DE102018132173A1 - Adjustable vibration damper and motor vehicle with such a vibration damper - Google Patents

Abstract

The present invention relates to an adjustable vibration damper (10) for a motor vehicle, which comprises an adjusting device (11) and a piston rod (12) with a piston (13), the adjusting device (11) having at least one first bypass valve (14) which is assigned to a first bypass channel (16) and comprises at least one second bypass valve (15) which is assigned to a second bypass channel (17), the bypass channels (16, 17) each having at least one bypass cross-section (18) which is characterized by the respective Bypass valve (14, 15) for setting a damper characteristic, in particular the compression stage or the rebound stage, can be changed. The invention further relates to a motor vehicle with an adjustable vibration damper.

Description

The invention relates to an adjustable vibration damper and a motor vehicle with such a vibration damper.

According to the prior art, single-tube dampers are equipped with valves which control the flow of a damper oil when a piston rod or a piston moves in a cylinder tube. Generally, these valves are arranged in the piston itself.

The valves are essentially designed as orifice valves, the valves having a different opening behavior in the pressure and pull directions of the piston rod. The piston rod dips into the cylinder tube in the direction of pressure. This corresponds to a compression or the pressure level of the vibration damper. The cover channels for the rebound are closed. In this case, the damper oil flows exclusively across the cross-section of the pressure stage orifices from a working area facing away from the piston rod, for example below the piston, into a working area facing towards the piston rod, for example above the piston.

The reverse is true when rebounding. The orifice channels of the compression stage are closed and the damper oil flows exclusively through the cross-sections of the rebound orifice panels from the working area facing the piston rod above the piston to the working area facing away from the piston rod below the piston.

The valves are usually designed as "slide valves". The principle is a clamped bending beam on the end of which a force acts which, depending on the size, causes the valve to deform and thus to open the flow cross-section.

In order to match an opening characteristic of the valves to the respective application, various mostly several sheets are stacked and / or different sheet thicknesses are combined. Alternatively, it is customary to change the free bending length of the valve, which leads to a change in the spring stiffness and thus to a change in the opening characteristic.

Since these valves are not accessible from the outside, a damper characteristic curve of the vibration damper can only be checked at the end of the manufacturing process. If the measured damper characteristic does not meet the target specifications, the vibration damper must be disassembled and reassembled. This has the disadvantage that the adjustment or fine adjustment of the damper characteristic requires increased rework, which results in increased manufacturing costs. Another disadvantage is that the setting of the damper characteristic after the manufacturing process of the vibration damper is not possible without disassembling the vibration damper.

For example, is off US 8 322 369 B2 a damping valve for a vibration damper is known, which is designed as a backpack valve and is used to adjust the damping forces occurring in the rebound and compression. The disadvantage here is that the damping valve has a complex, constructive structure and a large number of components. This leads to increased costs in the manufacture of the damping valve.

The invention is based on the object of specifying a vibration damper in which a damper characteristic can be set in a simple manner, as a result of which reworking and thus manufacturing costs are reduced. Furthermore, the invention is based on the object of specifying a motor vehicle with such a vibration damper.

According to the invention, this object is achieved with regard to the adjustable vibration damper by the subject matter of claim 1. With regard to the motor vehicle, the above-mentioned object is achieved by the subject matter of claim 26.

The invention is based on the idea of specifying an adjustable vibration damper for a motor vehicle, which includes an adjusting device and a piston rod with a piston. The setting device has at least one first bypass valve which is assigned to a first bypass channel and comprises at least one second bypass valve which is assigned to a second bypass channel. The bypass channels each have at least one bypass cross section, which can be changed by the respective bypass valve for setting a damper characteristic, in particular the compression stage or the rebound stage.

The bypass valves allow the bypass cross sections of the bypass channels to be changed independently of one another. In other words, the compression stage and the rebound stage can be set independently of one another by means of the bypass valves.

The invention has several advantages. By changing the bypass cross-sections of the bypass channels via the bypass valves, the damper characteristic or the compression stage and / or the rebound stage can be finely adjusted after the vibration damper has been assembled. In other words, after the vibration damper has been assembled, the bypass valves can be used advantageous to correct the damper characteristic. A requirement-specific damper characteristic of the vibration damper can thus advantageously be set easily and quickly. A dismantling of the vibration damper for the adjustment of piston valves of the piston in the event of a faulty damper characteristic curve is therefore eliminated. This reduces reworking costs and saves manufacturing costs.

The invention has the further advantage that the use of "standard plating", i.e. the use of a piston with standardized piston valves for different vehicle equipment or in general for different vehicle types is made possible. The vibration damper can have a basic setting of the damper characteristic and can be adapted to the different equipment or vehicle types by the bypass valves. This advantageously results in a variety of uses and thus an increase in the variety of the vibration damper.

It is conceivable that the damper characteristic of the vibration damper can only be set via the bypass channels or by changing the bypass cross sections. In other words, it is conceivable that the piston has no piston valve and the damper characteristic is set exclusively by the bypass valves. It is advantageous here that a system complexity and a number of components is reduced and thus manufacturing costs are saved.

Preferred embodiments of the invention are specified in the subclaims.

In a particularly preferred embodiment, a plurality of first bypass channels and / or a plurality of second bypass channels are provided, at least one of the bypass cross sections of the bypass channels being changeable for setting a damper characteristic. The setting device can thus have more than one first bypass channel and more than one second bypass channel, it advantageously being possible to change individual bypass cross sections. This has the advantage that the compression stage and / or the rebound stage can be set precisely, for example by changing one or more bypass cross sections. It is conceivable that the setting device has a plurality of first bypass channels, a bypass cross section of at least one first bypass channel being changeable and a bypass cross section of at least one further first bypass channel being unchangeable. Furthermore, the setting device can have a plurality of second bypass channels, a bypass cross section of at least one second bypass channel being changeable and a bypass cross section of at least one further second bypass channel being unchangeable. This has the advantage that a fine adjustment of the damper characteristic or the compression level and / or the rebound is made possible.

In a further particularly preferred embodiment, the bypass cross sections of the bypass channels can be changed, in particular adjustable, by a linear movement of the respective bypass valve transversely or lengthways to the direction of flow. The bypass valve, in particular an actuating element of the bypass valve, can execute a linear movement by means of which the bypass cross section of the associated bypass channel can be adjusted. This advantageously enables a precise setting of the compression stage as well as the rebound stage and thus the damper characteristic of the vibration damper.

In a further particularly preferred embodiment, the bypass channels for separate adjustment of the compression stage and the rebound stage are arranged separately from one another, the bypass channels being able to flow through, in particular exclusively, in one direction. The separate arrangement has the advantage that the bypass channels can be flowed through independently of one another. Furthermore, the compression stage and / or the rebound stage can each be set via a bypass channel.

In a preferred embodiment, the bypass cross sections of the bypass channels can be changed, in particular adjusted, from outside by actuating the bypass valves. In other words, the bypass cross sections of the bypass channels can be set from outside the vibration damper by actuating the bypass valves. If a faulty damper characteristic is measured after the vibration damper has been assembled, the damper characteristic can be easily and quickly corrected or fine-tuned from the outside using the bypass valves. It is therefore not necessary to disassemble the vibration damper to readjust the damper characteristic. This saves time and saves production costs.

In a further preferred embodiment, the first bypass valve is provided for setting the compression stage and the second bypass valve for setting the rebound stage. In other words, the compression level can be set by the first bypass channel and / or the rebound level can be set by the second bypass channel. The associated bypass cross section can be changed, in particular reduced or enlarged, by the respective bypass valve in order to set the compression stage and / or the rebound stage. As a result, fine adjustment of the damper characteristic is advantageously possible.

The adjusting device is preferably designed as a closure cover which closes the vibration damper in a fluid-tight manner. The Adjustment device can be arranged at least partially in an outer tube. The adjusting device closes an axial pipe end, in particular a pipe end near the piston rod, of the outer pipe. The setting device can therefore advantageously have a double function. On the one hand, the setting device seals the vibration damper to the outside in a fluid-tight manner and, on the other hand, the setting device includes the bypass valves and the bypass channels, by means of which the damper characteristic can be fine-tuned, in particular corrected. It is advantageous here that the bypass valves are easily accessible due to the arrangement of the adjusting device on the axial tube end of the outer tube, and thus a fine adjustment of the damper characteristic is simplified.

Further preferably, each bypass valve has a valve body and an actuating element, the associated bypass channel forming a through opening of the valve body. It is advantageous here that the respective bypass valve has a compact design and thus space is saved. The adjusting element can be inserted transversely to the flow direction to change the bypass cross section in the bypass channel. This advantageously enables a precise setting of the compression stage as well as the rebound stage and thus the damper characteristic. It is also conceivable that the bypass cross section of the bypass channels can be changed along the flow direction. In other words, the adjusting element for changing the bypass cross section can be inserted into the bypass channel along the flow direction. The actuating element can be insertable in or against the flow direction.

The adjusting element can be formed by an adjusting screw. This has the advantage that the actuating element is inexpensive and represents a simple possibility for changing the bypass cross section of the bypass channels. The adjusting element preferably has at least one sealing element, by means of which the bypass channel is sealed off from the outside. The sealing element can be formed by an O-ring. The sealing element advantageously prevents leakage due to escaping damper oil.

In one embodiment, the valve body of the bypass valve has a columnar valve seat, the bypass channel running along the valve seat. At the compression stage and / or the rebound stage, the damper oil flows around the columnar valve seat. In other words, the bypass channel is formed around the columnar valve seat. In order to change the respective bypass cross section of the bypass channels, the control element interacts with the valve seat. The actuating element is moved toward or away from the valve seat, as a result of which the bypass cross section is enlarged or reduced. In other words, a flow of the damper oil is controlled or regulated by the interaction of the control element with the valve seat. The columnar design of the valve seat reduces radial installation space, which results in a compact construction of the adjusting device.

In a further embodiment, the adjusting device has a base body with which the valve bodies of the bypass valves are integrally formed. The basic body of the adjusting device can be formed in one piece with the bypass channels and the valve bodies of the bypass valves. It is advantageous here that a compact design of the adjusting device is achieved and that manufacturing costs are saved by reducing the number of components.

In a preferred embodiment, the setting device is cylindrical, in particular hollow cylindrical. This advantageously enables simple and quick assembly of the adjusting device in and / or on the outer tube. Furthermore, the setting device is simple and inexpensive to manufacture.

In a particularly preferred embodiment, the adjusting device has an inner bypass diaphragm and an outer bypass diaphragm, with one bypass diaphragm closing at least one bypass channel depending on a direction of movement of the piston. The bypass orifices can thus close several first and / or several second bypass channels depending on the direction of movement of the piston. The bypass orifices function as a check valve. This ensures that only one bypass channel can flow through at the compression stage or the rebound stage. The compression stage and the rebound stage can thus advantageously be adjusted or finely adjusted independently of one another. The bypass orifices can each be formed by a C-shaped ring spring. The bypass diaphragm as a ring spring is inexpensive and advantageously easy to arrange on the adjusting device.

The inner bypass diaphragm is preferably arranged in the base body of the adjusting device in such a way that the inner bypass diaphragm closes the first bypass channel in a fluid-tight manner in a rebound stage. The inner bypass diaphragm can be arranged radially on the inside of the setting device. In other words, the inner bypass diaphragm can be arranged radially on the inside of the basic body of the adjusting device.

At a rebound stage, the inner bypass diaphragm is pressed against the base body of the adjusting device by the damper oil, whereby the first bypass channel is closed. The outer bypass orifice is the fluid pressure of the Damper oil is opened, in particular pressed on, which enables the damper oil to flow through the second bypass channel. The inner bypass orifice is thus assigned to the first bypass duct and serves as a check valve for closing the first bypass duct during the rebound. The first bypass channel can advantageously be closed easily and reliably by the inner bypass or closed during the rebound.

The setting device can have a locking recess into which the inner bypass diaphragm engages and through which the inner bypass diaphragm is held in a fixed position. This is advantageously a simple and inexpensive solution for positioning the bypass diaphragm on the setting device. The locking recess can be formed by a material recess, in particular an indentation, in the base body of the adjusting device.

In one embodiment, the bypass valves each comprise at least one bypass orifice with a spring rate that can be changed to set a damper characteristic, in particular the compression stage or the rebound stage. It is advantageous here that the damping characteristic curve or the compression stage and / or the rebound stage can alternatively or additionally be adjusted via the bypass valves by changing the spring rate of the bypass orifices. This advantageously enables a variety of variants for setting the damping characteristic.

In a preferred embodiment, the vibration damper comprises an outer tube and at least one inner tube, the piston separating a first working space and a second working space of the inner tube. In this case, an intermediate space can be formed between the outer tube and the inner tube, which is fluidly connected to the second working space and which can be fluidly connected or fluidly connected to the first working space of the inner tube by the stroke movement of the piston. The fluid flow of the damper oil is separated in a simple manner by forming the intermediate space between the inner tube and the outer tube. This configuration represents a simple solution for separating the fluid flow.

The inner tube can have at least one orifice opening which adjoins the second bypass duct and which forms a free passage from the first working space to the intermediate space with the second bypass duct in the case of a damping, in particular rebound, step. The orifice is closed at one pressure level by the outer bypass orifice. At the pressure stage, damper oil is pressed into the intermediate space, causing the outer bypass orifice to be moved, in particular pressed, against the inner tube, thus closing the orifice opening.

Furthermore, the inner tube can have at least one position opening into which the outer bypass diaphragm engages and through which the outer bypass diaphragm is held in a fixed position. This is advantageously a simple and inexpensive solution for positioning the bypass diaphragm on the setting device. The position opening can be formed by a bore or a slot.

The outer bypass orifice preferably encloses the inner tube at least partially in such a way that the outer bypass orifice closes the second bypass channel in a fluid-tight manner in the event of pressure damping, in particular pressure stage. The outer bypass diaphragm can be arranged radially on the outside around the inner tube.

At a pressure stage, the outer bypass orifice is pressed against the inner tube by the damper oil, which closes the second bypass duct. The inner bypass orifice is in this case opened, in particular pressed open, by the fluid pressure of the damper oil, as a result of which the damper oil can flow through the first bypass channel. The outer bypass orifice is thus assigned to the second bypass channel and serves as a further check valve for closing the second bypass channel during the compression stage. The second bypass channel can advantageously be closed easily and reliably by the outer bypass or closed during the pressure stage.

In a preferred embodiment, the piston rod is guided in the setting device in the damping direction, in particular in the axial longitudinal direction. The piston rod is thus slidably guided through the cover. In operation, the piston rod can dip into the inner tube through the adjusting device or at least partially extend out of the inner tube. It is advantageous here that components are reduced through functional integration and thus manufacturing costs are saved. The adjusting device advantageously also assumes a management function.

A secondary aspect of the invention relates to a motor vehicle with an adjustable vibration damper of the aforementioned type. Reference is made to the advantages explained in connection with the adjustable vibration damper. In addition, as an alternative or in addition, the motor vehicle can have individual or a combination of a plurality of features previously mentioned with regard to the adjustable vibration damper.

The invention is explained in more detail below with reference to the accompanying drawings. The illustrated embodiments are examples of how the Vibration damper according to the invention can be configured.

• 1 eine perspektivische Längsschnittansicht eines einstellbaren Schwingungsdämpfers nach einem bevorzugten erfindungsgemäßen Ausführungsbeispiel;
• 2 eine perspektivische Detailansicht des einstellbaren Schwingungsdämpfers gemäß 1 mit einer Einstelleinrichtung;
• 3 ein Schaltbild eines einstellbaren Schwingungsdämpfers gemäß 1;
• 4 eine perspektivische Detailansicht des einstellbaren Schwingungsdämpfers gemäß 1 mit einer Einstelleinrichtung zur Illustration der Zugstufe;
• 5 eine perspektivische Detailansicht des einstellbaren Schwingungsdämpfers gemäß 1 mit einer Einstelleinrichtung zur Illustration der Druckstufe;
• 6 eine perspektivische Ansicht einer inneren Bypassblende des einstellbaren Schwingungsdämpfers gemäß 1;
• 7 eine perspektivische Ansicht einer äußere Bypassblende des einstellbaren Schwingungsdämpfers gemäß 1; und
• 8 eine perspektivische Ansicht eines Innenrohres des einstellbaren Schwingungsdämpfers gemäß 1.

Show in these

• 1 a perspective longitudinal sectional view of an adjustable vibration damper according to a preferred embodiment of the invention;
• 2nd a detailed perspective view of the adjustable vibration damper 1 with an adjustment device;
• 3rd a circuit diagram of an adjustable vibration damper 1 ;
• 4th a detailed perspective view of the adjustable vibration damper 1 with a setting device to illustrate the rebound;
• 5 a detailed perspective view of the adjustable vibration damper 1 with a setting device to illustrate the pressure level;
• 6 a perspective view of an inner bypass diaphragm of the adjustable vibration damper according to 1 ;
• 7 a perspective view of an outer bypass diaphragm of the adjustable vibration damper according to 1 ; and
• 8th a perspective view of an inner tube of the adjustable vibration damper according to 1 .

1 shows a perspective longitudinal sectional view of an adjustable vibration damper 10th for a motor vehicle according to a preferred embodiment of the invention, wherein the vibration damper 10th forms a monotube damper. In general, the invention also includes two-tube dampers and / or multi-tube dampers.

The vibration damper 10th includes an adjustment device 11 and a piston rod 12 with a piston 13 . The piston 13 has two valve units 13a with standardized valve plating. The piston 13 thus defines a fixed compression stage and a fixed rebound stage of the vibration damper 10th . In other words, the piston 13 through the standardized valve plating of the respective valve units 13a a compression and a rebound on the piston 13 cannot be changed.

The valve units 13a are each formed by one or more stacked sheets. The stacked sheets can have different or the same sheet thicknesses. Generally the valve units 13a also referred to as "slide valves". The valve units 13a work on the principle of a clamped bending beam, on the beam end of which a force acts, whereby, depending on the magnitude of the force, a deformation of the metal sheets of the valve units 13a and thus an opening of a flow cross section takes place.

According to 1 to 5 instructs the setting device 11 a first bypass valve 14 on that a first bypass channel 16 assigned. The setting device also includes 11 a second bypass valve 15 which is a second bypass channel 17th assigned. The bypass channels 16 , 17th each have a bypass cross section 18th on by the respective bypass valve 14 , 15 for setting a damper characteristic, in particular the compression stage or the rebound stage, can be changed. Through the adjustment device 11 can after a finished assembly of the vibration damper 10th the damper characteristics are corrected or fine-tuned. Disassembling the vibration damper 10th for adjusting the valve units 13a of the piston 13 if the damper characteristic curve is faulty, this can be omitted. On the adjustment device 11 will be discussed later.

As in 1 shown, includes the vibration damper 10th an outer tube 26 and an inner tube 27th , the piston 13 a first work space 28 and a second work room 29 of the inner tube 27th separates. The piston 13 is with the piston rod 12 firmly connected and in the inner tube 27th slidably arranged in the axial direction. Between the outer tube 26 and the inner tube 27th is a space 30th trained with the second work space 29 is fluid-connected. The gap 30th is through the bypass valves 14 , 15 with the first work space 26 of the inner tube 27th by the stroke movement of the piston 13 is fluid-connectable or fluid-connected. The gap 30th is designed as an annular gap and has an annular cross section. In the assembled state of the vibration damper 10th are the workrooms 28 , 29 , The gap 30th and the bypass channels 16 , 17th filled with a damper oil.

The vibration damper also includes 10th a damper housing 36 and a separating piston 35 . The damper housing 36 has a housing receiving area 37 on, which is formed by a cylindrical material recess. The housing receiving area 37 can have an inner diameter that corresponds to an outer diameter of the outer tube 26 corresponds. In other words, the inside diameter of the housing receiving area 37 and the outer diameter of the outer tube 26 be the same size.

As in 1 is shown is the separating piston 35 cup-shaped. The separating piston 35 is of hollow cylindrical design, with an axial end, in particular facing away from the piston rod, of the separating piston 35 is closed. The separating piston 35 has several bridges 38 on, in the longitudinal direction from the separating piston 35 are protruding. The separating piston 35 can also only have two webs 38 have in the longitudinal direction of the separating piston 35 are protruding.

The following is based on 1 the structure of the vibration damper 10th described in more detail.

The outer tube 26 and the inner tube 27th are arranged coaxially with each other, the inner tube 27th in the outer tube 26 is arranged. The outer tube 26 and the inner tube 27th can be arranged eccentrically to each other. The outer tube 26 has an end near the piston rod 32a on which the setting device 11 is arranged. The adjustment device 11 is partly in the outer tube 26 arranged. The adjustment device 11 can also be completely in the outer tube 26 be arranged. The adjustment device 11 is as a cover 31 trained of the outer tube 26 at the end near the piston rod 32a sealed fluid-tight. In other words, the vibration damper 10th at the end near the piston rod 32a of the outer tube 26 through the adjustment device 11 sealed fluid-tight. The adjustment device 11 can do this with the outer tube 26 be positively and / or frictionally and / or cohesively connected. In particular, the setting device 11 for fluid-tight connection in the outer tube 26 pressed in and / or with the outer tube 26 be welded.

The piston rod 12 is in the setting device 11 slidably guided in the axial longitudinal direction, in particular in the damping direction. The piston rod 12 is through the cover 31 slidably guided. The piston rod 12 can be operated by the adjustment device 11 into the inner tube 27th immerse or from the inner tube 27th extend.

The outer tube 26 also has an end remote from the piston rod 32b with which the outer tube 26 in the damper housing 36 is arranged. The outer tube is concrete 26 with the end remote from the piston rod 32b in the housing receiving area 37 of the damper housing 36 arranged. The outer tube 26 is with the damper housing 36 connected in a fluid-tight manner. The vibration damper 10th is therefore at the end remote from the piston rod 32b of the outer tube 26 through the damper housing 36 sealed fluid-tight. The fluid-tight connection of the outer tube 26 with the damper housing 36 can be form-fitting and / or friction-locking and / or material-locking. In particular, the outer tube 26 for fluid-tight connection in the damper housing 36 pressed in and / or with the damper housing 36 be welded.

The inner tube 27th is with the adjustment device 11 connected in a fluid-tight manner. Furthermore, the inner tube 27th with the adjustment device 11 Positionally fixed, in particular non-displaceable and non-rotatable, connected. The inner tube is concrete 27th through a first pipe end 39a with an outer recording area 41 the adjustment device 11 connected in a fluid-tight manner. On the outer recording area 41 the adjustment device 11 will be discussed later.

The inner tube 27th is in the outer tube 26 arranged such that between a second pipe end 39b of the inner tube 27th and the damper housing 36 a compensation room 44 is trained. In the compensation room 44 is the separating piston 35 axially displaceable. The separating piston 35 separates the damper oil from a damper gas that is in the compensation chamber 44 is introduced. In other words, through the separating piston 35 the damper oil and the damper gas are separated from one another in a fluid-tight manner. The compensation room 44 is in the axial direction of the vibration damper 10th through the damper housing 36 and the separating piston 35 limited.

2nd shows a perspective detail view of the vibration damper 10th according to 1 . As described above, the adjustment device comprises 11 two bypass valves 14 , 15 and two bypass channels 16 , 17th , by changing the respective bypass cross sections 18th of the bypass channels 16 , 17th a damper characteristic, in particular the compression stage and / or the rebound stage, is adjustable.

The adjustment device 11 has a basic body 23 on. The basic body 23 is essentially cylindrical, in particular hollow cylindrical. The basic body 23 has a central through opening in which the piston rod 12 is guided axially. The adjustment device 11 also includes two sealing elements 43 who the piston rod 12 towards the main body 23 seal fluid-tight. The adjustment device 11 can also have one or more sealing elements 43 for sealing the piston rod 12 towards the main body 23 exhibit. The first workspace is concrete 28 through the sealing elements 43 sealed to the outside in a fluid-tight manner, which prevents leakage due to escaping damper oil.

The setting device also includes 11 an outer recording area 41 and an inner recording area 42 . The outer recording area 41 is on the main body 23 arranged radially on the outside. The inner recording area 42 is on the main body 23 formed radially inside. The outer recording area 41 serves to hold the inner tube 27th . The outer recording area 41 is from the main body 23 protruding in the axial direction. The outer recording area 41 has a cylindrical shape. The outer Recording area 41 also has a free end and a stop axially opposite the free end, in particular a shaft shoulder. Furthermore, the free end of the outer receiving area 41 an axial stop for the piston 13 form, the free end of a stroke of the piston 13 limited. In the assembled state of the vibration damper 10th is the inner tube 27th is on the outer recording area 41 , in particular by sliding, arranged and lies with the first pipe end 39a at the stop of the outer recording area 41 on.

Over the inner recording area 42 are the bypass channels 16 , 17th with the first work space 28 and the space 30th fluid-connected or fluid-connectable. The inner recording area 42 also serves to accommodate an inner bypass cover 24th , which will be discussed in more detail later. The inner recording area 42 is formed by a cylindrical material recess, which is from the free end of the outer receiving area 41 in the axial direction in the base body 23 extends. In other words, the inner recording area 42 to the first work space 28 trained open. The inner recording area 42 forms in the assembled state of the vibration damper 10th thus a part of the first work space 28 . The inner recording area 42 can also be formed by an angular material recess in cross section. The inner recording area 42 has a receiving floor 45 from which the central through opening of the base body starts 23 is formed axially outwards. The receiving floor 45 also serves as an axial stop for the inner bypass diaphragm 24th . This will assemble the inner bypass orifice 24th on the adjustment device 11 facilitated.

The bypass channels 16 , 17th are in the main body 23 the adjustment device 11 educated. Furthermore, the bypass valves 14 , 15 one valve body each 19th on that with the main body 23 the adjustment device 11 is integrally formed. The valve body 19th of the respective bypass valve 14 , 15 has a columnar valve seat 22 on, the bypass channel 16 , 17th along the valve seat 22 runs. In other words, the basic body 23 the adjustment device 11 with the bypass channels 16 , 17th and the valve bodies 19th of the bypass valves 14 , 15 integrally formed. The respective bypass channel 16 , 17th forms a through opening 21st of the valve body 19th of the associated bypass valve 14 , 15 . Through the bypass channels 16 , 17th is the space 30th with the first work space 28 fluid-connected or fluid-connectable. The function of the vibration damper 10th will be based on later 3rd to 5 described in more detail.

The bypass channels 16 , 17th are separated from each other to adjust the compression and rebound separately. In other words, the bypass channels 16 , 17th in the basic body 23 the adjustment device 11 trained separately from each other. The bypass channels 16 , 17th are each, especially exclusively, in one direction 50 flowable. The bypass sections 18th of the bypass channels 16 , 17th are by operating the bypass valves 14 , 15 changeable from the outside, in particular adjustable. Bypass cross sections are specific 18th of the bypass channels 16 , 17th by operating the bypass valves 14 , 15 from outside the vibration damper 10th adjustable. Will be after a finished assembly of the vibration damper 10th A faulty damper characteristic is measured, the damper characteristic through the bypass valves 14 , 15 can be corrected from the outside, especially fine-adjustable.

The first bypass valve 14 is for setting the pressure level and the second bypass valve 15 intended to adjust the rebound. It is also conceivable that the adjustment device 11 several, in particular more than one, first bypass channel 16 and / or more than a first bypass valve 14 to adjust the pressure level. Furthermore, the setting device 11 several, in particular more than one, second bypass channel 17th and / or more than a second bypass valve 15 to adjust the rebound.

The respective bypass valve 14 , 15 points next to the valve body 19th an actuator 20th on. The respective control element 20th is to change the bypass cross section 18th in the respective bypass channel 16 , 17th transverse to the direction of flow 50 can be introduced. The bypass sections 18th of the bypass channels 16 , 17th are thus a linear movement of the actuator 20th of the respective bypass valve 14 , 15 transverse to the direction of flow 50 changeable, especially adjustable. As in 2nd , 4th and 5 the control element is clearly visible 20th through a set screw 21a educated. The bypass cross section of the respective bypass channels 16 , 17th is infinitely variable. The actuator 20th can also be formed by a latching element through which the respective bypass cross section 18th is gradually changeable. The actuator 20th further comprises a sealing element through which the respective bypass channel 16 , 17th is sealed to the outside.

The respective control element 20th of the bypass valves 14 , 15 is used to change the associated bypass cross section 18th manually operated. It is also conceivable that the respective control element 20th is operated by an electric actuator. With this variant of the actuation, a continuous adjustment of the damper characteristic is possible. In other words, the damper characteristic of the respective vibration damper 10th be adapted to meet specific requirements.

Furthermore, the setting device 11 the inner bypass cover 24th and an outer bypass orifice 25th on, each with a bypass orifice 24th , 25th depending on a direction of movement of the piston 13 one bypass channel each 16 , 17th closes. The inner bypass cover 24th is in the main body 23 the adjustment device 11 arranged such that the inner bypass diaphragm 24th the first bypass duct at a rebound 16 sealed fluid-tight. The bypass cover 24th lies with a radially projecting side on an inner surface of the inner receiving area 42 on. The adjustment device 11 has a locking recess into which the inner bypass diaphragm 24th engages, and through which the inner bypass diaphragm 24th is held in position.

The outer bypass cover 25th is designed such that it is the inner tube 27th at least partially encloses. The outer bypass cover 25th encloses the inner tube 27th such that the outer bypass orifice 25th the second bypass duct at one pressure stage 17th sealed fluid-tight. The inner tube 27th has two apertures 33 on that to the second bypass channel 17th adjacent, and the one with the second bypass channel 17th at a rebound from the first work space 28 to the gap 30th forms a free passage. The inner tube 27th also has two position openings 34 into which the outer bypass cover 25th engages, and through which the outer bypass diaphragm 25th is held in position. The inner tube 27th can also have one or more position openings 34 exhibit. Furthermore, the inner tube 27th several, in particular more than two, aperture openings 33 exhibit. A detail of the inner tube 27th with the aperture openings 33 and the position openings 34 is in 8th shown.

As in 6 and 7 the bypass orifices are shown 24th , 25th each formed by a C-shaped ring spring. The bypass orifices 24th , 25th can each be made of spring steel, in particular spring steel sheet metal strip. According to 6 has the inner bypass 24th a locking element 46 which protrudes radially outwards. For a fixed arrangement of the inner bypass cover 24th this will be in the inner recording area 42 of the basic body 23 inserted. The inner bypass cover 24th snaps with the locking element 46 into the locking recess and is thereby held in position. According to 7 shows the outer bypass 25th a position element 47 which protrudes radially inwards. For the fixed arrangement of the outer bypass cover 25th this will be around the inner tube 27th in the area of the first pipe end 39a arranged. The outer bypass cover 25th snaps with the position element 47 into the position opening 34 and is held in position.

According to the 3rd to 5 is the flow of the damper oil in the vibration damper 10th described. 3rd shows a simplified circuit diagram of the vibration damper 10th with the valve units 13a of the piston 13 , the bypass valves 14 , 15 and the bypass orifices 24th , 25th . 4th shows a perspective detail view of the vibration damper 10th at a pressure level or when immersing the piston rod 12 into the inner tube 27th . Furthermore shows 5 a detailed perspective view of the vibration damper 10th at a rebound or when extending the piston rod 12 from the inner tube 27th .

At a pressure level according to 4th is the space 30th through the first bypass channel 16 with the first work space 28 fluid-connected. Here, the damper oil is generated by a stroke movement of the piston 13 from the second work room 29 in the space 30th and on through the first bypass channel 16 in the first work room 28 pressed. At the same time, the damper oil flows through the compression valve units 13a of the piston 13 from the second work room 29 in the first work room 28 . For setting the pressure level of the vibration damper 10th can be the first bypass valve 14 are actuated, causing the bypass cross section 18th of the first bypass channel 16 changed, in particular reduced or enlarged. The flow direction 50 is shown here by the arrow. Due to the resulting fluid pressure when the piston rod is immersed 12 into the inner tube 27th or by the stroke movement of the piston 13 becomes the outer bypass orifice 25th against the inner tube 27th pressed. The outer bypass cover 25th lies over the aperture openings 33 and thus seals them fluid-tight. The outer bypass cover 25th acts as a check valve. Through the second bypass channel 17th is at a pressure level between the space 30th and the first work space 28 therefore no fluid connection possible.

With a rebound according to 5 is the space 30th through the second bypass channel 17th with the first work space 28 fluid-connected. Here, the damper oil is generated by a stroke movement of the piston 13 from the first work room 28 through the second bypass channel 17th in the space 30th and on to the second work room 29 pressed. At the same time, the damper oil flows through the rebound valve units 13a of the piston 13 from the first work space 28 in the second work room 29 . For setting the rebound of the vibration damper 10th can the second bypass valve 15 are actuated, causing the bypass cross section 18th of the second bypass channel 17th changed, in particular reduced or enlarged. The flow direction 50 is shown here by the arrow. Due to the resulting fluid pressure when extending the piston rod 12 from the inner tube 27th or by the stroke movement of the piston 13 becomes the inner bypass orifice 24th against the inner surface of the inner receiving area 42 pressed. The inner bypass cover 25th lies over the bypass openings of the first bypass channel 16 and thus seals it fluid-tight. The inner bypass cover 24th also acts as a check valve. Through the first bypass channel 16 is at a rebound between the space 30th and the first work space 28 therefore no fluid connection possible.

Reference symbol list

10th

Vibration damper

11

Adjustment device

12

Piston rod

13

piston

13a

Valve unit

14

first bypass valve

15

second bypass valve

16

first bypass channel

17th

second bypass channel

18th

Bypass cross section

19th

Valve body

20th

Actuator

20a

Set screw

21st

Through opening

22

Valve seat

23

Basic body

24th

inner bypass cover

25th

outer bypass orifice

26

Outer tube

27th

Inner tube

28

first work space

29

second work space

30th

Space

31

Sealing cover

32a

end near the piston rod

32b

end remote from the piston rod

33

Aperture

34

Position opening

35

Separating piston

36

Damper housing

37

Housing receiving area

38

Walkways

39a

first tube end of the inner tube

41

outer recording area

42

inner recording area

43

Sealing elements

44

Compensation room

45

Receiving floor

46

Locking element

47

Position element

50

Flow direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 8322369 B2 [0008]

Claims (26)

Adjustable vibration damper (10) for a motor vehicle, which comprises an adjusting device (11) and a piston rod (12) with a piston (13), the adjusting device (11) having at least one first bypass valve (14) which has a first bypass channel (16 ) and has at least one second bypass valve (15) which is assigned to a second bypass channel (17), the bypass channels (16, 17) each having at least one bypass cross section (18) through the respective bypass valve (14, 15 ) to adjust a damper characteristic, in particular the compression or the rebound, is changeable. Vibration damper after Claim 1 , characterized in that a plurality of first bypass channels (16) and / or a plurality of second bypass channels (17) are provided, at least one of the bypass cross sections (18) of the bypass channels (16, 17) being changeable for setting a damper characteristic. Vibration damper after Claim 1 or 2nd , characterized in that the bypass cross sections (18) of the bypass channels (16, 17) can be changed, in particular adjustable, by a linear movement of the respective bypass valve (14, 15) transversely or longitudinally to the flow direction (50). Vibration damper according to one of the preceding claims, characterized in that the bypass channels (16, 17) are arranged separately from one another for separate adjustment of the compression stage and the rebound stage, the bypass channels (16, 17) in each case, in particular exclusively, in one direction (40) are flowable. Vibration damper according to one of the preceding claims, characterized in that the bypass cross sections (18) of the bypass channels (16, 17) can be changed, in particular adjusted, from the outside by actuating the bypass valves (14, 15). Vibration damper according to one of the preceding claims, characterized in that the first bypass valve (14) is provided for setting the compression stage and the second bypass valve (15) for setting the rebound stage. Vibration damper according to one of the preceding claims, characterized in that the adjusting device (11) is designed as a sealing cover (31) which closes the vibration damper (10) in a fluid-tight manner. Vibration damper according to one of the preceding claims, characterized in that in each case a bypass valve (14, 15) has a valve body (19) and an actuating element (20), the associated bypass channel (16, 17) having a through opening (21) in the valve body (19 ) forms. Vibration damper after Claim 8 , characterized in that the adjusting element (20) for changing the bypass cross-section (18) in the bypass channel (16, 17) can be inserted transversely or longitudinally to the flow direction (30). Vibration damper after Claim 8 or 9 , characterized in that the adjusting element (20) is formed by an adjusting screw (21a). Vibration damper according to one of the Claims 8 to 10th , characterized in that the adjusting element (20) has at least one sealing element, by means of which the bypass channel (16, 17) is sealed off from the outside. Vibration damper according to one of the Claims 8 to 11 , characterized in that the valve body (19) of the bypass valve (14, 15) has a columnar valve seat (22), the bypass channel (16, 17) running along the valve seat (22). Vibration damper according to one of the Claims 8 to 12 , characterized in that the adjusting device (11) has a base body (23) with which the valve body (19) of the bypass valves (14, 15) are integrally formed. Vibration damper after Claim 13 , characterized in that the base body (23) of the adjusting device (11) with the bypass channels (16, 17) and the valve bodies (19) of the bypass valves (14, 15) is formed in one piece. Vibration damper according to one of the preceding claims, characterized in that the adjusting device (11) is cylindrical, in particular hollow cylindrical. Vibration damper according to one of the preceding claims, characterized in that the adjusting device (11) has an inner bypass diaphragm (24) and an outer bypass diaphragm (25), each having a bypass diaphragm (24, 25) depending on a direction of movement of the piston (13) closes at least one bypass channel (16, 17). Vibration damper after Claim 16 , characterized in that the bypass orifices (24, 25) are each formed by a C-shaped ring spring. Vibration damper after Claim 16 or 17th , characterized in that the inner bypass diaphragm (24) in the base body (23) of the The adjusting device (11) is arranged such that the inner bypass diaphragm (24) closes the first bypass channel (16) in a fluid-tight manner when the train is damped. Vibration damper according to one of the Claims 16 to 18th , characterized in that the adjusting device (11) has a locking recess into which the inner bypass diaphragm (24) engages and through which the inner bypass diaphragm (24) is held in a fixed position. Vibration damper according to one of the preceding claims, characterized in that the bypass valves (14, 15) each comprise at least one bypass orifice (18, 19) with a spring rate which can be changed to set a damper characteristic, in particular the compression stage or the rebound stage. Vibration damper according to one of the preceding claims, characterized by an outer tube (26) and at least one inner tube (27), the piston (13) separating a first working space (28) and a second working space (29) of the inner tube (27), and wherein an intermediate space (30) is formed between the outer tube (26) and the inner tube (27), which is fluidly connected to the second working space (29) and which is connected to the first working space (26) through the bypass valves (14, 15) Inner tube (27) is fluidly connectable or fluidly connected by the stroke movement of the piston (13). Vibration damper after Claim 21 , characterized in that the inner tube (27) has at least one diaphragm opening (33) which adjoins the second bypass duct (17) and which with the second bypass duct (17) is subjected to a tensile damping from the first working space (28) to the intermediate space (30 ) forms a free passage. Vibration damper after Claim 21 or 22 , characterized in that the inner tube (27) has at least one position opening (34) into which the outer bypass diaphragm (25) engages and through which the outer bypass diaphragm (25) is held in a fixed position. Vibration damper according to one of the Claims 21 to 23 , characterized in that the outer bypass diaphragm (25) at least partially surrounds the inner tube (27) such that the outer bypass diaphragm (25) closes the second bypass duct (17) in a fluid-tight manner when pressure is damped. Vibration damper according to one of the preceding claims, characterized in that the piston rod (12) is guided in the adjusting device (11) so as to be displaceable in the damping direction, in particular in the axial longitudinal direction. Motor vehicle with an adjustable vibration damper according to one of the Claims 1 to 25th .

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