Spring devices – Resilient shock or vibration absorber – Nonmetallic – resilient element
Reexamination Certificate
2000-05-03
2002-05-07
Schwartz, Christopher P. (Department: 3613)
Spring devices
Resilient shock or vibration absorber
Nonmetallic, resilient element
C267S140120, C267S293000
Reexamination Certificate
active
06382605
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a vibration preventing apparatus suitably used as an engine mount or a bushing in a vehicle etc., for example.
2. Discussion of the Related Art
Conventionally, when an engine unit to be installed to a vehicle is mounted onto a vehicle body, it is supported in a vibration prevented state via a vibration preventing apparatus such as an engine mount etc. Thus, the vibration preventing apparatus reduces or damps transmission of the vibration generated by the engine unit to the vehicle body. One example of the engine mount is shown in
FIGS. 4 and 5
.
This engine mount is comprised of an inner member
5
formed into a pipe shape, a rubber elastic body
6
including a body portion
61
and a pair of stopper portions
62
,
62
, an mounting member
7
including a tubular portion
71
, and an elastic stopper
8
.
In detail, the tubular body portion
61
of the rubber elastic body
6
is fixed to an outer peripheral surface of the inner member
5
integral therewith and having two cavities
63
,
64
penetrating the body portion
61
axially, and the paired stopper portions
62
,
62
are protruded radially outwardly and extended circumferentially from both axial ends of the body portion
61
. The tubular portion
71
of the resin mounting member
7
is formed on an outer peripheral surface of the body portion
61
of the rubber elastic body
6
by an inject-forming (molding), and is adhered at each of end surfaces thereof to each of inner end surfaces of the stopper portions
62
,
62
. The elastic stopper
8
is fixed on an inner peripheral surface of the tubular portion
71
of the mounting member
7
and positioned in a cavity
63
to oppose to the inner member
5
.
This engine mount is normally produced as explained below. In the first embodiment, the rubber elastic body
6
and the elastic stopper
8
are vulcanized and formed together with the inner member
5
, and an adhering process is performed at a predetermined portion of a vulcanizedly formed body. Then, the vulcanizedly formed body is disposed in a resin forming mold for molding the mounting member
7
, and a resin material is inject-molded onto an outer peripheral surface of the body portion
61
of the rubber elastic body
6
to form the mounting member
7
. Thus, the mounting member
7
including the tubular body
71
is formed. Here, an inner peripheral surface of the tubular body
71
is adhered to the outer peripheral surfaces of the body portion
61
of the rubber elastic body
6
and the elastic stopper
8
, and both end surfaces of the tubular portion
71
are adhered to inner side surfaces of the stopper portions
62
,
62
. In this way, the engine mount shown in
FIGS. 4 and 5
is produced.
The engine mount thus produced is fixed at one of the inner member
5
and the mounting member
7
to the engine unit and is fixed at the other of them to the vehicle body for use so that the elastic stopper
8
positions in a main vibration inputting direction directed in the radial direction.
When the vibration is inputted from the engine unit to the engine mount, the body portion
61
of the rubber elastic body
6
disposed between the inner member
5
and the tubular portion
71
of the mounting member
7
elastically deforms to damp the vibration effectively. Here, in the case where the large vibration is inputted to the engine mount in the radial direction, the elastic stopper
8
regulates an excessive relative radial shift between the inner member
5
and the mounting member
7
. On the other hand, in the case where the large vibration is inputted to the engine mount in the axial direction, the stopper portions
62
,
62
disposed between end surfaces of the tubular portion
71
and a mating members (not shown) elastically attenuates a collision therebetween, so that excessive relative axial shift between the inner member
5
and the mounting member
7
is regulated. In this way, the satisfactory durability of the rubber elastic body
6
is secured by the excessive deformation prevention of the body portion
61
.
By the way, in the conventional engine mount, each of the paired stopper portions
62
,
62
provided at both axial ends of the rubber elastic body
6
has a small thickness in the axial direction, and therefore is unstable so as to easily fall down in the axial direction in the stage where the rubber elastic body
6
and the elastic stopper
8
are vulcanizedly formed together with the inner member
5
. Accordingly, when the rubber elastic body
6
and the elastic stopper
8
are set in the resin forming mold and form the mounting member
7
by inject-molding, the stopper portions
62
,
62
set in the resin forming mold may fall down. If such fall-down of the stopper portions
62
,
62
occurs, a problem may be caused, i.e. the end surfaces of the forming tubular portion
71
and the stopper portions
62
,
62
will not be adhered together in the desired condition. Especially, when a pour-in pressure of the resin forming material in the inject-molding step is insufficient, a bad adhesion between the end surfaces of the tubular portion
71
and the stopper portions
62
,
62
becomes remarkable.
In view of the above, as one means for preventing the bad adhesion, a resin pour-in port of the resin forming mold for performing the inject-molding of the mounting member
7
is disposed between the both stopper portions
62
,
62
to generate an outward resin flow. Such resin flows may press the stopper portions
62
,
62
onto an inner surface of the resin forming mold. However, by taking strength of the forming mounting member
7
into consideration, the resin pour-in port is selected at the position so that a weld portion of the mounting member
7
having the weakest strength (position where the poured in and flowing resin circumferentially joins) corresponds to the part of the engine mount to which the smallest vibration is inputted. That is, the resin pour-in port is selected so that the weld portion is shifted from the main vibration inputting direction in the circumferential direction. For this reason, if the resin pour-in port is disposed between the both stopper portions
62
,
62
, there may arise problems that position of the stopper portions
62
,
62
is restricted, or circumferential length of the stopper portions
62
,
62
is unnecessarily elongated.
On the other hand, the axial dimension (thickness) of each of the stopper portions
62
,
62
can be increased to secure stability of the stopper portions
62
,
62
. However, when thickness of each of the stopper portions
62
,
62
is increased outwardly, axial distance between the outer side surface of the stopper portion
62
and the mating member is decreased by a part or mount corresponding the increased part or mount of the stopper portion
62
. As s result, abutment between each of the stopper portions
62
,
62
and the mating member occurs earlier when the large axial vibration is inputted into the engine amount, which deteriorates the riding feeling of the passenger.
Also, when thickness of each of the stopper portions
62
,
62
is increased inwardly, an axial length of the tubular portion
71
is decreased corresponding to the thickness increase of the stopper portions
62
. As a result, not only the strength decrease of the tubular portion
71
is introduced but the durability deterioration of the rubber elastic body
6
due to increase of the relative radial shifted amount between the inner member
5
and the mounting member
7
is caused.
SUMMARY OF THE INVENTION
The present invention is made in view of the above circumstances, and has the subject matter to provide a vibration preventing apparatus having a structure in which influences to stopping function of the stopper portion and to strength of the tubular portion etc. are small, and which is convenient to secure stability of the stopper portion in forming the mounting member by the inject-forming, in an allowable mounting space.
In order to overcome subject matter, the vibration preventing apparatus of th
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Schwartz Christopher P.
Sy Mariano
Tokai Rubber Industries Ltd.
LandOfFree
Vibration preventing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vibration preventing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vibration preventing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2903620