CN215445169U

CN215445169U - Reversing valve, preferably for a coolant

Info

Publication number: CN215445169U
Application number: CN202120936800.XU
Authority: CN
Inventors: 托尼·施奈德; 迪特·迈什; 哈特莫特·韦伯
Original assignee: Eco Holding 1 GmbH
Current assignee: Eco Holding 1 GmbH
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2022-01-07
Anticipated expiration: 2031-04-30

Abstract

The utility model relates to a reversing valve, preferably for a coolant, having at least two switching positions and comprising a valve housing and a valve piston which is axially displaceable in the valve housing along a longitudinal axis and a drive device which axially displaces the valve piston, wherein the valve housing has a radial connection, wherein two working connections are provided between which a pressure connection is provided, wherein the valve piston is designed in a pressure-balanced manner.

Description

Reversing valve, preferably for a coolant

Technical Field

The utility model relates to a reversing valve, preferably for a coolant.

Background

In the case of fluid systems for at least partially electrically driven motor vehicles, the switching valve is subject to different requirements. These requirements are for example:

the medium can be applied in a liquid or gaseous state of aggregation

Very high internal tightness requirements also for gaseous media

Almost absolute sealing against the outside, also for gaseous media

Ports on the valve without pressure relief

High flow requirement

Since the interface of the directional valve is not pressure relieved, decompression cannot be safely performed.

Disclosure of Invention

The object of the present invention is to provide a reversing valve, preferably a coolant valve, which meets the above requirements and enables a safe pressure reduction.

This object is achieved by a reversing valve preferably for a coolant,

the switching valve has at least two switching positions and comprises a valve housing and a valve piston which is axially displaceable in the valve housing along a longitudinal axis and a drive device which axially displaces the valve piston. The valve housing has a radial connection, two working connections being provided, between which a pressure connection is provided, the valve piston being designed in a pressure-balanced manner.

Further advantages of the utility model are given by the description and the drawings.

In the reversing valve described above, the valve piston has a spherical section, wherein the spherical section can be placed against the valve housing in order to seal the respective non-pressurized working connection from the pressure connection.

In the reversing valve described above, a second sealing member is provided for sealing the working ports from each other.

In the reversing valve described above, the second seal is provided as a double-acting rod seal or comprises two single-acting rod seals.

In the reversing valve described above, components acting in both operating directions of the valve piston are arranged in the stepped installation space, wherein the components comprise a helical spring which can bear against two thrust bearings.

In the above-mentioned reversing valve, a stop geometry is provided in order to limit the stroke of the reversing valve to a preset number of revolutions.

In the above-described reversing valve, a speed reduction device is provided for detecting the axial position of the drive shaft of the drive device.

The utility model is further explained below with the aid of a description of embodiments and with reference to the drawings. Further advantageous embodiments and combinations of features of the utility model are given in the following description.

Drawings

In the drawings which illustrate embodiments:

FIG. 1 shows a side view of a reversing valve according to the present invention;

fig. 2 shows a longitudinal section through the reversing valve according to fig. 1;

fig. 3 shows a longitudinal section through a reversing valve according to a second embodiment.

Detailed Description

Figure 1 shows a two-position, three-way reversing valve 1 according to the utility model in a side view. The directional control valve 1 is used, for example, as a coolant valve in a fluid system of an at least partially electrically driven motor vehicle.

The directional valve 1 has two switching positions and comprises a valve housing 2 and a valve piston 3 which is axially displaceable in the valve housing 2 along a longitudinal axis and a drive device 4 which axially displaces the valve piston. The drive 4 is formed, for example, by a motor 5 and has a hollow shaft 6, in which hollow shaft 6 a central drive shaft 7 is arranged.

The hollow shaft 6 is arranged in a drive housing 8, the drive housing 8 being connected to the valve housing 2 in a sealing manner.

The drive shaft 7 is driven by the rotor 9 of the motor 5, so that the rotational movement of the drive shaft 7 allows an axial movement of the valve piston 3.

The valve housing 2 arranged in the housing 10 has three radial ports B, A, C, two working ports B, C being provided, and a pressure port a being arranged between the working ports B, C.

When the piston diameter is large, in particular when the pressure difference is large, a large hydraulic/pneumatic force acting axially on the valve piston 3 is often formed in the valve. This requires a greater actuating force. This in turn has to be prepared for provision by a correspondingly large driving force.

Since it is not defined that any of the working ports B, C can be relieved of pressure, it must be taken into account that the resultant force generated on the valve piston 3 to move the valve piston 3 in a first operating direction is as great as the force to move the valve piston 3 in an opposite second operating direction. The valve piston 3 is thus pressure-balanced.

Thereby, the valve piston 3 can always be moved in the valve with a low force irrespective of the pressure requirement. This is achieved by the shaping of the valve piston 3, as is achieved by the connection of the interior of the two end faces of the piston.

The pressure compensation of the valve piston 3 is achieved by means of a nested bushing design. This allows the valve piston 3 with a larger diameter to be inserted into the media area (port a). The media zones, by virtue of their symmetry, can provide seats in each operating direction, respectively. Thus, it is ensured that there is a force balance (pressure balance) not only when the valve piston abuts against the seat a/B, but also when the valve piston abuts against the seat a/C.

As can be seen in particular from the longitudinal section according to fig. 2, the valve piston 3 has a spherical section 11, which can be placed against the valve housing 2 in order to seal the respective non-pressurized working connection B or C from the pressure connection a.

In other words, the reversing valve 1 has a ball seat in order to provide the necessary high tightness.

Even if there are geometrical defects or if the valve piston 3 is tilted due to play, the spherical closing body (segment 11) will still reliably seal its respective seat on the valve housing 2.

Since the valve piston 3 is pressure-balanced, a second seal is also required on the valve piston 3, which separates the two working connections B, C from one another, so that no medium can flow from the first working connection B to the second working connection C via the pressure-balanced connection to the valve piston 3. The seal is a double-acting rod seal 12 or a single-acting rod seal comprising two correspondingly arranged rods.

The stem seal 12, which can project due to minimal leakage and low operating forces when moving the valve piston 3, can additionally have a plastic ring.

In order to reliably close the two valve seats, a defined pretension (axial force) is required in the seat. Since the drive means by means of the drive shaft 7 is substantially inelastic when entering the seat and this can therefore lead to a tensioning of the system, assemblies 13 acting in both operating directions are additionally provided. The assembly 13 is outstanding in performance because of the coil spring 14 and the stepped installation space 15. The stepped installation space 15 allows two thrust bearings to be produced, on which the inserted component 13 can be supported. Thereby, the same axial force acts on the respective valve seat in both operating directions, in relation to the axial inclination and the spring constant of the drive shaft 7, after the valve piston 3 has been seated against the seat surface. Since the elastic component counteracts cost-related influences, for example, due to component tolerances, the component costs can additionally be reduced thereby.

Fig. 3 shows a longitudinal section through a second embodiment of the reversing valve 1 according to the utility model.

The reversing valve 1 is constructed essentially identically to the first described embodiment. Only the differences will be explained.

In order to limit the stroke of the directional control valve 1 to a predetermined number of revolutions, a stop geometry is used, which is implemented by two interlaced

screws

16, 17.

In order to detect the shaft position of the drive shaft 7, a reduction gear (cycloid drive 18) is provided. The reduction gear is outstanding in performance because of a very large reduction ratio. Thus, when the reduction ratio is properly selected, the total number of revolutions can be reduced to exactly one revolution (maximum 360 °) on the rolling disc 19 (driving disc). The detection of the absolute position can be carried out by means of a magnetic target 20 with polarity, which is mounted on the roller disk 19, and a hall element, not shown, positioned at the end side, which makes a 360 ° measurement.

The cycloid drive 18 furthermore has a cam disk 21, an eccentric 22, a cycloid disk 23 and a spring 24.

Claims

1. A reversing valve for a coolant, having at least two switching positions and comprising a valve housing and a valve piston which is axially displaceable in the valve housing along a longitudinal axis, and a drive device which axially displaces the valve piston, wherein the valve housing has radial connections, wherein two working connections are provided, a pressure connection being provided between the working connections, wherein the valve piston is pressure-balanced.

2. The reversing valve according to claim 1, characterized in that the valve piston has a spherical section, wherein the spherical section can be placed against the valve housing in order to seal the respective non-pressurized working connection from the pressure connection.

3. The reversing valve according to claim 2, wherein a second seal is provided for sealing the working ports from each other.

4. A reversing valve according to claim 3, characterized in that the second seal is provided as a double-acting rod seal or comprises two single-acting rod seals.

5. The reversing valve according to any of claims 1 to 4, characterized in that components acting in both operating directions of the valve piston are arranged in stepped installation spaces, wherein the components comprise a helical spring which can bear against two thrust bearings.

6. A reversing valve according to any of claims 1-4, characterized in that a stop geometry is provided in order to limit the stroke of the reversing valve to a preset number of revolutions.

7. The reversing valve of claim 5, wherein a stop geometry is provided to limit the stroke of the reversing valve to a preset number of revolutions.

8. A reversing valve according to any of claims 1-4, characterized in that for detecting the axial position of the drive shaft of the drive means, a speed reduction means is provided.

9. A reversing valve according to claim 5, characterized in that for detecting the shaft position of the drive shaft of the drive means, a reduction means is provided.

10. A reversing valve according to claim 6, characterized in that for detecting the shaft position of the drive shaft of the drive means, a reduction means is provided.