The present invention concerns a hood module (cover module) for attachment on the cylinder head of an internal combustion engine with a hood body made of plastic and with at least one bearing bracket including metal material for holding at least one camshaft in the hood module in a rotatable manner.
Hood modules can also be described as cylinder head cover or camshaft modules and be used to hold mostly one or two camshafts that can work together with valves in the internal combustion engine by means of cam followers or rocker arms when the hood module is disposed on the cylinder head of the internal combustion machine. Through this method, hood modules are constructed to be as lightweight as possible, soundproof and be able to be easily assembled. For this purpose, it is already known that the hood module is to be developed in plastic, and the at least one bearing bracket includes metal material because said bracket holds the camshaft and is subject to greater mechanical loads.
The plastic of the hood body makes advantageous insulation characteristics possible in the hood module and in doing so, the metal material of the bearing bracket meets the fastening requirements in order to hold the camshaft in the hood module. Aside from a simple design, simple production, good insulation characteristics and a low weight, the hood modules should nonetheless be easily manageable, in particular during production and assembly, and in the best case, a hood module should be able to be delivered to a manufacturer, who can attach the hood module to the cylinder head of an internal combustion engine in a simple way without major adjustment and positioning procedures. Moreover, the production of the hood module should also, however, be developed as easily as possible itself.
DE 196 03 692 A1 reveals a cylinder head cover with a storage aisle carrier for the camshaft bearings where the storage aisle carrier extends under the entire hood body, which is produced in plastic, so that the cylinder head cover has a relatively high mass.
DE 100 34 329 C2 shows a valve hood for internal combustion engines and the bracket bearings shown are insert-molded through a hood body made of plastic, basically completely with the plastic material. The bracket bearings can in this way by precisely aligned so that the valve hood can easily be disposed ready-made on a cylinder head of an internal combustion engine, but the insert-molding of the bearing blocks requires a high mass fraction in plastic. The bearing blocks must additionally be connected with each other by a supporting structure that is formed from a metal material and so increases the weight of the valve hood.
Finally, DE 10 2008 007 091 A1 shows a pre-assembled camshaft module to attach to the cylinder head of an internal combustion engine, and bearing brackets made of a metal material are provided that can be pre-fused on a hood body made out of plastic. Screws, with which the bearing brackets are held on the cylinder head up till assembly, essentially free-moving, are provided here. First, in assembling the camshaft module, the bearing brackets are aligned to each other and fastened to the valves or the tapping elements of the valve on the cylinder head, and only subsequently can the screws that are inserted in the hood body be suitably tightened. Disadvantages that are to be avoided consequently arise in handling when the camshaft module is assembled. In the process, additional machining operations and positioning procedures are to be avoided in particular because these procedures must be dealt with at the client's, where optimal camshaft module mountability does not exist.
In particular, for mass-production capable manufacturing of cylinder head covers in hybrid construction, thermoplastic hoods/covers have to be connected with bearing brackets in short cycle times. The plastic hood itself advantageously uses the hermetic sealing of the valve drive and should consequently be fluid-impermeable—in particular oil-impermeable—on the surface. To do this, the joint locations in the materials must be realized without outward perforation, i.e. to the outer environment.
The object of the present invention is the preparation of a hood module (cover module) for attachment on a cylinder head of an internal combustion engine, where the hood module presents a low weight and should be easy and cost-efficient to assemble and where the hood module should also have good acoustic insulation and a simple design.
Said object is solved based on a hood module for attachment on a cylinder head of an internal combustion engine according to the generic term of Claim 1 and based on a procedure to form a hood module according to the known characteristics of Claim 11 with the respective characteristic features. Advantageous further features of the invention are stated in the dependent claims.
The invention includes the technical knowledge that the bearing bracket is disposed on the hood body with position accuracy by a joint connection, so that the bearing bracket is aligned for attachment on the cylinder head through the hood body.
The design of a hood module according to the invention allows simple handling of the hood module when operating with minimal weight, which can be fitted as a unit on the cylinder head of an internal combustion engine and fastened to said cylinder head without the bearing bracket or preferably several bearing brackets having to be attached to the cylinder head or aligned relative to each other and individually fastened, for example, bolted. According to the invention, the hood body is used to form a protective hood for sound insulation on the basis of plastic material and in particular as a carrier for one or more bearing brackets. According to the invention, the bearing brackets are at the same time to be provided without injecting a large mass of plastic, fastened relative to each other, and there merely remains the necessity of fastening the whole hood module to the cylinder head by simple means where as a result one or more bearing brackets is fastened relative to the cylinder head.
By a position-specific arrangement, an arrangement in particular is to be understood in which the planar orientation of the hood module on a cylinder head can be produced so that the arrangement of the hood module on the cylinder head can be screwed on ready for subsequent operation.
According to a particular advantage of the design of the joint connection according to the invention, this can contain at least two joint locations between the bearing bracket and the hood body. As a rule, a hood module has several bearing brackets for the rotatable holder of a camshaft, and each bearing bracket can contain two joint locations with which the joint connection is formed between the respective bearing bracket and the hood body. For production of the hood module, the bearing brackets can, for example, be fastened in a holding device so that the bearing brackets already have the location to each other that is required for holding the camshaft later. By way of example, the camshaft can be pre-fused in the bearing brackets so that the bearing brackets already have their ultimately required position relative to each other. Finally, a defined position arrangement of the bearing brackets relative to the means of fastening the hood module to the cylinder head is still required in the assembly tool. The plastic hood body made in the injection mold can be brought into connection with the bearing brackets after fixation of said bearing brackets without them having to be insert-molded even only partially with the plastic mass of the hood body. The hood body can consequently be injected from a minimal plastic mass; moreover the bearing brackets must not present any corresponding geometry in order to make form-locking injection of the bearing brackets possible.
In the framework of the present invention, plastic describes every material of low density that is at least lower than in a metal material used to form the hood body. Through this method, the plastic can have non-synthetic components as well, for example by fiber reinforcing. Laminated, fibrous materials or fiber glass or carbon fiber materials are also included under the concept of plastic.
Due to the design of the hood module according to the invention, a necessary support structure is also avoided because the hood body itself already provides this support between the bearing brackets. The hood module can therefore only be designed weight-minimally where said module is designed to be attached to the cylinder head with fastenings so that the bearing brackets are disposed in the force flow of said fastening between the hood module and the cylinder head.
According to an advantageous further feature of the invention, the joint connection and in particular the joint locations can be formed by at least one joint element. The joint element can in this way be designed in the form of a sleeve and be glued into or pressed into the bearing bracket and/or the hood body. The joint element can form the joint location between the bearing bracket and the hood body so that for every bearing bracket, for example, two joint elements are planned in two joint locations spaced apart from each other for attachment on the hood body.
The joint elements can be fitted to the plastic material of the hood body according to a further advantageous embodiment to form a melting zone. In this way, the joint elements are first disposed on the bearing brackets or the joint elements are formed on the bearing bracket and can in particular be heated together with an adjoining area of the bearing bracket. In this way, the joint elements can be brought to a temperature that ensures that the plastic material of the hood body will melt.
If the bearing bracket is imprinted with the joint elements in the plastic of the hood body or if the hood body is applied on the joint element in the bearing bracket by means of a stamp, there is local melting of the joint area on the hood body, and after the joint location cools down, a firmly bonded load-bearing or even a form-locking connection is made between the bearing bracket and the hood body by the joint element that is penetrated over a partial length in the plastic of the hood body.
Due to this connection technique, there are particular advantages in producing the hood module, because after simple heating, the joint element and the area of the bearing bracket of the hood bodies must only be put on one or more bearing brackets in order to produce the connection of the hood body to the bearing bracket(s) when the melting zone is formed. Alternatively, an auxiliary element can also be designed that is put on an end of the joint element, for example, pressed on or screwed on, by which a form-locking connection of the bearing bracket can also be created with the hood body by a joint element.
In the design of the hood module according to the invention, it depends in particular on the hood module, exactly positioned as a whole, being disposed on the cylinder body of the internal combustion engine. At least two mounting holes can be designed in the hood body and/or in the bearing bracket, in which fasteners can be accommodated and with which the hood module can be fastened to the cylinder head. The mounting holes can here extend through the hood body; the invention however preferably envisages that the mounting holes extend at least partially through the bearing brackets. The mounting holes can be dimensioned so that connecting elements that have been fed through have some clearance through them. One orientation of the hood module on the cylinder head is, for example, over two fastening locations that can be found in the bearing brackets, or the fastening locations are accommodated on the hood body or formed in it. If the hood module has been put on a cylinder head of an internal combustion engine and has been aligned over the (at least) two fastening locations, connecting elements can be fed through the mounting holes and the hood module can be screwed tightly on to the cylinder head over the bearing brackets. This screw connection is particularly simple because the connecting elements, for example, designed as screws, can be inserted and tightened in the mounting holes from the top side.
The joint elements designed in the form of a sleeve can align with the mounting holes. In particular, the joint elements in the form of a sleeve can at any one time form a part of the mounting holes. If the connecting elements are fed through the mounting holes and consequently through the joint elements in the form of a sleeve as well, there is additional protection of the connection between the hood body and the (at least one) bearing bracket. When the internal combustion engine operates later, it can be ensured in this way that the bearing brackets cannot be dismantled from the hood body.
Alternatively, the design according to the invention can have the joint elements in the shape of a pin or a feather and, for example, inserted next to the mounting holes between the bearing brackets and the hood body. These can heat up in the same way as the joint element in the form of a sleeve and be melted into the plastic of the hood body. Here, two joint elements can also be designed and for example, an adjacent joint element can be attached to each mounting hole used to pass a connecting element, for example a screw, through it.
The bearing bracket can be developed for holding one or two camshafts and in particular, the bearing bracket can have at least one bearing ring that is inserted in a fitting aperture in the bearing bracket and be used for holding the camshaft in a rotatable manner. The bearing bracket can here be produced in a metallic material, for example, aluminum, and in doing so, the bearing bracket does not have to be completely made of metal. The bearing bracket can for example have a plastic part and in this case, the metal covering for the bearing bracket can be bounded by at least one bearing ring, for example. If two camshafts are accommodated in the hood module, the bearing bracket can have two mounting apertures and a bearing ring can be introduced into each mounting aperture, for example pressed in.
The present invention is also based on a procedure to form a hood module that is designed to be attached onto a cylinder head of an internal combustion engine with a hood body made of plastic and with at least one bearing bracket including a metal material for rotary holding of at least one camshaft in the hood module, where the procedure includes at least the step of providing the hood body and at least one bearing bracket; moreover the procedure includes the alignment of the bearing bracket on the hood body and/or the alignment of several bearing brackets with each other, joining the bearing brackets to the hood body is provided for by a joint connection, in which the bearing bracket is disposed with the joint connection so that the bearing bracket is aligned for attachment to the cylinder head.
Thereby, the procedure can include providing at least one joint element that is disposed on the bearing bracket and the hood body to form the joint connection. In particular, at least two joint elements with a space between them can be designed to connect a bearing bracket to the hood body in order to form two joint locations between the bearing bracket and the hood body.
The joint locations and in particular the joint element can be heated more advantageously so that the joint element is brought into contact with said joint element to form a melting zone in the plastic material of the hood body or in an auxiliary element, and is fitted to this. In forming a melting zone, the following advantage is achieved: the bearing brackets can be pre-fused before the hood body is put on the bearing bracket, and putting the hood body on the bearing bracket occurs through a one-dimensional and essentially forceless joining movement, and the hood body is held by handling over the bearing bracket until the melting area has solidified around the joint element.
In the design of the hood module according to the invention, the precisely positioned arrangement of the hood body for the bearing bracket is not the focus of attention as long as the hood module is connected to the cylinder head over the bearing bracket(s) that are held by the hood body. Therefore, the advantage arises that an analogously precise attachment of the bearing brackets to the hood body is not necessary, through which the production of the hood module and the handling of the individual components in production is clearly simplified. At the focus of attention is the attachment of several bearing brackets relative to each other with a corresponding precision, which is maintained by the hood body that is used as a fastening and holding body for bearing brackets. If the hood module is provided with the bearing brackets aligned with each other on the cylinder head of an internal combustion engine, the bearing brackets can be mounted on the cylinder head with connection elements in which mounting holes are planned in the hood module that pass through the bearing bracket with particular advantage. Therefore, the bearing brackets can be solidly disposed on the cylinder head, where the hood body merely takes over the fixation of the bearing brackets to each other and relative to the cylinder head, in which the valve and/or tapping elements are held that are driven by the camshaft and that can be inserted in the hood module.
To orient the hood module, two positioning elements that correspond to each other, such as sleeves that fit in an opening, pin or nut feathering elements, can be formed especially on the bearing bracket and the cylinder head. By means of the positioning elements the hood module is then oriented on the cylinder head over said cylinder head before it is fastened to it.
Additionally, the invention-improving measures are presented in more detail below through the figures, together with the description of a preferred exemplary embodiment of the invention. The schematic diagrams show the following:
In the inner area of hood body 10, there are three visible bearing brackets 11 for rotatable holding of two camshafts 12 running parallel to each other. The side walls of hood body 10 include further bearing brackets in a not presented or only partially presented way so that camshafts 12 are held in a total of five bearing brackets on hood module 1. Camshafts 12 can be inserted through insertion apertures 18 on the side of hood body 10 that can at the same time be the first bearing position of camshaft 12, at which camshafts 12 are shown in simplified form without lifter elements.
Hood module 1 can be disposed on a cylinder head of an internal combustion engine and in order to achieve a sealed attachment of hood module 1 on the cylinder head, hood body 10 has seals 19, through which the camshaft space inside hood body 10 can be sealed and locked.
Bearing brackets 11 shown here are connected with hood body 10 over joint locations as is presented in more detail in the cross-section view of hood module 1 in
Joint elements 14 are partially inserted in bearing bracket 11 and partially in hood body 10. For example, joint element 14 can be pressed into the upper section of mounting hole 15, and joint element 14 can be inserted where a melting area is formed in a prepared through bore in hood body 10. When producing joint element 13, bearing bracket 11 is pre-fused in a joint tool, and when hood body 10 is put in production of joint connection 13, the exact position of bearing bracket 11 is properly frozen for later attachment on the cylinder head by hood body 10. Consequently, hood body 10 is used for both as a hood element protecting against contamination and humidity, as a sound insulation element, and also as a holding or fastening element for bearing brackets 11 for later attachment on the cylinder head of the internal combustion engine.
As a variant of the exemplary embodiment from
Generally, the joint element can be inserted before a casting process for the bearing brackets as an insert component in a tool. Subsequently, in metal pressure casting for example, aluminum or a similar material can then be poured in. In this way, a connection between the joint element and the bearing pressures can be created simply.
Finally,
Finally,
The different forms of joint area 20 of joint element 14 for melting into the plastic material of hood body 10 allows a form-locking connection of joint element 14 with hood body 10, in particular when plastic material that is melted by heating joint element 14 and is in this way ready to turn liquid, can be moved into the fluting of the knurling according to
In
As shown in
Joint element 14 is advantageously connected to the bearing bracket 11 in a force-fittings manner (frictional connection). It is, however, also conceivable for the joint element to be alternatively or additionally connected by form-locking and/or positive substance jointing using bearing bracket 11. Joint element 14 extends advantageously at least partially, advantageously completely within a recess 11.1 in bearing bracket 11.
When bearing bracket 11 is connected with hood body 10, hood body 10 is applied on joint element 14 so that this permeates in opening 24 and this is advantageously completely filled in by joint element 14. A surface of hood body 10, adjusted for bearing bracket 11, advantageously connects here, a surface of bearing bracket 11, adjusted for hood body 10. Due to the electrical current flowing through induction coil 23, the material of joint element 14 is heated, by which the material of hood body 10 in contact with joint element 14 is also heated so that it ends in a deviation at least in sections in the area adjacent to joint element 14. The now moldable material of hood body 10 surrounds surface structure 14.1 of joint element 14 advantageously so that both components produce a form-locking connection with each other at least in sections. Therefore, an advantageous permanent connection between hood body 10 and bearing bracket 11 is made possible.
The invention is not limited in its embodiment to the existing indicated favored exemplary embodiment. A number of variants that are used in fundamentally different embodiments of the solution presented is in reality conceivable. All characteristics and/or benefits arising from the claims, the description or the drawings, including constructive units, spatial arrangements, can be essential to the invention both for themselves and also in the different combinations.
1 Hood module
10 Hood body
11 Bearing bracket
11.1 Recess
12 Camshaft
13 Joint connection
14 Joint element
14.1 Surface structure of the joint element
15 Mounting hole
16 Bearing ring
17 Auxiliary element
18 Insertion opening
19 Gasket
20 Joining area
21 Insertion area
22 Tool
23 Induction coil
23.1 Induction coil wrap
24 Opening
25 Material thickening
A Joint section of the hood body
F Joint direction
Number | Date | Country | Kind |
---|---|---|---|
10 2014 106 561.1 | May 2014 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2015/057867 | 4/10/2015 | WO | 00 |