GB2171774A

GB2171774A - A sound-insulating mounting

Info

Publication number: GB2171774A
Application number: GB08604752A
Authority: GB
Inventors: Otto Weber; Volkmar Keck; Hubert Pletsch; Siegfried Grohnert
Original assignee: Wolf Woco & Co Franz J; Woco Franz Josef Wolf and Co GmbH; Volkswagen AG
Current assignee: Wolf Woco & Co Franz J; Woco Franz Josef Wolf and Co GmbH; Volkswagen AG
Priority date: 1985-02-27
Filing date: 1986-02-26
Publication date: 1986-09-03
Also published as: FR2577989A1; EP0192936B1; DE3506977C2; GB8604752D0; FR2577989B1; ES297029Y; JPS61211542A; GB2171774B; ATE39736T1; ES297029U; IT8619541A0; JPH0676815B2; EP0192936A3; IT1189999B; EP0192936A2; DE3661648D1; DE3506977A1; IT8619541A1

Abstract

A sound-insulating mounting, in particular for an internal combustion engine, and having an approximately S-shaped characteristic curve, comprises two metal dishes (6,7) whose openings face one another and which serve to introduce the opposing forces, and whose outwardly-bent edges (4,5) enclose between them a part (8) of a moulded body (13) made of elastomeric material to form an elastic stop. A metal ring (11) having an approximately C-shaped cross-section is fastened to one of the metal dishes (6) and projects behind the outwardly-bent edge (5) of the other metal dish (7) and encloses another part (12) of the moulded body (13) made of elastomeric material to form an elastic stop acting in the opposite direction. Between metal plates (1,3) forming the dishes (6,7) there is located a spring block (9) made of relatively soft elastomeric material containing channels or bores (16). <IMAGE>

Description

SPECIFICATION A sound-insulating mounting The invention relates to a sound-insulating mounting particularly for use with internal combustion engines. This type of mounting is known in the form of an oblique mounting from German Offenlegungsschrift No.

2149421, B60K 5/12, in which disclosure the metal plates have angled pieces on one side which are perpendicular to the main loading direction, a moulded body made of elastomer material being disposed between such pieces, and the spacing of the pieces co-operating with the moulded body to limit the spring compression. The angle piece adjacent to the spring block, which is made from an elastomer material such as rubber, is opposite the profiled edge of the spring block and is normally spaced therefrom, which spacing is obviated during compression by forces acting in a different direction, so that the profiled edge of the spring block is urged into abutment against the angled piece.

The present invention seeks to provide an axial mounting, which offers the advantage of overcoming sealing problems when using gas or fluid springs, which has an S-shaped characteristic curve (force-spring displacement graph) and whose design permits simplified manufacture.

According to the present invention, a sound-insulating mounting comprising a spring block of elastomeric material located between two force-directing metal plates provided with mutually opposed angled pieces enclosed by a moulded body also made of elastomeric material for limiting spring travel, is characterised in that, to form an axial mounting, the metal plates are formed as metal dishes accommodating the spring block by the addition of angled pieces, whose outwardly angled edges, perpendicular to the common axis of the metal dishes enclose between them one part of the moulded body, that a ring, having an approximately C-shaped cross-section, which is carried by one of the metal dishes projects behind the angled edge of the other metal dish and encloses a further part of the moulded body of elastomeric material, and that the spring block is made of soft elastomeric material provided with channels or bores.

As a result of the use of a spring body made of an elastomeric material, such as rubber and having channels or bores moulded in it, the invention has a high degree of acoustic insulation even in the low-frequency range of oscillation. The moulded body can be made of very soft elastomeric material (20 to 40 Shore). It can easily be designed, by the inclusion of one or more suitably shaped discs in one of the dishes, so that the operative point or operative range in the above-mentioned characteristic curve is dependent on the initial load or static load.

The invention will now be further described hereinafter by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sectional view through the mounting, and Figure 2 shows the characteristic curve of the mounting.

The internal combustion engine (not shown) of a motor vehicle rests, for example, by way of projections, on a metal plate 1 which is opposite another metal plate 3 connected to the body 2 of the motor vehicle. These metal plates 1 and 3 are formed into shaped dishes 6 and 7 having wali regions and out-turned edges 4 and 5, which are mutually opposed at a predetermined clearance and which surround one part 8 of a moulded body 13 made of elastomeric material. Between the metal plates 1 and 3, which form the basis of the shaped dishes 6 and 7, there is an approximately barrel-shaped spring block 9 made of a relatively soft elastomeric material such as rubber.

The angled out-turned edges 4 and 5 and the moulded body 8 together form elastic stops which become effective on compression.

Outwardly bent projections 10 secure a ring 11 having an approximately C-shaped crosssection to the dish 6, which ring 11 projects behind the angled out-turned edge 5 on the other dish 7 and encloses another part 12 of the moulded body 13 made of elastomeric material. The two moulded parts 8 and 12 form areas of the annular moulded body 13 which is provided with a radial recess 14 for accommodating the angled out-turned edge 5.

The recess 14 is of a size to permit free clearances on both sides of the edge 5 (as shown), except when it is in a compressed or expanded state, so that only the spring block 9 is effective within a predetermined operative range. The moulded part or component 12 of the body 13, the lower region 15 of the ring 11, and the angled edge 5 together form an elastic stop which becomes effective on expansion.

The spring block 9 is provided with transverse channels or bores 16; internal oscillations of the walls between the channels transforming sound energy into heat and interrupting the spread of flexural waves by multiple reflection.

At least one disc 17, in dish 7 and beneath block 9, serves to adjust the working area of the mounting in dependence upon the static load.

In the graph of the relationship of the spring travel s to the applied force P shown in Fig.

2, an initial load of A=80 kp is assumed.

This corresponds to a spring compression of 28 mm. In the case of relatively small changes in force in both directions, the mounting acts in a very soft manner, as indicated by the regions a which are defined by the abovementioned free clearances on either side of the edge 5. It can be said to have free movement or play. In the event of greater alterations in force, however, hardening very rapidly occurs as a result of compression of the elastomeric moulded parts 8 and 12 of body 13, so that the mounting becomes very stiff. The result as shown in the graph of Fig. 2, is a characteristic curve approximately in the form of an inverted S tilted at an angle of 90".

Claims

1. A sound-insulating mounting comprising a spring block of elastomeric material located between two force-directing metal plates provided with mutually opposed angled pieces enclosed by a moulded body also made of elastomeric material for limiting spring travel, characterised in that, to form an axial mounting, the metal plates are formed as metal dishes accommodating the spring block by the addition of angled pieces, whose outwardly angled edges, perpendicular to the common axis of the metal dishes enclose between them one part of the moulded body, that a ring, having an approximately C-shaped crosssection, which is carried by one of the metal dishes projects behind the angled edge of the other metal dish and encloses a further part of the moulded body of elastomeric material, and that the spring block is made of soft elastomeric material provided with channels or bores.

2. A mounting as claimed in claim 1, characterised in that the two parts of the moulded body are formed in one piece with a radial recess to accommodate the angled edge of said other metal dish.

3. A mounting as claimed in claim 1 or 2, characterised in that at least one disc is inserted in at least one of the metal dishes to set the operative range of the characteristic curve of the mounting.

4. A sound-insulating mounting substantially as herein described with reference to and as illustrated in the accompanying drawings.