System For Monitoring The Position Of A Valve Body In A Value Unit And A Value Unit For A Coolant Circuit Of An At Least Partially Electrically Driven

A system for monitoring the position of a valve body in a valve unit for a coolant circuit of an at least partially electrically powered vehicle includes: a valve housing for accommodating a valve body, wherein the valve body is accommodated in the valve housing between a first position, in which the valve body is arranged in contact with a valve seat and closes the valve unit, and a second position, in which the valve body is spaced from the valve seat and the valve unit is at least partially open, a piston rod for transmitting a drive movement to the valve body, wherein the piston rod includes a recess for accommodating a permanent magnet, and a sensor unit fixedly arranged in relation to the valve seat and designed to detect a position of a permanent magnet accommodated in the recess.

FIELD OF THE INVENTION

The invention relates to a system for monitoring the position of a valve body in a valve unit for a coolant circuit of an at least partially electrically powered vehicle. Furthermore, the invention relates to a valve unit for a coolant circuit of an at least partially electrically driven vehicle.

BACKGROUND OF THE INVENTION

Various types of sensors are used in the prior art to monitor the position of valve bodies in valve units. Depending on the specific application, it may be very important to detect the exact position of the valve body. For example, the exact position of the valve body in relation to the valve seat of the valve unit can be used to determine the possible flow rate of a coolant.

Monitoring the position of valve bodies is a safety-relevant aspect, especially in the field of motor vehicles. For example, components such as battery or brake systems are cooled by coolant, which is why the position of valve bodies within such coolant circuits is of great importance. The position of the valve body is therefore relevant for the functionality of safety-relevant components in a motor vehicle. The sensors are preferably accommodated on the drive of the valve unit.

A disadvantage of the prior art is that position measurement on the drive is associated with uncertainties. For example, the transmission of a drive movement of the drive to a valve body may be disturbed or defective. As a consequence, it is no longer possible to determine the actual position of the valve body. This results in major safety risks in the operation of motor vehicles.

BRIEF SUMMARY OF THE INVENTION

The task of the invention is to propose a system for monitoring the position of a valve body which belongs to the technical field mentioned at the beginning and which at least partially overcomes the disadvantages of the prior art. Furthermore, it is the task of the invention to provide a valve unit for a coolant circuit and a motor vehicle with such a system and/or valve unit.

An embodiment of the invention comprises a system for monitoring the position of a valve body in a valve unit for a coolant circuit of an at least partially electrically driven vehicle. The system comprises a valve housing for accommodating a valve body, wherein the valve body is designed to be transferable in the valve housing between a first position, in which the valve body is arranged in contact with a valve seat and closes the valve unit, and a second position, in which the valve body is spaced apart from the valve seat and the valve unit is at least partially open. The system also comprises a piston rod for transmitting a drive movement to the valve body, with the piston rod comprising a recess for arranging a permanent magnet. In addition, the system comprises a sensor unit which is permanently accommodated in relation to the valve seat and is designed to detect the position of a permanent magnet accommodated in the recess of the piston rod.

This presents the technical advantage, for example, that the position of the valve body is not measured at the actuator. This increases the reliability of the position determination because possible interference or interruptions between the drive and the valve body are eliminated as a source of error. Another advantage is that the magnet is not accommodated directly on the valve body itself, which further improves the quality of the measurement. By arranging the magnet on the piston rod, the measuring accuracy can be increased and the assembly of the valve unit simplified.

Definitions

A valve housing within the meaning of the present invention is used for the flow of refrigerant through the valve unit, wherein the valve body is arranged in the valve housing and can determine the flow rate of the refrigerant through the valve unit by its position relative to the valve seat. When the valve body is fully seated in the valve seat of the valve housing, the valve housing is closed and no refrigerant can flow through the valve unit. When the valve body is spaced from the valve seat, the valve unit is open to the flow of refrigerant and the extent of the distance between the valve body and the valve seat determines the possible flow rate of fluid through the valve body.

A piston rod in the sense of the present invention is understood as a direct connecting means which transmits an axial drive movement directly to the valve body.

According to a preferred embodiment, the valve body is transferred in the valve housing between a first position and a second position in the direction of a piston rod longitudinal axis L. This achieves the technical advantage, for example, that the movement of an actuator is transferred directly to the valve body. The direct transfer from the piston rod to the valve body enables particularly precise position measurement.

According to a further embodiment, the valve body and the recess are arranged at a distance from each other in the direction of the piston rod longitudinal axis L. This achieves the technical advantage, for example, that the valve body can be designed to be completely flow- and function-optimized. The valve body therefore does not have to include a recess for accommodating a permanent magnet, which greatly simplifies the provision of the valve body. Due to the spacing in the direction of the longitudinal direction of the piston rod, the position detection function of the valve body can be carried out at a distance from the piston rod.

According to a particularly preferred embodiment, a distance between the valve body and the recess in the direction of the piston rod longitudinal axis L is greater than a diameter of the valve body.

According to a further embodiment, the recess is radially spaced with respect to a piston rod longitudinal axis L and is arranged facing a side wall of the valve housing.

An important factor for the quality and accuracy of the signal output by the sensor is that the magnetic field strength is sufficiently high to hit the operating range of the sensor. This can be realized in particular by keeping the so-called air gap as small as possible and constant between a first position and a second position during the transfer of the valve body in the direction of the piston rod longitudinal axis L. The air gap thus corresponds to the geometric distance between the detecting sensor unit and the permanent magnet.

By arranging the recess for accommodating the permanent magnet facing the side wall of the valve housing, the air gap and the dimensions of the permanent magnet can be minimized. Overall, this can reduce manufacturing costs and improve the function of the system.

According to a particularly preferred embodiment, the recess comprises a latching mechanism for fixing a permanent magnet. This can, for example, achieve the technical advantage that the assembly of the system and the installation of the system in a valve unit can be carried out particularly efficiently and without assembly errors. The permanent magnet is configured to only be mounted in a very specific way, which is predetermined by the latching mechanism.

To further simplify the assembly of the permanent magnet, the latching mechanism comprises a first clamping arm and a second clamping arm for gripping around a permanent magnet. The permanent magnet is clamped in position by the first clamping arm and the second clamping arm. The clamping arms are arranged symmetrically to each other, whereby the position of the permanent magnet is precisely fixed in the middle between the clamping arms.

According to an additional embodiment, the valve housing comprises a bearing element for axially guiding the piston rod when transferring between a first position and a second position. This achieves the technical advantage, for example, that the piston rod is guided with particular precision. The precise guidance of the piston rod additionally improves the position measurement of the permanent magnet and thus of the valve body.

According to another preferred embodiment, the system comprises an anti-rotation device to prevent the piston rod from rotating relative to the valve housing. This achieves, for example, the technical advantage that the precision of the position detection of the permanent magnet is additionally improved. As already mentioned, it is important for the quality and accuracy of the signal output by the sensor that the magnetic field strength is sufficiently high to hit the sensor. For this purpose, the air gap should be as small as possible and should remain constant between a first position and a second position during the transfer of the valve body in the direction of the piston rod longitudinal axis L. The anti-rotation device prevents the piston rod from rotating relative to the valve housing. As a result, it is no longer necessary to use a large, specifically adapted magnetic ring, which on the one hand would require fluidic openings and on the other would cause high costs. In combination with the bearing element, the air gap and the dimensions of the permanent magnet are also minimized. The expensive magnetic material can be reduced to a minimum with high precision in position detection.

In order to additionally minimize the air gap and to further improve position detection, the anti-rotation device comprises a guide means for guiding the recess when transferring the valve body between a first position and a second position.

According to a particularly preferred embodiment, the first clamping arm and the second clamping arm are designed to slide on the guide means when transferring the valve body between a first position and a second position.

In order to additionally improve the guidance of the bearing element, the guide means comprises a first guide arm and a second guide arm, with the first guide arm and the second guide arm axially guiding the recess. This achieves the technical advantage, for example, that the guide means has a dual function. On the one hand, the guide means serves as an anti-rotation device. On the other hand, the guide means supports the bearing of the recess and thus the axial bearing of the piston rod. Overall, this results in a highly precise position detection of the permanent magnet, whereby the assembly of the system is particularly simple and error-free.

According to an alternative embodiment, the anti-rotation device is arranged on the bearing element, whereby the piston rod is designed to be non-rotatable in relation to the bearing element. This embodiment also presents the technical advantage, for example, that the piston rod is guided with particular precision. The precise guidance of the piston rod additionally improves the position measurement of the permanent magnet and thus of the valve body.

According to a particularly preferred embodiment, the sensor unit comprises a Hall sensor.

In order to make installation and maintenance of the valve unit particularly easy, the valve housing comprises a housing for accommodating the sensor unit and control electronics for the system, with the housing being arranged directly adjacent to the side wall of the valve housing.

For example, the entire electronics of the valve unit can be arranged in the housing. In this way, the components of the electronics are housed in an easily accessible location and are not distributed throughout the valve unit. This reduces the manufacturing costs and the assembly effort of the system and the valve unit.

According to a further aspect, the problem of the invention is solved by a valve unit for a coolant circuit of an at least partially electrically driven vehicle, with a system according to one of the above embodiments.

The advantages are essentially comparable to those of the above embodiments. In particular, for example, the technical advantage is achieved that the position of the valve body within the valve unit is not measured at the drive. This increases the reliability of the position determination because possible interference or interruptions between the drive and the valve body are eliminated as a source of error. Another advantage is that the magnet is not arranged directly on the valve body itself, which further improves the quality of the measurement. By arranging the magnet on the piston rod, the measuring accuracy can be increased and the assembly of the valve unit can be simplified.

According to a particularly advantageous embodiment, the valve unit comprises a control valve or a changeover valve. A further subsidiary aspect of the invention relates to a vehicle, in particular a motor vehicle, with a system and/or a valve unit according to one of the preceding embodiments. The advantages are essentially comparable to those of the preceding embodiments.

Further advantageous embodiments and combinations of features of the invention result from the following detailed description and the entirety of the patent claims.

In principle, identical parts are marked with identical reference signs in the figures.

DETAILED DESCRIPTION

FIG.1shows a perspective sectional view of an embodiment of a system100according to the invention for monitoring the position of a valve body220in a valve unit200for a coolant circuit of an at least partially electrically driven vehicle.

The system100comprises a valve housing210for accommodating a valve body220. The valve body220is used to regulate a coolant flow, wherein the valve body220is configured to be transferred between a position in contact with the valve seat230, in which the valve body220closes off the coolant flow through the valve housing210, and an open position, in which the valve body220is spaced apart from the valve seat230and thus allows a coolant flow through the valve housing210. Depending on the distance between the valve seat230and the valve body220, the volumetric flow rate of the coolant can be controlled. The valve body220is actuated by an actuator, the movement of the actuator being transmitted to the valve body220by means of a piston rod222.

In addition, the piston rod222comprises a recess240, which is designed to accommodate a permanent magnet300. Thus, the piston rod222serves on the one hand as an actuating element of a linear actuator and on the other hand as a holder for a permanent magnet300. The permanent magnet300can now be used by means of a housing-integrated sensor unit250(not shown) for position feedback of the piston rod222. Thus, the housing-integrated sensor unit250is fixed with respect to the valve seat230and is configured to detect the position of a permanent magnet300disposed in the recess240. Due to the linear drive and the transmission of the drive movement via the piston rod222to the valve body220, the piston rod222and the valve body220move in the direction of a piston rod longitudinal axis L.

The recess240is spaced from the valve body in the direction of the piston rod longitudinal axis L in order to make the position detection of the permanent magnet300as independent as possible of fluid turbulence and pressure differences. In addition, the precision of the position detection is improved by the recess240facing radially from the piston rod longitudinal axis L towards the side wall212of the valve housing210. This arrangement particularly improves the use of position measurement with a permanent magnet300and a sensor unit250in the form of a Hall sensor. The Hall sensor is configured to detect the change in the magnetic field through its current-carrying Hall elements and thus report back the current position by means of an electrical signal. This requires a strong external magnetic field, which is provided by the permanent magnet300. The permanent magnet300is firmly connected to the piston rod222. The field strength of the permanent magnet300is decisive for the quality and accuracy of the sensor-side signal in order to hit the working range of the Hall sensor. The geometric distance between the detecting sensor unit250in the form of the Hall sensor and the permanent magnet300is decisive for this function. It is therefore advantageous in terms of design to realize the smallest possible geometric distance, because this also allows the dimensions of the permanent magnet300to be reduced. This saves weight and manufacturing costs.

Between the valve body220and the recess240, the piston rod222is guided by a bearing element260. The bearing element260additionally supports the accuracy of the position detection. The bearing element260is located in the flow channel of the valve housing210and comprises openings that allow the refrigerant to flow through the valve housing210.

FIG.2shows a sectional view of a part of the system100according to the invention, showing the piston rod222with the recess240, wherein a permanent magnet300is arranged at the recess240. The piston rod222is arranged in the valve housing210along the piston rod longitudinal axis L and is guided by the bearing element260. The valve housing210comprises a further housing211, which is configured for accommodating the sensor unit250and other electronic components of the valve unit200. The housing211is preferably separated from the valve housing210and accessible via a separate opening; for example, the entire electronics such as a control unit and other electronic components are configured to be accommodated in the housing211. Preferably, the housing211is hermetically sealed, whereby separation from cooling water and the environment would be realized. This results in further advantages such as cooling of the electronic components by passing refrigerant in the valve housing210and precise position detection of the permanent magnet300through the side wall212between the housing211and the valve housing210by means of the sensor unit250in the form of a Hall sensor.

FIGS.3A to3Ceach show a perspective view of a recess240including a permanent magnet300.

The recess240comprises a latching mechanism242for accommodating a permanent magnet300. The latching mechanism242comprises two clamping arms243,244arranged in parallel, which comprise a space between them for accommodating a permanent magnet300. Here, the first clamping arm243and the second clamping arm244are designed to grip around a permanent magnet300, with the clamping arms243,244clamping the permanent magnet300by an elastic restoring force and thus forming the latching mechanism242.

FIG.3Ashows the permanent magnet300outside the recess240, with the directional arrow indicating the direction of insertion of the permanent magnet300into the recess240.

FIG.3Bshows the permanent magnet300in the recess240. The latching mechanism242has gripped the permanent magnet300with the first clamping arm243and the second clamping arm244, and the permanent magnet300is in a fixed state in the recess240.

FIG.3Cshows a cross-sectional view of the permanent magnet300in the recess240.

FIG.4Ashows a further perspective sectional view of an embodiment of a system100according to the invention. The illustration again shows the piston rod222with the recess240and the valve body220, wherein a permanent magnet300is arranged at the recess240. The piston rod222is arranged in the valve housing210and is guided by the bearing element260. In addition, the system100comprises an anti-rotation device262which blocks rotation of the piston rod222relative to the valve housing210. The anti-rotation device262comprises a guide means263in the form of two guide arms264,265(not shown) arranged in parallel on the side wall212of the valve housing210. The guide means263blocks the rotation of the piston rod222relative to the valve housing210but guides the recess240—including a permanent magnet300arranged in the recess—when transferring the valve body220in the direction of the piston rod longitudinal axis L between a first position and a second position. Here, the first clamping arm243and the second clamping arm244of the recess240slide between the guide arms264,265arranged on the side wall212of the valve housing210in the direction of the piston rod longitudinal axis L.

FIG.4Bshows a cross-sectional view of an embodiment of a system100according to the invention, showing the anti-rotation device262which blocks rotation of the piston rod222relative to the valve housing210. The anti-rotation device262comprises the guide means263with the first guide arm264and the second guide arm265. The guide means263guides the recess240with the permanent magnet300in the direction of the piston rod longitudinal axis L. The first guide arm264and the second guide arm265embrace the recess240like a clamp, so that the recess240must be clipped between the first guide arm264and the second guide arm265. As a result, the recess240is additionally guided in the piston rod longitudinal axis L, which additionally improves the quality of the position detection of the permanent magnet300and thus of the valve body220.

FIG.5Ashows a perspective view of a recess240and an anti-rotation device262of an embodiment of a system100according to the invention.

The illustration shows the piston rod222with the recess240, wherein a permanent magnet300is arranged at the recess240. The piston rod222is guided in the direction of the piston rod longitudinal axis L via a bearing element260. In addition to guiding the piston rod222in the direction of the piston rod longitudinal axis L, the anti-rotation device262blocks rotation of the piston rod222relative to the valve housing210(not shown). This anti-rotation device262is realized in that the piston rod222is designed to be non-rotatable in relation to the bearing element260. In this case, the cross-section of the piston rod222is not rotationally symmetrical, with the guide opening of the bearing element260being adapted to the non-rotationally symmetrical cross-sectional shape.

FIG.5Bshows a cross-sectional view of an embodiment of an anti-rotation device262of the system100according to the invention. The cross-section of the piston rod222is not rotationally symmetrical. In the present embodiment, the cross-section of the piston rod222is oval. Alternatively, however, the cross-section could be triangular, square or any other cross-sectional shape that prevents rotation between the piston rod222and the bearing element260.

LIST OF REFERENCES