U.S. patent application number 09/800686 was filed with the patent office on 2001-11-01 for damping valve.
This patent application is currently assigned to Mannesmann Sachs AG. Invention is credited to Moller, Robert.
Application Number | 20010035212 09/800686 |
Document ID | / |
Family ID | 7633892 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010035212 |
Kind Code |
A1 |
Moller, Robert |
November 1, 2001 |
Damping valve
Abstract
A damping valve comprising a one-piece damping-valve body with
axial through-passages for each direction of flow, at least one
side of the damping-valve body having arranged on it at least one
valve disk that at least partially covers an outlet opening of a
through-passage, the damping-valve body having a radial inflow
opening to the through-passages. The outlet openings of the
through-passages for a first direction of flow on one side of the
damping-valve body have a trapezoidal cross section, and the outlet
openings of the through-passages for a second direction of flow on
the other side of the damping-valve body open into a common
encircling annular channel. The through-passages with outlet
openings with the trapezoidal cross section are arranged on a
larger pitch circle than the through-passages that open into the
annular channel.
Inventors: |
Moller, Robert; (Aidhausen,
DE) |
Correspondence
Address: |
COHEN, PONTANI, LIEBERMAN & PAVANE
551 Fifth Avenue, Suite 1210
New York
NY
10176
US
|
Assignee: |
Mannesmann Sachs AG
|
Family ID: |
7633892 |
Appl. No.: |
09/800686 |
Filed: |
March 7, 2001 |
Current U.S.
Class: |
137/493.8 ;
137/493.9; 188/282.5 |
Current CPC
Class: |
Y10T 137/7779 20150401;
Y10T 137/778 20150401; F16F 9/348 20130101; F16F 9/3214 20130101;
Y10T 137/789 20150401 |
Class at
Publication: |
137/493.8 ;
137/493.9; 188/282.5 |
International
Class: |
F16K 017/26; F16F
009/348 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 8, 2000 |
DE |
100 11 168.8 |
Claims
I claim:
1. A damping valve comprising a damping valve body having opposed
first and second sides, and a valve disk on one of said sides, said
damping valve body comprising a plurality of first axial through
passages for flow in a first direction between said opposed sides,
each of said first though passages lying on a circle having a first
pitch and having an outlet opening on one of said sides and an
inflow opening on the other of said sides, said outlet openings
each having a trapezoidal cross section, said outlet openings being
at least partially covered by said valve disk, and plurality of
second axial through passages for flow in a second direction
between said opposed sides, said second direction being opposite to
said first direction, each of said second through passages lying on
a circle having a second pitch which is smaller than the first
pitch and having a radial inflow opening on said one of said sides
and an outlet opening on the other of said sides, each of said
outlet openings of the second through passages opening into an
annular channel in the other of said sides.
2. The damping valve of claim 1 further comprising an annular
channel in said one of said sides, said annular channel in said one
of said sides connecting said inflow openings of said second
through passages.
3. The damping valve as claimed in claim 2 further comprising a
ridge encircling each of said outlet openings of each said first
through passages, each said ridge having a portion bounding said
annular channel in said one of said sides.
4. The damping valve as claimed in claim 1 wherein each of said
inflow openings of said second through passages comprises a funnel
shaped portion on said second pitch circle and a radial portion
extending radially outward from said funnel shaped portion, said
radial portions lying between said outlet openings of said first
through passages on said first pitch circle.
5. The damping valve as claimed in claim 3 wherein each of said
radial inflow openings of said second through passages comprises a
funnel shaped portion on said second pitch circle and a radial
portion extending radially outward from said funnel shaped portion,
said radial portions lying between said outlet openings of said
first through passages on said first pitch circle, each said ridge
having a portion which frames an arc segment of one of said funnel
shaped portions.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a damping valve of the type having
a one piece damping valve body with axial through passages for each
direction of flow, a valve disk which at least partially covers
outlet openings of through passages on at least one of said sides,
and radial inflow openings for through passages.
[0003] 2. Description of the Related Art
[0004] In the case of a damping valve in a piston-cylinder unit,
especially a vibration damper, the aim is to make the
through-passages or at least the cross sections at the outlet
openings as large as possible. The installation space available for
the through-passages in the damping-valve body of the damping valve
is very limited. This has led to complex solutions that can often
only be implemented by sintering if multi-component damping-valve
bodies are used.
[0005] U.S. Pat. No. 5,259,294 discloses a sintered piston having
two interengaging halves that together define the through-passages.
With damping-valve bodies of this kind, there is, on the one hand,
a need for complex sintering dies and, on the other hand, there is
always the possibility that the damping-valve body will leak
between the contact faces of the two halves of the piston. The
complex form of the sintering dies is due to the fact that the
through-passages have oblique sections.
[0006] An alternative to the oblique through-passages is known from
DE 43 43 614 A1. The axially extending through-passages have a
radial inflow opening. A significant disadvantage of this damping
valve is that the inflow openings have to be machined into the
damping-valve body. In this context, attention is also drawn to DE
196 21 639 A1.
[0007] Another possibility for creating large through-passages in a
damping valve is known from DE 27 51 046 A1. The damping valve
comprises two piston halves with through-passages for two
directions of flow. Arranged on a radially outer pitch circle are
axially extending inflow passages, the ends of which are connected
to a common nonreturn valve. The nonreturn valve opens a transverse
passage that leads to the through-passages with the outlet
openings.
[0008] DE 40 33 186 A1 describes a restriction device with a bypass
circuit dependent on the direction of motion that has axially
extending through-passages in conjunction with radial inflow
openings. Among the disadvantages of this restriction device is
that measures have to be provided to prevent the valve disks
sticking on the piston surface, e.g. by roughening the piston
surface in the region of the valve disks. The through-passages or
at least the outlet openings are furthermore kept relatively small,
as a result of which the damping forces of the restriction device
are relatively large.
SUMMARY OF THE INVENTION
[0009] It is the object of the present invention to obtain a
damping valve that has a onepiece damping-valve body that requires
little mechanical finish machining, if any, and has all possible
fittings as regards its valve disks.
[0010] According to the invention, the outlet openings of the
through-passages for a first direction of flow on one side of the
damping-valve body have a trapezoidal cross section, and the outlet
openings of the through-passages for a second direction of flow on
the other side of the damping-valve body open into a common
encircling annular channel. The through-passages with outlet
openings with the trapezoidal cross section are arranged on a
larger pitch circle than the through-passages that open into the
annular passage.
[0011] The advantage of the new damping valve lies, on the one
hand, in its simple damping-valve body and, on the other hand, in
the large areas subjected to pressure on the valve disks. On the
one hand, the sum of the trapezoidal cross sections should be
regarded as one area subjected to pressure. The annular channel
forms the area subjected to pressure for the valve disk for the
other direction of flow. The larger pitch circle for the outlet
openings of trapezoidal cross section represents a larger lever arm
for the pressure acting on the valve disk. The annular passage
acting in its entirety as an area subjected to pressure can
therefore be made radially further inward and nevertheless produce
the desired low damping force.
[0012] In order to minimize the area of contact for the valve disk
for the first direction of flow and hence prevent sticking of the
valve disk, the radial inflow openings are connected by an
encircling channel at their radially inner ends.
[0013] In a further advantageous refinement, the outlet openings of
trapezoidal cross section are framed by an encircling ridge, one
portion of the encircling ridge bounding the encircling channel.
The ridge forms support surfaces for the valve disk for the first
direction of flow.
[0014] To achieve as large as possible a cross section for the
damping medium flowing into the damping valve, the radial inflow
openings are arranged between the outlet openings of trapezoidal
cross section, an adjoining portion of the through-passage being
embodied as a funnel. The funnel is a shape that is easy to form
and allows advantageous deflection of the damping medium from the
radial inflow opening into the axial through-passage.
[0015] According to another advantageous embodiment, the funnel of
the throughpassage is framed over an arc segment by the encircling
ridge of the outlet opening of trapezoidal cross section. The aim
of this measure is to achieve as large as possible a funnel
opening. For this purpose, it is advisable for the funnel to extend
right up to the trapezoidal outlet openings arranged in the
circumferential direction and to cancel out the pure trapezoidal
shape at said arc segment.
[0016] Other objects and features of the present invention will
become apparent from the following detailed description considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for
purposes of illustration and not as a definition of the limits of
the invention, for which reference should be made to the appended
claims. It should be further understood that the drawings are not
necessarily drawn to scale and that, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows a damping-valve body of the damping valve in
plan view,
[0018] FIG. 2 shows a damping-valve body in accordance with section
A-A,
[0019] FIG. 3 shows a damping-valve body in accordance with section
B-B, and
[0020] FIGS. 4a-4c show a damping valve with various fittings.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0021] FIG. 1 shows a damping-valve body 1, which is produced by a
sintering technique and is in one piece. Transverse
through-passages 5 for a first direction of flow are formed on a
first pitch circle 3. The transverse through-passages 5 have a
trapezoidal outlet opening. Each outlet opening is framed by an
encircling ridge 7. Radially extending inflow openings 9 for
through-passages 11 are formed on a smaller pitch circle 13 between
the circumferentially arranged transverse through-passages 5 with
the trapezoidal outlet openings. Toward the inflow openings 9, the
through-passages 11 have funnels 15 (see FIG. 2), contour lines
being provided to make this clear. The inflow openings 9 and hence
also the through-passages 11 are connected on one side 19 of the
damping valve by an encircling channel 17. On the opposite side 21
of the damping-valve body, the same through-passages 11 have an
encircling annular passage 23 (see FIGS. 2 and 3). The encircling
passage 17 is separated from the through-passages 5 by the ridge 7
and is filled with a damping medium. Consequently, only the sum of
the end faces of the ridge 7 plus an annular clamping surface 25
remain as valve support surfaces. Sticking of a valve disk on the
damping-valve body is therefore to be considered to be
unlikely.
[0022] The funnels 15 of the through-passages 11 are dimensioned in
such a way that they are framed by an arc segment 27 of the ridges
7, the trapezoidal outlet openings of the through-passages 5 having
an arc corresponding to the funnel shape.
[0023] In FIGS. 4a to 4c, the damping-valve body as depicted in
FIG. 2 is fitted with various valve disks 29 and valve springs 31.
Common to all the valve disks 29 is that they can be fitted without
alignment in the circumferential direction since the
through-passages 5; 11 are separated by the ridges 7. On side 21 of
the damping-valve body, at least one valve disk (not shown) covers
the encircling annular passage 23, preventing any short-circuiting
of the flow.
[0024] Thus, while there have shown and described and pointed out
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
* * * * *