Switchable hydraulic mount

Abstract

Switchable hydraulic mount (1), comprising: a first fluid chamber (3) which is partially bounded by a spring body (2), a second fluid chamber (5) which is fluidically connected to the first fluid chamber (3) via at least one fluid channel (9), so that a damping fluid can flow between the first fluid chamber (3) and the second fluid chamber (5) when the spring body (2) compresses and rebounds, a decoupling element (8) for decoupling the first and the second fluid chamber (3, 5), wherein the decoupling element (8) is arranged between the first fluid chamber (3) and a decoupling chamber (10) and fluidically separates them from each other, wherein the decoupling chamber (10) has a ventilation duct (11), and a switchable valve (12) which can selectively open or close the decoupling chamber (10) to the environment in order to change a decoupling effect of the decoupling element (8), wherein the switchable valve (12) has a valve housing (17) with a linear actuator arranged therein, wherein the linear actuator has an actuator head (22) which can be moved in the valve housing (17) between a closed position and an open position, wherein the valve housing (17) has at least one valve opening (19) which is fluidically connected to the ventilation channel (11) of the decoupling chamber (10), and which in the open position connects the decoupling chamber (10) to the environment and in the closed position is closed by the actuator head (22), wherein the ventilation channel (11) is otherwise sealed to the environment by the valve housing (17), and wherein the valve opening (19) runs at least in sections substantially transversely to the axis of movement (BA) of the actuator head (22).

Description

[0001] The present invention relates to a switchable hydraulic bearing.

[0002] Switchable hydraulic bearings, hereinafter referred to as hydraulic bearings, are known in the prior art, in which the decoupling effect of a decoupling membrane can be changed by closing an opening of a decoupling chamber using a linear actuator. The decoupling membrane is arranged between the fluid-filled working chamber and the air-filled decoupling chamber, fluidly separating these chambers. When the opening is closed, the volume of air enclosed in the decoupling chamber acts as an air spring. The spring stiffness depends, among other things, on the size of the decoupling membrane and the volume of the decoupling chamber. When the opening of the decoupling chamber is closed, the spring stiffness of the enclosed air volume is high; that is, when the decoupling membrane is deflected, the spring stiffness of the enclosed volume opposes the deflection.Conversely, opening the decoupling chamber reduces the spring stiffness, as the decoupling chamber is no longer a closed, fluid-tight volume but is connected via channels to other large volumes or the environment, and fluid exchange occurs when the diaphragm is deflected. As a result, the spring stiffness below the diaphragm decreases significantly, and consequently, so does the transmission of vibrations at certain excitation frequencies and amplitudes (decoupling).

[0003] The decoupling also means that the working chamber is decoupled from the collection chamber, so that fluid exchange between the working chamber and the collection chamber via the damping channel essentially does not occur, and therefore no hydraulic damping takes place. With the decoupling chamber open, the hydraulic bearing therefore exhibits low stiffness and low hydraulic damping for the specific excitation frequencies and amplitudes.

[0004] If, however, the opening of the decoupling chamber is closed by means of the linear actuator, no air can escape from the decoupling chamber into the environment. As a result, the decoupling membrane deflects less due to the spring stiffness of the air in the decoupling chamber. Depending on the deflection of the decoupling membrane, an overpressure or underpressure is created, which opposes the deflection. This reduces the decoupling effect of the decoupling membrane, and at specific excitation frequencies and amplitudes, the working fluid essentially flows back and forth between the working chamber and the collection chamber via the damping channel. Thus, with the decoupling chamber closed, the hydraulic mount exhibits high stiffness and high damping. In this way, for example, the stiffness and damping characteristics of engine mounts can be selectively altered when the vehicle is stationary and idling by switching the linear actuator.The switchable hydraulic bearings described above are disclosed, for example, in EP 1 443 240 A1 or WO 01 / 63 138 A1.

[0005] DE 10 2008 015 370 A1 discloses a switchable elastic bearing, in particular an engine mount for a motor vehicle, comprising an elastomer ring body as a support body with a central bearing core and a cup-shaped bearing housing, as well as a working chamber filled with hydraulic fluid within the bearing. The working chamber is bounded by a nozzle plate with an integrated decoupling membrane and an adjoining air chamber, wherein the air chamber can be vented to the ambient atmosphere via a vent channel with a switchable valve unit, with a compensating chamber adjoining the nozzle plate and bounded by a compensating membrane, which is connected to the working chamber via a damping channel, and with a space between the compensating membrane and the bearing housing with at least one vent opening.The vent channel is extended via the switchable valve unit and a connecting channel into the space below the compensating membrane.

[0006] DE 43 25 730 A1 discloses a device for vibration control, such as a hydraulically damped mounting device, which has a gas pocket partially bounded by a diaphragm subjected to vibration. In a hydraulically damped mounting device, the vibrations are transmitted to the diaphragm by means of a hydraulic fluid in a chamber partially bounded by a deformable wall connecting a first anchoring part and a second anchoring part. The gas pocket has a valve outlet and is also bounded by a movable part, which is movable in response to pressure changes in the gas pocket.

[0007] However, conventional switchable hydraulic mounts have the problem that high actuation forces from the linear actuator are required to close the decoupling chamber opening against the applied pressures and keep the chamber closed. Due to these high actuation forces, large and expensive linear actuators are used in switchable hydraulic mounts. Furthermore, the opening and closing noises of conventional switchable hydraulic mounts can be very loud and disruptive due to these high actuation forces.

[0008] It is therefore an object of the present invention to provide a switchable hydraulic bearing that requires low actuating forces of the linear actuator and thus allows the use of smaller, cheaper linear actuators and produces low closing noises.

[0009] This problem is solved by the subject matter of the independent claim. Preferred embodiments are set forth in the dependent claims.

[0010] According to one aspect of the present invention, a switchable hydraulic mount is provided, comprising: (i) a first fluid chamber which is partially bounded by a spring body, (ii) a second fluid chamber which is fluidically connected to the first fluid chamber via at least one fluid channel, so that a damping fluid can flow between the first fluid chamber and the second fluid chamber when the spring body compresses and rebounds, (iii) a decoupling element for decoupling the first and the second fluid chamber, wherein the decoupling element is arranged between the first fluid chamber and a decoupling chamber and fluidically separates them from each other, the decoupling chamber having a ventilation channel, and (iv) a switchable valve which selectively opens the decoupling chamber to the environment (ora switchable valve which can open or close channels that are connected to the environment in order to change a decoupling effect of the decoupling element, wherein the switchable valve has a valve housing with a linear actuator arranged therein, wherein the linear actuator has an actuator head that can be displaced in the valve housing between a closed position and an open position, wherein the valve housing has at least one valve opening which is fluidically connected to the ventilation channel and which, in the open position, connects the decoupling chamber to the environment and, in the closed position, is closed by the actuator head, wherein the valve opening extends, at least section by section, substantially transversely to the axis of movement of the actuator head.

[0011] Advantageously, the configuration of the switchable hydraulic bearing according to the invention allows the valve opening to close with low actuation force of the linear actuator, since at least one component of the flow direction of the oscillating airflow from the decoupling chamber through the valve opening runs at least partially transversely to the axis of movement of the actuator head of the linear actuator. The linear actuator therefore does not have to work completely against the underpressures or overpressures of the flow that develop, particularly during opening and closing. This allows the use of smaller, more economical linear actuators and reduces the opening and closing noise.

[0012] The switchable hydraulic mount can be, for example, an engine mount or a suspension mount. The first and second fluid chambers and the fluid channel of the hydraulic mount are filled or can be filled with a damping fluid. The first fluid chamber is partially bounded by the spring body, meaning that the first fluid chamber can be partially formed within the spring body. The first fluid chamber can also be referred to as the working chamber. The spring body can comprise elastomeric material and can have a substantially conical cross-section through the longitudinal axis of the hydraulic mount. The spring body can have a mounting port for connecting to a device to be damped, such as an engine. The mounting port can be located along the longitudinal axis of the hydraulic mount. A partition plate or channel disc can be arranged between the first and second fluid chambers to delimit them.The fluid channel, which can also be referred to as a damping channel, is preferably arranged in the partition plate. The switchable valve can be arranged on the partition plate, preferably on the side of the second fluid chamber. The second fluid chamber, which can also be referred to as a collecting chamber, is preferably partially delimited by an elastomeric bellows. The hydraulic mount can be designed to be substantially axially symmetrical.

[0013] The decoupling chamber and the decoupling element can be arranged or formed within the partition plate. The decoupling element can be designed as an elastomeric decoupling membrane clamped in the partition plate, which delimits the decoupling chamber towards the first fluid chamber. The decoupling chamber can have a ventilation channel, which can be formed within the partition plate. The switchable valve can be arranged in the hydraulic mount such that the ventilation channel is fluidically connected to the valve opening, but is otherwise sealed to the environment by the valve housing.

[0014] When the spring element compresses due to a load on the hydraulic mount, the volume of the first fluid chamber decreases, increasing the pressure of the damping fluid inside. This causes the decoupling element to deform elastically into the decoupling chamber, and simultaneously, at least some of the damping fluid flows from the first fluid chamber through the fluid channel into the second fluid chamber. When the spring element rebounds as the hydraulic mount is unloaded, the decoupling element elastically returns to its original shape or deforms into the first fluid chamber, and the damping fluid flows back from the second fluid chamber into the first.

[0015] The deformation of the decoupling element is strongly dependent on the compression and rebound speed, or rather on the frequency and amplitude of the compression and rebound, since pressure equalization occurs between the first and second fluid chambers over time. The frequency and amplitude of the compression and rebound can also be referred to as the excitation frequency and excitation amplitude.

[0016] Furthermore, the deformation of the decoupling element is also strongly dependent on the pressure prevailing in the decoupling chamber. With the decoupling chamber open, the ambient pressure is essentially constant, whereas with the decoupling chamber closed, the pressure changes due to the volume change caused by the deformation of the decoupling element, and a large counter-pressure is generated within it, particularly during compression.

[0017] The switchable hydraulic mount is preferably configured such that, at predetermined or predeterminable excitation frequencies and / or excitation amplitudes, the first fluid chamber is decoupled from the second fluid chamber, meaning that fluid exchange between the first and second fluid chambers via the fluid channel essentially does not occur. At these excitation frequencies and / or excitation amplitudes, the volume change of the first fluid chamber is then essentially completely absorbed by the deformation of the decoupling element. With the decoupling chamber open, the decoupling element thus exhibits a high decoupling effect, which means that the hydraulic mount, with the decoupling chamber open, has low stiffness and low damping for these specific excitation frequencies and amplitudes. At higher frequencies, i.e., well above the resonance frequency of the oscillation, the decoupling effect is significantly reduced.Due to the fluid's inertia, no significant fluid exchange occurs between the first and second fluid chambers during vibration of the fluid in the fluid channel. This means that even in this frequency range, opening or closing the decoupling chamber can significantly increase or decrease the stiffness. The hydraulic mount can be configured to exhibit a high decoupling effect of the decoupling element at excitation frequencies and / or amplitudes that typically occur during idling or in any other vehicle operating condition where low mount stiffness is desired.

[0018] If, however, the opening or ventilation channel of the decoupling chamber is closed by means of the switchable valve, no air can escape from the decoupling chamber into the environment. As a result, the decoupling element is essentially prevented from deflecting or moving due to the overpressure or underpressure of the air in the decoupling chamber that occurs when it is displaced. This reduces the decoupling effect of the decoupling membrane, and at specific excitation frequencies and amplitudes, the damping fluid flows back and forth between the first and second fluid chambers via the fluid channel. Therefore, when the decoupling chamber is closed, the hydraulic bearing exhibits high stiffness and high damping.

[0019] The linear actuator for closing or opening the valve opening can include a drive, such as an electromagnetic actuator, which can also be located in the valve housing. The valve housing further features an actuator head receptacle in which the actuator head can move back and forth between the closed and open positions along its axis of movement. The axis of movement or longitudinal axis of the actuator head can essentially run along the longitudinal axis or axis of symmetry of the hydraulic bearing. The actuator head receptacle has an inner contour that corresponds, at least partially, to the outer contour of the actuator head. The actuator head can be essentially cylindrical, at least partially, but is not limited to such a shape.

[0020] The direction of extension of the valve opening can have a component transverse to the axis of movement of the actuator head, at least in sections. The valve opening can extend through a side wall of the actuator head receptacle of the valve housing, at least in sections, substantially transversely or obliquely to the axis of movement of the actuator head. In other words, the radial side wall of the actuator head receptacle or the valve housing can have a recess that forms the valve opening. The shape of the valve opening is not restricted. In the simplest case, the valve opening can be a straight cylindrical bore or a straight channel.The valve opening can also be a larger recess in the valve housing, as long as it can be closed by the actuator head and as long as at least one component of the flow direction of the oscillating air through the valve opening, in the open position, runs at least section by substantially perpendicular to the axis of movement of the actuator head. One can also say that the valve opening has a radial extension component with respect to the actuator head or the valve housing. The direction of extension of the valve opening can form an angle of approximately 45° to approximately 90°, preferably approximately 60° to approximately 90°, with respect to the axis of movement of the actuator head. The valve housing can have 2, 3, 4, 5, 6, or more valve openings. All valve openings can be closed by moving the actuator head into the closed position or opened by moving the actuator head into the open position.

[0021] In the open position, the valve orifice is open, and the decoupling chamber is connected to the environment, so that essentially ambient pressure prevails in the decoupling chamber. The valve body and / or the actuator head may have passages and / or gaps that connect the valve orifice to the environment in the open position.

[0022] When the actuator head is switched to the closed position by the linear actuator, it moves in front of the valve opening and closes it, preventing air from escaping from the decoupling chamber to the environment. It should be noted that the hydraulic mount can also be configured so that the actuator head can be positioned in an intermediate position between the closed and open positions to adjust the decoupling effect of the decoupling element.

[0023] The valve housing can be made of metal or plastic, preferably plastic. The actuator head can be made of metal or plastic, preferably metal. Plastic also includes elastomers.

[0024] Preferably, the actuator head has an internal cavity which is connected to the environment, at least in the open position. An axial end face of the actuator head has an actuator head opening of the cavity, and a circumferential edge section thereof forms an actuator head sealing surface which, in the closed position, rests against an inner sealing surface of the valve housing.

[0025] Advantageously, the actuator head opening in the axial end face of the actuator head significantly reduces the total area of ​​the actuator head sealing surface on which pressure from the decoupling chamber can act when the valve closes. This allows the required actuation force of the linear actuator for closing the valve to be significantly reduced, enabling the use of smaller, more economical linear actuators and further reducing closing noise. Furthermore, the stroke of the actuator head between the closed and open positions can be set smaller, since the circumference of the annular actuator head sealing surface can be made larger. This means that only a small gap between the actuator head sealing surface and the inner sealing surface of the valve housing is sufficient to connect the decoupling chamber to the environment with virtually no loss.This allows for the use of an even smaller and more cost-effective linear actuator. Furthermore, the shorter stroke also reduces the valve's opening and closing noise, as the shorter acceleration path results in less kinetic energy being generated during closing and opening.

[0026] The cavity can, for example, be a cylindrical bore extending from an axial end of the actuator head along its axis of movement or longitudinal axis. The cavity can always be connected to the environment, i.e., open to it. Alternatively, the cavity can have a lateral actuator head ventilation passage that, only in the open position, is connected to or superimposed on a valve housing ventilation passage of the valve housing to connect the cavity to the environment. The term "actuator head opening" refers to the opening of the cavity on the actuator head side. In the open state of the decoupling chamber, air oscillates through the cavity in the actuator head. This configuration differs fundamentally from prior art systems with linear actuators, in which the airflows, when open, flow around the outside of the actuator head.

[0027] The axial end face can be located at a forward end of the actuator head in the closing direction, facing the decoupling chamber or ventilation duct. The axial end face and the actuator head sealing surface preferably extend substantially transversely to the axis of movement of the actuator head. The radial opening area of ​​the annular actuator head sealing surface in the open position is preferably approximately equal to the area of ​​the actuator head opening transverse to the axis of movement. However, the opening area of ​​the actuator head sealing surface can also deviate from the area of ​​the actuator head opening transverse to the axis of movement by, for example, approximately 20%. Thus, the opening area of ​​the actuator head sealing surface can be approximately 80% to approximately 120% of the area of ​​the actuator head opening. The stroke of the actuator head can be approximately 0.5 mm to approximately 3 mm.

[0028] The inner sealing surface of the valve housing, which faces the actuator head sealing surface, can be located internally at a front end of the valve housing, particularly the actuator head receptacle, in the closing direction of the actuator head. In other words, the inner sealing surface of the valve housing forms the axial inner wall of the actuator head receptacle or a section thereof. The inner sealing surface of the valve housing preferably extends substantially transversely to the axis of movement of the actuator head. Preferably, the valve opening is located substantially at a height in the valve housing that corresponds to the height of the inner sealing surface of the valve housing. Particularly preferably, the valve opening abuts the inner sealing surface of the valve housing. In the closed position, the actuator head sealing surface rests against the inner sealing surface of the valve housing, thus sealing the valve opening against the cavity.

[0029] Preferably, the switchable valve further comprises an auxiliary seal which, at least in the closed position, seals a gap between a radial outer wall of the actuator head and a radial inner wall of the valve housing against the environment.

[0030] Advantageously, the auxiliary seal ensures that, in the closed position, no air escapes from the decoupling chamber through the valve opening and a gap between the radial outer wall of the actuator head and the radial inner wall of the valve housing to the surrounding environment. This allows for a loose fit, i.e., a clearance fit, between the actuator head and the valve housing, particularly the actuator head receptacle, thereby simplifying manufacturing and further reducing the actuating force required to move the actuator head.

[0031] The auxiliary seal is preferably circumferential, particularly annular, and is preferably formed between the valve housing and the actuator head. The auxiliary seal is further preferably recessed relative to the actuator head sealing surface or the inner sealing surface with respect to the closing direction of the actuator head, such that the valve opening is located in a region of the valve housing between the actuator head sealing surface and the auxiliary seal, or between the inner sealing surface and the auxiliary seal.

[0032] Preferably, the auxiliary seal has an actuator head auxiliary sealing surface that projects radially and circumferentially onto the actuator head, and an inner auxiliary sealing surface that is formed in the valve housing, wherein the actuator head auxiliary sealing surface is arranged recessed relative to the actuator head sealing surface and the inner auxiliary sealing surface is arranged recessed relative to the inner sealing surface, and wherein in the closed position the actuator head auxiliary sealing surface rests against the inner auxiliary sealing surface.

[0033] Advantageously, the above configuration allows for a simple implementation of the auxiliary seal, which further reduces the cost of the switchable valve.

[0034] The actuator head auxiliary sealing surface is formed on the actuator head and can represent an axial end face of a section of the actuator head with an increased diameter. The actuator head auxiliary sealing surface is preferably formed substantially parallel to the actuator head sealing surface. With respect to the closing direction of the actuator head, the actuator head auxiliary sealing surface is set back from the actuator head sealing surface such that the valve opening is located in a region of the valve housing between the actuator head sealing surface and the actuator head auxiliary sealing surface.

[0035] The inner auxiliary sealing surface is formed on the valve housing and can represent an inner axial end face of a section of the valve housing with an increased diameter, in particular the actuator head receptacle thereof. The inner auxiliary sealing surface is preferably formed substantially parallel to the inner sealing surface of the valve housing. With respect to the closing direction of the actuator head, the inner auxiliary sealing surface is set back from the inner sealing surface such that the axial distance between the inner auxiliary sealing surface and the inner sealing surface corresponds approximately to the axial distance between the actuator head auxiliary sealing surface and the actuator head sealing surface. In the closed position, the actuator head auxiliary sealing surface abuts the inner auxiliary sealing surface in a sealing manner, forming a preferably circumferential or annular auxiliary seal.The valve opening is located in an area of ​​the valve housing between the inner sealing surface and the inner auxiliary sealing surface, so that the two spaced-apart seals, which are formed in the closed position, ensure a reliable seal of the valve opening or the decoupling chamber.

[0036] Preferably, the auxiliary seal has a sealing membrane that is connected to both the valve housing and the actuator head and extends at least partially in a radial direction from the actuator head to the valve housing.

[0037] Advantageously, the auxiliary seal, designed as a sealing membrane, ensures a reliable seal, since no sealing surfaces need to be pressed together in the closed position, but rather the seal is effective in any position of the actuator head.

[0038] The sealing membrane can be made of elastomeric material and can be at least partially vulcanized or bonded to the actuator head along its circumference. The sealing membrane can also be at least partially vulcanized or bonded to the radial inner surface of the valve housing, particularly the actuator head receptacle. The sealing membrane can bridge a gap between the outer surface of the actuator head and the inner surface of the valve housing to ensure a seal. The sealing membrane is configured with respect to its shape and / or elasticity to allow movement of the actuator head between the open and closed positions.

[0039] Preferably, a connection area of ​​the sealing membrane to the actuator head is designed in a bellows shape.

[0040] Advantageously, the bellows-shaped design of the sealing membrane in the connection area allows the actuator head to be moved between the open and closed positions without significant elastic stretching or compression of the sealing membrane, thereby reducing the actuating forces of the linear actuator and increasing the service life of the sealing membrane.

[0041] The sealing membrane with the bellows-shaped section can also be referred to as a rolling membrane. The actuator head can have an annular recess extending along its radial outer circumference, into which the bellows-shaped section of the sealing membrane projects, at least in the closed position. Preferably, in the closed position, the bellows-shaped section of the sealing membrane rests substantially completely against the surface of the annular recess, while when the actuator head is moved into the open position, the bellows-shaped section lifts at least partially from the surface of the annular recess. The bellows-shaped section can be partially vulcanized or bonded to the actuator head within the annular recess.

[0042] Preferably, the valve housing is made up of multiple parts and the sealing diaphragm is clamped between valve housing parts to connect the sealing diaphragm to the valve housing.

[0043] The multi-part design, particularly the two-part design, simplifies the assembly process of the switchable valve. Clamping or securing the sealing diaphragm between two or more valve housing parts ensures a reliable seal to the valve housing. The valve housing parts can be bonded, welded, or bolted together. The sealing diaphragm can have a circumferential bead that secures it between the valve housing parts, which have corresponding grooves.

[0044] Preferably, the actuator head sealing surface and / or the inner sealing surface of the valve housing has elastomeric sealing material.

[0045] The actuator head auxiliary sealing surface and / or the inner auxiliary sealing surface can also comprise elastomeric sealing material. The elastomeric sealing material can improve the sealing effect. Preferably, the elastomeric sealing material of the actuator head sealing surface and the elastomeric sealing material of the actuator head auxiliary sealing surface are integrally formed as a single piece, and / or the elastomeric sealing material of the inner sealing surface and the elastomeric sealing material of the inner auxiliary sealing surface are integrally formed as a single piece. The elastomeric sealing material of the actuator head sealing surface and the elastomeric sealing membrane can also be integrally formed as a single piece. This integral or single-piece design simplifies manufacturing. The elastomeric sealing material is preferably vulcanized to the actuator head or the valve housing, but can also be bonded to it.

[0046] Preferably, the sealing material of the actuator head sealing surface has an axially projecting, circumferential sealing lip, and the inner sealing surface of the valve housing has a circumferential sealing groove into which the sealing lip of the actuator head engages in the closed position, and / or the sealing material of the inner sealing surface of the valve housing has an axially projecting, circumferential sealing lip, and the actuator head sealing surface has a circumferential sealing groove into which the sealing lip of the valve housing engages in the closed position.

[0047] The sealing effect of the sealing material can be further improved by combining the sealing lip and the sealing groove. Preferably, the sealing lip and sealing groove are configured such that, in the closed position, the sealing lip is pressed against the inner surface of the sealing groove by the applied pressure, thereby reinforcing the sealing effect.

[0048] The sealing lip or sealing groove of the actuator head can be formed along an outer edge region of the actuator head sealing surface. The actuator head auxiliary sealing surface and the inner auxiliary sealing surface can also each have a sealing lip and / or a sealing groove that interlock in the closed position.

[0049] Preferably, the sealing material of the actuator head sealing surface has a circumferential, radially projecting sealing flange which rests against the inner sealing surface of the valve housing in the closed position.

[0050] Preferably, the switchable valve is electrically switchable. In particular, the switchable valve is a switchable solenoid valve.

[0051] The present invention also relates to the switchable valve described above without the remaining components of the switchable hydraulic bearing.

[0052] In the following, embodiments of the present invention are described in more detail with reference to the accompanying figures. It is understood that the present invention is not limited to these embodiments and that individual features of the embodiments can be freely combined to form further embodiments.

[0053] They show: Fig. 1 a sectional view of a switchable hydraulic bearing according to a first embodiment; Fig. 2 a switchable valve of a hydraulic bearing according to a second embodiment in a sectional view; Fig. 3 the switchable valve off Fig. 2 in a partially cropped perspective view; Fig. 4 a switchable valve of a hydraulic bearing according to a third embodiment in a sectional view; Fig. 5 the switchable valve off Fig. 4 in a partially cropped perspective view; Fig. 6 a switchable valve of a hydraulic bearing according to a fourth embodiment in a sectional view, in the closed position; Fig. 7 the switchable valve off Fig. 6 in a sectional view, in open position; Fig. 8 a switchable valve of a hydraulic bearing according to a fifth embodiment in a sectional view, in the closed position; Fig. 9 a switchable valve of a hydraulic bearing according to a sixth embodiment in a sectional view, in the closed position.

[0054] Fig. Figure 1 shows a sectional view of a hydraulic mount 1 according to a first embodiment, the section passing through the central axis of the hydraulic mount 1. The hydraulic mount 1 has a spring body 2 made of elastomeric material, which partially delimits a first fluid chamber 3 formed therein, and an elastomeric bellows 4, which partially delimits a second fluid chamber 5 formed therein. The spring body 2 is essentially disc-shaped or conical and has a mounting connection 6 with a threaded bore at its tip. The hydraulic mount 1 can be connected to, for example, an engine via the mounting connection 6.

[0055] The second fluid chamber 5 is arranged below the first fluid chamber 3, with a separating plate 7 arranged between and defining the boundaries of the first fluid chamber 3 and the second fluid chamber 5. It should be noted that directional terms such as "top" or "bottom" in this application are to be understood as referring to a hydraulic bearing in its installed position, i.e., when the mounting connection 6 is located at the top and the longitudinal axis of the threaded bore is vertical.

[0056] The separating plate 7, which can also be referred to as a channel disk, comprises two sub-plates 7a and 7b, between which a disk-shaped decoupling membrane 8 is clamped as a decoupling element. A fluid channel 9 is also formed in the separating plate 7, which fluidically connects the first fluid chamber 3 and the second fluid chamber 5. The fluid channel 9 extends at least partially along an outer edge region of the separating plate 7 in order to generate damping by means of the oscillating damping fluid during operation of the hydraulic bearing 1.

[0057] The separating plate 7 further comprises an annular decoupling chamber 10 formed below the decoupling membrane 8, which is bounded at the top by the decoupling membrane 8. A ventilation duct 11 extends downwards from the decoupling chamber 10, the ventilation duct 11 being closed in the assembled state by the switchable valve 12 in the form of a solenoid valve.

[0058] The hydraulic bearing 1 further comprises a lower bearing housing 13. The lower bearing housing 13 has a valve receptacle 14 in its center, in which the switchable valve 12 is received or arranged such that the axis of movement BA of the valve 12 coincides with the longitudinal axis of the threaded bore of the mounting connection 6 and also with the central axis of the hydraulic bearing 1. The valve 12 is essentially cylindrical. An outer edge section of the bellows 4 is clamped between the separating plate 7 and an outer edge section of the lower bearing housing 13, and an inner edge section of the bellows 4 is clamped between the separating plate 7 and an inner edge section of the valve receptacle 14 of the lower bearing housing 13.

[0059] The hydraulic mount 1 further comprises an upper bearing housing 15, which has a flange 16 that clamps together an outer edge section of the spring body 2, an outer edge section of the two partial plates 7a, 7b, the outer edge section of the bellows 4, and the outer edge section of the lower bearing housing 13, thus fixing these components. The lower bearing housing 13 and the upper bearing housing 15 can be pressed into a mounting structure to connect the hydraulic mount 1 to, for example, a vehicle frame. The valve 12 can be pressed or bonded into the valve receptacle 14, but can also be fixed by the mounting structure when the hydraulic mount 1 is pressed into it.

[0060] The lower bearing housing 13 has a recess in the center of the valve receptacle 14, through which an axially projecting, cylindrical central section of the valve housing 17 of the valve 12, reduced in diameter, extends. The valve housing 17 is sealed to the lower bearing housing 13 by means of an O-ring 18. The ventilation channel 11 of the decoupling chamber 10 is closed by the valve housing 17, but a valve opening 19 of the valve housing 17 is fluidically connected to the ventilation channel 11.

[0061] The valve housing 17 has a linear actuator arranged therein, comprising a drive coil 20, an armature 21, and an actuator head 22. The actuator head 22 is arranged coaxially with the armature 21 and is rigidly connected to the armature 21 at its axially rear end in the closing direction. The actuator head 22 and the armature 21 are movable back and forth in an actuator head receptacle of the valve housing 17 along the axis of movement BA between a closed position and an open position. Fig. Figure 1 shows the closed position in which the valve opening 19 is fluid-tightly sealed by the actuator head 22. The valve opening 19 extends straight through the valve housing 17 in the region of the axially projecting section with reduced diameter in a direction essentially transverse to the axis of movement of the valve or the actuator head 22.

[0062] The actuator head 22 and the anchor 21 are essentially cylindrical. The actuator head 22 is also hollow and has a cylindrical cavity 23 formed within it. The axial end face of the actuator head 22, facing forward in the closing direction, has an actuator head opening 24 in the cavity 23. A circumferential actuator head sealing surface 25 is formed around the actuator head opening 24 on the actuator head 22, and elastomeric sealing material 26 is arranged circumferentially on this surface. The actuator head 22 also has a section whose diameter is larger than the diameter of the front axial end section of the actuator head 22. The transition from the front axial end section to the section with the larger diameter is stepped.has a step, wherein the axial end face of the step forms a circumferential actuator head auxiliary sealing surface 27, which has circumferentially arranged elastomeric sealing material 28 on it.

[0063] In the Fig. In the closed position shown in Figure 1, the actuator head sealing surface 25 rests fluid-tight against the inner surface of the valve housing 17 or against the inner surface of its actuator head receptacle. Simultaneously, the actuator head auxiliary sealing surface 27 also rests fluid-tight against the inner surface of the valve housing 17 or against its inner surface of its actuator head receptacle to form an auxiliary seal. For this purpose, the inner contour of the valve housing 17 or the actuator head receptacle is shaped according to the outer contour of the actuator head 22. The sections of the inner surface of the valve housing 17 against which the actuator head sealing surface 25 and the actuator head auxiliary sealing surface 27 rest can each be referred to as the inner sealing surface and inner auxiliary sealing surface of the valve housing 17, respectively.In the closed position, the actuator head sealing surface 25 prevents air from escaping from the decoupling chamber 10 via the ventilation duct 11, the valve opening 19, and the cavity 23 to the environment. The auxiliary seal, or the actuator head auxiliary sealing surface 27, prevents air from escaping from the decoupling chamber 10 via the ventilation duct 11, the valve opening 19, and any gap or space between the inner surface of the valve housing 17 and the outer surface of the actuator head 22 to the environment. This ensures that the valve opening 19 is fluid-tight from the environment.

[0064] The actuator head 22 has at least one actuator head ventilation passage 29, which extends laterally from the cavity 23 through the actuator head 22 below the actuator head auxiliary sealing surface 27. In the closed position, the actuator head ventilation passage 29 is closed to the environment by the inner surface of the valve housing 17, and at least in the open position, the actuator head ventilation passage 29 is open to the environment. The actuator head 22 has a circumferential actuator head ventilation channel 30, which extends along the radial outer circumference of the actuator head 22 and into which the at least one actuator head ventilation passage 29 opens from the cavity 23. In the closed position, the actuator head ventilation channel 30 is closed radially outwards by the inner surface of the valve housing 17.

[0065] The valve housing 17 has at least one valve housing ventilation passage 31, which, in the closed position, extends laterally from the actuator head receptacle through the valve housing 17 below the actuator head ventilation channel 30. At least in the open position, however, the valve housing ventilation passage 31 is fluidically connected to the actuator head ventilation channel 30 and the actuator head ventilation passage 29. The valve housing ventilation passage 31 is fluidically connected to the environment. The valve housing 17 has a circumferential valve housing ventilation channel 32, which extends along the radial outer circumference of the valve housing and into which the at least one valve housing ventilation passage 31 opens from the actuator head receptacle. Although the valve housing ventilation channel 32 is radially covered outwards by the wall of the valve receptacle 14 in the assembled state, it is not fluid-tightly sealed by it.

[0066] When the actuator head 22 is moved downwards from the closed position to the open position along the axis of movement BA, the valve opening 19 is opened, the actuator head sealing surface 25 is detached from the inner sealing surface of the valve housing 17, the actuator head auxiliary sealing surface 27 is detached from the inner auxiliary sealing surface of the valve housing 17, and the actuator head ventilation channel 30 is fluidically connected to the valve housing ventilation passage 31. This fluidly connects the decoupling chamber 10 to the environment in the open position.

[0067] Fig. 2 and Fig. Figure 3 shows a switchable valve 12 of a switchable hydraulic bearing according to a second embodiment. The section in Fig. 2 runs through the central axis of the valve 12. The second embodiment differs from the first embodiment in the configuration of the switchable valve 12. In particular, in the second embodiment, the elastomeric sealing material 26, 28 is provided on the valve housing side, specifically on the inner sealing surface and on the inner auxiliary sealing surface of the valve housing 17. Furthermore, both the actuator head sealing surface 25 and the actuator head auxiliary sealing surface 27 are each formed at the tip of a section that tapers in the closing direction, so that one can also speak of an actuator head sealing line and an actuator head auxiliary sealing line, respectively. Fig. 2 and Fig. Figure 3 shows valve 12 in the open position. Fig. 2 and Fig. Figure 3 shows the control cable 33 for controlling the switchable valve 12, wherein the control cable 33 is connected at least to the drive coil 20.

[0068] Fig. 4 and Fig. Figure 5 shows a switchable valve 12 of a switchable hydraulic bearing according to a third embodiment. The section in Fig. 4 runs through the central axis of the valve 12. The third embodiment differs from the first and second embodiments in that the actuator head 22 and the armature 21 are formed in one piece. Furthermore, according to the third embodiment, the actuator head ventilation passage 29 has a circular cross-section and is not rectangular as in the preceding embodiments. A total of three actuator head ventilation passages 29 are formed in the actuator head 22 at uniform angular intervals, extending radially. Correspondingly, three valve housing ventilation passages 31 are formed in the valve housing 17 at uniform angular intervals, extending radially. The valve housing 17 also has three valve openings 19, which are formed in the valve housing 17 at uniform angular intervals, extending radially. On the underside of the actuator head 22, respectively,A damping ring 40 made of elastomeric material is arranged on the anchor 21 to reduce impact noise when opening the valve.

[0069] Fig. Figure 6 shows a switchable valve 12 of a switchable hydraulic bearing according to a fourth embodiment in the closed position, and Fig. Figure 7 shows the switchable valve 12 of the fourth embodiment in the open position. The sections in the Fig. 6 and Fig. 7 run through the central axis of the valve 12. In the fourth embodiment, the actuator head 22 does not have an auxiliary sealing surface that rests against an inner auxiliary sealing surface in the closed position to form the auxiliary seal. In the fourth embodiment, the sealing material 26 of the actuator head sealing surface 25 and the auxiliary seal are realized by means of a one-piece, continuous sealing membrane 34 in the form of a rolling membrane. In the area of ​​the actuator head sealing surface 25 and an upper section of the radial side wall of the actuator head 22, the sealing membrane 34 can also be vulcanized or bonded to the actuator head 22, depending on the configuration of the actuator head 22. A radially outer edge section of the sealing membrane 34 is clamped or clamped in the valve housing 17.For this purpose, the valve housing 17 has two valve housing parts 17a, 17b divided transversely to the axis of movement BA, which clamp the outer edge section of the sealing membrane 34, which has a circumferential bead 41.

[0070] The connection area 36 of the sealing membrane 34 to the actuator head 22 is bellows-shaped or designed in the form of a rolling membrane section. The bellows-shaped section of the sealing membrane 34 is arranged in a designated annular recess 37 of the actuator head 22 and, in the closed position, rests essentially over its entire surface against the annular recess 37, thus providing good support for the sealing membrane 34. The sealing membrane 34 may also be partially vulcanized or bonded to the actuator head 22 in an upper section of the annular recess 37. When moving from the closed position to the open position, the bellows-shaped section rolls away, at least partially, from the surface of the recess 37.

[0071] The section of the sealing membrane 34 on the actuator head sealing surface 25, i.e., the elastomeric sealing material 26 of the actuator head sealing surface 25, has a circumferential sealing lip 38 projecting axially in the closing direction at its radial edge. In the closed position, this lip engages or projects into a circumferential sealing groove 39, the sealing groove 39 being formed in the inner sealing surface of the valve housing 17. The sealing lip 38 and the sealing groove 39 are designed such that the pressure acting in the valve openings 19 presses the sealing lip 38 against the inner surface of the sealing groove 39, thereby increasing the sealing effect. The valve 12 of the fourth embodiment has four valve openings formed at equal angular intervals in the valve housing 17.

[0072] The switchable valve 12, in particular the valve housing 17, the actuator head 22 with the annular recess 37, and the sealing diaphragm 34, are preferably configured such that a resulting force of the pressure acting on the actuator head 22 in the closed position acts in the closing direction. For this purpose, the diameter of the actuator head receptacle of the valve housing 17 below the sealing diaphragm 34 can be smaller than above the sealing diaphragm 34. Alternatively or additionally, the diameter of the actuator head 22 below the annular recess 37 can be smaller than above the annular recess 37 in the area of ​​the actuator head sealing surface 25.

[0073] Because the applied pressure exerts a force on the actuator head 22 in the closing direction in the closed position, the actuating force required to move and hold the actuator head 22 in the closed position can advantageously be further reduced. This results in a further pressure reduction or pressure compensation. This allows the use of even smaller, more economical linear actuators and further reduces closing and opening noise. It should be noted that the linear actuator can include a spring element (not shown) that pushes the actuator head 22 in the closing direction, whereby when the drive coil 20 is actuated, the actuator head 22 is moved against the spring force into the open position and held there. However, a reverse configuration is also possible.The fourth embodiment thus enables the use of a spring element with even lower stiffness and the use of a drive coil-armature combination with even lower power to bring the switchable valve 12 into the closed or open position during operation and to hold it in the closed or open position.

[0074] Fig. Figure 8 shows a switchable valve 12 of a switchable hydraulic bearing according to a fifth embodiment in the closed position, the section in Fig. 8 runs through the central axis of the valve 12. The fifth embodiment is a modification of the fourth embodiment. In the fifth embodiment, the section of the actuator head 22 above the annular recess 37 is initially smaller in diameter than the lower section of the actuator head 22 below the annular recess 37. However, at the actuator head sealing surface 25, the sealing material 26 of the actuator head 22 has a circumferential, radially projecting sealing flange 42, so that the actuator head 22 in the area of ​​the actuator head sealing surface 25 is larger in diameter than the lower section of the actuator head 22 below the annular recess 37, thereby achieving the pressure reduction or pressure compensation.

[0075] Fig. Figure 9 shows a switchable valve 12 of a switchable hydraulic bearing according to a sixth embodiment in the closed position, the section in Fig.9 runs through the central axis of the valve 12. The sixth embodiment is also a modification of the fourth embodiment. In the sixth embodiment, the annular recess 37 of the actuator head 22 has a substantially rectangular or square cross-section. The section of the actuator head 22 above the annular recess 37 up to the actuator head sealing surface 25 has a larger diameter than the section of the actuator head 22 below the annular recess 37. Furthermore, the inner diameter of the valve housing 17, i.e., the diameter of the actuator head receptacle of the valve housing, is smaller below the sealing diaphragm 34 than above the sealing diaphragm 34. This configuration achieves pressure reduction or pressure compensation. In the sixth embodiment, the sealing material 26 of the actuator head 22 and the sealing diaphragm 34 are formed separately from each other.The sealing membrane 34 can be vulcanized or bonded to the actuator head 22 at a radial inner edge thereof, in particular at the lower axial inner surface of the annular recess 37. Reference symbol list 1 switchable hydraulic mount 2 spring bodies 3 first fluid chamber 4 bellows 5 second fluid chamber 6 Mounting connection 7 Dividing plate 7a, 7b partial plates 8 decoupling membrane 9 Fluid channel 10 Decoupling chamber 11 Ventilation duct 12 switchable valves 13 lower bearing housing 14 Valve mount 15 upper bearing housing 16. Flanging 17 Valve housings 17a, 17b Valve housing part 18 O-ring 19 Valve opening 20 Drive coil 21 anchors 22 Actuator head 23 Cavity 24 Actuator head opening 25 Actuator head sealing surface 26 Sealing material 27 Actuator head auxiliary sealing surface 28 Sealing material 29 Actuator head ventilation passage 30 Actuator head ventilation channel 31 Valve housing ventilation passage 32 Valve housing ventilation channel 33 control cables 34 Sealing membrane 35 Valve housing part 36 Connection area 37 ring-shaped depressions 38 Sealing lip 39 Sealing groove 40 damping ring 41 circumferential bead 42 Sealing flange BA axis of movement

Claims

[1] Switchable hydraulic mount (1) comprising: a first fluid chamber (3) which is partially bounded by a spring body (2), a second fluid chamber (5) which is fluidically connected to the first fluid chamber (3) via at least one fluid channel (9), so that a damping fluid can flow between the first fluid chamber (3) and the second fluid chamber (5) when the spring body (2) compresses and rebounds, a decoupling element (8) for decoupling the first and the second fluid chamber (3, 5), wherein the decoupling element (8) is arranged between the first fluid chamber (3) and a decoupling chamber (10) and fluidically separates them from each other, wherein the decoupling chamber (10) has a ventilation duct (11), and a switchable valve (12) which can selectively open or close the decoupling chamber (10) to the environment in order to change a decoupling effect of the decoupling element (8), wherein the switchable valve (12) has a valve housing (17) with a linear actuator arranged therein, wherein the linear actuator has an actuator head (22) which can be moved in the valve housing (17) between a closed position and an open position, wherein the valve housing (17) has at least one valve opening (19) which is fluidically connected to the ventilation channel (11) of the decoupling chamber (10), and which in the open position connects the decoupling chamber (10) to the environment and in the closed position is closed by the actuator head (22), wherein the ventilation channel (11) is otherwise sealed to the environment by the valve housing (17), and wherein the valve opening (19) runs at least in sections substantially transversely to the axis of movement (BA) of the actuator head (22). [2] Switchable hydraulic bearing (1) according to claim 1, wherein the actuator head (22) has an internal cavity (23) which is connected to the environment at least in the open position, and wherein an axial end face of the actuator head (22) has an actuator head opening (24) of the cavity (23) and a circumferential edge section thereof forms an actuator head sealing surface (25) which in the closed position rests against an inner sealing surface of the valve housing (17). [3] Switchable hydraulic bearing (1) according to claim 2, wherein the switchable valve (12) further comprises an auxiliary seal which, at least in the closed position, seals a gap between a radial outer wall of the actuator head (22) and a radial inner wall of the valve housing (17) against the environment. [4] Switchable hydraulic bearing (1) according to claim 3, wherein the auxiliary seal has an actuator head auxiliary sealing surface (27) which is radially projecting and circumferentially formed on the actuator head (22), and has an inner auxiliary sealing surface which is formed in the valve housing (17), wherein the actuator head auxiliary sealing surface (27) is arranged recessed from the actuator head sealing surface (25) and the inner auxiliary sealing surface is arranged recessed from the inner sealing surface, and wherein in the closed position the actuator head auxiliary sealing surface (27) rests against the inner auxiliary sealing surface. [5] Switchable hydraulic bearing (1) according to claim 3, wherein the auxiliary seal has a sealing membrane (34) which is connected to both the valve housing (17) and the actuator head (22) and extends at least sectionally in a radial direction from the actuator head (22) to the valve housing (17). [6] Switchable hydraulic bearing (1) according to claim 5, wherein a connection area (36) of the sealing membrane (34) to the actuator head (22) is bellows-shaped. [7] Switchable hydraulic bearing (1) according to claim 5 or 6, wherein the valve housing (17) is formed in multiple parts and the sealing diaphragm (34) is clamped between valve housing parts (17a, 17b) to connect the sealing diaphragm (34) to the valve housing (17). [8] Switchable hydraulic bearing (1) according to any one of the preceding claims 2 to 7, wherein the actuator head sealing surface (25) and / or the inner sealing surface of the valve housing (17) comprises elastomeric sealing material (26). [9] Switchable hydraulic bearing (1) according to claim 8, wherein the sealing material (26) of the actuator head sealing surface (25) has an axially projecting, circumferential sealing lip (38) and the inner sealing surface of the valve housing (17) has a circumferential sealing groove (39) into which the sealing lip (38) of the actuator head (22) engages in the closed position, and / or wherein the sealing material of the inner sealing surface of the valve housing (17) has an axially projecting, circumferential sealing lip and the actuator head sealing surface (25) has a circumferential sealing groove into which the sealing lip of the valve housing (17) engages in the closed position. [10] Switchable hydraulic bearing (1) according to claim 8 or 9, wherein the sealing material (26) of the actuator head sealing surface (25) has a circumferential, radially projecting sealing flange (42) which, in the closed position, rests against the inner sealing surface of the valve housing (17).

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