U.S. patent number 3,632,230 [Application Number 05/081,281] was granted by the patent office on 1972-01-04 for hydraulic intensifier.
This patent grant is currently assigned to Aisin Seiki Kabushiki Kaisha. Invention is credited to Atsumi Ueda.
United States Patent |
3,632,230 |
Ueda |
January 4, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
HYDRAULIC INTENSIFIER
Abstract
A hydraulic intensifier interposed between an accumulator and a
source of pressure fluid including a hydraulic pump, comprising a
housing with small and large diameter cylindrical bores therein, a
small diameter piston reciprocatably engaged in the small diameter
cylindrical bore to form a pressure chamber for amplifying fluid
pressure from the source of pressure fluid, a large diameter piston
reciprocatably engaged in the large diameter cylindrical bore to
operate the small diameter piston, and a control valve means
incorporated within the large diameter piston to control
reciprocation of the large diameter piston, thereby, easy
assembling work is realizable with a small number of parts and
accurate operation of the device is obtainable, and above all, the
time necessary to charge the accumulator with fluid pressure can
much be reduced.
Inventors: |
Ueda; Atsumi (Kariya,
JA) |
Assignee: |
Aisin Seiki Kabushiki Kaisha
(Asahi-machi, Kariya-shi, Aichi-ken, JA)
|
Family
ID: |
26340429 |
Appl.
No.: |
05/081,281 |
Filed: |
October 16, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Oct 18, 1969 [JA] |
|
|
44/83503 |
Jan 20, 1970 [JA] |
|
|
45/6323 |
|
Current U.S.
Class: |
417/225; 91/422;
417/349 |
Current CPC
Class: |
F04B
53/164 (20130101); F01L 21/00 (20130101); F15B
1/02 (20130101); F01L 25/066 (20130101); F04B
9/107 (20130101); F15B 3/00 (20130101) |
Current International
Class: |
F01L
21/00 (20060101); F01L 25/06 (20060101); F15B
1/00 (20060101); F04B 53/00 (20060101); F04B
53/16 (20060101); F15B 1/02 (20060101); F04B
9/00 (20060101); F04B 9/107 (20060101); F01L
25/00 (20060101); F15B 3/00 (20060101); F04b
017/00 (); F04b 035/00 (); F15b 011/08 () |
Field of
Search: |
;60/54.5HA,54.6HA,54.5A,54.6A ;91/422,460 ;417/225,226,349 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Geoghegan; Edgar W.
Assistant Examiner: Zupcic; A. M.
Claims
What I claim is:
1. In a hydraulic intensifier; a housing having therein a
stepped-diameter cylindrical bore forming a small diameter bore
portion connected to a first inlet conduit to receive fluid
pressure from a source of fluid pressure and and outlet conduit to
charge fluid pressure to an accumulator and a large diameter bore
portion connected to a second inlet conduit to receive fluid
pressure from the source of fluid pressure, said housing also
including an exhaust conduit communicating with said large diameter
bore portion, a stepped piston comprising a small diameter piston
portion reciprocable within said small diameter bore portion to
form a first pressure chamber for amplifying the fluid pressure
supplied to said outlet conduit from said first inlet conduit and a
large diameter piston portion reciprocatably engaged in said large
diameter bore portion to form a second pressure chamber selectively
in communication with said second inlet conduit and an exhaust
chamber connected to said exhaust conduit, said large diameter
piston portion including a bore drilled therein along the axial
center thereof, a control valve means reciprocatably engaged in
said bore within said large piston portion, a third pressure
chamber formed between said control valve means and said last named
bore, an inlet-outlet port connecting said third pressure chamber
alternately to said second inlet conduit and said exhaust chamber,
a first passageway to communicate said second pressure chamber with
said second inlet conduit, and a second passageway to connect said
second pressure chamber with said exhaust chamber, said control
valve means operating to close said second passageway and open said
first passageway when the fluid pressure supplied to said third
pressure chamber through said second inlet conduit and said
inlet-outlet port reaches a predetermined value, the operation
causing the fluid pressure within said second pressure chamber
acting on said large diameter piston portion to urge said small
diameter piston portion to amplify the fluid pressure within said
first pressure chamber, and said control valve means continuously
operating to open said second passageway after connecting said
third pressure chamber to said exhaust chamber through said
inlet-outlet port.
2. A hydraulic intensifier as set forth in claim 1, wherein said
stepped piston is an integral piston having the small diameter
piston portion and the large diameter piston portion formed
therein.
3. A hydraulic intensifier as set forth in claim 1, wherein said
stepped piston comprises a small diameter piston and a separate
large diameter piston, said small and large diameter pistons being
in constant contact with each other.
4. A hydraulic intensifier as set forth in claim 1, wherein said
large diameter piston has a cylinder-shaped shock absorbing member
made of resilient material at one end thereof, said cylinder-shaped
shock absorbing member being provided with an orifice communicable
with said second pressure chamber around the circumference
thereof.
5. A hydraulic intensifier as set forth in claim 1, wherein there
is provided at the sides of said large diameter piston an inlet
port connecting said second inlet conduit to said third pressure
chamber and an exhaust port connecting said exhaust chamber to said
third pressure chamber.
Description
The present invention relates to a hydraulic intensifier to amplify
fluid pressure supplied from a source of fluid pressure and to
store the amplified fluid in an accumulator, and more particularly
to a novel intensifier to be utilized for a hydraulic system to
operate a plurality of hydraulically actuated devices.
A first important object of the present invention is accordingly to
provide a hydraulic intensifier which supplies fluid pressure from
a source of fluid pressure directly to an accumulator until the
source of fluid pressure produces fluid pressure of a predetermined
value, and then, amplifies the fluid pressure of the predetermined
value, storing the fluid pressure amplified up to a desired value
in the accumulator, thereby, reducing the time necessary to charge
the accumulator with fluid pressure.
A second important object of the present invention is to provide a
hydraulic intensifier comprising a housing incorporated with a
large diameter cylindrical bore and a small diameter cylindrical
bore, a small diameter piston reciprocatably engaged in the small
cylindrical bore to form a first pressure chamber which amplifies
fluid pressure from a source of fluid pressure and delivers the
amplified fluid pressure into an accumulator, a large diameter
piston reciprocatably engaged in the large diameter cylindrical
bore and constantly being in contact with said small diameter
piston at one end and further provided with a bore inside thereof
along its axial center, said large diameter piston urging the small
diameter piston against fluid pressure acting on the small diameter
piston by means of fluid pressure from the source of fluid
pressure, and control valve means installed reciprocatably within
the bore of the large diameter piston to control movements of the
large diameter piston is response to fluid pressure from the source
of fluid pressure, said large and small diameter pistons being
separately engaged in the cylindrical bores respectively prepared
within the housing, thereby, precise corresponding cocentricity is
not required between the large and small diameter pistons and yet
high accuracy is obtainable with easy assembling work.
A third important object of the present invention is to provide a
hydraulic intensifier having the above described characteristics,
wherein a cylinder-shaped resilient member made of rubber or
rubberlike materials covers up one end of the large diameter
piston, which is the opposite to the one in constant contact with
one end of the small diameter piston, to absorb effectively
impulsive force the large diameter piston produces against the
inner wall of the housing at the reciprocation thereof, the
structures of the device as well as the resilient member rendering
high durability of the resilient member.
A further important object of the present invention is to provide a
hydraulic intensifier having the above described characteristics,
wherein the control valve means is operated so smoothly within the
large diameter piston as to assure accurate reciprocation of the
large diameter piston.
It is yet an important object of the present invention to provide a
hydraulic intensifier having the above described characteristics,
wherein the device is designed to require a small number of parts
with a simple and compact construction.
Other objects and advantages of the present invention will be made
more apparent in the following description, particularly when
considered in connection with the accompanying drawings, in
which;
FIG. 1 is a view of a longitudinal cross section of an embodiment
in accordance with the present invention at the initial operation
stage thereof;
FIg. 2 is a view of a longitudinal cross section of the embodiment
as shown in FIG. 1 but at the final operation stage thereof;
FIG. 3 is a view of a longitudinal cross section of another
embodiment in accordance with the present invention at the initial
operation stage thereof;
FIG. 4 is a view of a longitudinal cross section of the embodiment
shown in FIG. 3 but at the final operation stage thereof.
Referring now to the drawings, and particularly to FIG. 1, a
hydraulic intensifier in accordance with the present invention is
interposed between a pump driven by a power takeoff from the
vehicle engine, said pump including a source of fluid pressure, and
hydraulic actuated accessories such as a power steering unit and/or
a power brake unit. The hydraulic intensifier mainly comprises a
housing 1, a small diameter piston 5, a large diameter piston 6,, a
control valve means 8 regulating the reciprocation of the large
diameter piston 6, and a return spring 10 to control the operation
of the control valve means 8.
The housing 1 is illustrated as having a small diameter cylindrical
bore 2 and a large diameter cylindrical bore 3. The small diameter
cylindrical bore 2 has the small diameter piston 5 reciprocatably
engaged therein and forms a pressure chamber 4 which is connected
at one side to a pump P through a port 51 and a check valve 52 and
at another side to an accumulator 43 through a port 41 and a check
valve 62. The large diameter cylindrical bore 3 has the large
diameter piston 6 reciprocatably engaged therein and forms a
pressure chamber 19 which is selectively connected with the pump P
through a port 24, and an exhaust chamber 118 in communication with
a reservoir R through a port 40.
In the initial operation, the large diameter piston 6 engaged
within the large diameter cylindrical bore 3 touches at its left
shoulder 14 to the annular surface 16 of a plug 15 threaded in the
housing 1, and at the right shoulder 17 thereof to the small
diameter piston 5. The control valve means 8 is reciprocatably
installed within a bore 7 drilled in the large diameter piston 6
along the axial center thereof, said control valve means 8 being
for forwarding and reversing the large diameter piston 6. One end
of the control valve means 8 is positioned at the right end portion
of the large diameter piston 6, the other end being constantly
urged rightward in the figure by the return spring 10 secured on
the left shoulder 12 of the control valve means 8 at one end
thereof with the other end secured on a retainer 13 fixed on the
left end of the large diameter piston 6. In the initial operation,
the control valve means 8 keeps the right end 9 thereof in touch
with the right end inner wall 11 of the large diameter piston
6.
A first port 20 drilled in the large diameter piston 6 along the
radius line thereof connects a chamber 21 to the pump P through a
groove 45 and passageways 46 and 53 as the control valve means 8
moves leftward. A second port 22 is prepared to connect the chamber
21 to the pump P when the control valve means 8 is in the initial
operation as well as in the leftward movement. The control valve
means 8 being incorporated within the large diameter piston 6, the
second port 22, thus, connects furthermore the chamber 21 to the
exhaust chamber 118, which is in communication with the reservoir
R, through passageways 53, 46 and the groove 45, when the large
diameter piston 6 reaches its rightward stroke end keeping the
control valve means 8 in its leftward stroke end as illustrated in
FIG. 2. A third port 23 produces connection between the chambers 21
and 118 through the passageways 53, 46 and the groove 45 when the
control valve means 8 returns to the original position thereof,
that is to say when it makes the rightward movement.
A chamber 28 formed between an inner circumferential groove of the
large diameter piston 6 and the outer circumferential wall of the
control valve 8 is connected to the pump P through a vertical hole
27 of the large diameter piston 6, a chamber 26 formed between an
outer circumferential groove of the large diameter piston 6 and the
inner circumferential wall of the housing 1, a chamber 25 formed
between an inner circumferential groove of the housing 1 and the
outer circumferential wall of the large diameter piston 6, and the
port 24. When the control valve means 8 is in the original position
as illustrated in FIG. 1, the chamber 28 is closed to a chamber 30
by the fit between the back-portion 50 of the control valve means 8
and a land 29 of the large diameter piston 6, said chamber 30 being
formed between the inner circumferential groove of the large
diameter piston 6 and the outer circumferential groove of the
control valve means 8. The leftward movement of the control valve
means 8 opens the chamber 28 to the chamber 30. The chamber 30 is
open constantly to the chamber 19 through a slant passageway 31
drilled in the large diameter piston 6 and also open to a chamber
34 formed with the inner circumferential groove of the large
diameter piston 6 through a passageway 33 when the control valve
means 8 is in the original position thereof. The leftward movement
of the control valve means 8 closes the chamber 30 to the chamber
34 by the fit between a land 32 of the large diameter piston 6 and
a land 36 of the control valve means 8. The chamber 34 is in
communication with the reservoir R through a passageway 35 drilled
in the large diameter piston 6 and the chamber 118 and, on the
other hand, is open to a chamber 37, on which the return spring 10
is secured, through a passageway 39 made along a radius line of the
control valve means 8 and a passageway 38 made along the axial line
of the control valve means 8.
Described below is the operation in detail of the preferred
embodiment of the present invention, the construction of which has
heretofore been explained in the above.
Reference is made to FIG. 1, the pump P delivers pressure fluid to
the ports 51 and 24 of the hydraulic intensifier. The pressure
fluid supplied to the port 51 through the check valve 52 gets in
the chamber 4 and, then, flows directly into the accumulator 43
through the port 41 and the check valve 62. The bypassed flow of
pressure fluid to the port 24 runs through the chamber 25, the
second port 22, the groove 45, the passageways 46 and 53, and the
chamber 21 to act on the right area of the control valve means 8.
At the same time, the fit between the shoulder 50 of the control
valve means 8 and the land 29 of the large diameter piston 6 blocks
the hydraulic flow of the pressure fluid supplied into the chamber
28 through the port 24, the chambers 25 and 26, and the passageway
27.
When the pressure fluid within the chamber 21 as well as the
chamber 4 reaches the predetermined value, the control valve means
8 starts moving leftward against the force of the return spring 10.
This produces the fit between the lands 36 and 32 to close the
connection between the chamber 30, which opens to the chamber 19,
and the chamber 34, which is in communication with the chamber 118.
As the control valve means 8 is further moving leftward, the fit
between the shoulder 50 of the control valve means 8 and the land
29 gets off each other to lead the hydraulic flow within chamber 28
to the chamber 19 through the chamber 30 and the passageway 31.
Accordingly, as the control valve means 8 is moving leftward, the
large diameter piston 6 starts moving rightward urged by the
pressure fluid supplied into the chamber 19. At the same time,
pressure fluid flows into the chamber 21 through the first port 20
to help maintaining the leftward movement of the control valve
means 8. The rightward thrusting force of the large diameter piston
6 urges the small diameter piston 5 rightward to supply the
accumulator 43 with such pressure fluid as of a higher pressure
value than that of the pump pressure.
When the pistons 5 and 6 reaches the right stroke end as
illustrated in FIG. 2, the inner circumferential wall of the
housing 1 closes the first and second ports 20 and 22. Thus,
pressure fluid from the pump P is prevented from entering into the
chamber 21 through the port 24. The chamber 21 becomes now open to
the chamber 118 by way of the passageways 53 and 46, the groove 45,
the second port 22, and the enlarged section 54. The pressure fluid
within the chamber 21 consequently returns to the reservoir through
the port 40 and the return spring 10 urges the control valve means
8 rightward. At this moment, the third port 23 works to assure the
displacement of the pressure fluid from the chamber 21. Now the fit
between the lands 32 and 36 comes off to lead the pressure fluid in
the chamber 19 to the reservoir R by way of the passageway 31, the
chamber 30, the passageway 33, the chamber 34, the passageway 35,
the chamber 118, and the port 40. The large diameter piston 6
returns to the original position by the leftward thrusting force of
the small diameter piston 5, the leftward thrusting force being
produced by the pressure fluid in the chamber 4.
In the hydraulic intensifier in the present invention, pressure
fluid delivered to the port 24 from the pump P moves, as in the
above described operation, the control valve means 8 leftward to
urge again the large diameter piston 6 rightward. Consequently, the
hydraulic intensifier keeps the fluid pressure amplifying operation
until the accumulator 43 is charged to its desired pressure.
In the above described embodiment, the small and large diameter
pistons 5 and 6 are separately provided within the respective
cylindrical bores 2 and 3 of the housing 1, thereby easy assembly
works of the small and large diameter pistons 5 and 6 into the
housing 1 are realized, and yet accurate working of the intensifier
is maintained.
Furthermore, in the above described embodiment, accurate operation
of the control valve means 8 is obtained by help of the first port
20, an inlet port, and the third port 23, an outlet port, prepared
in addition to the second port 22 to receive the pressure fluid
from the port 24 and to drain the pressure fluid into the exhaust
chamber 118.
Another embodiment of the present invention is to be described
below with reference to FIG. 3 and 4, in which similar reference
numerals as in FIGS. 1 and 2 indicate such parts as of same or
substantially similar functions. The feature in this embodiment is
that a cylinder-shaped resilient member 101 made of rubber or
rubberlike materials covers the left-end portion 6a of the large
diameter piston 6'. The cylinder shaped resilient member 101 is
provided with an orifice 104 and touches at the left end thereof to
the inner surface of the plug 15' threaded in the left end of the
housing 1'. The orifice 104 is to connect the chamber 19' to a
chamber 18 when the resilient member 101 is tightly pressed onto
the inner surface of the plug 15'. Passageways 6b and 6c drilled in
the large diameter piston 6' along radius lines thereof are
additionally made for the manufacturing convenience in drilling the
passageways 35 and 31, and are sealed with balls b and c.
Operation of the second embodiment is the same as that of the first
embodiment; in the case of the second embodiment, however, the
impulsive force which the large diameter piston 6', produces
against the plug 15' is well absorbed by the shock-absorbing effect
of the cylinder shaped resilient member 101 and compression of the
pressure fluid within the chamber 18', the impulsive force being
produced when the large diameter piston 6' returns leftward after
amplifying the fluid pressure inside the chamber 4' by the
rightward movement thereof through the controlling work of the
control valve means 8'.
When the large diameter piston 6' starts its rightward movement,
the connection between the chambers 18 and 19' prevents the
cylinder-shape resilient member 101 from sucking on the inner face
of the plug 15'. The large diameter piston 6', thus, leaves off the
plug 15' easily and makes smoothly its rightward movement.
As clearly described above, in the second preferred embodiment, the
reciprocation of the large diameter piston 6' within the large
diameter cylindrical bore 3' makes no impulsive touch of the large
diameter piston 6' direct to metal members such as the plug 15' by
means of the cylinder shaped resilient member 101 which, also,
absorbs effectively impulsive force between the large diameter
piston 6' and the plug 15'. Thus the noneffective stroke of the
large diameter piston 6' is much reduced, and noises caused by the
impact of the large diameter piston 6' against the plug 15' is
eliminated. The compression of the hydraulic fluid within the
chamber 18 helps the cylinder shaped resilient member 101 in
absorbing the impulsive force of the large diameter piston 6'
against the plug 15', the resilient member 101 being this provided
with good durability.
While the remaining primed reference numerals in FIGS. 3 and 4 have
not been shown in detail it should be understood that each has the
same function as its unprimed counterpart described in the
embodiment of FIGS. 1 and 2.
It will be understood that the present invention is not to be
limited to the exact construction shown and described, but that
various changes and modifications may be made without departing
from the spirit and scope of the present invention, as defined in
the appended claims.
* * * * *