WO2016139171A1

WO2016139171A1 - Use of a fiber composite material to produce a shift fork and corresponding shift fork

Info

Publication number: WO2016139171A1
Application number: PCT/EP2016/054203
Authority: WO
Inventors: Bernd Schulze
Original assignee: Koki Technik Transmission Systems Gmbh
Priority date: 2015-03-02
Filing date: 2016-02-29
Publication date: 2016-09-09
Also published as: CN107548342A; CN107548342B; BR112017018509A2; KR20170126461A; DE102015120635A1; KR102473712B1; BR112017018509B1

Abstract

The invention relates to the use of a fiber composite material to produce a shift fork (1), characterized by the following steps: a fiber, a laid fabric composed of fibers, or a woven fabric composed of fibers is inserted as a supporting structure into a negative injection mold in the shape of the shift fork (1); plastic is injected and/or pressed into the negative injection mold; the supporting structure is overmolded with plastic, wherein the plastic is a matrix for the fiber, the laid fabric, or the woven fabric.

Description

USE OF A FIBER COMPOSITE FOR MANUFACTURING A SHIFT FORK AND CORRESPONDING SHIFTER

The invention relates to a method according to the preamble of claim 1, a shift fork according to claim 7, and a use according to claim 9.

STATE OF THE ART

Various types of shift forks are known and commonly used in the prior art.

It is in the known from the prior art shift forks made of metal sheet, wire or cast materials. The disadvantage here is the fact that metal shift forks have a high weight and are expensive to manufacture. OBJECT OF THE INVENTION

The object of the invention is to eliminate the disadvantages of the prior art and to provide a method for producing a shift fork, which makes it possible to produce low-weight shift forks with sufficient stability and low cost.

SOLUTION OF THE TASK To achieve the object, the features according to claim 1.

The invention is that fiber composites are used for the production of shift forks. From the fiber composite material, the fiber-plastic composite is to be distinguished. A fiber-plastic composite is a material consisting of reinforcing fibers and a plastic matrix. The matrix surrounds the loose fibers that are bonded to the matrix by adhesive or cohesive forces. Fiber-plastic composites have a dependent on the orientation of the fibers elastic behavior. Without the matrix material surrounding the fibers, the high specific strengths and stiffnesses of the oriented or unoriented reinforcing fiber can not be utilized. It is only through the suitable combination of fiber and matrix material that a new construction material is created. The fibers are oriented or unoriented in fiber-plastic composites, but loosely arranged in the matrix.

In contrast, a fiber composite material generally consists of two main components, an embedding matrix and a reinforcing fiber structure. The fibers are not arranged unoriented in the matrix, but rather are arranged in the form of loops or fabrics in a specifically defined manner. This results in a particularly good usability of fiber composites for the production of structural parts, such. B. Shift forks. Through mutual interactions of the two components, fabric and matrix, this fiber composite obtains higher quality properties than either of the two components involved as well as compared to fiber composite materials of loose fibers and a surrounding plastic matrix.

Fiber composites thus consist of the matrix and fibers, wherein the fibers can be arranged in the form of a so-called tissue or Geleges. The fabric or scrim is embedded / enclosed by the matrix. The matrix material is a polymeric plastic such as, duromers, elastomers or thermoplastics.

Since the fibers can be aligned and adjusted in density depending on the load, tailor-made components are produced with the aid of appropriate manufacturing processes. In order to influence the strength in different directions, instead of individual fibers, fabrics or scrims are used which are produced before contact with the matrix. Also, the matrix of the surrounding tissue may be reinforced with loose fibers.

A special feature of the fabrics or the clutch for shift forks is the prefabrication of the tissue structures. In this case, the fabric structures are designed in the direction of the expected loads, so that supporting elements, such as a reinforcement as well as enclosing elements, such as a socket can form the overall composite of the shift fork.

In the fabric individual functional elements, such as metallic or made of other plastics existing bushes or drivers and / or joints and / or partial reinforcement parts integrated. During encapsulation, these functional elements, together with the tissue, are completely or only partially enclosed by the matrix material. Further mechanical processing of the fiber composite shift fork and / or a joining process can follow in the process chain.

In the inventive use of a fiber composite material for producing a shift fork, the following steps are carried out. First, a support structure is introduced into a negative injection mold in the form of the shift fork. The support structure here represents specifically arranged as a fabric or scrim fibers. The scrim itself can already be enclosed with a matrix material (organic sheet).

As negative injection mold is to be understood a hollow mold, which represents the negative to the positive shape of the shift fork. This in turn means that when filling the negative injection mold with the matrix plastic, a shift fork with the desired shape is formed by overmolding the fabric / scrim.

The support structure, which is encapsulated in a further step by plastic, wherein the plastic is a matrix for the fiber or the scrim of fibers or the fabric of fibers. The support structure assumes a carrier function to take over loads that z. B. arise when switching manual or dual clutch transmissions.

The sole use of plastic in this case is usually not sufficiently strong enough to withstand the constant loads. Plastics that have higher stiffness are extremely expensive and therefore unsuitable for solving the problem.

The support structure or fabric structure can be made of glass, plastic, carbon, natural, ceramic or metal fibers. As plastics according to the invention it is possible with preference to use plastics with short or long fibers of glass or carbon fibers.

In addition, however, webs with component stiffeners can also be used as the support structure in the inventive shift forks.

As a result, fiber composites are achieved, in which the support structures described above are encapsulated with plastic. Fiber composites according to the invention consist of reinforcing fibers and a plastic matrix surrounding the fibers. By using fiber composites, the properties of the later obtained shift fork can be particularly well influenced. Depending on which fibers are used and how the fibers are arranged in the fiber composites in the form of woven or laid, the shift forks can be made elastic in some places and stiff in other places. Consequently, the shift forks can be optimally adapted to the conditions of use. The support structures are usually aligned in a fiber direction, so that the resulting properties of the fiber composite material are direction-dependent. For fibers made from fibers and / or fibers, user-oriented prefabrication can be carried out, which in turn leads to further cost savings. This results from the circumstance that, depending on the shift fork model, the determined load ranges can be purposefully supported and resulting forces can be specifically derived.

In order to obtain non-directional properties of the fiber composite, the use of tissues is targeted, in which the fibers are structured in different directions with each other. With the encapsulation of the fibers of fibers and / or scrim of fibers arise completely new ways of influencing the properties of shift forks.

Suitable plastics include thermoplastics such as polyetheretherketone (PEEK), polyvinylidene sulfide (PPS), polysulfone (PSU), polyetherimide (PEI), polytetrafluoroethylene (PTFE), polyamide (PA) and thermosetting materials.

As already indicated above, plastic is also injected or pressed in before, during or after the introduction of the support structure into the negative injection mold. In this case, the support structure is preferably encapsulated with plastic.

Subsequently, the shift fork is removed from the negative injection mold and processed further. Here, for example, drilling or grinding or the like can be performed to adapt the shift fork to the individual needs of the user.

Further, in the inventive shift fork in the negative injection mold, a shoe can be introduced. In addition, but also reinforcing parts, such as sheet metal or Drahtinlets or sheet metal wire structures that are encapsulated with plastic, can be introduced into the negative injection mold before the plastic is injected and the shift fork is manufactured. It is also conceivable that, for example, a bush in the negative injection mold is arranged at a predefined location and correspondingly at least partially encapsulated or pressed around by the matrix, ie the plastic holders.

For example, the support structure can be designed supporting the shoe. Specifically, this means, for example, that long-fiber support structures or fabrics supporting the shoe can be used. In addition to the sliding shoe, a shift rod receptacle can be introduced into the negative injection mold. In addition to the use of a fiber composite material for producing a shift fork and the shift fork is claimed. Such a shift fork has a body made of fiber composite material, as described above. Further, the shift fork may have injected in its body a shoe and / or a shift rod receptacle.

DESCRIPTION OF THE FIGURES

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings; these show in:

Figure 1 is a perspective view of an inventive

Shift fork 1 obliquely from above, Figure 2 is a horizontal view of the inventive shift fork 1, which allows the view of the sides of two outer legs 8 and 9,

Figure 3 is a vertical plan view of the inventive

Shift fork 1,

Figure 4 is a horizontal view of the inventive shift fork 1, which allows the view of the outer leg 8.

1 shows a shift fork 1 according to the invention, with a shift rod 2 shown in partial detail. The shift fork 1 has a fork 6 and a fork-shaped slide shoe 7. The fork 6 is divided into two outer legs 8 and 9. The fork-shaped sliding shoe 7 is divided into two inner legs 10 and 1 1. The outer legs 8 and 9 and the inner legs 10 and 1 1 are integrally formed of plastic. This means that they were extruded from an extrusion machine in one step. Further details of the outer legs 8 and 9 and the inner legs 10 and 1 1 are described in more detail in the following figures. The fork 6 comprises a bush-shaped shift rod receptacle 4. The shift rod receptacle 4 is provided on the side facing the shift rod 2 with a bearing 5, via which the shift rod receptacle 4 receives the shift rod 2.

Furthermore, the shift rod receptacle 4 comprises a switching arm 3. The switching arm 3 is U-shaped and accordingly comprises two webs 12.1 and 12.2. These webs 12.1 and 12.2 are formed flattened at their respective inner edges i1 and i2.

The switching arm 3 is mounted transversely to the shift rod 2 on a projection U2 of the shift fork receptacles 4 in a tapered angle. This is illustrated further in FIGS. 2, 3 and 4. In Figure 2, the inventive shift fork 1 is shown in a horizontal side view, in which the fork 6 and the fork-shaped shoe

7 can be seen from the side.

The fork 6 merges into the two outer legs 8 and 9. The fork-shaped slide shoe 7 merges into the two inner legs 10 and 11.

The fork 6 is connected to the fork-shaped slide shoe 7 via three fork slats 13.1, 13.2 and 13.3. Between the fork slats 13.1, 13.2 and 13.3 are corresponding chambers 17.1, 17.2, 17.3, 17.4.

Furthermore, there is a connection between the respective outer legs 8 and 9 and the inner legs 10 and 1 1. These have the outer thighs

8 and 9 via an outer leg groove 16.1 and 16.2 and the inner leg 10 and 1 1 via an inner leg 15.1 and 15.2. The outer leg grooves 16.1, 16.2 and the inner leg grooves 15.1, 15.2 have an opening angle of about 90 °. The inner legs 10 and 1 1 and the outer legs 8 and 9 are formed such that they form fit in insert the respective inner leg groove 15.1 and 15.2 or in the respective outer leg groove 16.1 and 16.2.

In addition, the inner legs 10 and 1 1 on the side that extends to the outer leg 8 and 9, via a contact surface 14.1 and 14.2.

At the point where the contact surface 14.1 or 14.2 ends by the separation of the outer leg 8 and 9 of the inner legs 10 and 1 1, the tapered chamber begins 17.1 and 17.4.

The inner legs 10 and 1 1 have on their sides facing rounded inner edges 18.1 and 18.2.

The fork-shaped shoe 7 with its inner legs 10 and 1 1 has the shape of a semicircle, wherein the length of the inner legs 10 and 1 1 slightly exceed the length of an imaginary Kreishalbierenden.

Also visible is the U-shaped switching arm 3 with its webs 12.1 and 12.2, which is arranged at an oblique angle transversely to the shift rod 2 on a projection U2 of the shift rod receptacle 4. The two inner edges i1 and i2 of the webs 12.1 and 12.2 formed flattened.

Between the shift rod 2 and the shift rod receptacle 4, the bearing 5 is arranged in a ring.

FIG. 3 shows a plan view of the shift fork 1 according to the invention. Here it can be seen that the shift rod receptacle 4 is wider by the length of a supernatant U1 and the supernatant U2, as the widest point of the fork 6, which is limited by main blades 19.1, 19.2, 19.3, 19.4. In this case, the supernatant U1 has a shorter length than the supernatant U2, since the switching arm 3 is arranged on the projection U2. Furthermore, it can be seen that the fork 6 tapers with the transition to the outer legs 8 and 9 by the width B1 and B2. The outer legs 8 and 9 are flanked by the tapered to each other, but not hitting main fins 19.1, 19.2, 19.3 and 19.4.

Between the main blades 19.1 and 19.2 of the one outer leg 8 there are three star blades 20.1, 20.2 and 20.3. Likewise located between the main blades 19.3 and 19.4 of the other outer leg 9 three star blades 20.4, 20.5 and 20.6. These star blades are described in more detail in FIG.

FIG. 4 shows a view of the one outer leg 8 of the shift fork 1. Here are clearly visible the three star blades 20.1, 20.2 and 20.3 with their tubular shaped basic bodies.

The star blade 20.1 has three radial extensions. Two of the three radial projections extend in the direction of the shift fork rod 2 and go laterally into the respective main blade 19.1 or 19.2. A third radial extension first forms two cross-shaped connections to the main blades 19.1 and 19.2 and then extends to a leg tip 22.1, in the region of which it melts with the two main blades 19.1 and 19.2.

The leg tip 22. 1 and the opposite leg tip 22. 2, which can not be seen as a result of the imaging, have a straight end that appears to be cut off.

The star blade 20.2 has five radial extensions. Two of these radial projections extend obliquely in the direction of the leg tip 22.1 and then go into the respective main blade 19.1 or 19.2. Three further radial projections extend in the opposite direction to the shift fork rod 2. The right radial extension goes into the Main lamella 19.2, the left radial projection in the main lamella 19.1 on. The middle radial extension extends straight in the direction of the shift rod 2 and establishes a connection to the star blade 20.3. The star blade 20.3 has eight radial extensions. These radial projections are each arranged at an angular distance of approximately 45 ° about the star blade 20.3 around. Of the eight radial extensions each go the outer three in the main blade 19.1 and 19.2 of the respective side. The pointing in the direction of the leg tip 22.1 radial extension establishes a connection to the underlying star blade 20.2. The opposite radial projection nestles against the rounding of the shift rod receptacle 4, so that it is encompassed by the radial extension in part. Similarly, the main blades 19.1, 19.2, 19.3 and 19.4, the shift rod receptacle 4 a.

Together, the star blades 20.1, 20.2, 20.3, 30.4, 20.5, 20.6, a honeycomb-like and stabilizing structure between the respective main blades 19.1, 19.2, 19.3, 19.4.

On the outside of each other in the direction of the leg tip 22.1 tapered main fins 19.1 and 19.2 each one vane fins 21 .1 and 21 .2 is arranged. The outer edges of the two vane lamellae 21 .1 and 21 .2 extend parallel to one another up to the region on the thigh seat 22.1, so that the one outer leg 8 does not become narrower due to the tapered main fins 19.1 and 19.2. The tapering of the outer legs 8 and 9 represented by the widths B1 and B2 is stopped by the wing louvers 21 .1 and 21 .2. The first mutually parallel outer edges of the vane fins 21 .1 and 21 .2 are arcuately narrower in the region of the leg tip 22.1, so that they respectively conform to the edge of the straight end of the leg tip 22.1. The present description of the one outer leg 8 shown in FIG. 4 is to be transferred to the identically designed other outer leg 9. The two outer legs 8 and 9 are constructed in mirror image.

LIST OF REFERENCE NUMBERS

Claims

1 . Use of a fiber composite material for producing a shift fork (1), characterized by the following steps:

- In a negative injection mold in the form of the shift fork (1) is introduced a fiber, scrim made of fibers or a fabric of fibers as a support structure;

- In the negative injection mold plastic is injected and / or pressed;

- The support structure is overmolded with plastic, wherein the plastic is a matrix for the fiber, the scrim or the tissue.

2. Use according to claim 1, characterized in that the shift fork (1) is subsequently removed from the negative injection mold.

3. Use according to claim 1 or 2, characterized in that the shift fork is subsequently processed further.

4. Use according to one of the preceding claims, characterized in that in the negative injection mold a sliding shoe (7), a partial reinforcement or a driver is introduced.

5. Use according to claim 4, characterized in that the support structure is designed to support the sliding shoe (7).

6. Use according to one of the preceding claims, characterized in that in the negative injection mold, a shift rod receptacle (4) is introduced in the form of a socket.

7. shift fork (1) for a motor vehicle transmission, characterized by a body made of fiber composite material, wherein a fiber, a scrim of fibers or a fabric of fibers is present as a support structure and the support structure is encapsulated in plastic, wherein the plastic is a matrix for the fiber , the clutch or the tissue, wherein a fork (6) and a fork-shaped sliding block (7) is present, the fork (6) is divided into two outer legs (8, 9), wherein the fork-shaped sliding block (7) in two Inner leg (10, 1 1) divides and the two outer legs (8, 9) and the inner legs (10, 1 1) are integrally formed of plastic, wherein the fork (6) comprises a bush-shaped shift rod receptacle (4) and the shift rod receptacle (4 ) is on the one shift rod (2) facing side with a bearing (5) equipped, via which the shift rod receptacle (4) receives the shift rod (2), wherein the shift rod receptacle (4) has a Sc holding arm (3) and the switching arm (3) is U-shaped and has two webs (12.1, 12.2), which are formed flattened at their respective inner edges (i1, i2) to each other, wherein the switching arm (3) in a tapered angle transverse to the shift rod (2) on a supernatant (U2) of the shift fork receptacle (4) is placed, the fork (6) merges into the two outer legs (8, 9) and the fork-shaped sliding shoe (7) in the two inner legs (10, 1 1), wherein the fork (6) with the fork-shaped shoe (7) via three fork lamellae (13.1, 13.2 and 13.3) is connected and between the fork slats (13.1, 13.2 and 13.3) are corresponding chambers (17.1, 17.2, 17.3, 17.4), wherein a connection between the respective outer legs (8, 9) and the inner legs (10, 1 1), wherein the outer legs (8, 9) via an outer leg groove (16.1, 16.2) and the inner legs (10 , 1 1) have an inner leg (15.1, 15.2) and the outer leg grooves (16.1, 16.2) and the inner leg grooves (15.1, 15.2) have an opening angle of about 90 °, wherein the inner legs (10, 1 1) and the outer legs (8, 9) form fit into the respective inner thigh groove (15.1, 15.2) and / or in the respective outer leg groove (16.1, 16.2) insert and the inner leg (10, 1 1) on the side, to the outer legs (8, 9) is sufficient, have a contact surface (14.1, 14.2) and the Schaltstangenaufnahnnne (4) by the length of a supernatant (U1) and a supernatant (U2) is wider than the widest point of the fork (6) by main blades (19.1, 19.2, 19.3, 19.4) is limited.

8. shift fork (1) according to claim 7, characterized in that in the body of a sliding shoe (7) and / or a shift rod receptacle (4) is injected.

9. shift fork (1) according to claim 7, characterized in that in the body partial reinforcing elements of wire and / or plastic and / or encapsulated.

10. shift fork (1) according to claim 7, characterized in that instead of shift rod receptacle (4) and bearing (5), the shift rod (2) with the body of the shift fork (1) is injected into an overall component.