EP3198163A1

EP3198163A1 - Release cylinder for actuating a friction element

Info

Publication number: EP3198163A1
Application number: EP15766822.9A
Authority: EP
Inventors: Burkhart Breinesberger; Roland HINTRINGER; Udo Hans KNEITZ
Original assignee: AVL Commercial Driveline and Tractor Engineering GmbH
Current assignee: AVL Commercial Driveline and Tractor Engineering GmbH
Priority date: 2014-09-25
Filing date: 2015-09-21
Publication date: 2017-08-02
Also published as: AT516355A1; WO2016046126A1; CN107076221A; AT516355B1

Abstract

The invention relates to a release cylinder (1) for actuating a friction element, in particular a friction clutch, comprising: an actuating piston (3), which is movably supported in an actuation cylinder (2) and which adjoins an actuation chamber (4), into which actuation chamber (4) a flow path (5) for an actuation medium, in particular air, leads; a piston rod (6), which has at least two rod parts (7, 8) that can be moved one inside the other coaxially in a telescopic manner; and an enabling pin (11), which can be moved between a blocking position and an enabling position coaxially within the piston rod (6), for an automatic adjusting device (12) for the length of the piston rod (6), which adjusting device is arranged within the piston rod (6). In the release position, the enabling pin (11), which adjoins the actuation chamber (4), lies against an end face (24) or a stop (25) of the actuation cylinder (2) and can be deflected against a restoring force. Reliable automatic length adjustment can be realized in the case of the release cylinder (1) in that the adjusting device (12) has at least one preferably wedge-shaped clamping element (13), which is operatively connected to the enabling pin (11) and can be axially moved within the piston rod (6) between the first and the second rod part (7, 8) by means of the enabling pin.

Description

Release cylinder for actuating a friction element

The invention relates to a release cylinder for actuating a friction element, in particular a friction clutch, with a displaceable in an actuating cylinder, adjacent to an operating space actuating piston, in which operating space a flow path for an actuating medium, in particular air, opens, with at least two telescopically coaxial with each other Stem parts having piston rod and a coaxially displaceable within the piston rod between a locking and a release position release pin for an arranged inside the piston rod automatic adjustment device for the length of the piston rod, wherein the adjacent to the operating space release pin in the release position on an end face or a stop of the actuating cylinder is present and deflectable against a restoring force.

It is known to use a readjustment for clutches for clutches to compensate for the clutch wear and all component tolerances can.

From WO 2012/119 612 AI a pneumatically actuated self-adjusting clutch actuator for actuating a vehicle clutch is known, wherein the adjusting device has a disposed within the actuating piston and an integrally formed with this first rod part disc-shaped locking body, which via a thread with a telescoping in the first rod part slidable second rod part is connected. The two rod parts are pushed apart by a spring. In a blocking position of the locking body, a rotation of this is prevented by a brake disc of the locking body is pressed against a friction surface of the actuating piston. The locking body has a projecting into the operating space release pin, which is supported on pressure relief of the operating space on the end face of the actuating cylinder. In this release position, the brake disc is lifted by the actuating piston, whereby a relative rotation of the locking body is possible. By the thread thus takes a length adjustment and readjustment of the Kupplungsaktuators.

Further adjusting devices for brakes and transmission linkage are known from DE 2 255 281 AI or DE 29 10 421 AI. The known adjusting devices have the disadvantage that they require a high production cost, take up a lot of space and / or are not always reliable. The object of the invention is to enable a reliable automatic length adjustment in a release cylinder with the least possible effort.

According to the invention this is achieved in that the adjusting device has at least one preferably wedge-shaped clamping element, which is operatively connected to the release pin and axially displaceable by this within the piston rod between the first and second rod part. The clamping element can be displaced axially in both directions by the release pin.

Preferably, the clamping element has at least one pressure side with at least one pressure surface and a clamping side with at least one clamping surface, wherein the pressure side and the clamping side are arranged on opposite sides of the clamping element and - viewed in a longitudinal section - an angle> 0 ° span each other. The clamping element is arranged between a first counter-surface formed by a first rod part and a second counter-surface formed by a second rod part, wherein preferably the pressure side of the first counter-surface and the clamping side of the second counter-surface are facing. It can be provided that the second mating surface is arranged farther away from the piston axis, as the first mating surface. This allows a very compact design.

A reliable locking of the telescopic relative movement of the two rod parts can be achieved if at least one surface of the group pressure surface and clamping surface - preferably the pressure surface -, and the corresponding first and second mating surface, viewed in a longitudinal section, with the piston axis an angle> 0 ° spans. The other of the two surfaces - preferably the clamping surface -, as well as the corresponding second or first mating surface can, also viewed in a longitudinal section, be formed parallel to the piston axis.

In order to enable a secure release of the two rod parts for adjusting the selbigen, is provided in a preferred embodiment of the invention that between the pressure surface and the first mating surface at least one preferably spherical rolling elements is arranged, wherein preferably the pressure surface and / or the first mating surface at least comprising a pocket for receiving the rolling element. A jamming of the clamping element between the two rod parts can thus be largely excluded by the rolling elements.

In the blocking position of the release pin, which preferably opens into the actuating chamber, the pressure surface and / or the clamping surface of the clamping element is replaced by a blocking force, which is preferably formed by a locking spring. gene pressed the first and second mating surface. In the release position of the release pin, however, the clamping and pressure surfaces are relieved of pressure by axial displacement of the clamping element against the blocking force, wherein preferably the release pin is supported against a particular housing formed by the actuating cylinder stop.

Preferably, the first rod part is fixedly connected to the actuating piston and the second rod member axially spaced from the actuating piston elastically, preferably supported by a reset spring on the actuating piston or on the first rod part.

A particularly good clamping effect can be achieved if a plurality of clamping elements are arranged between the first rod part and the second rod part, wherein preferably the clamping elements are distributed uniformly over the circumference of the first rod part.

The blocking position is associated with the open, ie actuated, coupling and the release position of the closed coupling. When the clutch is closed, the actuating piston is decoupled from the release mechanism and can adjust itself, so that virtually no dead volume arises. Only when the clutch is actuated, a rigid connection between the actuating piston and the second rod part leading to the disengagement mechanism of the clutch is established and the clutch begins to open.

In detail, this adjusting mechanism works so that when the clutch is closed, the actuating piston abuts the rear end side of the actuating cylinder facing away from the disengagement mechanism. At this time, all clamping elements are released by the central release pin. Once the clutch is opened and the actuating piston moves a piece, the clamping elements are brought by the spring-loaded release pin in blocking position (clamping position). In order for the clamping or release of the clamping elements happens friction, the clamping elements are roller bearings.

The invention is explained in more detail below with reference to the non-limiting figures. They show schematically:

1 shows a known release cylinder for actuating a friction clutch.

Fig. 2 shows a release cylinder according to the invention for actuating a

Friction clutch in a first embodiment in a longitudinal section in a first position; Fig. 3 shows the detail III of FIG. 2;

FIG. 4 shows the release cylinder according to the invention in a second position; FIG. Fig. 5 shows the detail V of Fig. 4;

6 shows a release cylinder according to the invention in a second embodiment in a first position in a detail view analogous to FIG. 3 and 5;

7 shows this release cylinder in a second position;

8 shows a release cylinder according to the invention in a third embodiment in a first position in a detail view analogous to FIG. 3 and 5; and

Fig. 9 this release cylinder in a second position.

Functionally identical parts are designated in the embodiment variants of the invention with the same reference numerals.

Fig. 1 shows a pneumatically actuated disengaging cylinder 101 for actuating a friction clutch 130 for a vehicle. The release cylinder 101 has an actuating cylinder 102 with an actuating piston 103 mounted displaceably therein, which adjoins an actuating space 104 spanned by the actuating cylinder 102 and the actuating piston 103. In the operating chamber 104 opens a flow path 105 for an actuating medium, such as compressed air, a. Upon pressurization of the actuating chamber 104 of the actuating piston 103 is deflected in Fig. 1 to the right and the friction clutch via the piston rod 106, the actuating rod 131 and the bell crank 132 according to the arrows S, the piston rod 106 acts via a sliding joint 110 on the actuating rod 131 , When pressure relief, the friction clutch 130 is closed by a return spring, not shown, wherein the actuating piston 103 in FIG. 1 is pushed back to the left. With release cylinders without adjustment mechanism occurring clutch wear and component tolerances can not be compensated. In release cylinders, which have no adjustment mechanism, all these additional deviations must be taken into account in the design of the piston stroke of the release cylinder, the actuating piston must therefore have more stroke available, as would actually be required for the actuation of the friction clutch. This means that a certain dead volume or an air cushion must be generated, which has a negative effect on the controllability of such a system. FIGS. 2 to FIGS. Figures 4 show a pneumatically actuable disengaging cylinder 1 for actuating a friction element, for example a friction clutch for a vehicle. The disengagement cylinder 1 has an actuating piston 3 which is displaceably mounted in an actuating cylinder 2 and which adjoins an actuating space 4. In the operating space 4 opens a flow path 5 for an actuating medium, such as air, a. The piston rod 6 has a first 7 rod part and a second rod part 8, wherein the first rod part 7 are fixedly connected to the actuating piston 3. The first and the second rod part 7, 8 are telescopically and coaxially designed to be slidable into one another along the piston axis 3a, wherein the first rod part 7 can be partially inserted into the tubular second rod part 8. First and second rod part 7, 8 are biased by an adjusting spring 9, wherein the spring force of the actuating piston 3 and the second rod part 8 supporting adjusting spring 9 pushes the rod parts 7, 8 apart in the axial direction. The second rod part 8 engages via a sliding joint 10 on an actuating rod not shown.

Inside the first rod part 8, a release pin 11 displaceable between a blocking and a release position is arranged coaxially for an automatic adjusting device 12 arranged inside the piston rod 6 for the length of the piston rod 6, the release pin 11 having its first end 11a the piston surface 3b of the piston Actuation piston 3 penetrates and adjacent to the operating space 4. The first end 11a facing away from the second end I Ib of the release pin 11 is operatively connected to a plurality of clamping elements 13, which can be moved axially with this. Each clamping element 13 has a pressure side 14 and a clamping side 15 with a clamping surface 15a, wherein the pressure side 14 and the clamping side 15 are arranged on opposite sides of the clamping element 13 and - viewed in longitudinal section - an angle α> 0 ° span each other. The clamping elements 13 are axially displaceable in a spanned by the two rod parts 7, 8 annular cavity 19 and distributed around the circumference of the first rod member 7 between a first rod member 7 formed by a first mating surface 17 and a second rod portion 8 formed by the second mating surface 18, wherein the pressure side 14 of the first mating surface 17 and the clamping side 15 of the second mating surface 18 are facing. Since the second rod part 8 surrounds the first rod part 7, the second mating surface 18 is farther from the piston axis 3 a than the first mating surface 17. The pressure side 14 and the corresponding first mating surface 17 span the piston axis 3 a as viewed in a longitudinal section Angle ß> 0 °. The clamping surface 15a and the corresponding second mating surface 18 are formed parallel to the piston axis 3a. Between the pressure side 14 and the first mating surface 17, a rolling element 20 is arranged in each case, wherein in the exemplary embodiment both the pressure side 14 and the first mating surface 17 each have a pocket 21, 22 for receiving the rolling element 20. The Wälzköper 20 are spherical in the embodiment shown, but they can of course have a different, for example, cylindrical shape.

The Fig. 2 and FIG. 3 show the release pin 11 in a locked position during an operation or during an opening operation of the friction clutch. The piston rod 6 acts according to the arrow F on the actuating rod, not shown, for opening the friction clutch. The release pin 11 is biased by a locking spring 23 relative to the first rod member 7 in the direction of arrow P, wherein in the locked position of the release pin 11, the pressure side 14 and / or the clamping side 15 of the clamping member 13 by acting on the release pin 11 locking spring 23 against the first and second mating surface 17, 18 is pressed. The pressure surface 14a of the pressure side 14 is pressed via the rolling body 20 against the first counter surface 17, as shown in FIG. 3 can be seen. The clamping element 13 rolls on the rolling elements 20 from. By the rolling elements 20 a low-friction clamping and releasing the clamping elements 13 is ensured.

In FIGS. 4 and FIG. 5, the release pin 11 is shown in its release position associated with the closed friction clutch. In the release position of the release pin 11 abuts against the end face 24 or a housing-fixed stop 25 of the actuating cylinder 2, as shown in FIG. 4 can be seen. The release pin 11 is thereby pressed against the force of the locking spring 23 in the first rod member 7, whereby the pressure side 14 and the clamping side 15 are relieved of pressure by axial displacement of the release pin 11 firmly connected clamping elements 13, wherein a gap 26 between the clamping surface 15 a of the clamping element 13 and the second mating surface 18 of the second rod part 8 is formed. As a result, the clamping connection between the first and second rod part 7, 8 is repealed and the rod parts 7, 8 are now coaxially displaceable, wherein the two rod parts 7, 8 are pushed apart by the adjusting spring 9. Once the friction clutch is opened again and the release pin 11 is pressed by the locking spring 23 again from the actuating piston 3 in the operating space 4, the clamping elements 13 are brought by the spring-loaded release pin 11 back into the clamping position.

When the friction clutch is closed, the actuating piston 3 is decoupled from the release mechanism of the friction clutch and thus allows a self-adjustment by means of the adjusting device 12 described so that virtually no dead volume arises. Only when you press - so open - the friction clutch a rigid connection between the actuating piston 3 and the release mechanism is made and the friction clutch begins to open. This allows in every release position a perfect clearance compensation, whereby a play-free operation is ensured when opening the friction clutch.

In the in Figs. 2 to FIG. 5, the clamping elements 13, viewed in the longitudinal section shown, are wedge-shaped or tapered on their inner side facing the first rod part 7 and the first rod part 7 is conically shaped in the region of the clamping elements 13. At the second rod part 8 facing outside the locking elements 13 are cylindrically shaped.

6 and FIG. 7 show a second embodiment variant of the invention, wherein the clamping elements 13 are also cylindrically shaped on their inner side facing the first rod part 7. Also, the first rod part 7 is cylindrical in the region of the clamping elements 13. Fig. 6 shows the clamping elements 13 in the blocking position, and FIG. 7 in the release position.

However, the inner side of the clamping elements 13 can also have a shape deviating from the conical or cylindrical shape, as shown in FIGS. 8 and 9. In the in Fig. 8 and FIG. 9 shown third embodiment, the clamping elements 13 on its inner side on both sides of the pockets 21 paragraphs 21a, 21b, wherein the first paragraph 21a of the piston axis 3a is farther away than the second paragraph 21b. The first rod part 7 has, in the region of the clamping elements 13, a tapered, for example, rotationally symmetrical shape, which can deviate from a truncated cone.

All variants have in common that formed by the bottoms of the pockets 21, 22 first and second mating surfaces 17, 18 of the first rod member 7 and the clamping elements 13 in which roll the rolling elements formed for example by balls or rollers 20, in the same sense with respect are inclined to the piston axis 3a and clamp with the piston axis 3a the angle ß> 0. This ensures that the clamping elements 13 are pressed by the rolling elements 20 rolling therein outwards against the inner wall 8a of the tubular second rod part 8. Initially, the clamping elements 13 are pressed by means of the central release pin 11 and the locking spring 23 in this clamping position. Once a frictional engagement between the clamping elements 13 and the second rod part 8 is formed, the system is self-locking and the clamping effect can not be reversed. Only when the actuating piston 3 and also the central release pin 11 on the end face 24 and / or the housing-fixed stop 25 pending, the clamping elements 131 are pulled out of their clamping position by the central release pin 11 and the clamping action is canceled. At this time, the system is open and can self-adjust.

Claims

PATENT APPLICATIONS

1. release cylinder (1) for actuating a friction element, in particular a friction clutch, with a in an actuating cylinder (2) slidably mounted, to an operating space (4) adjacent actuating piston (3), in which operating space (4) has a flow path (5) an actuating medium, in particular air, opens, with a at least two telescopically coaxial telescoping rod parts (7, 8) having piston rod (6) and within the piston rod (6) coaxially displaceable between a locking and a release position release pin (11) for a in the piston rod (6) arranged automatic adjusting device (12) for the length of the piston rod (6), wherein the actuating space (4) adjacent release pin (11) in the release position on an end face (24) or a stop (25) of the Actuating cylinder (2) is applied and against a restoring force is deflected, characterized in that the Adjusting device (12) has at least one preferably wedge-shaped clamping element (13), which is operatively connected to the release pin (11) and axially displaceable thereby within the piston rod (6) between the first and second rod part (7, 8).

2. disengaging cylinder (1) according to claim 1, characterized in that the clamping element (13) has a pressure side (14) with at least one pressure surface (14a) and a clamping side (15) with at least one clamping surface (15a), wherein the pressure side ( 14) and the clamping side (15) on opposite sides of the clamping element (13) are arranged and - viewed in a longitudinal section - an angle (a)> 0 ° span each other.

3. disengaging cylinder (1) according to claim 1 or 2, characterized in that the clamping element (13) between a first rod member (7) formed by a first mating surface (17) and a second rod member (8) formed second mating surface (18 ), wherein preferably the pressure side (14) of the clamping element (13) of the first mating surface (17) and the clamping side (15) of the clamping element (13) of the second mating surface (18) is facing.

4. release cylinder (1) according to claim 3, characterized in that the second mating surface (18) of the piston axis (3a) is arranged further away, as the first mating surface (17).

5. release cylinder (1) according to one of claims 3 to 4, characterized in that at least one surface of the group pressure surface (14a) and clamping surface (15a) - preferably the pressure surface (14a) -, and the corresponding first or second mating surface (17; 18), viewed in a longitudinal section, with the piston axis (3a) an angle (ß)> 0 ° spans.

6. disengaging cylinder (1) according to claims 5, characterized in that the other of the two surfaces - preferably the clamping surface (15a) -, and the corresponding second or first mating surface (18; 17), viewed in a longitudinal section, parallel to the piston axis (3a) is formed.

7. disengaging cylinder (1) according to one of claims 3 to 6, characterized in that between the pressure surface (14a) and the first mating surface (17) at least one preferably spherical rolling elements (20) is arranged, wherein preferably the pressure surface (14a) and / or the first mating surface (17) has at least one pocket (21, 22) for receiving the rolling body (20).

8. disengaging cylinder (1) according to one of claims 3 to 7, characterized in that in the blocking position of the - preferably opening into the operating space - release pin (11) the pressure surface (14a) and / or the clamping surface (15a) of the clamping element (13 ) are pressed by a preferably by a locking spring (23) formed blocking force against the first and second counter-surface (17, 18).

9. release cylinder (1) according to claim 8, characterized in that in the release position of the release pin (11) the pressure surface (14 a) and / or the clamping surface (15 a) by axial displacement of the clamping element (13) are relieved of pressure against the blocking force, wherein preferably the release pin (11) against a particular by an end face (24) of the actuating cylinder (2) formed housing-fixed stop (25) is supported.

10. disengaging cylinder (1) according to one of claims 1 to 9, characterized in that a plurality, preferably at least three, clamping elements (13) between the first rod part (7) and the second rod part (8) are arranged, wherein preferably the clamping elements ( 13) are distributed uniformly over the circumference of the first rod part (7).

11. release cylinder (1) according to one of claims 1 to 9, characterized in that the first rod part (7) is fixedly connected to the actuating piston (3) and the actuating piston (3) axially spaced second rod member (8) elastically, preferably is supported by an adjusting spring (9) on the actuating piston (2) or on the first rod part (7).