments of the invention which meet the object and are subject to further development are specified in the respective dependent claims.

The electromagnetic pressure regulating valve according to the invention has an electromagnetic actuator for positioning the piston, which is accommodated in an accommodating opening of the regulator housing in an axially displaceable manner in the regulator housing. The plurality of ports of the pressure regulating valve can be opened and/or closed by means of a piston in a flow-through manner. The piston has a pin on its end face configured opposite the electromagnetic adjuster, wherein a relative movement can be produced between the pin and the piston. Opposite the stop, a pin end face is provided in the actuator housing, which pin end face is formed opposite the piston. In order to avoid a movement of the pin in the direction of the stop, the pin is designed to be spring-loaded, wherein a pretensioning element designed to bring about the spring loading is designed to engage on the pin.

In other words, the pin can be designed to abut against the stop by means of the pretensioning element, independently of the pressure acting on the pressure regulating valve. A pretension force, which can also be referred to as a spring force, is thus introduced, as a result of which lifting of the pin from the stop can be avoided. Due to the spring force introduced, the pin is prevented from lifting from and striking against the stop under adverse pressure conditions and damage to the stop is thereby avoided. To this end, an improved electromagnetic pressure regulating valve with an extended service life is constructed.

In one embodiment of the electromagnetic pressure regulating valve according to the invention, the pretensioning element is designed to be supported on the piston and the pin. The pretensioning element can therefore be used for resetting the piston and for the pin bearing against the stop.

In a compact embodiment, the pretensioning element is configured to comprise the pin, which pretensioning element is preferably embodied in the form of a helical spring.

For a reliable arrangement of the pretensioning element on the pin, the pin has a first diameter and a second diameter, wherein the first diameter is smaller than the second diameter, and wherein the second diameter is assigned to a pin head or a pin seat on which the pretensioning element can be supported.

The pin head is configured for abutting against a stop. The pin can thus be produced simply, for example in the form of a mushroom. In other words, the pin head has the largest diameter of the pin and therefore no undercuts are present in its manufacture, which undercuts then have to be made in a complex form.

In order to reduce the hysteresis effect caused by angular errors between the stop and the pin, for example, the bearing is designed in the form of a point contact or in the form of a line contact. The point or line contact can thus be realized in a simple manner by spherically, convexly or convexly configuring the pin head facing the stop or by spherically, convexly or convexly configuring the stop facing the pin head.

According to a further development of the invention, which is in particular cost-effectively producible, the pin can have a single diameter and be designed to bear with a pin end face on the stop and with a further pin end face on the pretensioning element, wherein the pretensioning element is designed to be positioned between the piston and the pin.

In order to reduce the hysteresis effect caused by angular errors between the stop and the pin, for example, the bearing is designed in the form of a point contact or in the form of a line contact. A point contact or a line contact can be easily achieved in that the stop has a spherical, convex or convex-spherical projection for the abutment of the pin. The stop can be constructed in one piece or in multiple pieces.

By producing the pin and/or the stop from a synthetic material, a cost-effective electromagnetic pressure control valve can be obtained. In addition to the advantageous material outlay, cost-effective processes, such as deep-drawing processes or die-casting processes, can also be used.

In order that the movement of the piston does not cause a variable volume filled with hydraulic fluid between the stop and the end face of the piston configured to face the stop to be unable to cause the lifting of the pin from the stop, the actuator housing has a relief opening, in particular in the region of the pretensioning element, through which the variable volume can flow.

In a further embodiment, the stop has an opening through which a flow can pass. By means of the through-flow opening, a further adjusting element can be formed for adjusting the pressure in the variable volume between the stop and the end face of the piston formed facing the stop, so that the pressure reduction to be brought about is adapted to the respective operating condition of the electromagnetic pressure control valve. The through-flowable tank connection can also be realized with a through-flowable opening.

And arranging an unloading hole according to the installation position of the electromagnetic pressure regulating valve. The advantage of this embodiment is that the relief opening of the electromagnetic pressure control valve does not have to be formed at a constant point on the pressure control valve. The only requirement is that the relief opening be installed such that a reliable filling and emptying of the variable volume formed between the piston and the cover is achieved. Thus, predetermined installation positions and possible installation spaces can be taken into account.

In a further embodiment of the electromagnetic pressure regulating valve according to the invention, the stop is designed in the form of a cover closing the first receiving opening. Thus, a cost-effective pressure control valve can be produced, since the first receiving opening can be realized, for example, in the form of a bore, cost-effectively. Furthermore, the pin and the pretensioning element are simply arranged in the first receiving opening before the cover is inserted into the first receiving opening, resulting in a cost-effective installation.

The cover is designed for simplified assembly by means of a chamfer on the outer circumference of the element end face of the cover designed to face the pin. The chamfer assists in a simpler introduction of the cover into the regulator housing.

In a further embodiment of the electromagnetic pressure regulating valve according to the invention, the cover is fastened to the regulator housing by means of at least one clamping element.

In order to fix the cover on the regulator housing, preferably by means of a clamping element, the element end face of the cover, which is formed opposite the piston, is rounded. The advantage is that the clamping element engages in the cover in a simplified manner, in particular if the cover has a receiving opening on the end face of the element which is formed opposite the piston.

The electromagnetic pressure regulating valve according to the invention therefore has an extended service life, irrespective of whether the stop is embodied, for example, in the form of a wall connected in a material-locking manner to the regulator housing or in the form of a cover embodied in a force-fitting manner with a press-fit seat, since acceleration of the pin and thus possible impact on the stop are avoided.

In addition to a violent impact, the invention also prevents the pin from lifting, since the moving impulse of the pin is suppressed in both directions by means of the pretension. Thus, the effects due to the superposition of dynamic disturbances and pressure oscillations are effectively cancelled in both directions. Therefore, the cause of the failure of the electromagnetic pressure regulating valve is prevented at the beginning.

Drawings

Further advantages, features and details of the invention emerge from the following description of preferred embodiments and from the drawings. The features and feature combinations mentioned above and those mentioned in the following description of the figures and/or shown in the figures alone can be used not only in the respectively given combination but also in other combinations or on their own without departing from the scope of the invention. Identical or functionally identical elements are provided with the same reference symbols. For the sake of clarity, it is possible that the elements are not provided with their reference numbers in all the figures, but their assignment is not lost. Wherein:

figure 1 shows an electromagnetic pressure regulating valve according to the prior art in longitudinal section,

figure 2 shows in longitudinal section a first embodiment of an electromagnetic pressure regulating valve according to the invention,

figure 3 shows in longitudinal section the hydraulic unit of the electromagnetic pressure regulating valve according to the invention according to figure 2,

fig. 4 shows an electromagnetic pressure regulating valve according to the invention in a second embodiment in longitudinal section, and

fig. 5 shows an electromagnetic pressure regulating valve according to the invention in a third exemplary embodiment in longitudinal section.

Detailed Description

According to fig. 1, an electromagnetic pressure control valve 10 for a clutch of a not further illustrated automatic transmission for a not further illustrated motor vehicle according to the prior art is configured. The pressure regulating valve 10 is shown in fig. 1 in a first position, which is characterized by a non-energization of the electromagnetic regulator 12 of the pressure regulating valve 10.

The pressure regulating valve 10 has a regulator housing 14 which is designed for connection to a plurality of hydraulic connections, namely a supply connection P, a consumer connection a and a tank connection T. A piston 20, which is axially displaceable along the longitudinal axis 18 of the actuator housing 14, is movably accommodated in a first receiving opening 16 formed in the actuator housing 14. The actuator housing 14 is designed to be rotationally symmetrical about a longitudinal axis 18.

The piston 20 is designed to adjustably flow through the hydraulic interface P, A, T. The piston has two control grooves formed on its circumference, a first control groove 22 and a second control groove 24. The first control channel 22 is designed to establish a flow-through connection between the supply interface P and the consumer interface a. The second control channel 24 is used to establish a flow-through connection between the consumer interface a and the tank interface T.

In order to provide a flow-through connection, the regulator housing 14 has a plurality of flow openings arranged in series along the longitudinal axis 18, which completely penetrate the regulator housing 14, wherein a first flow opening 26 is assigned to the supply port P, a second flow opening 28 is assigned to the consumer port a, and a third flow opening 30 is assigned to the tank port T. In the first flow opening 26, a filter screen 32 is accommodated, which serves to filter the hydraulic fluid flowing through the pressure control valve 10, which hydraulic fluid is supplied to the pressure control valve 10 via the supply connection P.

For positioning the piston 20, the electromagnetic actuator 12 is designed with an axially movable plunger 34, which assumes its axial position as a result of the energization of the electromagnetic actuator 12. Fig. 1 shows the electromagnetic adjuster 12 in a non-energized state with the plunger 34 in a rest position. On its punch end 36, which is configured to face the piston 20, the punch is connected in contact with the piston 20. The piston 20 thus also moves axially when the plunger 34 moves.

In a second position of the pressure regulating valve 10, which is not illustrated in any further detail, the consumer connection a is charged with hydraulic fluid from the supply connection P. The piston 20 is then positioned by means of the plunger 34 in such a way that the first control groove 22 opens the first through-flow opening 26 and the second through-flow opening 28. The first control edge 38 of the first control groove 22, which is formed opposite the second through-flow opening 28, is moved axially toward the housing end 40 of the regulator housing 14, which is formed opposite the electromagnetic actuating device 12, to such an extent that a through-flow of the second through-flow opening 28 is possible, since the second control edge 72 of the first control groove 22, which is opposite the first control edge 38, is positioned in such a way that the first through-flow opening 26 is open.

The piston 20 has a cylindrical pin 44 on its end face 42 facing the housing end 40, which pin is received in a second receiving opening 46 formed in the piston 20. In the second receiving opening 46, the pin 44 is movable therein, in particular relative to the piston 20, and is positioned in the second receiving opening 46 coaxially with the piston 20.

The pin 44 is limited in its movement in the axial direction, which is configured opposite the piston 20, by a cover 48 which is designed opposite its pin end face 45. In relation to the pressure relationships present at the pressure regulating valve 10, the pin 44 has an acceleration.

A first variable volume V1 is formed between the second receiving opening 46 and the pin 44, which serves to damp the piston movement. For supplying the first volume V1 with hydraulic fluid, the piston 20 has an inlet opening 66 at the end region 62 of the second receiving opening 46 opposite the pin 44. The inlet opening 66 is formed in the piston 20 in such a way that a supply of hydraulic fluid to the first volume V1 and a discharge of hydraulic fluid can be brought about via the consumer connection a. A total of two inlet openings 66 are regularly provided on the circumference of the piston 20. Likewise, it is also possible to construct a plurality of input openings 66 or only one single input opening 66.

The pin 44 is supported on a cover 48, which is designed as a stop, wherein the pin is designed to engage in a third receiving opening 50 associated with the cover 48, which is designed coaxially with the longitudinal axis 18. The cover 48 serves to close the first receiving opening 16 of the housing end 40 in addition to receiving the pin 44. In other words, the cover 48 is designed to cause a substantially sealed covering of the regulator housing 14.

Starting from the third receiving opening 50 formed on the first element end face 80 of the rotationally symmetrical cover 48, the cover 48 has a fourth receiving opening 52 on its second element end face 82, which is formed opposite the first element end face 80.

The cover 48 is configured as a semi-hollow cylinder and has, along its cover axis 60, which is configured coaxially with the longitudinal axis 18, a section having a first diameter D1 and a section having a second diameter D2, wherein the first diameter D1 is configured to be larger than the second diameter D2. The first diameter D1 substantially corresponds to the inner diameter D1 of the first receiving opening 16. Preferably, the first diameter D1 is configured to create an interference fit between the regulator housing 14 and the cover 48. An additional safeguard against the cover 48 being released is designed in the form of a clamping element 54 which is configured to engage from the regulator housing 14 into the fourth receiving opening 52.

By means of the two diameters D1, D2, the cover 48 has a shoulder 56 comprising a shoulder face 84. A second compressible volume V2 is formed between the shoulder 56 disposed opposite the piston 20 and the regulator housing 14. For the controlled movement of the piston 20 during the displacement and for the resetting of the piston 20 in the direction of the electromagnetic actuator 12, a pretensioning element 64, which is embodied in the form of a helical spring in this embodiment, is arranged between the piston 20 and the cover 48.

The pretensioning element 64 is supported at one end on the shoulder 56 and at the other end on the piston 20. For a secure positioning, the pretensioning element 64 is accommodated at the other end in the second receiving opening 46, wherein it bears in contact there against a further shoulder 65 formed in the piston 20.

This further shoulder 65 serves, in addition to supporting the pretensioning element 64, to limit the axial piston movement, since the other section with the second diameter D2 is designed to protrude into the second receiving opening 46 and can be stopped against this further shoulder 65.

In order to prevent the pin 44 from lifting off the cover 48, the pressure regulating valve 10 according to the invention has a hydraulic end position damping 68 for damping the movement of the pin 44 in the direction of the cover 48. The hydraulic end-position damper 68 is characterized in that the pin 44 is hydraulically supported on its end which is formed opposite the piston 20. The hydraulic support is designed in such a way that a force is formed by the hydraulic fluid present between the pin end face 45, which is designed to face the cover 48, and the cover 48, said force counteracting the movement of the pin 44 and thereby damping the movement of the pin 44.

For the unloading of the second volume V2, an unloading opening 70 is provided in the regulator housing 14, which in the exemplary embodiment shown is embodied in the regulator housing 14 as a through-flow opening next to the tank connection T. The relief orifice 70 establishes a flow-through connection between said second volume V2 and the tank port T.

The relief opening 70 is formed in the pressure regulating valve 10 in such a way that the second volume V2 is completely filled with hydraulic fluid. In the illustrated embodiment, the horizontal position of the pressure regulating valve 10 is shown to correspond to its installed position. Thus, to reliably fill the second volume V2, the relief hole 70 is disposed above the pin 44 and the cap 48 at a 90 ° angle relative to the longitudinal axis 18.

In an embodiment not shown in detail, the unloading aperture 70 is connected in a fluidable manner to the tank interface T by means of a further connection in order to position it independently. In other words, the pressure regulating valve 10 can be installed independently of the position-oriented orientation of the relief opening 70, while ensuring a complete filling of the second volume V2.

For a quick fit on the outer circumference of the shoulder surface 84, the cover 48 has a chamfer 76, so that a simplified insertion of the cover 48 is possible. For a simple and reliable accommodation of the clamping element 54, the second element end face 82 is provided curved in the clamping element direction.

In order to ensure that the lifting of the pin 44 from the stop 48 is avoided, the pressure regulating valve 10 according to the invention, which is constructed according to fig. 2, has a pretensioning element 64 which engages on the pin 44. By means of the inherent pretensioning of the pretensioning element 64, the pin 44 is therefore pressed against the cover 48 under all pressure conditions applied to the pressure-regulating valve 10, wherein the pretensioning element 64 is designed according to the greatest possible pressure relationship.

For better illustration, fig. 3 shows the hydraulic unit 200 of the electromagnetic pressure regulating valve 10 according to fig. 2 in an enlarged manner, comprising the regulator housing 14, the piston 20, the pin 44 and the cover 48.

The pretensioning element 64 is therefore designed to be supported on the piston 20, on a further shoulder 65 designed to face the cover 48, and on the pin 44. The piston 20 is therefore returned further by means of the pretensioning element 64, wherein the pin 44 is simultaneously pressed against the cover 48 as a result of the pretensioning force. In other words, when the piston 20 is retracted in the direction opposite the cover 48, the pretensioning element 64 can extend on both sides, wherein it is pressed with its pretensioning force against the piston 20 on one side and against the pin 44 on the other side.

In a first exemplary embodiment, the pin 44 of the electromagnetic pressure regulating valve 10 according to the present invention has a cylindrical pin section 86 with a pin diameter DS, and a pin head 88 which is formed integrally with the pin section 86 and has a head diameter DK, wherein the head diameter DK is implemented larger than the pin diameter DS.

The pin head 88 is implemented spherically facing the lid 48. In other words, the head surface 90, which is configured to face the cover 48, is spherically configured. Likewise, the pin head 88 can also be designed convexly or spherically. The head surface 90 is the surface of the pin 44 that abuts the cover 48, and corresponds to the pin end surface 45.

The pin 44 has a pin seat 92 facing the pin head 88 for radially supporting the pretensioning element 64, which receives the pin section 86, on a support surface 94 of the pin head 88, which is formed opposite the head surface 90. The pin 44 is therefore designed to support the pretensioning element 64 in the axial direction and in the radial direction.

The diameter DV of the pretensioning element 64 is smaller than the diameter DK and larger than the diameter DS, in order to be able to obtain a reliable and free displaceability of the pretensioning element 64, which in this embodiment is implemented cost-effectively in the form of a helical spring.

The pin head 88 is configured to rest against the cover 48. For this purpose, the cover 48 is embodied as a semi-hollow cylinder, wherein the first element end face 80 of the cover is embodied as flat and extends over the entire first diameter D1. This results in a cost-effective manufacture of the cover 48 compared to the cover 48 of the prior art, which is embodied with two diameters D1, D2 and two receiving openings 50, 52.

The ball-shaped pin head 88 forms a point contact for optimum force transmission between the cover 48 and the pin 44. Likewise, the pin head 88 may also be configured to cause line contact. The first element end face 80, which makes convex curved contact with the pin 44, may also be of convex or spherical design, wherein in this case the head face 90 is preferably of flat design.

Fig. 4 illustrates a second exemplary embodiment of an electromagnetic pressure regulating valve 10 according to the invention, which is comparatively configured for this purpose. The cover 48 is designed to accommodate at least the pin head 88 and the pretensioning element 64 supported on the pin head 88. The head face 90 is embodied flat and rests against a convexly designed internal shoulder 96 of the cover 48, which is designed in the receiving opening 50. The cover 48 has an outlet opening 70, wherein an outlet opening is formed, which can be connected in a flow-through manner with a second volume V2.

In the present second exemplary embodiment, the cover 48 is produced cost-effectively in a deep-drawing process, wherein the inner shoulder 96 can be formed in a simple manner below the receiving opening 52 formed for receiving the clamping element 54.

The cover 48 of the pressure regulating valve 10 constructed according to the second exemplary embodiment has a relief opening 70, which is a flow-through connection of the first receiving opening 16 to the leakage tank connection TL. The relief opening 70 serves for discharging leakage liquid, in particular in the movement of the piston 20 for causing a fluid connection between the tank connection P and the supply connection a.

In the second exemplary embodiment, the pretensioning element 64 is designed to rest on a shoulder 102, which is formed on the lateral surface 100 of the piston 20. The shoulder 102 is receivable in the receiving opening 50 configured to face the pin 44 when the piston 20 is moved in the direction of the cap 48.

Fig. 5 shows a part of the third embodiment. In contrast to the first exemplary embodiment according to fig. 2, the pin 44 is of cylindrical design without a pin head or pin seat and rests with its end face 45 against the stop 48. In other words, the pins 44 have a unique diameter DS. The stop 48 has, for example, a projection 89 of convex design on its element end face 80.

The projection 89 can be formed in one piece on the stop 48. However, it is likewise conceivable, for example, to press a ball into the stop 48 or into a projection of the stop 48, so that a point or line contact between the pin 44 and the stop 48 can be established and thus the hysteresis effect caused by, for example, an angular error between the stop 48 and the pin 44 is reduced.

As can be seen from fig. 5, in this exemplary embodiment, the pin 44 is also guided axially displaceably in the second receiving bore 46. As a further difference, the pretensioning element 64 provided for pretensioning the pin 44 is not designed to contain the pin 44, but is positioned in the second receiving bore 46 between the piston 20 and the pin 44. Furthermore, the pretensioning element 64 rests against a further pin end face 91 facing away from the stop 48 and against a base 93 of the second receiving opening 46.

In addition, for the purpose of pretensioning the pin 44, the pretensioning element 64 moves the piston 20 into its zero position or into the starting position in the unenergized state of the electromagnetic actuating device 12.

A further spring element, not shown here, can be provided, which is arranged directly or indirectly between the piston 20 and the stop 48, pretensioning the piston 20 into its starting position.