JP3265810B2 - Liquid-filled bush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled bush used for, for example, an automobile suspension system.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional liquid-filled bush. This liquid-filled bush is composed of a spindle metal fitting 71, an outer cylinder metal fitting 72 disposed coaxially outside the main spindle metal fitting 71, and interposed between the outer cylinder metal fitting 72 and the main spindle metal fitting 71 to form an integral body. And a rubber elastic body 74 having a pair of liquid chambers 73, 73 formed on both sides in the radial direction with the spindle metal fitting 71 interposed therebetween, and protrudes into each of the liquid chambers 73, 73 from the center of the outer peripheral surface of the spindle metal fitting 71, A stopper 76 having an orifice passage 75 communicating the two liquid chambers 73, 73 and a liquid 77 sealed in the two liquid chambers 73, 73 and the orifice passage 75 are provided. The rubber elastic body 74 has a pair of annular side walls (not shown) that define both axial end surfaces of the two liquid chambers 73, 73 and a pair of arm-shaped sections that define the circumferential direction of each of the liquid chambers 73, 73. Arm-shaped partition wall 7 having partition walls 78, 78;
Numerals 8 and 78 have both ends in the axial direction connected to the annular side wall, and both sides in the radial direction are connected to the outer cylinder fitting 72 and the stopper 76 to seal both the liquid chambers 73 and 73 in a liquid-tight manner.

[0003] This liquid-filled bush is provided with an outer cylinder fitting 72.
Is press-fitted and fixed in the fitting hole of the mounting member on the wheel side, and the spindle metal fitting 71 is fixed to the supporting member on the vehicle body side for use, and the vibration acting between the spindle metal fitting 71 and the outer cylindrical metal fitting 72 is provided. The elastic action of the rubber elastic body 74 and the orifice passage 7
5 is effectively attenuated by the liquid column resonance action of the liquid 77 flowing.

[0004]

However, when a large input in the torsion direction acts between the spindle metal fitting 71 and the outer cylindrical metal fitting 72 when the liquid-filled bush is used, as shown in FIG. Large distortion occurs in the arm-shaped partition portions 78, 78 extending in the radial direction of the elastic body 74. In particular,
Since a large distortion is likely to occur in the portion A connected to the stopper 76 on the radially inner side of the arm-shaped partition walls 78, 78, a crack is generated by a large input in the torsional direction acting on this portion A repeatedly. Or even progress to fracture. When the cracks or breaks occur in the arm-shaped partition portions 73, 73 in this manner, the two liquid chambers 73, 73 communicate with each other at that portion, and the liquid 77 sealed in the two liquid chambers 73, 73 flows through the orifice passage 75. The vibration damping effect obtained by flowing cannot be obtained.

The present invention has been devised in view of the above problems, and provides a liquid-filled bush that can improve durability by preventing cracks and breaks from occurring in arm-shaped partition walls of a rubber elastic body. This is an issue to be solved.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a spindle metal fitting, an outer cylindrical metal fitting coaxially disposed outside the main spindle metal fitting, and an outer cylindrical metal fitting and the main spindle metal fitting. A rubber elastic body having a plurality of liquid chambers formed on both sides in the radial direction with the main shaft bracket interposed therebetween and having a plurality of liquid chambers communicating with each other via orifice passages, In a liquid-filled bush provided with a liquid sealed in an orifice passage, the rubber elastic body includes a pair of annular side walls that define both axial end surfaces of each of the liquid chambers, and both ends of the annular side wall. A plurality of arm-shaped partition portions which are connected and extend in the axial direction from the outer cylinder fitting side, and whose leading end portions are pressed against the outer peripheral surface of the main spindle fitting side to partition the circumferential direction of each of the liquid chambers, It is characterized by having.

In a preferred embodiment of the present invention, the distal end of the arm-shaped partition wall of the rubber elastic body can be formed in a substantially wedge shape that becomes thinner toward the distal end.

[0008]

According to the liquid-filled bush of the present invention, when a large input in the torsion direction acts between the spindle metal fitting and the outer cylindrical metal fitting,
A radially inward end portion of the arm-shaped partition wall portion of the rubber elastic body and an outer peripheral surface of the main shaft fitting side to which this is pressed are slid in a twisting direction. As a result, large distortion does not occur in the arm-shaped partition portion, and cracks and breaks can be avoided. Therefore, the durability is improved. Further, when a small input acts in the torsional direction, the distal end of the arm-shaped partition wall is hardly slid, and is elastically deformed to absorb the relative displacement between the main shaft and the outer cylinder.

If the distal end of the arm-shaped partition wall is formed in a substantially wedge shape that becomes thinner toward the distal end, the same portion of the distal end is securely pressed against the pressure-contact surface on the other side, and is formed in the torsional direction. It follows the displacement in a state where it is securely pressed. Thereby, the sealing property between the two liquid chambers is improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view in the direction perpendicular to the axis of the liquid-filled bush of the present embodiment, FIG. 2 is a cross-sectional view in the direction perpendicular to the axis showing a state before the outer cylinder fitting is mounted, and FIG. FIG. 3 is a cross-sectional view of a part corresponding to line III-III in FIG. 2 showing a state before mounting.

The liquid-filled bush according to the present embodiment is provided with a spindle metal fitting 1, an intermediate cylindrical metal fitting 2 disposed coaxially outside the main spindle metal fitting 1, and an intervening member between the intermediate cylindrical metal fitting 2 and the main spindle metal fitting 1. A rubber elastic body 3 having a pair of liquid chambers 31, 31 formed on both sides in the radial direction with the spindle metal fitting 1 therebetween and communicating with each other via an orifice passage 51; And a relative displacement between the main shaft 1 and the outer cylinder 2 in the direction perpendicular to the axis, the outer cylinder 4 being coaxially disposed outside the cylinder and forming the liquid chambers 31 with the rubber elastic body 3. And a liquid 6 sealed in each of the liquid chambers 31, 31 and the orifice passage 51 as main components.

The spindle fitting 1 is formed in a pipe shape from metal. The intermediate cylindrical member 2 is formed in a pair with the pair of ring portions 21 and 21 (see FIG. 3) located at both ends in the axial direction, and is bridged between the two ring portions 21 and 21 and arranged in the circumferential direction together with the two ring portions 21 and 21. Two bridging portions 2 that partition two windows
2, 22 and are integrally formed of metal.

The rubber elastic body 3 is vulcanized and bonded between the inner peripheral surface of the intermediate cylindrical metal fitting 2 and the outer peripheral surface of the spindle metal fitting 1, and integrally connects the two. This rubber elastic body 3 is used for the intermediate cylindrical fitting 2.
A pair of annular side walls 32, 32 (see FIGS. 2 and 3) formed at both ends in the axial direction corresponding to the respective ring portions 21, 21 and defining both end surfaces of the liquid chambers 31, 31; 22,
A pair of arm-shaped partition portions 3 formed between the annular side wall portions 31 corresponding to 22 and defining the circumferential direction of the liquid chambers 31.
3 and 33, and a bottom wall 34 that forms the bottom of both liquid chambers 31 and 31. An arm-shaped partition 33 that characterizes the present invention;
33 has both ends connected to the annular side wall portions 32, 32 and extends in the axial direction from the outer side, and the wedge-shaped tips 33a, 33a which are thinner toward the tips have the spindle fittings 1 and 33. The bottom wall portion 34 that covers the stopper 5 is pressed against the outer peripheral surface.

The outer tube fitting 4 is formed of a metal into a cylindrical shape, and a seal rubber layer 41 for closing the outer peripheral sides of the two liquid chambers 31 is vulcanized and bonded to the inner peripheral surface thereof. The outer cylinder 4 is formed by integrally vulcanizing the main shaft 1, the intermediate cylinder 2, the rubber elastic body 3, and the stopper 5 as shown in FIGS. 2 and 3. It is mounted by applying drawing processing to the outside. Thereby, the tip portions 33a, 33a of the arm-shaped partition portions 33, 33 are pressed against the outer peripheral surface of the bottom wall portion 34 during the drawing process.

The stopper 5 has a central hole, and its outer peripheral shape is formed in a substantially oval shape. The stopper 5 is fitted to the central portion of the outer peripheral surface of the spindle metal fitting 1 via the central hole. Both ends of the stopper 5 in the longitudinal direction protrude into the respective liquid chambers 31, and the front end surface thereof forms a predetermined gap with the seal rubber layer 41 of the outer cylinder 4. An orifice passage 51 is formed in the stopper 5 from one of the two ends to the other through the inner periphery of the central hole. Through the orifice passage 51, the two liquid chambers 31, 31 are formed. Communicating. Note that the bottom wall portion 34 of the rubber elastic body 3 covers a portion except for the opening of the orifice passage 51.

Each liquid chamber 31, 31 and orifice passage 51
Inside, a liquid 6 made of an incompressible fluid such as water, alkylene glycol, or silicone oil is sealed. The liquid-filled bush of the present embodiment configured as described above is
When a large input in the torsional direction acts between the main shaft 1 and the outer tube 4, the distal end portions 33 a, 33 a of the arm-shaped partition portions 33, 33 of the rubber elastic body 3 and the bottom wall 3, which is pressed against the same.
The outer peripheral surface of the main body 4 slides in the torsion direction to absorb the relative displacement between the main shaft 1 and the outer tube 4. Thereby, large distortion does not occur in the arm-shaped partition walls 33, 33, and cracks and breaks can be avoided. Therefore, the durability is improved.
When the tip portions 33a, 33a of the arm-shaped partition portions 33, 33 slide, the wedge-shaped tip portions 33a, 33a,
3a follows the displacement in the torsional direction in a state in which it is securely pressed against the bottom wall portion 34, and the sealing property between the two liquid chambers 31, 31 is ensured.

When a small input acts in the torsional direction, the tip portions 33a, 33a of the arm-shaped partition portions 33, 33
Absorbs relative displacement between the main shaft 1 and the outer tube 4 by being elastically deformed with little sliding. As described above, the liquid-filled bush according to the present embodiment is configured such that the tip portions 33a, 33a of the arm-shaped partition portions 33, 33 of the rubber elastic body 3 are provided.
Is pressed against the outer peripheral surface of the bottom wall portion 34, so that even if a large input in the torsional direction acts between the spindle metal fitting 1 and the outer cylindrical metal fitting 4, a large distortion does not occur in the arm-shaped partition walls 33, 33. Therefore, it is possible to avoid the occurrence of cracks or breaks in the arm-shaped partition walls 33, 33, and to improve the durability.

Further, the distal end portion 33 of the arm-shaped partition walls 33, 33
Since a and 33a are formed in a wedge shape that becomes thinner toward the front end, the press contact between the front end portions 33a and 33a is ensured, and the sealing performance between the two liquid chambers 31 and 31 can be improved. The liquid-filled bush of the above embodiment has two liquid chambers 3 defined by a pair of arm-shaped partition walls 33, 33.
The present invention can be applied to a liquid-filled bush of a type having three or more arm-shaped partition walls and three or more liquid chambers.

In the liquid-filled bush of the above embodiment, the orifice passage 51 is formed in the stopper 5, but as shown in FIG.
An orifice passage 51a can be formed outside 2a, 22a. In this case, it is advantageous to form an orifice passage longer than that formed in the stopper 5a. Note that, as in a liquid-filled bush shown in FIG. 4, the distal ends 33a, 33a of the arm-shaped partition walls 33, 33 may be directly pressed against the planar side surface of the stopper 5a.

[0020]

According to the liquid-filled bush of the present invention,
The arm-shaped wall portion of the rubber elastic body is configured such that both ends are connected to the annular side wall portion and extend in the axial direction from the outer cylinder fitting side, and its tip is pressed against the outer peripheral surface of the main spindle fitting side. Therefore, even if a large input in the torsion direction acts between the spindle metal fitting and the outer cylindrical metal fitting, the tip of the arm-shaped bulkhead slides, and no large distortion occurs. Can be avoided, thereby improving the durability.

Further, by forming the distal end of the arm-shaped partition wall into a substantially wedge-like shape that becomes thinner toward the distal end, it is possible to more reliably press the distal end and to improve the sealing property between the two liquid chambers. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view in a direction perpendicular to an axis of a liquid-filled bush according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view in a direction perpendicular to the axis, showing a state before the outer metal fitting is mounted on the liquid-filled bush according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a portion corresponding to line III-III in FIG. 2 showing a state before the outer metal fitting is attached to the liquid-filled bush according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view in a direction perpendicular to the axis of a liquid-filled bush according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view in a direction perpendicular to an axis of a conventional liquid-filled bush.

FIG. 6 is an explanatory view showing a deformed state when an input in a torsional direction acts on a conventional liquid-filled bush.

[Description of Signs] 1 ... Spindle bracket 2 ... Intermediate cylinder bracket 3 ... Rubber elastic body
DESCRIPTION OF SYMBOLS 4 ... Outer cylinder fitting 5 ... Stopper 6 ... Liquid 31 ... Liquid chamber 32 ... Annular side wall part 33 ... Arm-shaped partition part 33a ... Tip part 51 ... Orifice passage

Claims (2)

(57) [Claims] 1. A spindle metal fitting, an outer cylinder metal arranged coaxially outside the main shaft metal fitting, interposed between the outer cylinder metal fitting and the main shaft metal fitting, and integrally connected to each other; A rubber elastic body having a plurality of liquid chambers formed on both sides in the radial direction with the main spindle metal being interposed therebetween and communicating with each other via an orifice passage; and a liquid sealed in each of the liquid chambers and the orifice passage. In the liquid-filled bush, the rubber elastic body has a pair of annular side walls that define both axial end surfaces of each of the liquid chambers, and both ends are connected to the annular side walls and the axial center from the outer cylinder fitting side. A plurality of arm-shaped partition portions extending in a direction and having a leading end portion thereof pressed against an outer peripheral surface on the side of the spindle metal fitting to partition a circumferential direction of each of the liquid chambers. 2. The liquid-filled bush according to claim 1, wherein the distal end portion of the arm-shaped partition wall portion is formed in a substantially wedge shape that becomes thinner toward the distal end.