U.S. patent application number 13/995414 was filed with the patent office on 2014-01-30 for piston pump having a cylinder barrel.
This patent application is currently assigned to Robert Bosch GmbH. The applicant listed for this patent is Oliver Gaertner, Daniel Gosse, Heiko Jahn, Marc Zimmermann. Invention is credited to Oliver Gaertner, Daniel Gosse, Heiko Jahn, Marc Zimmermann.
Application Number | 20140030128 13/995414 |
Document ID | / |
Family ID | 44936254 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140030128 |
Kind Code |
A1 |
Gaertner; Oliver ; et
al. |
January 30, 2014 |
PISTON PUMP HAVING A CYLINDER BARREL
Abstract
A piston pump for delivering fluids includes a piston configured
to be driven to perform a reciprocating stroke movement. The piston
pump includes a cylinder barrel in which the piston is held in an
axially displaceable manner. The piston pump also includes a
displacement chamber which is arranged in the cylinder barrel
between an inlet valve and an outlet valve. The outlet valve is
arranged on a cylinder barrel base, and, on a side of the cylinder
barrel base which faces away from the displacement chamber, an
annular projection is formed. The annular projection is configured
to surround an installation space for the outlet valve.
Inventors: |
Gaertner; Oliver; (Abstatt,
DE) ; Jahn; Heiko; (Tamm, DE) ; Zimmermann;
Marc; (Sonthofen, DE) ; Gosse; Daniel;
(Berlin, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gaertner; Oliver
Jahn; Heiko
Zimmermann; Marc
Gosse; Daniel |
Abstatt
Tamm
Sonthofen
Berlin |
|
DE
DE
DE
DE |
|
|
Assignee: |
Robert Bosch GmbH
Stuttgart
DE
|
Family ID: |
44936254 |
Appl. No.: |
13/995414 |
Filed: |
October 24, 2011 |
PCT Filed: |
October 24, 2011 |
PCT NO: |
PCT/EP11/68543 |
371 Date: |
October 10, 2013 |
Current U.S.
Class: |
417/559 |
Current CPC
Class: |
F04B 53/168 20130101;
F04B 53/166 20130101; B60T 8/4031 20130101; F04B 53/1002 20130101;
F04B 53/22 20130101; F04B 1/0421 20130101 |
Class at
Publication: |
417/559 |
International
Class: |
F04B 53/10 20060101
F04B053/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 2010 |
DE |
10 2010 064 084.0 |
Claims
1. A piston pump for delivering fluids, comprising: a piston
configured to be driven to perform a reciprocating stroke movement;
a liner configured to receive the piston such that the piston is
axially displaceable; a displacement chamber arranged in the liner
between an inlet valve and an outlet valve; and a liner base,
wherein the outlet valve is arranged on the liner base, and wherein
an annular extension of the liner is configured to enclose an
installation space for the outlet valve, the annular extension
formed on a side of the liner base that is remote from the
displacement chamber.
2. The piston pump as claimed in claim 1, further comprising a
circumferential recess formed on the side of the liner base that is
remote from the displacement chamber.
3. The piston pump as claimed in claim 2, further comprising a
radial duct configured to connect the installation space to the
circumferential recess, the radial duct formed in the liner.
4. The piston pump as claimed in claim 1, further comprising a
closure element configured as a closure cap, the closure element
attached to the annular extension.
5. The piston pump as claimed in claim 4, wherein the closure
element is made of aluminum.
6. The piston pump as claimed in claim 4, wherein the closure
element is produced by machining.
7. The piston pump as claimed in claim 4, wherein the outlet valve
includes: a closing member; a pre-tensioning device; and a base
element configured to support the pre-tensioning device.
8. The piston pump as claimed in claim 7, wherein the closing
member is a ball.
9. The piston pump as claimed in claim 7, further comprising a
space configured to accommodate a damping device, the space
arranged between the closing member and the closure element.
Description
STATE OF THE ART
[0001] The invention relates to a piston pump for delivering
fluids, having a piston which can be driven to perform a
reciprocating stroke movement, and a liner in which the piston is
received so that it is axially displaceable, and a displacement
chamber arranged in the liner between an inlet valve and an outlet
valve, wherein the outlet valve is arranged on a liner base.
[0002] Piston pumps of various designs are known. They are used in
motor vehicles having vehicle hydraulic brake systems. The known
piston pumps comprise an inlet valve, an outlet valve and a
displacement, working or delivery chamber, which is arranged
between the inlet valve and the outlet valve. The displacement
chamber is arranged in a pump cylinder, which here forms a liner
and is usually of a substantially cup-shaped design. A passage
opening, which is opened and closed by the outlet valve, is formed
in a liner base of the pump cylinder. Here the outlet valve, which
is usually embodied as a non-return valve, is arranged in an outlet
valve cover, which is mounted externally on the liner. An outflow
into a delivery line, into which the then pressurized fluid,
especially the brake fluid, is discharged, is furthermore formed in
the outlet valve cover.
[0003] In the brake system the piston pump serves, for example, to
return brake fluid from a wheel brake cylinder or from a plurality
of wheel brake cylinders into a brake master cylinder and/or to
deliver brake fluid from a reservoir into a wheel brake cylinder or
into a plurality of wheel brake cylinders.
[0004] The piston pump is needed in vehicle brake systems with
wheel slip control (ABS or ASR), a traction control system (TCS)
and/or in a brake system serving as a steering aid (FDR) and/or in
an electro-hydraulic brake system (EHB) or an electronic stability
program (ESP).
[0005] DE 10 2006 027 555 A1 discloses a piston pump for delivering
fluids, having a piston, a cylinder element and a delivery chamber
arranged between an inlet valve and an outlet valve, wherein the
outlet valve comprises a closing member, a pre-tensioning device
and a disk element. The outlet valve is arranged in a cover and an
outflow into a delivery line ensues via this cover. A sealing seat
of the outlet valve is arranged on the disk element.
[0006] On opening of the outlet valve, unwanted noises can occur
due to dimensional tolerances of the individual components. Efforts
are therefore underway to optimize just such piston pumps as these,
acting as ABS, ASR or ESP pump elements, with regard to their noise
emissions and to improve the assembly of the individual
sub-assemblies of such piston pumps.
DISCLOSURE OF THE INVENTION
[0007] According to the invention a piston pump is created for
delivering fluids, having a piston which can be driven to perform a
reciprocating stroke movement, and a liner, in which the piston is
received so that it is axially displaceable, and a displacement
chamber arranged in the liner between an inlet valve and an outlet
valve, wherein the outlet valve is arranged on a liner base. An
annular extension of the liner, which encloses an installation
space for the outlet valve, is formed on the side st of the liner
base remote from the displacement chamber.
[0008] According to the invention two functional units are combined
in one single liner, that is to say a displacement chamber on the
one hand and the fitting space for the outlet valve on the other.
This simplifies the assembly of the inventive piston pump of a
vehicle hydraulic brake system and also creates further space for
damping measures or for a device used for damping.
[0009] This measure also makes it possible to reduce the
dimensional tolerances of the components, and therefore to reduce
the noise generated.
[0010] The hydraulic piston pump comprises a cylindrical piston,
which in a liner of substantially cup-shaped design is supported so
that it can be run into and out of a cylinder bore. The liner is
inserted, in particular, into a cylinder bore of a pump housing of
the piston pump in a hydraulic unit. Inside the cylinder bore of
the liner a fluid-filled delivery area or delivery chamber is
provided between an inlet valve and an outlet valve. When the
piston runs out of the cylinder, a vacuum is built up in the
delivery area and the piston sucks fluid into the delivery area via
the inlet valve. When it runs in on the other hand, the piston
displaces the fluid out of the delivery area via the outlet valve
into the hydraulic system for performing work. A passage opening,
which is opened and closed by the outlet valve, is formed in the
base of the liner.
[0011] The outlet valve comprises a closing member, which is
advantageously embodied as a ball or plate. The liner is preferably
combined with an annular extension or the latter is subsequently
formed onto the liner as a hollow cylindrical continuation on the
liner, in order to then accommodate the outlet valve inside the
hollow cylindrical continuation. This has the advantage that
components such as the closing member, the spring and noise damping
means can be arranged inside the hollow cylindrical continuation
from the outlet valve-side, as part of a simple assembly process,
which is performed in the opposite direction to the usual one.
[0012] Here the outlet valve, which is preferably embodied as a
non-return valve, is arranged in the part of the extension joined
onto the liner, and an outflow into a delivery line of an
associated pump housing is furthermore formed in the extension. The
outflow is advantageously formed by means of a circumferential
recess and a radial duct. The circumferential recess is preferably
formed on the liner on the side remote from the displacement
chamber, and the radial duct preferably connects the installation
space of the outlet valve to the recess. The outlet valve here
advantageously comprises the closing member, a pre-tensioning
device for pre-tensioning the closing member and a base element for
supporting the pre-tensioning device.
[0013] Here the liner of the piston pump may be of longer design
dimensions, thereby additionally affording further space in the
area of the outlet valve for any damping measures.
[0014] A closure element in the form of a closure cap is
advantageously attached to the annular extension. The closure
element is advantageously caulked into the liner and for its part
caulked in the pump housing itself. Alternatively the closure
element may also just be attached to the extension of the liner and
caulked only in the pump housing, in order to create a fluid-tight
and force-absorbing positional safeguard for the closure element in
this area. Overall the closure element is integrated into the liner
and the two combined with one another to form one unit, so that
unwanted noises due to opening of the outlet valve are thereby
already reduced.
[0015] The integrated closure element, which is preferably designed
as an outlet valve cover or as an integrated closure cap of the
outlet valve, is preferably made from aluminum. This affords
external protection against corrosion and secure caulking in the
pump housing. The aluminum has a ductility such that the caulking
of the closure element in the housing wall of the liner can easily
be achieved by positive interlock and frictional connection.
[0016] An exemplary embodiment of the solution according to the
invention is explained in more detail below with reference to the
schematic drawings attached, of which:
[0017] FIG. 1 shows a longitudinal section of a piston pump
according to the invention, having a liner and a closure element in
the associated pump housing and
[0018] FIG. 2 shows a perspective view of the liner together with a
closure element of the piston pump according to FIG. 1.
[0019] FIG. 1 represents a piston pump 10, which comprises a
stepped cylinder bore 12 in a hydraulic unit, which forms a pump
housing 14. The hydraulic unit, of which only a fragment
surrounding the piston pump 10 is represented in the drawing, is an
integral part of a vehicle hydraulic brake system with wheel-slip
control, not represented further. Besides the piston pump 10,
further hydraulic components such as solenoid valves or pressure
accumulators are incorporated therein and are hydraulically
connected to one another and to the piston pump 10 according to the
invention.
[0020] The piston pump 10 comprises a piston 16, one end of which,
remote from the displacement chamber 18, is guided in the pump
housing 14 by a first guide ring 20 and sealed off by a sealing
ring 22. The other end of the piston 16, facing the displacement
chamber 18, is guided in a liner 26 of the piston pump 10 by a
second guide ring 24 and sealed off by a sealing ring 28. The liner
26 is inserted with a press fit into the cylinder bore 12 of the
pump housing 14. The press fit produces a seal between the inlet
side and the outlet side, that is to say between the low-pressure
side and the high-pressure side of the piston pump 10.
[0021] For the pump inlet an axial blind bore 30, which is crossed
by transverse bores 32 close to its base, is fitted in the piston
16 from a side facing the displacement chamber 18. Through windows
34 in a peripheral wall 36 of the liner 26, the blind bores and
transverse bores 30, 32 communicate with an admission bore 38,
which is inserted in the hydraulic unit forming the pump housing 14
radially to the piston pump 10.
[0022] At the displacement chamber end of the piston 16, a
non-return valve is fitted as inlet valve 40. As valve closing
member the inlet valve 40 comprises a valve ball 42, which
interacts with a tapered valve seat 44, which is inserted at an
orifice of the blind bore 30 of the piston 16. A helical
compression spring as valve closing spring 46 presses the valve
ball 42 against the valve seat 44. The valve ball 42 and the valve
closing spring 46 are accommodated in a valve housing 48, which is
made from sheet metal as a cup-shaped deep-drawn part having a
diameter corresponding approximately to the diameter of the piston
16, and is provided with flow passage openings 50. The valve
housing 48 has an annular step 52, with which it bears on an end
face of the piston 16 facing the displacement chamber 18. It
comprises an integral, externally projecting radial flange 54,
against which a helical compression spring serving as piston return
spring 56 presses and in this way holds the valve housing 48 on the
piston 16. At the same time the radial flange 54 retains the guide
ring 24 and the sealing ring 28 between it and a support ring 60,
resting on an annular shoulder 58 of the piston 16, on the piston
16 in an axial direction.
[0023] Via the radial flange 54 of the valve housing 48, the piston
return spring presses the piston 16 in an axial direction against
an eccentric 62, which can be driven by an electric motor and which
serves for driving the piston 16 to perform a reciprocating stroke
movement in a known manner.
[0024] On a displacement chamber side the liner 26 comprises an
integral liner base 64, in which a central through-hole 66 is
inserted for the pump outlet. The liner 26 is extended beyond this
liner base 64 by a hollow cylindrical portion or annular extension
67 on its side remote from the displacement chamber 18. The annular
extension 67 comprises an installation space 69, integral with the
liner 26, for an outlet valve 72, which can be fitted in this
installation space 69 on the liner 26 in reverse order.
[0025] Adjoining the annular extension 67 is a closure element 68,
which has the form of a closure cap, which is integrated into the
annular extension 67 by pressing in a step 73, and in so doing is
inserted directly into the cylinder bore 12. The closure element 68
is positively connected by a caulking 70 to the pump housing 14 and
sealed fluid-tightly. The closure element 68 is thereby
additionally also secured in the liner 26.
[0026] The closure element 68 is preferably formed from aluminum.
This ensures external protection against corrosion and owing to the
ductility of the aluminum affords a secure connection through the
caulking 70 of the closure element 68 in the pump housing 14.
[0027] The outlet valve 72 is designed with a spherical closing
member 74 and a return spring 76 as pre-tensioning device, and a
damping device 78 as support and base element for the return spring
76. The return spring 76 exerts a return force on the closing
member 74, so that this is pressed in the direction of the central
hole 66.
[0028] The liner 26 has a radial duct 79 passing through it, which
leads to an annular recess 80, in particular an annular duct,
formed on the outside thereof, for the fluid to flow out of the
pump housing 14 through an outflow duct 82 when the outlet valve 72
is opened.
[0029] In its longitudinal extent, therefore, the liner 26 is of
extended design in order to afford additional space in conjunction
with the integrated closure element 68. Due to the integrated
arrangement of the annular extension 67 in the form of a sleeve
extension and the caulking of the closure element 68 directly in
the liner 26, however, the overall length of the piston pump 10 is
not necessarily extended.
[0030] The design of the piston pump 10 according to the invention
with the liner 26, the annular extension 67 and the integrated
closure element 68 allows the closing member 74, the return spring
76 and the damping device 78 to be easily fitted from the outlet
valve-side. The liner 26 itself is machined during manufacture. The
machining according to the invention for producing the liner 26
with the hollow cylindrical portion and the annular extension 67 is
therefore not only feasible but also cost-neutral. In addition, the
design according to the invention affords additional space for the
installation of the damping device 78.
[0031] FIG. 2 shows an external view of the liner 26 with the
annular extension 67 extended thereon and the integrated closure
element 68.
[0032] Also externally visible are the recess 80 for the outflow of
fluid, which passes from inside the delivery chamber into the
recess 80 through the radial duct 79 (not shown here).
[0033] All features represented in the description, the following
claims and the drawings may be essential for the invention, both
individually and in any combination with one another.
* * * * *