阅读说明：本技术 具有可变弹簧刚度的弹簧减振器系统 (Spring damper system with variable spring rate ) 是由 M·迪特里希 U·沙茨贝格 J·施罗德 于 2018-09-14 设计创作，主要内容包括：本发明涉及一种用于机动车的车轮悬架的弹簧减振器系统,其包括具有弹簧常数k<Sub>T</Sub>的承载弹簧(10)和与承载弹簧(10)并联的并且填充有流体的减振器(20),其特征在于,弹簧减振器系统还包括至少两个附加弹簧模块(31、32、33、34),通过所述附加弹簧模块能够改变弹簧减振器系统的总弹簧常数k<Sub>G</Sub>。(The invention relates to a spring damper system for a wheel suspension of a motor vehicle, comprising a spring constant k T And a damper (20) connected in parallel with the carrier spring (10) and filled with fluid, characterized in that the spring damper system further comprises at least two additional spring modules (31, 32, 33, 34) by means of which the overall spring constant k of the spring damper system can be changed G 。)

1. A spring damper system for a wheel suspension of a motor vehicle, comprising a spring with a spring constant k_TAnd a shock absorber (20) connected in parallel with said load spring (10) and filled with a fluid, characterized in that,

the spring damper system further comprises at least two additional spring modules (31, 32, 33, 34) each having an additional container (311, 321, 331, 341), wherein each additional container comprises an additional container volume which is formed by a material having a spring constant k_nAnd the additional springs (312, 322, 332, 342) are pressurized and the additional tank volumes are each fluidically connected via a fluid line (30) to a damper section (21) of the damper (20), the damper section volumes of which are compressed in the damper (20)A reduction in stages, wherein at least one of the at least two additional spring modules (31, 32, 33, 34) comprises a controllable shut-off valve (314, 324, 334, 344), with which the respective fluid line (30) can be shut off.

2. The spring damper system according to claim 1, wherein at least one of the at least two additional spring modules (31, 32, 33, 34) comprises a throttle valve (315, 325, 335, 345) acting in parallel with a shut-off valve (314, 324, 334, 344) throttling the flow through the respective fluid line.

3. The spring damper system according to any one of the preceding claims, wherein the respective additional spring (312, 322, 332, 342) of one of the at least two additional spring modules (31, 32, 33, 34) is a gas spring or a helical spring.

4. The spring damper system according to any one of the preceding claims, wherein each of said spring constants k_nAre different from each other.

5. Spring damper system according to one of the preceding claims, wherein each spring constant k_nOf a spring constant k_nBetween 1 and 2N/mm.

6. The spring damper system according to any one of the preceding claims, wherein the spring constant k of the additional springs (312, 322, 332, 342) of each additional spring module (31, 32, 33, 34) is_nAre multiples of each other.

7. Spring damper system according to one of the preceding claims, wherein the additional container is a cylinder (311, 321, 331, 341) having two cylinder chambers which are variable in their volume and which are separated by a movable separating piston (313, 323, 333, 343), wherein,

the first cylinder chamber is connected as an additional reservoir volume to the damper section (21) via a corresponding fluid line (30), the damper section volume of the damper section being reduced in the compression phase of the damper (20), and

the second cylinder chamber accommodates a corresponding additional spring (312, 322, 332, 342) which acts upon the first cylinder chamber under pressure via the separating piston (313, 323, 333, 343).

8. The spring damper system according to the preceding claim, wherein at least two further spring modules (41, 42) have a common cylinder (40) with at least three cylinder chambers which are separated by a separating piston (43), respectively, wherein the first cylinder chamber accommodates the further springs (44) of a first further spring module (41) and the third cylinder chamber accommodates the further springs (45) of a second further spring module (42).

9. The spring damper system according to any one of the preceding claims 7 or 8, wherein the dividing piston has a diaphragm between one of the cylinder chambers and a cavity formed by the dividing piston.

10. Spring damper system according to one of the preceding claims, wherein at least one of the additional spring modules (31, 32, 33, 34, 41, 42) is configured integrally to form one structural unit with the damper.

11. Method for spring constant control with a spring damper system according to one of the preceding claims, wherein the shut-off valves (314, 324, 334, 344, 46) of the at least two additional spring modules (31, 32, 33, 34, 41, 42) are each controlled by a shut-off valve controller depending on the total spring constant k to be achieved_GControlling the fluid flow between the respective additional reservoir (311, 321, 331, 341) and the damper section (21) in a blocking or releasing manner, the reductionThe damper section volume of the damper section is reduced in the compression phase of the damper (20), so that at least in the case of identical hydraulic transmission ratios between the damper (20) and each of the additional spring modules, the overall spring constant k is obtained from the following formula_G，

Wherein only the spring constant k of the additional spring module (31, 32, 33, 34, 41, 42) whose shut-off valve (314, 324, 334, 344, 46) is in a position releasing the fluid flow_nIs calculated into the spring constant k_nThe sum of the reciprocal of (a).

Technical Field

The invention relates to a spring damper system with a variable spring rate, in particular for a wheel suspension of a motor vehicle.

Background

In the design of spring damper systems, a target conflict arises between the driving comfort achievable by the spring damper system and the driving dynamics achievable.

On the one hand, the spring damper system can be designed as comfortably as possible (high ride comfort), which can be achieved, for example, by a low spring rate (also referred to as spring constant). However, the comfort coordination of the spring damper system leads to limitations in the mobility and safety of the driving characteristics of the motor vehicle (poor driving dynamics).

On the other hand, the spring damper system can be matched to the best possible dynamics or kinematics (good driving dynamics). For this purpose, high spring rates are used, which results in a limitation in terms of driving comfort.

In order to be able to achieve a variable coordination of the spring damper system and thus to be able to vary between a movement coordination and a comfort coordination of the spring damper system, different active spring damper systems are known from the prior art.

In systems known in the prior art, the spring rate of a spring damper system is controlled in part by an air spring that is variable in its spring rate. However, the pressure of the air to be generated has to be generated in a unit which has high control costs and has high installation space requirements and high energy requirements.

Other known systems use, for example, spring packs consisting of steel springs acting in series, which must be designed to be stable in order to withstand the mass to be elastically damped. With a stable design, the spring assembly has a high weight and a high installation space requirement, which is a great disadvantage, in particular, in the context of energy consumption in motor vehicles. Furthermore, the extension between the driving comfort control and the driving dynamics control and the variability thereof that can be achieved with such a system are small.

Disclosure of Invention

The object of the present invention is therefore to provide a spring damper system which has a controllable overall spring constant, has a small installation space requirement and can be switched between different overall spring constants quickly and without great energy consumption.

This object is achieved by a combination of features according to claim 1.

According to the invention, a spring damper system for a wheel suspension of a motor vehicle or a single-track motor vehicle is proposed for this purpose. The spring damper system comprises for this purpose a spring constant k_TAnd a damper which is parallel to the support spring and acts in parallel and is filled with fluid. Furthermore, the spring damper system comprises at least two further spring modules, each having a further container, wherein each further container comprises a further container volume. The additional container volume consisting of_nAdditional spring loading pressure. The additional spring can be arranged in or on the additional container. The additional reservoir volumes of the additional spring modules are each fluidically connected to a damper section of the damper via a tubular fluid line. The shock absorber section of the shock absorber has a shock absorber section volume that decreases during a compression phase of the shock absorber. Furthermore, at least one of the at least two additional spring modules comprises a controllable shut-off valve, with which the respective fluid line of the respective additional spring module can be shut off. The spring damper system can be integrated into a telescopic fork of a single-track motor vehicle, for example, or comprise such a telescopic fork.

The fluid flowing through the damper and the additional spring element is in particular oil. The carrier spring and the shock absorber support the mass of the motor vehicle relative to one of the vehicle axles. The vibration damper is preferably arranged within a support spring designed as a helical spring, so that the support spring and the vibration damper form a compact structural unit.

The shock absorber has two internal volumes separated by a piston within its interior. When the spring damper system is elastically compressed or elastically extended, the piston is displaced by the piston rod, so that the two internal volumes of the damper change. When the spring damper system is elastically extended, the damper is loaded in tension (tensile phase) and when elastically compressed, in compression (compression phase). Thus, the internal volumes of the shock absorber change their respective volumes in the compression phase and the extension phase. The fluid in the respective internal volumes flows partly and according to the movement from one internal volume of the shock absorber through the valve into the other part of the internal volume. However, the total internal volume of the shock absorber does not remain constant during the compression phase and the extension phase, because the shock absorber with the retracted piston rod has a smaller total volume due to the volume of the piston rod in the shock absorber, compared to a shock absorber with an extended piston rod. In the present invention, the difference in total volume (differential volume) is pressed into the additional spring module during the compression phase. The additional spring module is therefore fluidically connected directly to the damper section of the damper, the internal volume of which, or the damper section volume of which, is reduced in the compression phase of the damper, so that fluid can flow into the additional spring module in the compression phase of the damper and from the additional spring module into the damper in the extension phase of the damper. The support spring takes over the main spring action and preferably has a spring constant of between 100 and 200N/mm. The additional springs of the additional spring module, on the basis of their spring travel, form an expansion (Spreizeng) which can be demonstrated with the spring damper system, that is to say a difference between the respective possible overall spring constants (or overall spring rates). By allocating the tasks between the support spring, which takes over the main spring action, and the additional spring, which takes over the extended additional spring action, the entire spring damper system can be arranged in the vehicle in different ways and in a particularly space-saving manner, so that the proposed spring damper system has a particularly advantageous installation space requirement.

The connection of the support spring to the additional spring of the additional spring module yields: the additional springs of the additional spring modules act in series with one another and the additional springs connected in series act in common parallel to the support spring.

Thus, the overall spring constant k of the spring damper system_GIs the spring constant k of the carrier spring_TTotal additional spring constant k with additional spring_GnThe additional spring acts with pressure on an additional reservoir, which is in flow-effective connection with the damper section. In this case, the only flow-effective connection to the damper section is the additional container in which the fluid flow through the fluid line is not blocked by the shut-off valve.

Thus, the total spring constant k_GThe formula of (1) is:

k_G＝k_T+k_Gn

total additional spring constant k_GnBased on a series circuit with all spring constants k_nThe reciprocal of the sum of the reciprocals.

However, this applies only if the damper is identical to the hydraulic transmission ratio of each of the additional spring modules, so that the forces acting on the damper from the outside and pressing the hydraulic fluid from the damper into the additional spring modules are distributed evenly to the additional spring modules or to the additional springs, so that the same forces act on the additional springs in each case.

Thus, it is possible to provideIn the case of the same hydraulic transmission ratio between the vibration damper and each of the additional spring modules or a transmission ratio between the additional spring modules of 1: 1, for the total additional spring constant k_GnApplicable formula

Wherein only such spring constant k_nIn this case, the additional spring of this spring constant acts as a pressure medium for an additional container which is not separated from the respective shut-off valve and the damper in terms of flow.

Therefore, in this case, the following formula applies to the total spring rate k_G：

If the hydraulic transmission ratio between the additional spring modules is not 1: 1 (for example due to different active surfaces, via which the hydraulic fluid acts on the respective additional spring) or, if forces of different magnitudes act on the additional spring via the hydraulic fluid, the total additional spring constant k_GnCannot be calculated according to the above formula because of the additional spring constant k of the individual effects_nThe resulting total additional spring constant is included in relation to the force acting on the respective spring.

Furthermore, a design is advantageous in which at least one of the at least two additional spring modules comprises a throttle valve acting in parallel with the shut-off valve. The throttle valve throttles the flow through the respective fluid line when the associated shut-off valve blocks an unthrottled flow between the respective additional reservoir of the additional spring module and the vibration damper. If the shut-off valve is controlled in order to control the overall spring rate of the spring damper system and is brought from its flow position into its shut-off position, the pressure prevailing in the additional reservoir (shut-off position) separated by the shut-off valve remains. If, at a later point in time, the shut-off valve is again brought into a position in which throughflow through the shut-off valve is achieved (throughflow position) and the pressure in the damper changes in the process, a sudden pressure equalization can occur between the different sections of the spring damper system, so that the damper suddenly pushes in or out the piston rod as a result of the pressure shock occurring during the pressure equalization. By means of the throttle valves, the pressures between the sections can be matched to one another slowly, so that no pressure differences between the sections and therefore no sudden pressure equalizations occur. The throttle valve is adjustable and controllable with respect to its throttle, in order to be able to specifically control the flow rate of the fluid through the throttle valve.

In order to be able to control the pressure compensation in a targeted manner, an advantageous development provides that at least one of the additional spring modules comprises a check valve which is blocked by a throttle valve from the fluid flow from the shock absorber to the respective additional container, the check valve being connected in series with the throttle valve and in parallel with the shut-off valve. Instead of the check valve, the respective additional spring module can also comprise a controllable second shut-off valve.

In a further advantageous embodiment, the respective additional spring of one of the at least two additional spring modules is a gas spring or a helical spring. Alternatively, the spring can also be formed by a rubber spring, an air spring or another spring which acts upon the additional container volume. The different additional springs of the additional spring modules of the spring damper system can each be formed by another spring type. Preferably, the additional spring is constituted by a nitrogen-based gas spring having a spring constant of 1 to 2N/mm.

In order to be able to generate different spring constants by controlled blocking of the blocking valve, a particularly advantageous development provides that the spring constants k are each_nAre different from each other.

Furthermore, it is advantageous if all spring constants k_nA unique spring constant k_nBetween 1 and 2N/mm. Furthermore, it is advantageous if the other spring constant k_nBetween 10 and 50N/mm.

Due to additional cartridge with additional springThe spring module has a very low spring constant k, in particular between 1 and 2N/mm_nFor a spring with a very small spring constant k_nAdditional spring module pair total additional spring constant k_GnTo the extent that this contributes, a constant k is derived for the total additional spring constant_GnIs less than or equal to a very small spring constant k_n. Thus, the overall spring constant k of the spring damper system_GSubstantially equal to the spring constant k of the carrier spring_T. In this case, the additional reservoir serves only as a compensation reservoir for the volume displaced by the piston rod.

In an advantageous development of the additional spring module, the spring constant k of the additional springs is_nAre multiples of each other. Optionally, each individual spring constant k_nCan be generated by a fixed intermediate value, such that the spring constant k_nIs a value that is increased in, for example, ten steps. Independent of whether the spring constants are derived from a fixed intermediate value or are multiples of one another, the additional spring can have a very small and comparable spring constant k_nIndependent spring constant k_nSo that the additional reservoir of the spring module can be used as a compensating reservoir for the fluid.

In an advantageous embodiment, the additional container is a cylinder which has two cylinder chambers which are variable in their respective volumes and which are separated by a displaceable separating piston. The first of the two cylinder chambers of the cylinder block is connected as an additional reservoir volume via a respective fluid line to the shock absorber section, the shock absorber section volume of which is reduced in the compression phase of the shock absorber. The second of the two chambers of the cylinder block houses a respective additional spring of a respective additional spring module. An additional spring accommodated in the second cylinder chamber acts with pressure on the first cylinder chamber by means of the separating piston and is supported for this purpose on the cylinder body.

In order to save material and installation space for the integrated construction of a plurality of additional spring modules, an advantageous development provides that at least two additional spring modules have a common cylinder. The common cylinder block has at least three cylinder chambers, which are each separated by a separating piston. The first cylinder chamber houses the additional springs of the first additional spring module and the third cylinder chamber houses the additional springs of the second additional spring module. The additional springs are each supported on the common cylinder and can act upon the second cylinder chamber with a common application of pressure. Alternatively, the two additional springs can each act upon a cylinder chamber with pressure, wherein the additional spring in the first cylinder chamber acts upon the second cylinder chamber with pressure and the additional spring in the third cylinder chamber acts upon the fourth cylinder chamber with pressure. If the second and fourth cylinder chambers are directly adjacent to one another, they are constructed separately from one another by a wall arranged between them.

In order to improve the response behavior of the additional spring module or the separating piston, an advantageous embodiment provides that the separating piston has a diaphragm between one of the cylinder chambers and the cavity formed by the separating piston. The diaphragm is pressed into the cavity or sucked into the cylinder chamber by the pressure acting in the cylinder chamber. At low pressures, which are not sufficient to move the entire separating piston, the diaphragm acts as a spring element, so that at low pressures, too, spring work is performed. At a sufficiently high pressure, the entire separation piston moves. The response behavior of the additional spring module is thereby improved, so that it performs spring work more quickly or already at lower pressures when the pressure in the cylinder chamber changes. The so-called slip-stick effect of the separating piston is therefore also reduced, since the separating piston is moved only at a sufficiently high pressure and performs spring work via the diaphragm at pressures below this pressure.

In order to be able to realize a particularly compact spring damper system which saves installation space, a development provides that at least one of the additional spring modules is formed integrally with the damper and forms a structural unit. The damper is preferably arranged with the integrally formed additional spring module inside the support spring, in order to form a compact spring damper system overall.

Furthermore, a method for controlling the spring constant of a spring damper system is proposed according to the invention. For this purpose, use is made ofThe spring damper system according to the invention as described above. For adjusting or controlling the spring constant, the shut-off valves of the at least two additional spring modules are each controlled by a shut-off valve controller as a function of the total spring constant k to be achieved_GThe fluid flow between the respective additional reservoir and the damper section is controlled in a blocking manner (blocking position) or in a release manner (flow-through position), the damper section volume of the damper section being reduced in the compression phase of the damper.

By means of this control and the above-described construction, the total spring constant k is determined for the total spring constant k at least in the case of identical hydraulic transmission ratios between the damper and each additional spring module_GThe following formula is obtained

In this case, only the spring constants k of the spring modules are added_nIs calculated into the spring constant k_nIn a position (flow-through position) releasing the fluid flow between the respective additional reservoir volume and the damper section volume.

Drawings

The features disclosed above can be combined in any desired manner, provided that this is technically possible and that these are not technically contradictory. Further advantageous developments of the invention are characterized in the dependent claims or are shown in detail below together with the description of preferred embodiments of the invention with the aid of the drawings. Displaying:

FIG. 1 shows a spring damper system with two additional spring modules;

FIG. 2 shows a spring damper system with four additional spring modules;

fig. 3 shows a spring damper system with two additional spring modules which are designed integrally with one another.

Detailed Description

The figures are schematic and exemplary. Like reference numbers in the figures refer to like functional and/or structural features.

Fig. 1 to 3 each show a spring damper system according to the invention, which are each distinguished only by their respective additional spring modules. The vehicle body FK and the vehicle axle FA are supported relative to one another by the support spring 10, wherein the vibration damper 20 damps the movements and the forces occurring there. Shock absorber 20 is a cylinder supported on vehicle body FK into which extends a piston rod 24 from vehicle axle FA. The piston rod 24 is fixed on the piston 23 within the cylinder and is thus configured to move the piston 23 within the cylinder by movement of the piston rod 24. The cylinder of the shock absorber 20 is divided by a piston 23 into a first shock absorber section 21 and a second shock absorber section 22, each defining a shock absorber section volume. The shock absorber sections 21, 22 and the respective associated shock absorber section volumes decrease and increase in accordance with the movement of the piston rod 24 and the piston 23. When the piston rod 24 moves into the cylinder (compression phase), the first damper section 21 and the associated damper section become smaller in volume, and the second damper section 22 and the associated damper section become larger in volume, and if the piston rod 24 moves out of the cylinder (extension phase), the first damper section 21 and the associated damper section become larger in volume, and the second damper section 22 and the associated damper section become smaller in volume.

In fig. 1, two additional spring modules 31, 32 are connected to the first damper section 21 or the damper section volume via a fluid line 30. The additional spring module 31 comprises an additional container configured as a cylinder 311 filled with a fluid. The fluid in cylinder 311 is pressurized by additional spring 312 by means of a partition piston 313, so that the spring force of additional spring 312 exerts a pressure on the fluid, which is transmitted via fluid line 30 into shock absorber 20 and via shock absorber 20 to vehicle body FK and vehicle axle FA. Since the shut-off valve 324 of the second additional spring module 32 is in a position (shut-off position) in which the fluid line to the additional container designed as a cylinder 321 is interrupted, the additional spring 322 does not act on the fluid which is effectively connected to the shock absorber 20 in terms of flow. Thus, the second additional spring 322 does not act on the vehicle body FK and the vehicle axle FA. Of shut-off valve 324 in FIG. 1In the illustrated switching state, the additional spring 312 and the support spring 10 act in parallel with one another, so that the overall spring constant k of the spring damper system of fig. 1 results_G1By the spring constant k of the carrier spring_TAnd the spring constant k of the first additional spring module₃₁To give (k)_nWhere n is replaced by the reference numeral of the functioning additional spring module 31). The total spring constant in FIG. 1 is thus given by the formula k_G1＝k_T+k₃₁And (6) obtaining. Spring constant k of the additional spring 322₃₂Specific spring constant k₃₁Many times smaller, so that by switching the shut-off valve 324 from the shut-off position shown into the flow-through position, in which a connection to the damper is established, the total spring rate k_GSubstantially corresponds to k_T。

In the spring damper system shown in fig. 2, the four additional spring modules 31, 32, 33, 34 are each designed with a shut-off valve 314, 324, 334, 344, to which a throttle 315, 325, 335, 345 is connected in parallel fluidically, so that a slow pressure equalization occurs in the case of high pressure differences between the additional spring modules 31, 32, 33, 34 or the damper 20. Each additional spring module has a cylinder 311, 321, 331, 341, in which the fluid is pressurized by an additional spring 312, 322, 332, 342 by means of a separating piston 313, 323, 333, 343. The shut-off valves 324, 334 of the second and third additional spring modules are in their respective flow-through positions, so that the additional springs 322, 332 of the second and third additional spring modules 32, 33 transmit their spring force to the shock absorber 20 and thus to the vehicle body FK and the vehicle axle FA by means of a fluid. The additional springs 322, 332 act in series with one another and parallel to the support spring 10, so that in the switching position of the shut-off valves 314, 324, 334, 344 shown in fig. 2, the total spring constant k is obtained as a total spring constant for the spring damper system_G2Formula (2)

Figure 3 shows an alternative embodiment to the spring damper system of figure 1,the first and second additional spring modules 41, 42 have a common cylinder 40, in which respective additional containers pressurized by additional springs 44, 45 are arranged. Only the second additional spring module 42 of the additional spring modules 41, 42 comprises a shut-off valve 46, to which a throttle 47 is connected in parallel. Due to the switching position of the shut-off valve 46 in its flow-through position, the additional springs 44, 45 of the additional spring modules 41, 42 act in series with one another. Since, as described in fig. 1, one of the spring constants of the additional springs 41, 42 is very small, the additional reservoir of the additional spring modules 41, 42 essentially serves as a compensation reservoir for the fluid displaced by the piston rod 24, without the overall spring constant k for the spring damper system_GA large influence is produced. Thus, the overall spring constant k of the spring damper system of FIG. 3_GSubstantially equal to the spring constant k of the carrier spring_TAre equal.

The invention is not limited in its embodiments to the preferred embodiments described above. On the contrary, many variants are conceivable which can be used by the illustrated solution even in substantially different types of embodiments. For example, the respective pretensioning of the additional spring can be adjusted mechanically by means of a respective pretensioning mechanism.