DE102016222836A1 - Device for actuating a clutch of a vehicle - Google Patents

Abstract

The invention relates to a device (1) for actuating a clutch (70) of a vehicle, comprising a cam disc (2) which is rotatable about a cam axle (3); further comprising a plunger (4) extending along a longitudinal axis (A) with a first end (5) facing the cam (2) and a second end (6) facing the coupling (70); further comprising a clevis (50) disposed between the cam (2) and the plunger (4); furthermore comprising a roller bearing (7) which is connected to the fork head (50) and which is rotatable about an axis (8) fastened to the fork head (50) and bears against an end face (2a) of the cam disc (2). The clevis (50), viewed along the longitudinal axis (A), has a first section (10) facing the plunger (4) and a second section (20) facing the cam (2). The clevis (50) is coupled in the first section (10) to the first end (5) of the plunger (4). The clevis (50) is fork-shaped in the second section (20) with two arms (21, 22) projecting in the direction of the longitudinal axis (A). The two arms (21, 22) are spaced apart transversely to the longitudinal axis (A). The two arms (21, 22) have mutually opposite openings (23, 24) for receiving the axis (8) of the roller bearing (7). The clevis (50) is made in one piece by metal injection molding from a first material.

Description

Field of the invention

The invention relates to a device or an actuator for actuating a clutch of a vehicle. The invention further relates to a clevis for a device or an actuator for actuating a clutch of a vehicle. The invention also relates to a method for producing a clevis.

State of the art

Devices or actuators for actuating a clutch of a vehicle are known from the prior art. Recently, attempts are increasingly being made to use couplings in which the coupling process is effected by an electromechanical actuator. In automatic transmissions such electromechanically activated clutches are already known. Such clutches or devices for actuating a clutch of a vehicle can also be referred to as so-called "electronic clutch" or shortly as "eClutch".

In such eClutch systems, often in an actuator of the eClutch system, a rotary motion of an engine or a transmission coupled to the engine is translated into a linear motion to actuate a hydraulic cylinder. This hydraulic cylinder can then actuate a further hydraulic cylinder, via which a clutch disc coupled to the further hydraulic cylinder is disengaged (open state) in order to interrupt a torque transmission between the clutch disc and a flywheel. The flywheel is connected to the drive train of the vehicle. Counter-rotating movement of the motor of the actuator or device results in e.g. due to springs in the clutch to a counter-linear movement, which actuates the hydraulic cylinder and thus also the other hydraulic cylinder, thus causing engagement of the clutch disc relative to the flywheel. When the clutch is engaged (closed state), torque is transferred between the flywheel and the clutch disc.

In order to achieve the conversion of the rotary movement into the linear movement, a cam disc and a ram connected or coupled to the cam can be used. The cam is firmly connected to a gear, which in turn is connected to the engine. In this way, the cam can be rotated by rotation of the motor by means of the transmission. By changing the radius of the cam as a function of the angle of rotation (for example, by the profile of the cam on its front side) may result in a known manner, a linear movement of the plunger.

In order to effect a low-friction coupling or operative connection between the plunger and the cam is often provided in such devices or actuators for actuating a clutch of a vehicle, to arrange a roller bearing between the plunger and the cam. In this case, an axis of the roller bearing is aligned substantially parallel to a cam axis of the cam. The axis of the roller bearing can be attached to the plunger.

From the DE 10 2014 226 120 A1 Such a device for actuating a clutch of a vehicle is known.

Disclosure of the invention

The invention is based on the recognition that the direct attachment of the axle of the roller bearing on the plunger could lead to a tilting in the implementation of the rotational movement of the motor in a linear movement of the plunger. Furthermore, problems can arise when pressing the axis of the roller bearing into a receptacle for the axis in the plunger when the material of the plunger has a greater hardness than the material of the axis. Because this can lead to an undesirable deformation of the axis during the press-fitting process.

There may therefore be a need to provide a device or an actuator for actuating a clutch of a vehicle, in which or at which a tilting of the plunger is avoided as possible during a linear movement of the plunger. At the same time, no deformation of the axis should occur during assembly or pressing in of the axis of the roller bearing into an associated receptacle for the axis of the roller bearing and still be given a high mechanical stability of the axle.

Advantages of the invention

This need can be met by the subject matter of the present invention according to the independent claims. Advantageous embodiments of the present invention are described in the dependent claims.

According to a first aspect of the invention, an actuator for actuating a clutch of a vehicle is proposed. The device or the actuator comprises a cam which is rotatable about a cam axis. The device or the actuator, for example, a motor for rotating the Have cam. The device further comprises a ram extending along a longitudinal axis with a first end facing the cam and a second end facing the coupling. The device further comprises a clevis, which is arranged between the cam and the plunger. In particular, this arrangement relationship results when viewed along the longitudinal axis. The device further comprises a connected to the fork head roller bearing, which is rotatable about an axis attached to the fork head and rests on an end face of the cam or can be applied. The clevis, viewed along the longitudinal axis, has a first section facing the tappet and a second section facing the cam. The clevis is coupled in the first section to the first end of the plunger. In this case, the first end of the fork head can be designed substantially spherical. The fork head is fork-shaped in the second section with two arms projecting in the direction of the longitudinal axis. The two arms are viewed from each other transversely to the longitudinal axis. The two arms have opposing openings for receiving the axis of the roller bearing. The clevis is made in one piece by an injection molding process in the manner of Metal Injection Molden. The clevis is in the finished state ("final state") made of a first material ("end material").

The first material thus exists in two states: a first material, before injection molding (material M1a or "pre-material") and a first material after completion of the fork head (material M1b or "end material").

Viewed along the longitudinal axis, the clevis can be designed such that a middle section is arranged between the first section and the second section.

The cam plate is designed to convert a rotational movement into a linear movement by rolling the roller bearing on the end face of the cam disc. For this purpose, the cam can have different radii in their profile.

The longitudinal axis of the plunger may e.g. perpendicular to the cam axis and thus also perpendicular to the axis of the roller bearing.

The axis of the roller bearing may e.g. be pressed into the openings of the arms. In this case, the openings of the two arms of the fork head can be designed such that they are closed in an annular manner.

A substantially spherical configuration of the first section of the fork head can be understood, for example, to mean a spherical shape which has flattenings or flattened regions perpendicular to the longitudinal axis on end faces.

By providing the fork head is advantageously effected that the plunger is no longer directly connected to the roller bearing. Rather, the roller bearing is fixed by means of the axle on the clevis in the second section. The first portion of the clevis is then in mechanical contact with the plunger and may be mechanically connected and / or operatively connected, for example, in the manner of a ball joint with the plunger. Thereby, a power transmission in both directions of the longitudinal axis take place, wherein the first end of the plunger may be formed in the manner of a socket and the first portion of the clevis forms a kind of condyle. In such an embodiment, both tensile and compressive forces can be transmitted. In principle, however, embodiments are also conceivable in which only a compressive force can be transmitted.

The advantage of relative mobility between the first portion of the clevis and the first end of the plunger is mechanical decoupling. As a result, for example, the risk of tilting of the plunger, in particular during rapid movements of the device or of the actuator, can be reduced. The provision of the clevis also allows the adaptation of the respective materials or materials for the plunger or for the clevis such that the corresponding mechanical requirements can be taken into account. For example, the manufacture of the fork head by means of the metal injection Moldens the use of materials possible, which allow a particularly lightweight construction of the clevis compared to a production of the fork head, for example by a solid metal. In this way, the mass to be moved can be significantly reduced. The production by means of metal injection Molden also allows almost any shape design of the clevis, so that an outer shape (ie, an outer contour and an inner contour) can be selected, which can absorb the forces acting as possible without local stress peaks. Furthermore, the clevis can be produced in large quantities with only small tolerances and also very cost-effective by the metal injection Molden. Finally, the injection molding process can be carried out as such at considerably lower temperatures than the melting temperature of the metal used, for example at a mold temperature of 20 ° C to about 50 ° C and a temperature of the injected material of about 100 ° C to 160 ° C. . preferably from 120 ° C to 140 ° C. The final composite material can then arise, for example, in a subsequent sintering process at temperatures of, for example, more than 1200 ° C.

A further development provides that a first material of the fork head has a lower first hardness than a second hardness of a second material of the axis of the roller bearing. In this case, for example, it may be provided that the first hardness has at most 70% or, for example, at most 50% of the second hardness. As a result, the pressing or attachment of the axle in the openings of the two arms of the second portion of the roller bearing can be done particularly easily. On the one hand, it is avoided by the softer material of the fork head that occur during mounting or pressing the axis stress cracks on the serving as receptacles for the axis openings or their edges. This is because the material of the clevis is more ductile than the material of the axle. At the same time a deformation of the axis during pressing is avoided. Finally, the first material can still be formed mechanically stable and temperature-stable than when using material of a plastic injection molding process.

It is understood that the first hardness of the first material refers to the material in the finished (sintered) state of the clevis, the "final state": it is then the "end material".

A further embodiment provides that at least one outwardly projecting pin is arranged on at least one of the two arms of the fork head. This at least one outwardly projecting pin is suitable for effecting an axial guidance of the fork head along the longitudinal axis by engagement in a groove on a component of the device. The device of the device, which has such a groove or guide groove, for example, be the housing of the device or be attached to the housing of the device. By protruding outward pin is advantageously causes the clevis reliably performs a linear movement along the longitudinal axis and can not break across the longitudinal axis, even with rapid or jerky movements of the device or the cam of the device.

In a further development, it is provided that an outer contour and / or an inner contour of the fork head along the longitudinal direction or viewed in a section along the longitudinal axis is designed such that the outer contour or the inner contour in a central portion and the transition from the first section to Central portion and the transition from the central portion to the second portion only angle greater than 90 °, preferably only greater than 105 ° angle, having. The middle section is arranged between the first section and the second section along the longitudinal axis.

In embodiments of the clevis without central section, the angles for the transition from the first section to the second section apply.

Under outer shape is to be understood from the externally accessible form of the clevis.

Under an outer contour is to be understood the outwardly facing surface of the clevis or the shape of the clevis. The inner contour is accordingly to be understood as the inwardly facing or inner surface of the shape of the clevis or the outer shape of the clevis.

By this development advantageously a particularly lightweight construction of the clevis is possible. At the same time this design avoids the build-up of voltage peaks at acute angles or rectangular transitions between different sections of the fork head. In this way, the clevis can be made particularly lightweight and stable.

It can be provided that the fork head is designed such that it can absorb axial forces along the longitudinal axis of at least 5000 N. The fork head should withstand these forces without being destroyed. This will ensure that the clevis will have the necessary forces to actuate the coupling at all times, i. even at all temperatures, for example in a temperature range of -40 ° C to 150 ° C, can withstand.

A further development provides that the first material before the injection molding process ("pre-material") or before the metal injection molding process comprises a plastic, as well as wax and metal powder. The plastic may be, for example, polyamide. This composition of the first material allows the clevis to be injection molded at comparatively low temperatures compared to the melting point of the metal used. This advantageously allows the injection molding process with the metal at relatively low temperatures, without having to use negative molds or a plant that would have to withstand the melting temperatures of the metal. In this way, a stable execution of the clevis can be accomplished particularly cost-effective.

A further development provides that the first material after an injection process and a Sintering process ("final material") to at least 85 weight percent (wt%), preferably at least 93 wt% or at least 97 wt% and most preferably at least 99 wt% of a metal or a metal alloy. This advantageously causes the first material undergoes a change in the composition by the manufacturing process and in the final state of the clevis is particularly stable and can absorb large forces. Preferably, there is a component that corresponds to a casting of metal almost or completely or nearly or completely corresponds to a metallic component.

It may be provided that the metal or metal alloy of the "end material" is selected from the group consisting of titanium, aluminum, chromium, nickel, steel, bronze. With these materials is a mechanically particularly stable and against corrosive media particularly resistant design of the clevis is possible.

According to a second aspect of the invention, a clevis is provided for a device for actuating a clutch of a vehicle. In this case, viewed along a longitudinal axis, the clevis has a first section and a second section. The clevis may be designed substantially spherical in the first section, for example. The fork head is fork-shaped in the second section with two arms projecting in the direction of the longitudinal axis. The two arms are viewed from each other transversely to the longitudinal axis. The two arms have opposed openings for receiving an axle of a roller bearing. The clevis is manufactured in one piece by an injection molding process in the manner of metal injection molding. The clevis is in the finished state ("final state") made of a first material ("end material").

By this design of the fork head of the clevis can be particularly easily formed and mechanically stable. For example, compared to full metal production, weight savings of at least 30%, or even at least 40%, can be achieved with the same stability. At the same time, an axle of a roller bearing can be pressed into such a clevis in a particularly simple and damage-free manner. The clevis is therefore particularly advantageous for devices or actuators for actuating a clutch of a vehicle, in which high forces in short times, i. high pulses, must be transmitted.

• -- einen ersten Schritt: Bereitstellen einer Spritzgussform, die das Negativ einer Außenform des Gabelkopfes aufweist,
• -- einen zweiten Schritt: Bereitstellen eines ersten Materials, wobei das erste Material wenigstens einen ersten Anteil an Kunststoff, wenigstens einen zweiten Anteil an Wachs und wenigstens einen dritten Anteil an einem Metallpulver umfasst,
• -- einen dritten Schritt: Einspritzen des ersten Materials in die Form, so dass ein Gabelkopfrohling gebildet wird,
• --einen vierten Schritt: Entfernen des zweiten Anteils an Wachs aus dem Gabelkopfrohling; dabei kann das Entformen beispielsweise unter Zuhilfenahme eines Lösungsmittels erfolgen, beispielsweise unter Zuhilfenahme von Aceton; es kann eine Temperatur von ca. 20°C bis 50°C, z.B. 40°C angewendet werden;
• -- einen fünften Schritt: Entfernen von wenigstens 90 gew-% des zweiten Anteils des Kunststoffs; insbesondere kann z.B. wenigstens 99 gew-% des zweiten Anteils des Kunststoffes entfernt werden;
• -- einen sechsten Schritt: Sintern des Gabelkopfrohlings.

According to a further aspect of the invention, a method for producing a clevis for a device for actuating a clutch of a vehicle is proposed. The method comprises the following steps:

• a first step: providing an injection mold having the negative of an outer shape of the clevis,
• a second step: providing a first material, wherein the first material comprises at least a first portion of plastic, at least a second portion of wax and at least a third portion of a metal powder,
• a third step: injecting the first material into the mold so that a fork head blank is formed,
• a fourth step: removing the second portion of wax from the clevis blank; The demolding can be carried out, for example, with the aid of a solvent, for example with the aid of acetone; it can be a temperature of about 20 ° C to 50 ° C, for example 40 ° C are applied;
• a fifth step: removing at least 90% by weight of the second portion of the plastic; in particular, for example, at least 99% by weight of the second portion of the plastic can be removed;
• - a sixth step: sintering of the fork head blank.

By the proposed method, the clevis can be manufactured in relation to the melting temperature of the metal at relatively low temperatures in an injection mold. Its final hardness and mechanical stability is then obtained by sintering. The first material ("pre-material") existing materials plastic and wax are expelled at the latest during the sintering step. Thus, the method provides a clevis that is nearly identical to a metallic casting - the clevis may under some circumstances have a very low porosity. This makes it possible to give the fork head substantially the stability of the metal used from the "starting material". In this way, a particularly light and mechanically stable clevis can be produced. Finally, the hardness of the clevis in the finished, i. sintered, state be such that the hardness of an axis to be pressed into the clevis of a roller bearing is higher than the hardness of the clevis. As a result, the axle can be pressed into the clevis in a particularly simple and damage-free manner or mounted on the clevis.

list of figures

Other features and advantages of the present invention will become apparent to those skilled in the art from the following description of exemplary embodiments, which are not to be construed as limiting the invention with reference to the accompanying drawings.

• 1: eine teilweise geschnittene Ansicht einer Einrichtung bzw. eines Aktuators zu Betätigung einer Kupplung eines Fahrzeugs;
• 2: eine schematische Darstellung des Verfahrens zur Herstellung des Gabelkopfes
• 3a: eine perspektivische Ansicht eines Gabelkopfes gemäß einem ersten Ausführungsbeispiel der Erfindung;
• 3b: den Gabelkopf aus 3a in einer anderen Perspektive;
• 3c: eine weitere Ausführungsform eines erfindungsgemäßen Gabelkopfes in einer perspektivischen Ansicht.

Show it:

• 1 a partially sectioned view of an actuator for actuating a clutch of a vehicle;
• 2 : A schematic representation of the method for producing the clevis
• 3a a perspective view of a fork head according to a first embodiment of the invention;
• 3b : the clevis out 3a in a different perspective;
• 3c a further embodiment of a fork head according to the invention in a perspective view.

1 shows a device 1 or an actuator 1 to actuate a clutch 70 of a vehicle. The device 1 includes a cam 2 around a cam axle 3 is rotatable. The device 1 further comprises a ram extending along a longitudinal axis A. 4 with one of the cam 2 facing first end 5 and one of the clutch 70 facing the second end 6 , Furthermore, the device comprises a clevis 50 which is between the cam 2 and the pestle 4 is arranged. The clevis 50 can with the pestle 4 directly in mechanical contact or articulated on the plunger 4 be set. The device 1 finally includes one with the clevis 50 connected roller bearing 7 , which is one at the fork head 50 fixed axis 8th is rotatable and on an end face 2a the cam 2 is applied. The roller bearing 7 can on the frontal area 2a the cam 2 roll off when the cam 2 by a motor 9 the device 1 is turned.

The clevis 50 has along the longitudinal axis A viewed a the plunger 4 facing first section 10 and one of the cam 2 facing the second section 20 on. Here is the clevis 50 in the first part 10 with the first end 5 of the plunger 4 coupled. The clevis 50 can in the first section 10 be designed substantially spherical. Here, by a substantially spherical shape to understand that the first section 10 predominantly has the shape of a sphere. However, it can be provided that this ball has flattened areas on its outer surface. The clevis 50 is in the second section 20 bifurcated with two projecting in the direction of the longitudinal axis A arms 21 . 22 designed. Here are the two arms 21 . 22 spaced apart transversely to the longitudinal axis A. The two arms 21 . 22 have opposing openings 23 . 24 for receiving the axle 8th of the roller bearing 7 on. The clevis 50 is made in one piece by metal injection Molden from a first material M1. As shown above, this is the first material in the "final state", ie the "final material" M1b.

Under the process of metal injection Molden here is an injection molding process to understand.

• -- einen ersten Schritt 100: Bereitstellen einer Spritzgussform, die das Negativ einer Außenform des Gabelkopfes 50 aufweist,
• -- einen zweiten Schritt 200: Bereitstellen eines ersten Materials M1 - es handelt sich dabei um das „Vormaterial“ M1a; dabei umfasst das erste Material M1 (Vormaterial M1a) wenigstens einen ersten Anteil an Kunststoff, wenigstens einen zweien Anteil an Wachs und wenigstens einen dritten Anteil an einem Metallpulver; erster Anteil, zweiter Anteil und dritter Anteil sind in diesem Stadium des Verfahrens beispielsweise größer als Null;
• -- einen dritten Schritt 300: Einspritzen des ersten Materials M1 in die Form, so dass ein Gabelkopfrohling gebildet wird;
• -- einen vierten Schritt 400: Entfernen des zweiten Anteils an Wachs aus dem Gabelkopfrohling; dabei kann das Entformen beispielsweise unter Zuhilfenahme eines Lösungsmittels erfolgen, beispielsweise unter Zuhilfenahme von Aceton; es kann eine Temperatur von ca. 20°C bis 50°C, z.B. 40°C angewendet werden;
• -- einen fünften Schritt: Entfernen von wenigstens 90 gew-% des zweiten Anteils des Kunststoffs; insbesondere kann z.B. wenigstens 99 gew-% des zweiten Anteils des Kunststoffes entfernt werden;
• -- einen sechsten Schritt 600: Sintern des Gabelkopfrohlings - nach dem Sintern liegt das erste Material als „Endmaterial“ M1b im Endzustand vor.

2 shows the method for producing the clevis 50 , It comprises the following steps:

• - a first step 100 : Provide an injection mold, which is the negative of an outer shape of the clevis 50 having,
• - a second step 200 : Providing a first material M1 - this is the "starting material"M1a; In this case, the first material M1 (starting material M1a) comprises at least a first portion of plastic, at least a second portion of wax and at least a third portion of a metal powder; for example, the first, second, and third shares are greater than zero at this stage of the process;
• - a third step 300 Injecting the first material M1 into the mold so as to form a clevis blank;
• - a fourth step 400 Removing the second portion of wax from the clevis blank; The demolding can be carried out, for example, with the aid of a solvent, for example with the aid of acetone; it can be a temperature of about 20 ° C to 50 ° C, for example 40 ° C are applied;
• a fifth step: removing at least 90% by weight of the second portion of the plastic; in particular, for example, at least 99% by weight of the second portion of the plastic can be removed;
• - a sixth step 600 : Sintering of the fork head blank - after sintering, the first material is present as the "end material" M1b in its final state.

Before or after the fourth step 400 a further step can be provided: removal of the fork head blank from the injection mold.

At the latest by the sintering of the fork head blank, the plastic and the wax are for the most part removed from the fork head blank and a fork head is created 50 consisting of the first material M1 ("final material" M1b) after sintering, ie predominantly of metal with a certain porosity.

As such, the injection molding process as such can be done at relatively low temperatures, e.g. at a mold temperature of 20 ° C to about 50 ° C and a temperature of the injected material M1 ("starting material" M1a) of about 100 ° C to 160 ° C, preferably from 120 ° C to 140 ° C. The final composite material may then be e.g. in a subsequent sintering process at temperatures of e.g. more than 1200 ° C, e.g. at 1300 ° C - the clevis is then made of the first material ("end material" M1b) which is e.g. is more than 95% by weight, preferably more than 99% by weight, metallic.

In this connection, it should again be pointed out that the first material before the injection molding process or before the sintering ("starting material" M1a) differs from the first material ("end material" M1b) of the fork head 50 different in its final design.

3a shows a perspective view of a fork head 50 according to a first embodiment of the invention. The clevis 50 points along the longitudinal axis A, resulting from the linear movement of the plunger 4 gives a first section 10 as well as a second section 20 on. Between the first section 10 and the second section 20 here is a neck-like midsection 30 arranged. Depending on the embodiment, however, the first section 10 immediately to the second section 20 adjoin. The clevis 50 has an outer shape. With the outer shape of the entire externally visible or recognizable form is meant. The outer shape can be in an outer contour 51 and an inner contour 52 be divided. It is under the outer contour 51 the outward facing surface of the clevis 50 to understand. In contrast, under the inner contour 52 eg to understand those surfaces which are on other surfaces of the clevis 50 are facing.

The clevis 50 points in his first section 10 a spherical shape. In the illustrated embodiment is adjacent to the central portion 30 the first paragraph 10 in the form of a sphere 11 educated. In the exemplary embodiment, the middle section 30 thus formed neck-shaped, the first section 10 head-shaped. The ball 11 has only as an example transverse to the longitudinal axis A flattened end faces 12 on. The ball 11 For example, as a coupling element to the first end of the plunger 4 be used. If the first end 5 of the plunger 4 is formed in the manner of a socket, the ball 11 at least pressure forces on the plunger 4 transmitted, with the relative mobility between clevis 50 and pestles 4 a tilting of the plunger 4 is avoided during its movement along the longitudinal axis A.

The condyle 50 points in his second section 20 a first arm 21 and a second arm 22 on. Both arms 21 . 22 protrude along the longitudinal direction A of the clevis 50 from. The first arm 21 and the second arm 22 are spaced transversely to the longitudinal axis A. The first arm A has a first opening 23 on and the second arm 22 has a second opening 24 on. The first opening 23 and the second opening 24 are annularly closed in their respective arms in the illustrated embodiment 21 . 22 intended. In another embodiment, it is also conceivable that the openings 23 . 24 have the shape of an open ring so that they can be shaped like the ends of a bicycle fork. The two openings 23 . 24 are viewed transversely to the longitudinal axis A, ie in a direction B (see drawing), coaxially aligned opposite each other.

In the second section 20 is still a roller bearing 7 between the two arms 21 . 22 arranged. The roller bearing 7 is through an axis 8th on the clevis 50 attached. The axis extends 8th along the direction B, ie perpendicular to the longitudinal axis A. The axis 8th can eg in the two openings 23 . 24 the two arms 21 . 22 be pressed. However, other mounting options are conceivable. The axis 8th is formed from a second material M2. For example, the second material M2 may have a greater hardness than the first material M1 ("end material" M1b in the final state) of the fork head 50 , For example, the first material M1 of the clevis 50 have a first hardness H1, which is at most 70%, preferably at most 50% of a second hardness H2 of the second material M2 of the axis 8th of the roller bearing 7 having.

The metal from which the first material M1 ("end material" M1b in the final state) of the clevis 50 may be formed, for example, titanium, aluminum, chromium, nickel, steel or bronze.

3b indicates the clevis 3a in another perspective view. In 3b are the roller bearings 7 and the axis 8th of the roller bearing 7 omitted for clarity. 3b allows a particularly good view of the inner contour 52 of the clevis 50 ,

From the 3a and 3b it will be seen that in cuts along the longitudinal axis A through the clevis 50 no angles less than 90 ° or equal to 90 ° occur. By this shaping is preferred in a force application along the longitudinal axis A on the clevis 50 a particularly even distribution of mechanical stresses in the body of the clevis 50 causes. In other words, the fork head shaped in this way 50 has only low voltage spikes, so the clevis 50 despite its lightweight construction is mechanically strong and stable at the same time.

3c shows a further embodiment of the invention. Here are the two arms 21 . 22 two spaced along the direction of the longitudinal axis A pin 25a . 25b arranged. In each case there is a first pin 25a at the extreme end of each arm 21 . 22 , ie in the direction of the roller bearing 7 , The second pin 25b is closer to the second section 20 of the clevis 50 , In the illustrated embodiment, the first section is adjacent 10 immediately to the second section 20 on, the middle section 30 eliminated. Nevertheless, also an embodiment not shown here with middle section 30 and the pin 25a . 25b conceivable.

By providing such pins 25a . 25b can be an axial guide along the longitudinal axis A of the fork head 50 be effected particularly easily. This may be the device 1 or the actuator 1 for actuating a clutch 70 of a vehicle to the cones 25a . 25b complementary component, such as the housing of the device 1 , exhibit. This complementary component can therefore be, for example, a guide groove or provide a guide groove which runs essentially parallel to the direction of the longitudinal axis A. The cones 25a . 25b can then engage in the groove or guide groove. For a strong and / or sudden force on the clevis 50 Thus, a breaking of the fork head transversely to the direction of the longitudinal axis A can be advantageously avoided. Such sudden forces can, for example, by a sudden rotation of the cam 2 and the transmission of the rotational movement of the cam 2 over the roller bearing 7 on the clevis 50 be effective.

The clevis 50 is in particular designed such that it can absorb forces along the longitudinal axis A of at least 5000 N, without being destroyed. The absorption of forces of 5000 N over at least 3,500,000 switching cycles (3.5 million) is made possible by the presented clevis.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely 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.

Cited patent literature

• DE 102014226120 A1 [0006]

Claims (10)

Device for actuating a clutch of a vehicle, comprising - A cam (2) which is rotatable about a cam axis (3), a plunger (4) extending along a longitudinal axis (A) with a first end (5) facing the cam disk (2) and a second end (6) facing the coupling (70), a clevis (50) disposed between the cam (2) and the plunger (4), a roller bearing (7) which is connected to the clevis (50) and which is rotatable about an axis (8) fixed to the fork head (50) and bears against an end face (2a) of the cam disc (2), wherein the clevis (50), viewed along the longitudinal axis (A), has a first section (10) facing the plunger (4) and a second section (20) facing the cam (2), wherein the clevis (50) in the first section (10) is coupled to the first end (5) of the plunger (4) and in particular is substantially spherical in shape, wherein the clevis (50) in the second portion (20) fork-shaped with two in the direction of the longitudinal axis (A) projecting arms (21, 22) is formed, wherein the two arms (21, 22) transversely to the longitudinal axis (A) are spaced from each other . wherein the two arms (21, 22) have opposing openings (23, 24) for receiving the axis (8) of the roller bearing (7), wherein the clevis (50) is made in one piece by metal injection molding of a first material , Setup after Claim 1 wherein the first material (M1) of the clevis (50) has a lower first hardness (H1) than a second hardness (H2) of a second material (M2) of the axis (8) of the roller bearing (7), in particular the first hardness (H1) has at most 70% of the second hardness (H2). Device according to one of the preceding claims, wherein at least one of the two arms (21, 22) of the clevis (50) at least one outwardly projecting pin (25a, 25b) is arranged, which is suitable by engaging in a groove on a component the device (1) to effect an axial guidance of the fork head (50) along the longitudinal axis (A). Device according to one of the preceding claims, wherein an outer contour (51) and / or an inner contour (52) of the fork head (50) viewed along the longitudinal direction (A) is designed such that the outer contour (51) in the central portion (30) and at Transition from the first portion (10) to the central portion (30) and the transition from the central portion (30) to the second portion (20) only angles greater than 90 °, preferably greater than 105 °. A device according to any preceding claim, wherein the clevis (50) is configured to receive axial forces along the longitudinal axis (A) of at least 5000N. Device according to one of the preceding claims, wherein the first material (M1) prior to the molding process comprises a plastic, in particular polyamide (PA), and wax and metal powder. Device according to one of the preceding claims, wherein the first material (M1) after an injection process and a sintering process to at least 85 wt%, preferably at least 93 wt% of a metal or a metal alloy. Setup after Claim 7 wherein the metal or metal alloy is selected from the group consisting of titanium, aluminum, chromium, nickel, steel, bronze. Clevis for a device for actuating a clutch of a vehicle, the clevis (50) having a first portion (10) and a second portion (20) as viewed along a longitudinal axis (A), wherein the clevis (50) in the first section (10) is in particular substantially spherical in shape, wherein the clevis (50) in the second portion (20) fork-shaped with two in the direction of the longitudinal axis (A) projecting arms (21, 22) is formed, wherein the two arms (21, 22) transversely to the longitudinal axis (A) are spaced from each other . said two arms (21, 22) having opposed openings (23, 24) for receiving an axle (8) of a roller bearing (7), said clevis (50) being integrally formed by metal injection molding of a first material (M1 ) is made. Method for producing a fork head according to Claim 9 the method comprising the steps of: - a first step (100) of providing an injection mold having the negative of an outer shape of the clevis (50), - a second step (200) of providing a first material (M1), wherein the first material (M1) comprises at least a first portion of plastic, at least a second portion of wax and at least a third portion of a metal powder, - a third step (300): injecting the first material (M1) into the mold, so that a fork head blank is formed; - A fourth step (400): removal of the fork head blank, in particular with the aid of a solvent; a fifth step (500): removing at least 90% of the second portion of the plastic; - a sixth step (600): sintering the clevis blank.

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