U.S. patent application number 09/997040 was filed with the patent office on 2003-05-29 for a unit pump with an actuator carrier and an actuator carrier thereof.
Invention is credited to Coldren, Dana R., Forck, Glen F., Ibrahim, Daniel R..
Application Number | 20030099562 09/997040 |
Document ID | / |
Family ID | 25543585 |
Filed Date | 2003-05-29 |
United States Patent
Application |
20030099562 |
Kind Code |
A1 |
Coldren, Dana R. ; et
al. |
May 29, 2003 |
A UNIT PUMP WITH AN ACTUATOR CARRIER AND AN ACTUATOR CARRIER
THEREOF
Abstract
An actuator carrier comprises an aperture being adapted to
receive actuator and a bore being adapted to carry high pressure
fluid through the carrier. The actuator carrier can be incorporated
into a unit pump allowing for a more efficient design and
manufacture process, including linear alignment of all of the unit
pumps primary components.
Inventors: |
Coldren, Dana R.; (Fairbury,
IL) ; Forck, Glen F.; (Peoria, IL) ; Ibrahim,
Daniel R.; (Bloomington, IL) |
Correspondence
Address: |
CATERPILLAR INC.
100 N.E. ADAMS STREET
PATENT DEPT.
PEORIA
IL
616296490
|
Family ID: |
25543585 |
Appl. No.: |
09/997040 |
Filed: |
November 29, 2001 |
Current U.S.
Class: |
417/470 |
Current CPC
Class: |
F02M 59/366 20130101;
F02M 59/466 20130101; F02M 59/44 20130101 |
Class at
Publication: |
417/470 |
International
Class: |
F04B 019/00; F04B
037/00 |
Claims
What is claimed is:
1. A unit pump comprising: a tappet moveable between a first
position and a second position, a cam being adapted to come in
contact with said unit pump and move said tappet between said first
and said second position; a spring connected to bias said tappet in
said first position; a pump body having a fuel cavity; a plunger
connected to said tappet and at least partially disposed in said
fuel cavity and being moveable between a third position and a
fourth position within said fuel cavity, said plunger being adapted
to pressurize fuel in said fuel cavity; a spill valve disposed
within said pump body; said spill valve adapted to control a flow
of fuel from said fuel cavity; an actuator carrier having an
aperture; an actuator disposed in the said aperture and being
adapted to actuate said spill valve; a bore disposed in said
actuator carrier and being adapted to pass said pressurized fuel
from said fuel cavity through said actuator carrier; and a fuel
line fitting.
2. The unit pump of claim 1 wherein said solenoid carrier is
metallic.
3. The unit pump of claim 1 wherein said solenoid carrier's said
bore communicates between a first surface of said carrier and a
second surface of said carrier.
4. The unit pump of claim 3 wherein said first and second surfaces
are adapted to seal with adjacent components.
5. The unit pump of claim 1 further comprising dowel holes for
positioning said carrier and preventing rotation.
6. The unit pump of claim 1 wherein said tappet, said spring, said
fuel cavity, said plunger, said spill valve, and said actuator
carrier, are substantially linearly aligned.
7. The unit pump of claim 1 wherein said spill valve is aligned
linearly with said unit pump.
8. The unit pump of claim 1 wherein said actuator is a
solenoid.
9. A unit pump comprising: a tappet moveable between a first
position and a second position, a cam being adapted to come in
contact with said unit pump and move said tappet between said first
and said second position; a spring connected to bias said tappet in
said first position; a pump body having a fuel cavity; a plunger
connected to said tappet and at least partially disposed in said
fuel cavity and being moveable between a third position and a
fourth position within said fuel cavity, said plunger being adapted
to pressurize fuel in said fuel cavity; a spill valve disposed
within said pump body; said spill valve adapted to control a flow
of fuel from said fuel cavity; an actuator being adapted to actuate
said spill valve; wherein said tappet, said spring, said fuel
cavity, said plunger, said spill valve, and said actuator, are
substantially linearly aligned.
10. An actuator carrier comprising: a carrier having an aperture,
said aperture adapted to receive an actuator; and a bore; said bore
being adapted to carry high pressure fluid through said carrier
with contacting said actuator.
11. The actuator carrier of claim 10 wherein said carrier is
metallic.
12. The actuator carrier of claim 10 wherein said bore communicates
between a first surface of said carrier and a second surface of
said carrier.
13. The actuator carrier of claim 12 wherein said first and second
surfaces are adapted to seal with adjacent components.
14. The actuator of claim 13 wherein said first surface is adapted
to seal with a valve body and said second surface is adapted to
seal with an adapter.
15. The actuator carrier of claim 10 further comprising dowel holes
for positioning said carrier and preventing rotation.
16. The actuator carrier of claim 10 wherein said actuator is a
solenoid.
Description
TECHNICAL FIELD
[0001] The present invention is directed to unit pumps and
specifically actuator carriers.
BACKGROUND
[0002] Engine manufacturers are constantly striving to become more
efficient in their design and manufacture of engine components. One
area in particular in which manufacturers have strived to become
more efficient is the design of unit pumps. Unit pumps must
pressurize fuel to injection pressure levels and deliver that fuel
to an injector. One of the concerns with unit pumps is the
packaging size or area/volume that the unit pump requires in the
engine. It is desirable to have the unit pump be as small as
possible. Further, it is desirable to make the manufacturing
process as simple as possible to reduce manufacturing time and
cost.
[0003] In the past unit pumps have not been designed as efficiently
as possible due to the desire to keep high pressure fluid away from
the pump's electronics. For example, some unit pumps use a
horizontal spill valve with an actuator that is not incorporated
into the body of the unit pump. This results in more complicated
manufacturing process as well as an increased packaging size. In
another type of unit pump design, the solenoid and the fuel line
are both offset outside the pump body at one end of the unit pump;
again requiring a more complicated manufacturing process and a
larger packaging size.
[0004] The present invention is directed to addressing one or more
of the above problems.
SUMMARY OF THE INVENTION
[0005] In a first embodiment for the present invention, an actuator
carrier comprises a carrier with an aperture being adapted to
receive an actuator and a bore adapted to carry high pressure fluid
through the carrier. In a second embodiment of the present
invention, a unit pump comprises a tappet movable between a first
position and a second position, a spring positioned adjacent to the
tappet and being adapted to return the tappet to its first
position, a fuel cavity, a plunger attached to the tappet and
movable between a third and a fourth position within a fuel cavity
and being adapted to pressurize fuel within the fuel cavity, spill
valve to control the flow of fuel leaving the fuel cavity, an
actuator carrier with an aperture adapted to receive an actuator
and a bore adapted to carry pressurized fuel from the fuel cavity
through the actuator carrier, and a fuel line fitting.
[0006] In yet another embodiment of the present invention, a unit
pump comprises a tappet movable between the first position and a
second position, a spring positioned adjacent to the tappet and
being adapted to return tappet to its first position, a fuel
cavity, a plunger attached to the tappet and movable between the
third and fourth position within said fuel cavity and being adapted
to pressurize fuel in the fuel cavity, a spill valve to control the
flow of fuel leaving the fuel cavity, an actuator to control the
spill valve, and a substantially linear alignment for the tappet,
spring, fuel cavity, plunger, spill valve, an actuator.
BRIEF DESCRIPTION OF DRAWINGS
[0007] FIG. 1 is a diagrammatic isometric cross section of a unit
pump incorporating the present invention.
[0008] FIG. 2 is a diagrammatic isometric view of one embodiment of
the present invention.
DETAILED DESCRIPTION
[0009] In FIG. 1 a diagrammatic cross section of a unit pump 10 is
illustrated. A tappet carrier 12 is attached to a roller 14 by a
pin 16. The tappet is moved by a cam (not shown) from the cam shaft
(not shown). The tappet carrier 12 contacts plunger 18 which is
slidably moveable in fuel cavity 22. A plunger return spring 20 is
positioned within the tappet carrier 12 to return the plunger to
its original position after the cam (not shown) has passed.
[0010] A tappet sleeve 48 surrounds the tappet carrier 12, plunger
return spring 20, and part of plunger 18. The fuel cavity 22 is
located within body 46 of the unit pump 10. A spacer/seal 32 fits
between body 46 and valve body 24, which is located within a bore
of body 46. The valve body 24 contains a spill valve 30 which
controls the flow of pressurized fuel from fuel cavity 22. An
actuator 28, located in carrier 26, controls the opening and
closing of spill valve 30. Actuator 28 could be selected from a
variety of actuators well know in the art, including a solenoid,
piezo, or other electromagnetic actuator. Spill valve 30 is biased
in a first position by return spring 52. In the first position,
fuel from fuel cavity 22 is open to the low pressure fill/spill
line 54, such that pressurized fuel is actually not created but is
instead directed out of the injector. When actuator 28 is
energized, spill valve 30 is moved to a second position, against
the force of the return spring 52, which closes the fill/spill line
54 and allows the fuel to be pressurized.
[0011] When fill/spill line 54 is closed, high pressure fuel is
transferred through the unit pump 10 from the fuel cavity 22 to the
fuel line fitting 44 through the seal 32, valve body high pressure
passage 36, located in body 46, the carrier high pressure passage
38, located in carrier 26, and the adapter high pressure passage
42, located in adapter 40.
[0012] The flange 34 is part of body 46 and allows the unit pump 10
to be clamped to an engine (not shown) or other base.
[0013] FIG. 2 is a diagrammatic isometric view of the carrier 26.
The carrier 26 includes an aperture 50 which is adapted to receive
an actuator 28, which is preferably a solenoid but could be any
type of mechanical or electrical actuator, including a piezo. The
carrier 26 also has a bore, which is high pressure fluid passage
38, which allows high pressure fluid to pass through carrier 26
without contacting actuator 28.
[0014] Carrier 26 must also have sealing surfaces to prevent
leakage between carrier 26 and valve body 24 and adapter 40.
Additionally, carrier 26 could have small dowel holes adapted to
receive a dowels for positioning, assembly and to prevent rotation
within unit pump 10.
Industrial Applicability
[0015] The unit pump's primarily purpose is to pressurize fuel for
injection into a combustion chamber. The unit pump's 10 roller 14
comes into contact with a cam (not shown). As the cam passes, it
moves roller 14, which is attached to the tappet carrier 12,
causing plunger 18 to move within fuel cavity 22 and pressurize the
fuel located in the fuel cavity 22. Once the cam has passed its
maximum lift, the plunger returns spring 20 returns the plunger 18
and tappet carrier 12 to their original positions.
[0016] Pressurized fuel from the fuel cavity 22 moves to the valve
body 24 where the spill valve 30 regulates the flow. Spill valve 30
is controlled by actuator 28 located in carrier 26. Spill valve 30
is biased in a first position by a return spring 52, such that
fill/spill line 54 is open. If fuel injection is not desired,
actuator 28 is not energized, leaving fill/spill line 54 open such
that pressurized fuel is not created. In the open position, fuel
from fuel cavity 22 is free to flow out of the low pressure
fill/spill line 54. However, when actuator 28 is energized, spill
valve 30 is moved to a second position, against the force of return
spring 52, closing the fill/spill line 54. This allows pressurized
fuel to be created by closing the drain path, fill/spill line 54.
Fuel from fuel cavity 22 then travels through the valve body high
pressure passage 36 to the carrier high pressure passage 38, the
adapter high pressure passage 42 and on to the fuel line fitting 44
where the fuel is then transferred to a fuel line (not shown) going
to a fuel injector which subsequently injects the fuel into the
combustion cylinder (not shown). Note that carrier 26 must provide
sealing surfaces between the valve body 24 and adapter 40 to
prevent loss of fluid and prevent fluid from contacting the
actuator. When it is desired to stop injection, actuator 28 is
de-energized, causing return spring 52 to move spill valve 30 back
to its first position and opening low pressure fill/spill line
54.
[0017] One key aspect of the unit pump 10 is the design of the
carrier 26. Specifically, carrier 26 has an aperture and a bore.
The aperture is an actuator cavity 50 which positions an actuator
28, such as a solenoid, within the unit pump body 26. The bore is a
high pressure fluid passage 38 which allows pressurized fuel to
move through the unit pump 10 and around actuator 28. By
incorporating a carrier that can both hold the actuator 28 and
provide fluid passage by means of carrier high pressure passage 38,
the unit pump's overall package size is substantially reduced.
Package size is reduced specifically by packaging the actuator
within the unit pump body 46 but still being able to route high
pressure fluid through the carrier 26 without leakage. Carrier 26
also reduces the number components need for manufacture by
streamlining the design, thereby reducing manufacturing time and
cost.
[0018] The carrier 26 allows for substantially linear alignment of
the unit pump 10 by combining the actuator 28 and high pressure
passage 38 into one piece. Specifically, the roller 14, tappet
carrier 12, plunger 18, spill valve 30, actuator 40 can be assemble
on or close to the same axis. This again allows for a reduced
package size and ease of manufacturing.
[0019] Other aspects, features, and advantage of the present
invention may be obtained from a study of this disclosure and
drawings, along with the appended claims.
LIST OF ELEMENTS
[0020] TITLE: A Solenoid Carrier with a High Pressure Passage
[0021] FILE: 01-261
[0022] 10 Unit Pump
[0023] 12 Tappet Carrier
[0024] 14 Roller
[0025] 16 Pin
[0026] 18 Plunger
[0027] 20 Plunger Return Spring
[0028] 22 Fuel Cavity
[0029] 24 Valve Body
[0030] 26 Carrier
[0031] 28 Actuator
[0032] 30 Spill Valve
[0033] 32 Spacer/Seal
[0034] 34 Flange/Hold Down Clamp
[0035] 36 Valve Body High Pressure Passage
[0036] 38 Carrier High Pressure Passage
[0037] 40 Adapter
[0038] 42 Adapter High Pressure Passage
[0039] 44 Fuel Line Fitting
[0040] 46 Body
[0041] 48 Tappet Sleeve
[0042] 50 Aperture
[0043] 52 Return Spring
[0044] 54 Fill/spill Line
* * * * *