SILENT BLOCK

Abstract

The silent block comprises a pipe (2) around the circumference of which rubber (1) is arranged, a casing (4) being arranged on at least a substantial portion of the outer circumference of the rubber (1). The casing (4) is divided into at least two separate parts in the axial direction. On the contact surfaces between the casing (4) and rubber (1), at least one outer protrusion (5) is arranged on one of the contact surfaces that fits into at least one opposite outer recess (7) arranged in the other contact surface.

Claims

1. A silent block comprising: (a) a pipe comprising a circumference; (b) a rubber arranged around the circumference of the pipe, wherein the rubber comprises an outer circumference; (c) a casing arranged on at least a substantial portion of the outer circumference of the rubber, wherein the casing is divided into at least two separate parts in an axial direction; (d) contact surfaces between the casing and rubber comprising a first contact surface and a second contact surface; and (e) at least one outer protrusion arranged on the first contact surface that fits into at least one opposite outer recess arranged in the second contact surface.

2. The silent block according to claim 1, wherein the outer protrusion is arranged on the casing and the opposite outer recess is arranged in the rubber.

3. The silent block according to claim 1, wherein the outer protrusion is a circumferential protrusion and the opposite outer recess thereto is a circumferential recess.

4. The silent block according to claim 1, wherein the casing is made of flexible material.

5. The silent block according to claim 1, further comprising: (a) a tubular shaped part arranged between the rubber and the pipe, wherein the tubular shaped part is arranged all around the circumference of the pipe, (b) additional contact surfaces between the tubular shaped part and the rubber comprising a first additional contact surface and a second additional contact surface; and (c) at least one inner protrusion arranged on the first additional contact surface that fits into at least one opposite inner recess arranged in the second additional contact surface.

6. The silent block according to claim 5, wherein the inner protrusion is arranged on the tubular shaped part and the opposite inner recess is arranged in the rubber.

7. The silent block according to claim 5, wherein the inner protrusion is a circumferential protrusion and the opposite inner recess thereto is a circumferential recess.

8. The silent block according to claim 5, wherein the tubular shaped part is made of a sliding material.

9. The silent block according to claim 5, wherein the casing or the tubular shaped part comprises, at ends of the rubber, a shoulder extending towards the rubber.

10. The silent block according to claim 5, wherein the rubber is attached to one or more of the following: the tubular shaped part, the casing, and/or the pipe by vulcanization.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0029] The silent block according to this invention will be described in more detail with the use of examples of particular embodiments, schematically shown in the attached drawings.

[0030] FIG. 1 shows a sectional view of the arrangement of a silent block with a shaped part without rubber being attached to the casing and to the shaped part by vulcanization.

[0031] FIG. 2 shows a front view of the arrangement of the silent block of FIG. 1.

[0032] FIG. 3 shows a sectional view of the arrangement of a silent block with a shaped part with rubber attached to the shaped part by vulcanization.

[0033] FIG. 4 shows a sectional view of the arrangement of a silent block with a shaped part with rubber attached to the casing by vulcanization.

[0034] FIG. 5 is a sectional view of the arrangement of a silent block with a shaped part with rubber attached to the shaped part as well as to the casing by vulcanization.

[0035] FIG. 6 shows a sectional view of the arrangement of a silent block without a shaped part with rubber attached to the pipe by vulcanization.

EXAMPLES OF EMBODIMENTS OF THE INVENTION

[0036] The silent block according to the embodiment of FIG. 1 and FIG. 2 comprises a pipe 2 around the circumference of which a tubular shaped part 3 is arranged. Around the shaped part 3, a rubber 1 is circumferentially arranged and on the outer circumference of the rubber 1 a casing 4 is arranged.

[0037] On the contact surfaces between the casing 4 and rubber 1, on the casing 4, three outer protrusions 5 are arranged that fit into three opposite outer recesses 7 arranged in the rubber 1. On the contact surfaces between the shaped part 3 and rubber 1, protrusions and recesses are also arranged in such a way that two inner protrusions 6 are arranged on the shaped part 3 that fit into two opposite inner recesses 8 arranged in the rubber 1. The protrusions 5,6 and recesses 7,8 according to the embodiment of FIG. 1 are circumferential, i.e., they extend around the entire circumference of the parts they are formed on. The number, size, shape and positions of the protrusions 5,6 and recesses 7,8 are governed by the required axial and radial stiffness of the silent block and are based on the design calculation of the silent block. The protrusions 5,6 and recesses 7,8 according to the embodiment of FIG. 1 have a conical shape. A skilled person will also imagine other shapes fulfilling the required function of ensuring radial and axial stiffening of the silent block.

[0038] The shaped part 3 comprises at both its ends, after the ends of the rubber 1, a shoulder 9 that extends towards the rubber 1. The shoulder 9 according to the embodiment of FIG. 1 is circumferential. The purpose of the shoulder 9 is to ensure axial stiffness of the silent block. Without the shoulder 9, the rubber 1 would recede laterally outside the casing 4 under load and the silent block would be softer. Implementing the shoulder 9 as part of the shaped part 3 eliminates an additional production step of installation of separate spacer rings used in the prior art.

[0039] The pipe 2 is thrust into the shaped part 3. Rubber 1 is fitted onto the shaped part 3 in such a way that after vulcanization, rubber 1 is cut in the axial direction and fitted onto the shaped part 3. Instead of cutting of the rubber 1, a longitudinal joint may be produced in the cavity of the vulcanizing mould of rubber 1 to interrupt the rubber 1 during vulcanization already. The casing 4 is divided in the axial direction into two equally sized separate parts, as shown in FIG. 2. Both the halves of the casing 4 are fitted on the rubber 1. The casing 4 holds on the rubber 1 thanks to a bias between the geometry of the rubber 1 and casing 4, which is also supported by the play between the engaging outer protrusions 5 and outer recesses 7. In the completed state of the silent block, there is a gap between the ends of the rubber 1 and the shoulder 9. Both the halves of the casing 4 of the completed silent block are not in a tight mutual contact. The distance between the halves of the casing 4 enables biasing of the silent block on its thrusting into the working position, e.g. into the leaf spring lug. In the working position of the silent block, the play between the protrusions 5,6 and the recesses 7,8 and the gap between the ends of the rubber 1 and the shoulder 9 is filled with compressed rubber 1.

[0040] In the embodiment of FIG. 1, rubber 1 is attached by vulcanization neither to the shaped part 3, nor to the casing 4. Rubber 1 that is not attached by vulcanization to the casing 4 reduces stressing of the leaf spring lug or another element where the silent block is installed. Rubber 1 that is not attached to the shaped part 3 by vulcanization reduces torsional stress of rubber. The shaped part 3 with the rubber 1 acts as a bearing enabling slippage between individual parts of the silent block. Without the rubber 1 attached by vulcanization, the protrusions 5,6 and recesses 7,8 are also used to center the rubber with respect to the shaped part 3 and casing 4, otherwise the rubber 1 with the casing 4 might freely axially move on the pipe 2, which is not desirable.

[0041] The silent block according to this embodiment is completely dismountable and enables easy replacement of damaged components. Compared to existing designs, the silent block according to the invention is characterized by simpler production as, e.g., the processes of rubber vulcanization, thrusting of spacer rings onto the pipe etc. are eliminated. This is also associated with lower production costs. Compared to existing silent blocks, the inventive silent block has a lower weight.

[0042] The embodiment of silent block according to FIG. 3 differs from the embodiment of FIG. 1 in that the rubber 1 is attached to the shaped part 3 by vulcanization. The vulcanization attachment supports further enhancement of stiffness of the silent block.

[0043] The embodiment of silent block according to FIG. 4 differs from the embodiment of FIG. 1 in that the rubber 1 is attached to the casing 4 by vulcanization. The vulcanization attachment supports further enhancement of stiffness of the silent block.

[0044] The embodiment of silent block according to FIG. 5 differs from the embodiment of FIG. 1 in that the rubber 1 is attached both to the shaped part 3 and to the casing 4 by vulcanization. The vulcanization attachment supports further enhancement of stiffness of the silent block.

[0045] In the embodiment of FIG. 6, the silent block does not comprise the shaped part 3, and the rubber 1 is attached to the pipe 2 by vulcanization. On the contact surfaces between the casing 4 and rubber 1, on the casing 4, one outer protrusion 5 is arranged that fits into one opposite outer recess 7 arranged in the rubber 1. The outer protrusion 5, and the outer recess 7, are circumferential, i.e. they extend around the entire circumference of the parts they are formed on. The casing 4 comprises at both its ends, near the ends of the rubber 1, a shoulder 9 that extends towards the rubber 1. The shoulder 9 is circumferential. The purpose of the shoulder 9 is to ensure axial stiffness of the silent block. Without the shoulder 9, the rubber 1 would recede laterally outside the casing 4 under load and the silent block would be softer. The implementation of the shoulder 9 as part of the casing 4 eliminates additional production step of fitting the end of the casing 4 with a rim and bending it towards the rubber 1.

LIST OF REFERENCE MARKS

[0046] 1 rubber [0047] 2 pipe [0048] 3 shaped part [0049] 4 casing [0050] 5 outer protrusion [0051] 6 inner protrusion [0052] 7 outer recess [0053] 8 inner recess [0054] 9 shoulder