DE202011001961U1 - heat shield - Google Patents

Abstract

Heat shield (1) for shielding hot areas, for example an internal combustion engine, with at least one metallic sheet-metal layer (2), the at least one metallic sheet-metal layer (2) having at least one through opening (3) for receiving a fastening means (5), and at least in one of the through openings (3) at least one decoupling element (10) for at least partial decoupling or damping of the transmission of vibrations or heat from the at least one sheet metal layer (2) is characterized in that the at least one sheet metal layer (2) is adjacent to the peripheral edge of the at least one through opening (3) has at least one opening (6), and the decoupling element (10) has at least one retaining element (14) which is arranged on a first side of the heat shield (1) in the radial direction outside the peripheral edge of the through opening (3) and which rests on one of the sheet metal layers (2), as well as at least one in radial direction ung outside the circumferential edge of the through opening (3) arranged locking element (16) which the sheet metal layer (2) containing the opening (6) through one of the openings ...

Description

The present invention relates to a heat shield, which is used for shielding hot areas, such as an internal combustion engine. Such heat shields conventionally have at least one metallic sheet metal layer. This sheet metal layer reduces the radiation of heat from a heat source of the hot, the hot area facing side of the sheet metal layer and their transmission to the cold, the hot area facing away from the sheet metal layer. Furthermore, such a heat shield not only serves to dampen the transfer of heat from the hot to the cold side of the heat shield, but also to dampen the transmission of vibrations from one side of the heat shield to the other side.

In other designs, such heat shields on at least two sheet metal layers, which are connected to each other, for example, at their peripheral edge at least in sections. Such a connection can be made, for example, by crimping one layer around the edge of the other layer. The two sheet metal layers then form a housing, in which further intermediate layers, such as soft materials, cardboard, nonwoven fabrics or mica, expanded mica, graphite or expanded graphite - each loose or pressed to fillet - can be stored.

Conventionally, such heat shields or their sheet metal layers have bores as passage openings which pass through the at least one metallic sheet metal layer. In these holes fastening means, such as screws, can be introduced during assembly, so that the heat shield can be attached to an internal combustion engine, for example.

The fastening means are usually firmly connected to the corresponding component, for example an internal combustion engine. They can therefore transmit both heat and vibrations from the component to the heat shield. Therefore, in the prior art decoupling elements are already provided which decouple the fastening means of the heat shield with respect to the heat transfer and the vibration transmission as far as possible. As such decoupling elements, wire knits and the like are used.

Such knitted fabrics are on the one hand very expensive and on the other hand have a considerable weight, which is undesirable in particular in the case of light-metal heat shields.

The disadvantage of this is in addition that such decoupling elements are expensive to assemble, since their installation takes place in each case from both sides of the heat shield. Furthermore, it is necessary to stockpile not only the heat shield and the fastening means but also the decoupling element and provide the worker for the assembly separately available.

The installation of such decoupling elements represents an additional complication for the worker.

Object of the present invention is therefore to provide a heat shield at your disposal, which has a low-cost, lightweight and easy-to-install decoupling element, which thermally and / or vibration technology isolated the heat shield. Essential for the present invention is also the durability of the heat shield and its economy.

This object is achieved by the heat shield according to claim 1. Advantageous developments of the heat shield according to the invention are given in the dependent claims.

The heat shield according to the invention is particularly suitable for use on internal combustion engines or their ancillaries. In particular, heat shields of light metal, such as aluminum, may be advantageously designed according to the present invention.

The heat shield according to the invention can be mounted quickly and easily. As a result, the assembly costs are kept within an economical framework. Depending on the application, it is possible to choose between exemplary embodiments in which the fastening element is already preassembled on the heat shield or in which the fastening element is to be used when mounting the heat shield. The heat shield according to the invention makes it possible, in the case of preassembled fastening elements, in particular to mount heat shields with short cycle times without joints of a further element or reshaping or setting of individual areas.

The heat shield according to the invention has at least one metallic sheet-metal layer which has a passage opening for receiving a fastening means. In this passage opening a decoupling element is introduced according to the invention. The decoupling element serves for the at least partial decoupling or damping of the transmission of vibrations or heat from a fastening means to the heat shield. For this purpose, the decoupling element holding elements and locking elements. The holding elements rest on one side of the at least one sheet-metal layer of the heat shield. For this purpose, the retaining elements outside the passage opening in the region of Be arranged sheet metal layer. The decoupling element further has latching elements, which are also arranged outside the passage opening and openings in the sheet metal layer, which are also arranged outside the passage opening for the fastening means, reach behind or engage behind. The latching elements thus engage, starting from the side on which the holding elements are arranged, on the side of the heat shield opposite to the holding elements or its at least one sheet metal layer, whereby the decoupling element is held positively on both sides of the sheet metal layer or the heat shield. This allows a simple mounting of the decoupling element in the passage opening of the heat shield.

The holding elements and the latching elements can be connected by means of connecting elements with respect to the through-opening radially extending connecting elements with a central, arranged in the region of the passage opening the first element of the decoupling element. The holding elements and latching elements can thus be arranged radially spaced from a first central element of the decoupling element. The first element is advantageously arranged in the passage opening of the respective sheet metal layer or the heat shield. Particularly advantageously, the first element may be formed as disc-shaped, in particular circular element, which is arranged concentrically to the passage opening and advantageously has a concentrically arranged to the passage opening own opening for the passage of a fastening means. The outer diameter of the first element may be less than the clear width of the passage opening of the sheet-metal layer, so that the first element is arranged completely in the region of the passage opening.

In the case of strongly asymmetrical oscillation behavior of a heat shield, an eccentric arrangement relative to the passage opening, for example via a slot-shaped passage opening, may be advantageous. Such unbalanced vibration behavior results in z. B. interactions with other tethering points.

Particularly advantageously, the first element is arranged in the plane of the sheet metal layer in the passage opening, wherein the radially extending connecting elements can then be cranked such that the holding elements and locking elements connected to them are arranged on one side of the sheet metal layer. The locking elements engage behind by means of another offset then openings in the sheet-metal layer, so that the ends of the locking elements lie in the passage direction through the through hole form fit to the sheet metal layer.

To optimize the decoupling effect or in the case of strongly asymmetrical oscillation behavior of the heat shield, the connecting elements are advantageously designed asymmetrically. For example, the distance of the connecting elements can be made uneven with each other. Likewise, the height of the cranks can be different. Next, the width of the connecting element, in particular in the cranking, can be varied. For example, the connecting element can be fitted in the crotch area.

The contact between the holding elements and latching elements on the one hand and the sheet metal layer of the heat shield adjacent thereto on the other hand can be further improved if the latching elements and / or holding elements in their course or at their ends semi-beads (cropping) or full corrugations. As a result, an elastic resilient contact between the holding elements or latching elements and the respective adjacent sheet metal layer is generated. At the same time the bearing surface of the decoupling element is reduced to the heat shield or on the component, so that a lower heat transfer takes place.

An advantage of the decoupling element according to the invention is that it can be fastened in a simple manner in the passage opening of a heat shield by screwing in the manner of a bayonet closure. Due to the cropping in the transition between the holding elements and the locking elements, the decoupling element can no longer detach itself from the passage opening after a tightening of the heat shield to a further component. Thus, a very stable and secure connection between the decoupling element and the sheet metal layer of the heat shield is effected.

In particular, the invention comprises two alternative embodiments: Either the fastening means is preferably mounted captively when mounting the decoupling element on the heat shield at the manufacturer of the heat shield or the decoupling element is already mounted in the heat shield manufacturer and the fastener until the attachment of the heat shield on the adjacent component inserted. In the latter embodiment, both screws and bolts may be used as fasteners as known in the art.

Advantageously, the fastening means in the opening of the decoupling element captive, but can be arranged movable. This is particularly advantageous with a screw as a fastener possible. Thus, it is no longer necessary to provide the fastener separately to the responsible for the assembly workers. Furthermore, the worker is relieved, as the Fastener is already provided together with the heat shield and the decoupling element and can be easily mounted on a component. Such a design also avoids costly separate storage and disposition and thus the risk that a wrong fastener is used during assembly.

As captive arranged fasteners screws are preferably used. In the case of a screw as a fastening means, this is at least rotatably mounted in the opening of the decoupling element. It is advantageous if the screw is additionally movable in the passage direction of the passage opening. In the case of, for example, a screw, the worker can attach the heat shield according to the invention to the component during assembly, wherein the screw does not project forward and can not fall out behind, and then screw the screw directly into a corresponding threaded hole in the component.

A screw according to the invention in the through hole of the decoupling element thereby movable, but be arranged captive that the screw has a shank which has a smaller diameter between the screw head and screw thread than the adjacent screw head and the adjacent screw thread. If this tapered region is inserted into a correspondingly narrow passage opening of the heat shield or the decoupling element, then the screw can not be released from the passage opening.

In another advantageous embodiment, the screw is designed as a stepped threaded bolt, d. H. as a threaded bolt with two areas of different thread diameter and is provided only after performing the threaded bolt through the heat shield with a screw head, for example screwed.

Advantageously, the captive arranged fastening means, for example, the screw in the direction of its screw head, biased, for example, mounted on a spring. Characterized the screw is pushed back within the passage opening, so that with a suitable choice of the length of the screw shank of the screw shank on the side facing the component of the heat shield does not project beyond the passage opening. This avoids that during assembly the screw protrudes on the component side and can hinder the exact positioning of the heat shield. Then then the screw can be screwed against the bias in a corresponding threaded hole on the component. This is particularly advantageous in the case of planar or downward mounting if, without such springs, gravity would move the screw in the direction of the component.

Such a spring is another way to rotate the screw, but to secure captive in the through hole. For this purpose, the spring can be positively or materially connected to both the screw head and with the through hole or the decoupling element. The spring then pushes the screw head and thus the entire screw away from the sheet metal layer of the heat shield, but prevents the screw from falling out of the through hole.

In the case of a two-layered or multi-layered heat shield, it is advantageous if the passage opening in the sheet metal layers is arranged in a region in which no further intermediate layer is arranged between the two sheet metal layers of the housing. This allows a good adhesion between the fastener and the component to which the heat shield is attached, produce.

In the following some examples of heat shields according to the invention are given. Also, individual elements described for each example individually represent elements of the present invention and are not to be considered merely in the overall context of the following exemplary illustration. Hereinafter, the same or similar reference numerals are used throughout for the same or similar elements.

Show it

1 a mounted heat shield with conventional decoupling element;

2 an inventive decoupling element;

3 a decoupling element according to the invention mounted in a through-opening of a heat shield in a plan view of a first side of a sheet-metal layer;

4 a plan view of a present invention in a through hole of a heat shield decoupling element according to the invention;

5 an inventive heat shield with inserted fastener;

6 another inventive decoupling element;

7 another inventive decoupling element;

8th in two subfigures 8A and 8B further inventive decoupling elements; and

9 another inventive decoupling element.

1 shows a conventional heat shield 1 , the two mutually and mutually parallel sheet layers 2a and 2 B having. These sheet metal layers have a passage opening 3 to carry out a screw 5 as a fastener. The screw 5 has a shaft with thread 8a , this in 1 is shown in supervision.

By means of the screw 5 is the heat shield 1 in another component 4 , For example, an engine block or exhaust manifold, bolted.

Between the component 4 and the heat shield 1 as well as between the heat shield 1 and the head 7 the screw 5 is as a conventional decoupling each wire mesh 10a inserted, which is the passage opening 3 together with a sleeve 10b completely surrounds. The wire mesh 10a acts as a decoupling element between the screw 5 and the heat shield 1 , so that heat and vibration from the component 4 not or only to a reduced extent over the screw 5 on the heat shield 1 be transmitted.

Unlike the in 1 illustrated conventional heat shield 1 with conventional decoupling element 10a shows 2 an inventive decoupling element 10 , This decoupling element 10 has as the first element a middle element 11 having a circular outer periphery. The middle element 11 has an opening 20 , which with mounted decoupling element 10 concentric with the passage opening 3 through the heat shield 1 (please refer 1 ) is arranged. In 2 is the opening 20 with a peripheral edge 21 provided in hexagonal shape, so that for example by means of a hexagonal wrench, the decoupling element 10 around the passage axis of the opening 20 can be turned.

From the middle element 11 branch - each other by 120 ° about the central axis of the central element 11 offset - three radial arms 12a . 12b respectively. 12c starting in the radial direction from the middle element 11 proceed outwards. At the transition from the middle element 11 in the arm 12a . 12b or 12c is each a crank 13a . 13b respectively. 13c intended. At the end of the respective radial arm 12a . 12b respectively. 12c divides this arm in each case in the circumferential direction around the central element 11 extending arm 14a and 16a . 14b and 16b respectively. 14c and 16c , The poor 14a and 14b and 14c serve as holding arms, which extend essentially in that plane, by the cranks 13a . 13b and 13c are predetermined, and thus in the plane of the radial arms 12a . 12b and 12c , In the other direction extending from the radial arms 12a . 12b and 12c locking arms 16a . 16b and 16c passing through a bend between the radial arms 12a . 12b and 12c and the latching arms 16a . 16b and 16c in the direction of the plane of the middle element 11 opposite the radial arms 12a . 12b and 12c are offset. At their end, they have another bend or half-bead 18a . 18b and 18c , which - based on the level of the arms 12a . 12b u. 12c - in the same direction as the crops 17a . 17b and 17c has.

3 now shows such a decoupling element 10 on a sheet metal layer 2 a heat shield 1 attached. The heat shield 1 has three radially extending, but concentric with the opening 20 arranged openings or slots 6a . 6b and 6c on. The decoupling element 10 is in 3 shown in the state where it is in the heat shield 1 is used. For this purpose, the decoupling element with the locking arms 16a . 16b and 16c in a suitable position on the sheet metal layer 2 put on and then rotated in such a clockwise direction that the latching arms 16a . 16b and 16c through the slots 6a . 6b and 6c reach through and the sheet metal layer 2 engage behind. This is the decoupling element 10 in the sheet metal situation 2 of the heat shield 1 securely attached. The mounted decoupling element is used here for thermal decoupling.

4 shows a view of another heat shield 1 , which is a similar decoupling element 10 as in 3 having. In contrast to 3 is now the outer diameter of the central element 11 smaller than the clear width of the passage opening 3 the sheet metal situation 2 , This is the middle element 11 of the decoupling element 10 from the peripheral edge of the opening 3 spaced. This further improves the decoupling between one in the opening 20 arranged fastening means and the sheet metal layer 2 of the heat shield.

In 5 is the same heat shield as in 4 shown, but here on the central element 11 a washer 9 and a screw 5 with screw head 7 is applied. In this condition, the heat shield can 1 be bolted to another component, with component and screw through the opening 3 mounted decoupling element 10 with regard to heat transfer and vibration transfer as far as possible from the sheet metal layer 2 of the heat shield 1 are decoupled.

6 shows the view of another decoupling element 10 similar to the one in 2 is shown. Here, however, as in the two following embodiments, an explicit representation of the booster 13a . 13b . 13c in the area of the radial arms 12a . 12b . 12c waived. The 6 especially serves the comparison with the two following embodiments.

7 shows a plan view of another inventive decoupling element now with four retaining arms 14a . 14b . 14c and 14d as well as with four locking arms each 16a . 16b . 16c and 16d ,

Compared to 2 are in this decoupling element 10 the positions of the holding arms 14a . 14b . 14c and 14d as well as latching arms 16a . 16b . 16c and 16d interchanged. Otherwise, this decoupling element 10 designed similarly. Only the ends of the support arms 14a to 14d and latching arms 16a to 16d are provided with an incision.

8th shows in 8A and in 8B two further decoupling elements 10 similar to the one in 6 , Both decoupling elements 10 However, they have an asymmetrical design.

In the embodiment of 8A is the radial arm 12b different from the radial arms 12a and 12c designed. He has both a sidecut and a recess 22 on. This will be the arm 12b towards the other two arms 12a and 12c softer and more elastic, it also vibrates in a different frequency range than the arms 12a and 12c , So there is an unbalanced vibration decoupling. Next is the opening 20 designed here as a round opening instead of a hexagonal opening. In the decoupling element in 8A are also the holding arms 14a . 14b and 14c angled at their ends, so that they are in the area between the latching arms 16a . 16b . 16c and 16d on the one hand and the middle element 11 on the other hand.

The ends 18a . 18b and 18c the holding arms 14a . 14b and 14c are also widened, so that an edition of the support arms 14a . 14b and 14c results, on the one hand in the vicinity of the passage opening 20 is arranged and on the other hand has a large area for a secure holder.

8B also shows an asymmetrical embodiment of a decoupling element 10 , On the one hand is the opening 20 designed here as a slot, so that a fastener can also be introduced eccentrically. On the other hand, the arms point 12a and 12b a smaller distance from each other than the third arm 12c , the lengths of the support arms 14a . 14b , and 14c are as well as the latching arms 16a . 16b and 16c adapted and thus different lengths. Again, an unbalanced vibration decoupling occurs.

9 shows another decoupling element 2 similar to the one in 2 is constructed. In 9 is in addition a screw in the decoupling element 5 with a shaft 8b arranged. The shaft 8th the screw 5 is from a spring 25 surround. This spring is stuck to the head 7 or federal government 27 the screw 5 connected. In the same way, the other end of the spring with the decoupling element 10 firmly connected. This is the screw 5 captive in the passage opening 3 respectively. 20 arranged. The feather 25 is on the head 7 the screw 5 arranged so that they are not from the screw 5 can solve the head of the screw 7 but still can be rotated against the spring. This makes it possible to screw 5 against the force of the spring 25 through the passage opening 3 to press and then screw in a threaded hole in an adjacent component. Due to the bias of the spring of the screw head is in the unloaded state as far as possible from the heat shield 1 printed away, so that with a suitable choice of the length of the shaft 8th the shaft 8th the screw 5 not about the sheet metal position 2 protrudes. This avoids that when applying the heat shield 1 to the adjacent component the heat shield 1 to hang on projections and the like of the adjacent component and thereby the mounting of the heat shield 1 is obstructed on an adjacent component. For clarity was at 9 on the representation of the heat shield 1 self-dispensed.

Claims (22)

Heat shield ( 1 ) for shielding hot areas, such as an internal combustion engine, with at least one metallic sheet metal layer ( 2 ), wherein the at least one metallic sheet metal layer ( 2 ) at least one passage opening ( 3 ) for receiving a fastener ( 5 ), and wherein at least in one of the passage openings ( 3 ) at least one decoupling element ( 10 ) for the at least partial decoupling or damping of the transmission of vibrations or heat from the at least one sheet metal layer ( 2 ) is arranged, characterized in that the at least one sheet metal layer ( 2 ) adjacent to the peripheral edge of the at least one passage opening ( 3 ) at least one opening ( 6 ), and the decoupling element ( 10 ) at least one on a first side of the heat shield ( 1 ) in the radial direction outside the peripheral edge of the passage opening ( 3 ) arranged holding element ( 14 ), which on one of the sheet metal layers ( 2 ) rests, as well as at least one in the radial direction outside the peripheral edge of the passage opening ( 3 ) arranged locking element ( 16 ), which is the the Breakthrough ( 6 ) containing sheet metal layer ( 2 ) through one of the openings ( 6 ) engages behind. Heat shield according to the preceding claim, characterized in that the detent element ( 16 ) on the first side over the peripheral edge of the passage opening ( 3 ) survives. Heat shield according to one of the preceding claims, characterized in that the decoupling element ( 10 ) a first element ( 11 ), advantageously a disk-shaped, advantageously circular first element which, advantageously concentric with the passage opening ( 3 ) an opening ( 20 ) for carrying out a fastening element ( 5 ) having. Heat shield according to the preceding claim, characterized in that the first element ( 11 ) concentric with or concentric in the passageway ( 3 ) is arranged. Heat shield according to one of the two preceding claims, characterized in that the outer diameter of the first element ( 11 ) smaller than the clear width of the passage opening ( 3 ). Heat shield according to one of claims 3 to 5, characterized in that one, several or all of the retaining elements ( 14 ) and / or one, several or all of the locking elements ( 16 ) radially spaced from the first element ( 11 ), advantageously concentrically around the passage opening ( 3 ) are arranged. Heat shield according to one of claims 3 to 5, characterized in that one, several or all of the retaining elements ( 14 ) and / or one, several or all of the locking elements ( 16 ) a substantially radially extending connecting element ( 12 ) for connecting the retaining element ( 14 ) or the latching element ( 16 ) with the first element ( 11 ). Heat shield according to the preceding claim, characterized in that one, several or all of the connecting elements ( 12 ), advantageously at the transition between the first element ( 11 ) and the connecting element ( 12 ), are dripped. Heat shield according to one of the two preceding claims, characterized in that one, several or all of the latching elements ( 16 ) at the transition between the connecting element ( 12 ) and the locking element ( 16 ) are bent, advantageously in a to the crank of the connecting element ( 12 ) opposite direction are cranked. Heat shield according to one of the preceding claims, characterized in that one, several or all of the retaining elements ( 14 ) and / or one, several or all of the locking elements ( 16 ) are bent or cranked at their free end. Heat shield according to one of the preceding claims, characterized in that one, several or all of the retaining elements ( 14 ) and / or one, several or all of the locking elements ( 16 ) have a bead, which with its beading belly to the adjacent sheet metal layer ( 2 ). Heat shield according to one of the preceding claims, characterized in that the decoupling element ( 10 ) is made in one piece from a sheet metal layer. Heat shield according to one of the preceding claims, characterized in that a fastening means ( 5 ) in the passage opening ( 3 ) is arranged and with the decoupling element ( 10 ), in particular with the first element ( 11 ) of the decoupling element ( 10 ), positively and / or non-positively connected. Heat shield according to the preceding claim, characterized in that the fastening means ( 5 ) in the at least one passage opening ( 3 ) with respect to one, several or all degrees of freedom at least partially movable, but is arranged in a captive manner. Heat shield according to one of the preceding claims, characterized in that the fastening means ( 5 ) is a screw. Heat shield according to one of the preceding claims, characterized in that the captive arrangement by press fit of the fastening means ( 5 ) in the decoupling element ( 10 ) in the passage opening ( 3 ) is effected. Heat shield according to one of the preceding claims, characterized in that the fastening element ( 5 ) is a screw, wherein the screw head ( 7 ) on the decoupling element ( 10 ) by means of a, advantageously in the direction of the screw head ( 7 ) prestressed spring ( 25 ) is stored. Heat shield according to the preceding claim, characterized in that the spring ( 25 ) on the one hand form-fitting and / or cohesive with the screw head ( 7 ) and on the other hand positive locking and / or material fit with one of the sheet metal layers ( 2 ) and / or with the decoupling element ( 10 ) connected is. Heat shield according to one of the two preceding claims, characterized in that the shank diameter of the screw ( 4 ) in the area between threads ( 8th ) and head ( 7 ) is smaller than the inside width of the opening ( 20 ) of the decoupling element ( 10 ), and the thread diameter of the screw ( 5 ) is greater than the clear width of the opening ( 20 ) of the decoupling element ( 10 ). Heat shield according to one of the preceding claims, characterized in that at least two metallic sheet metal layers ( 2 ) a housing forming at least partially connected to each other at their edges, wherein the housing at least one passage opening ( 3 ) for receiving a fastener ( 5 ), wherein in at least one of the passage openings ( 3 ) one of the decoupling elements ( 10 ) is arranged. Heat shield according to the preceding claim, characterized in that the passage opening ( 3 ) is arranged in a region in which between the at least two sheet metal layers ( 2 ) of the housing no intermediate layer is arranged. Heat shield according to one of the preceding claims, characterized in that at least one element of one of the following element groups of at least one other element from the same group in length and / or width and / or course and / or at a distance from adjacent elements of the same group or one of the other groups, said element groups comprising: a) the group of substantially radially extending connecting elements ( 12 ) b) the group of holding elements ( 14 ) and c) the group of locking elements ( 16 ).

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