U.S. patent application number 14/124160 was filed with the patent office on 2014-08-14 for device for metering lubricants in metal cutting.
The applicant listed for this patent is Werner Studer. Invention is credited to Werner Studer.
Application Number | 20140224832 14/124160 |
Document ID | / |
Family ID | 46208039 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140224832 |
Kind Code |
A1 |
Studer; Werner |
August 14, 2014 |
DEVICE FOR METERING LUBRICANTS IN METAL CUTTING
Abstract
The pump block of a metering pump for metering liquids including
a first feed duct system for the liquid to be delivered; a metering
chamber connected to said feed duct system; a pump duct; a metering
piston arranged in the metering chamber such that it can slide
along an axis, said metering piston being set up to pump a certain
quantity of a liquid present in the metering chamber through a stop
valve into the pump duct when moved in a direction along said axis;
and an actuator device for moving the metering piston along said
axis.
Inventors: |
Studer; Werner; (Egerkingen,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Studer; Werner |
Egerkingen |
|
CH |
|
|
Family ID: |
46208039 |
Appl. No.: |
14/124160 |
Filed: |
June 1, 2012 |
PCT Filed: |
June 1, 2012 |
PCT NO: |
PCT/EP2012/060398 |
371 Date: |
March 4, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61494735 |
Jun 8, 2011 |
|
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|
Current U.S.
Class: |
184/55.1 |
Current CPC
Class: |
F16N 13/02 20130101;
F04B 13/02 20130101; F04B 23/025 20130101; F04B 13/00 20130101;
F04B 53/16 20130101; F16N 11/10 20130101; F04B 23/06 20130101; F04B
53/162 20130101 |
Class at
Publication: |
222/71 |
International
Class: |
F04B 23/02 20060101
F04B023/02; F04B 23/06 20060101 F04B023/06 |
Claims
1. A metering pump for metering liquids, with at least one pump
block comprising: a first feed duct system for the liquid to be
delivered; a pump duct; and a pump device for pumping the liquid
from the feed duct system into the pump duct, wherein the pump
block has a housing cover in the form of a cylinder or of a
truncated cone, the feed duct system leading to at least one
opening arranged in the housing cover.
2. The metering pump as set forth in claim 1, wherein the pump
device has a metering chamber connected to the first feed duct
system, a metering piston arranged in the metering chamber so as to
be slidable along an axis, and an actuator device for moving the
metering piston along said axis, the metering piston being set up
to pump a certain quantity of a liquid present in the metering
chamber through a stop valve into the pump duct when moved in a
direction along said axis.
3. The metering pump as set forth in claim 1, characterized-by
further comprising: a pneumatic actuator device operable by a
pneumatic medium, particularly pressurized air, and a second feed
duct system for the pneumatic medium for operating the pneumatic
actuator device, said second feed duct system leading to at least
one opening arranged in the housing cover.
4. The metering pump as set forth in claim 1, further comprising: a
mounting block with at least one receptacle that is adapted to the
shape of the housing cover of the pump block and in which the pump
block is arranged in a flush-fitting manner.
5. The metering pump as set forth in claim 4, further comprising: a
circumferential groove, on the housing cover of the pump block, as
well as a screw arranged in a continuous threaded hole in the
mounting block, the groove, the threaded hole and the screw being
embodied and arranged such that, in an assembled pump block, the
screw can reversibly engage with the groove, thus enabling the
reversible positive fixation of the pump block in the mounting
block in the direction of the longitudinal axis.
6. The metering pump as set forth in claim 4, wherein the mounting
block has a third feed duct system for the liquid; and a first
circumferential groove is provided on the wall of the receptacle
connected to the third feed duct system and arranged such that the
at least one opening of the first feed duct system of a pump block
arranged in the mounting block overlaps with the first
circumferential groove; or that the third feed duct system leads to
at least one opening arranged in the wall of the receptacle, and a
first circumferential groove is provided on the housing cover of a
pump block arranged in the mounting block that is connected to the
first feed duct system and arranged such that the at least one
opening of the third feed duct system overlaps with the first
circumferential groove; so that the first and third feed duct
systems form a continuous feed duct system for liquid.
7. The metering pump as set forth in claim 6, wherein the mounting
block has a fourth feed duct system for pneumatic medium; and a
second circumferential groove is provided on the wall of the
receptacle is connected to the fourth feed duct system and is
arranged such that the at least one opening of the second feed duct
system of a pump block arranged in the mounting block overlaps with
the second circumferential groove; or that the fourth feed duct
system leads to at least one opening arranged in the wall of the
receptacle, and a second circumferential groove is provided on the
housing cover of a pump block arranged in the mounting block that
is connected to the second feed duct system and arranged such that
the at least one opening of the fourth feed duct system overlaps
with the second circumferential groove; so that the second and
fourth feed duct system form a continuous feed duct system for
pneumatic medium.
8. The metering pump as set forth in claim 6, characterized by
further comprising: sealing elements that are arranged at least one
of in the receptacle of the mounting block and around the housing
cover of the pump block along the periphery and are capable of
connecting in a sealing manner the at least one opening of the
first feed duct system or at least one of the third feed duct
system and the first circumferential groove and of connecting in a
sealing manner the at least one opening of the second feed duct
system or of the fourth feed duct system and the second
circumferential groove.
9. The metering pump as set forth in claim 4, wherein the mounting
block has two parallel flat walls and at least one of the third
feed duct system and the fourth feed duct system leads to an
opening on both walls, the corresponding two openings being
arranged such that one opening coincides with a corresponding
opening of another, equivalent metering pump when the two metering
pumps are placed with their walls one on top of the other.
10. The metering device for metering liquids, with at least one
metering pump as set forth in claim 1.
11. The metering device as set forth in claim 10, wherein two or
more metering pumps have a mounting block with a receptacle that is
adapted to the shape of the housing cover of a pump block of the
metering pump and in which the pump block is arranged.
12. The metering device as set forth in claim 11, wherein the two
or more metering pumps are arranged in a stack, wherein two
parallel, flat walls of each of the mounting blocks of two adjacent
metering pumps lie flush one on top of the other.
13. The metering device as set forth in claim 12, further
comprising: a reservoir for the liquid, a common feed duct system
of the metering pumps for the liquid, and a shut-off valve for the
reversible disconnection of the feed duct system from the
reservoir.
14. The metering device as set forth in by claim 10, further
comprising: a device for the detachable connection of the mounting
blocks of two adjacent metering pumps, that are functionally
connected to the mounting blocks to be connected.
15. The metering device as set forth in claim 14, wherein the
device is embodied such that, when the functionally connection of
the device to the mounting blocks to be connected is established,
the mounting blocks are braced against each other.
Description
TECHNICAL FIELD
[0001] The invention relates to metering pumps for liquids,
particularly lubricants, as well as lubricant metering devices for
minimum-quantity cooling lubrication in metalworking.
BACKGROUND
[0002] In metal cutting, it is usually necessary to cool and/or
lubricate the tool during machining in order to achieve the
required quality and extend the service life of the tool. Combined
cooling and lubrication can be achieved, for example, using
conventional emulsion cooling lubrication. The cooling emulsions
used for this contain about 3-6 vol. % of oil-like lubricant in
water. Relatively large quantities of cooling emulsion are needed
which, due to their composition, then require expensive disposal
and can be harmful to health.
[0003] The amount of lubricant needed can be reduced with
minimum-quantity cooling lubrication. With it, small quantities of
viscous lubricant/cutting oil are delivered in a continuous airflow
and applied in a targeted manner onto the tool and/or workpiece
over a short distance as an atomized spray. The airflow
simultaneously provides for cooling.
[0004] The lubricant is applied directly in the cutting area. In
doing so, the quantities of lubricant required are substantially
smaller than with conventional cooling emulsion. Accordingly, the
operating costs are lower. Other advantages of minimum-quantity
cooling lubrication are higher cutting speeds, dry workpieces,
lower environmental burden and less cleaning effort. Since the
machined-off material also remains dry, it is easier to recycle.
Furthermore, no emulsion fogs or vapors are generated that are
harmful to health, which increases workplace safety.
[0005] In order to transport the viscous lubricant to the target
site, small quantities of the lubricant are introduced into a
continuous pressurized airflow and carried along by it. This
occurs, for example, with a coaxial metering nozzle in which an
inner nozzle for the lubricant is arranged within the outer annular
nozzle for the pressurized air.
[0006] In a known system, the lubricant is delivered pneumatically
using pneumatically actuated metering pumps which deliver small
quantities of lubricant via a delivery line to the nozzle and from
there into the airflow. A separate metering pump is used there for
each metering nozzle.
[0007] Such pneumatic metering pumps are known, for example, from
U.S. Pat. No. 3,888,420 and U.S. Pat. No. 4,125,176. In these
metering pumps, a metering piston is pushed by a pulse of
pressurized air in a metering chamber filled with the viscous
lubricant to be delivered, whereby a defined quantity of liquid is
pressed through a non-return valve into a delivery line.
Accordingly, at the other end of the delivery line, the same
quantity of liquid is forced out through a coaxial nozzle into a
continuous pressurized airflow, where it is carried along and
atomized, thus reaching the tool.
[0008] FIG. 1 shows an example of such a metering pump 1 from the
prior art. In a cuboid pump mechanism 10, a cylindrical metering
chamber 12 is arranged in the direction of the longitudinal axis
101. This [metering chamber] is sealed on one side with a stop
valve 131 and connected on the other side to a feed duct system 11.
The feed duct system 11 feeds the liquid 21 to be metered, that is,
the lubricant, into the metering chamber 12. A metering piston 13
that can be actuated by a pneumatic actuator device 16 is arranged
so as to slide along the longitudinal axis 101. The pneumatic
actuator device comprises an actuator piston 163 operatively
connected to the metering piston 14 that is arranged in an actuator
cylinder 162 such that it can slide in the longitudinal direction
101.
[0009] The actuator cylinder 162 is connected to a feed duct system
17 for the pneumatic medium, usually pressurized air. Without
pressurization of the actuator, a return spring 161 presses the
actuator piston in the actuator cylinder into the home position
(toward the left in the depicted example). The front end 141 of the
metering piston is located in a position in which the lubricant 21
can continue to flow from the feed duct 11 into the metering
chamber 12.
[0010] If pressure is now applied to the actuator cylinder 162 via
the feed duct 17, then the actuator piston 163 moves to the right
in the cylinder, and with it the metering piston 14, until the
provided end position is reached. In doing so, the metering piston
first seals the metering chamber off from the feed duct 11 and
subsequently forces the viscous lubricant located within it through
the stop valve 131 into the pump duct 13 and the lubricant delivery
line 45 connected to it.
[0011] Since the metering pump and therefore the cross section of
the actuator piston is relatively small, the pressure must be
commensurately large in order to produce the required force.
Several bar can be necessary. The pressurization occurs as a short
pulse that is produced by a corresponding pressure pulse generator
(not shown). After the end of the pressure pulse, the return
element 161 moves the metering piston 14 again to the left. The
stop valve 131 closes, and liquid 21 continues to flow into the
chamber 12.
[0012] At the longitudinal-side end of the actuator 16, a knob 165
is provided with which the actual can also be operated manually by
pressing the knob.
[0013] In the depicted exemplary embodiment, the position of the
metering piston can be adjusted and adapted in relation to the
actuator piston 163 in the longitudinal direction to a certain
degree. For this purpose, the metering piston can be extended
beyond the actuator piston and provided with an external thread
164. The external thread is screwed into a corresponding continuous
thread of the actuator piston, and the two elements are thus joined
together in a positive manner. When the knob 165 is turned, the
metering piston rotates in the thread of the actuator piston and
moves accordingly in the longitudinal direction 101. The home
position and the end position of the actuator piston in the
actuator cylinder, and hence also the stroke of the metering
piston, is established by appropriate stops. However, by moving the
metering piston, the home position and the end position of the
metering piston can be adjusted and, with it, the actual effective
stroke within the metering chamber that determines the delivered
volume of lubricant per stroke.
[0014] For lubricant metering devices with several lubrication
nozzles, the metering pumps required for them are preferably
supplied via a common lubricant feed. An especially compact device
is known from U.S. Pat. No. 5,725,071 in which the metering pumps
are stacked. Metering pumps for such devices, such as the pump from
FIG. 1, for example, must be designed appropriate for this purpose.
The feed duct system 11 for the liquid 21 in such a metering pump
has an opening 111, 111' on two opposing parallel side walls 102,
102'. A recess 103, 103' around the opening is used to accommodate
a sealing element in the form of an O-ring.
[0015] Several such identical, individual metering pumps 1, 1a, 1b
embodied as cuboid pump blocks 10 are combined into a stack as
shown schematically in FIG. 2 in a cross section through the feed
duct 11. The openings 111, 111' of the feed duct system are
arranged here such that, when the pump blocks are stacked, the
openings of adjacent metering pumps lie one on top of the other,
with an O-ring 104 or another suitable sealing means ensuring a
sealing connection. This results in a continuous feed line for the
pump stack 42 comprising the individual feed duct systems 11
connected in a sealing manner. At its lower end, the feed line is
sealed by a closure block 414 and at its upper end by a connection
block 415 for the feed line 46, which is connected to a reservoir
43 for the liquid. The liquid flows by force of gravity from the
reservoir 43 to the pumps. Alternatively, delivery into the feed
can be achieved through the constant application of pressure.
[0016] Analogously, in the metering pump 1 from FIG. 1, the feed
duct system 17 for the pneumatic medium is also embodied such that,
when several metering pumps are stacked, a common feed line
results. In this way, several metering pumps can be operated
simultaneously by a single pulse of pressurized air.
[0017] In the example shown, the pump blocks 10 of the standardized
metering pumps 1, 1a, 1b are arranged between two clamping plates
413 that press the pump blocks 10 along the stack axis in a
positive and nonpositive manner by means of clamping bolts 410 and
nuts 411. This enables cost-effective manufacturing of the entire
lubricant metering device 4, with the number of pumps being
changable as needed. In this way, the individual lubricant metering
devices can be adapted efficiently to individual customer
preferences. Only the length of the clamping bolts 410 need be
selected accordingly.
[0018] The pump stack of such a conventional metering device
enables trouble-free assembly. However, if a malfunction occurs in
a single metering pump during operation and it needs to be changed
out for repair, then the entire pump stack 42 has to be emptied,
disassembled and broken down. This leads to expensive down time of
the affected metalworking machines. The danger of missing scheduled
maintenance cycles is also just as great, which can then lead to
even greater malfunctions.
Object of the Invention
[0019] It is one object of the invention to provide metering pumps
for liquids, particularly lubricant, and lubricant metering devices
for metal cutting which do not have the drawbacks of the prior
art.
[0020] Particularly, the intention is to enable the individual and
efficient construction of such lubricant metering devices. The
individual metering pumps of such a lubricant metering device and
their faster-wearing parts are to be exchangeable in a quick and
simple manner.
[0021] It is another object of the invention to provide lubricant
metering devices and metering pumps for such devices for which
there are shorter down times as a result of maintenance work.
[0022] In addition, such lubricant metering devices and metering
pumps are to be manufacturable in an efficient and cost-effective
manner.
[0023] These and other objects are achieved by an inventive
lubricant-metering pump and an inventive lubricant metering device
according to the independent claims. Additional advantageous
embodiments are described in the dependent claims.
Description of the Invention
[0024] The inventive metering pump for metering liquids has at
least one pump block comprising a first feed duct system for the
liquid to be delivered, a pump duct, and a pump device for pumping
the liquid from the feed duct system into the pump duct. The pump
block has a housing cover in the form of a cylinder or a truncated
cone, and the feed duct system leads to at least one opening
arranged in the housing cover.
[0025] Advantageously, the pump device of the metering pump has a
metering chamber connected to the first feed duct system, a
metering piston arranged so as to be slidable in the metering
chamber along an axis, and an actuator device for moving the
metering piston along the abovementioned axis, the metering piston
being set up to pump a certain quantity of the liquid present in
the metering chamber through a stop valve into the pump duct.
[0026] Also advantageously, the actuator device of the metering
pump is set up to operate the metering piston electromagnetically
or pneumatically.
[0027] An especially advantageous variant of a metering pump
according to the invention has a pneumatic actuator device that can
be driven through a pneumatic medium, particularly pressurized air,
and a second feed duct system for the pneumatic medium for
operating the pneumatic actuator device. This second feed duct
system leads to at least one opening arranged in the housing
cover.
[0028] The actuator device can have a return element for the
metering piston, for example a return spring.
[0029] An especially advantageous embodiment of a metering pump
according to the invention has a mounting block with at least one
receptacle that is adapted to the shape of the housing cover of the
pump block. The pump block can be arranged flush in the receptacle.
Such a metering pump can comprise means for fixing the pump blocks
in the receptacle of the mounting block. Advantageously, such a
metering pump comprises recess, particularly a circumferential
groove on the housing cover of the pump blocks, as well as a screw
arranged in a continuous threaded hole in the mounting block, the
groove, threaded hole and screw being embodied and arranged such
that, when a pump block is mounted, the screw can engage reversibly
with the groove, thus enabling the reversible positive attachment
of the pump block in the mounting block in the direction of the
longitudinal axis. Especially advantageously, the screw is made of
a material that has a lesser hardness than the cover of the pump
block. For example, if the cover is made of steel or brass, then
the screw can be made of a polymer, for example.
[0030] The mounting block of an advantageous embodiment of such a
metering pump according to the invention has a third feed duct
system for the liquid. A circumferential groove is provided on the
wall of the receptacle that is connected to the third feed duct
system. The groove is arranged such that the at least one opening
of the first feed duct system of a pump block arranged in the
mounting block overlaps with the first circumferential groove, so
that the first and third feed duct systems form a continuous feed
duct system for liquid.
[0031] The mounting block of another advantageous embodiment of
such a metering pump according to the invention has a third feed
duct system for the liquid that leads to at least one opening
arranged in the wall of the receptacle. A first circumferential
groove is provided on the housing cover of the pump block arranged
in the mounting block that is connected to the first feed duct
system. The groove is arranged such that the at least one opening
of the third feed duct system overlaps with the first
circumferential groove, so that the first and third feed duct
systems form a continuous feed duct system for liquid.
[0032] Especially advantageously, such metering pumps have sealing
elements that are arranged in the receptacle of the mounting block
and/or around the housing cover of the pump blocks along the
periphery. They are suited to connecting the at least one opening
of the first feed duct system or of the third feed duct system and
the first circumferential groove in a sealing manner.
[0033] The mounting block of the metering pump can have a fourth
feed duct system for pneumatic medium, and a second circumferential
groove on the wall of the receptacle that is connected to the
fourth feed duct system. The groove is arranged such that the at
least one opening of the second feed duct system of a pump block
arranged in the mounting block overlaps with the second
circumferential groove, so that the second and fourth feed duct
systems form a continuous feed duct system for pneumatic
medium.
[0034] Likewise, in another embodiment of the mounting block, the
metering pump can have a fourth feed duct system for pneumatic
medium that leads to at least one opening arranged in the wall of
the receptacle. A second circumferential groove is provided on the
housing cover of a pump block arranged in the mounting block that
is connected to the second feed duct system and is arranged such
that the at least one opening of the fourth feed duct system
overlaps with the second circumferential groove. The second and
fourth feed duct systems thus form a continuous feed duct system
for pneumatic medium.
[0035] In this case as well, it is especially advantageous if such
metering pumps have sealing elements that are arranged in the
receptacle of the mounting block and/or around the housing cover of
the pump block along the periphery and that are suited to
connecting the at least one opening of the second feed duct system
or of the fourth feed duct system and the second circumferential
groove in a sealing manner.
[0036] Advantageously, the mounting block of a metering pump
according to the invention has two parallel, flat walls. Such a
metering pump offers the advantage that it can be assembled in a
stack and thus saves space.
[0037] In an especially advantageous variant, the mounting block
has two parallel, flat walls, and the third feed duct system leads
to an opening on both walls. The two openings are arranged such
that one opening coincides with a corresponding opening of another
identical metering pump when the two metering pumps are placed with
their walls one on top of the other.
[0038] Analogously, the mounting block can have two parallel, flat
walls, and the fourth feed duct system leads to an opening on both
walls, the two openings being arranged such that one opening
coincides with a corresponding opening of another identical
metering pump when the two metering pumps are placed with their
walls one on top of the other.
[0039] A lubricant metering device according to the invention has
at least one inventive metering pump.
[0040] In an advantageous variant, a lubricant metering device
according to the invention has two or more inventive metering
pumps, these having a mounting block with a receptacle that is
adapted to the shape of the housing cover of a pump block of the
metering pump and in which the pump block can be arranged and fixed
so as to be flush.
[0041] In an especially advantageous embodiment, two or more
metering pumps are arranged in a stack in such a lubricant metering
device according to the invention, with two parallel, flat walls of
the mounting blocks of two adjacent metering pumps lying flush one
on top of the other. A lubricant metering device can further
comprise a reservoir for the liquid, a common feed duct system of
the metering pumps for the liquid, and a stop valve for the
reversible separation of the feed duct system from the
reservoir.
[0042] Advantageously, in such an embodiment of a lubricant
metering device according to the invention, a means is provided for
the detachable connection of the mounting blocks of two adjacent
metering pumps. Especially advantageously, this connection means
comprises clips or clamps that are connected in a non-positive
manner to the mounting blocks to be connected.
[0043] Preferably, these clips or clamps are embodied such that,
when the non-positive connection of the clips or clamps to the
mounting blocks to be connected is established, the mounting blocks
are braced against each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] To facilitate understanding of the present invention,
reference is made in the following to the drawings, which merely
show exemplary embodiments of the object of the invention.
[0045] FIG. 1 shows a schematic view of a longitudinal section
through a pneumatic lubricant-metering pump as is known from the
prior art.
[0046] FIG. 2 shows a schematic cross section through lubricant
metering devices with several stacked metering pumps as is known
from the prior art.
[0047] FIG. 3 shows a schematic view of one embodiment of a
metering pump according to the invention (a) as a longitudinal
section only through the pump block, (b) as a longitudinal section
only through the mounting block, (c) as a cross section only
through the mounting block along the plane A-A, and (d) as a
longitudinal section through the mounting block and pump block in
the assembled state.
[0048] FIG. 4 shows a schematic cross section through two metering
pumps from FIG. 3 in a stacked arrangement.
[0049] FIG. 5 shows a schematic view of detail of an embodiment of
a metering pump according to the invention with longitudinal-side
attachment of the pump block in the mounting block.
[0050] FIG. 6 shows a schematic view of detail of an embodiment of
a metering pump according to the invention with lateral attachment
of the pump block in the mounting block.
[0051] FIG. 7 shows a schematic view of a variant of a metering
pump according to the invention in which the circumferential
grooves of the feed duct system are arranged on the cylindrical
cover 15 of the pump block (a) as a longitudinal section through
the mounting block and pump block in the assembled state, and (b)
as a longitudinal section only through the mounting block.
[0052] FIG. 8 shows a schematic view of a longitudinal section (a)
through an especially advantageous variant of a metering pump
according to the invention, and (b) only through the mounting
block.
[0053] FIG. 9 shows a side view of the pump block of yet another
especially advantageous embodiment of a metering pump according to
the invention.
[0054] FIG. 10 shows a mounting block fitting with the pump block
from FIG. 9, (a) in a top view of the mounting block, (b) in a side
view of the mounting block, (c) in a longitudinal section through
the two side walls of the mounting block along the plane A-A, (d)
in a cross section through the plane B-B, (e) in a cross section
through the plane C-C, and (f) in a cross section through the plane
D-D.
[0055] FIG. 11 shows an advantageous clip for the positive and
nonpositive connection of two metering pumps according to the
invention (a) in a top view, and (b) in a section through the plane
F-F.
[0056] FIG. 12 shows another mounting block fitting with the pump
block from FIG. 9, with a connection for a reservoir and a shut-off
valve (a) in a top view of the mounting block, (b) in a side view
of the mounting block, (c) in a longitudinal section through the
two side walls of the mounting block along the plane A-A, (d) in a
cross section through the plane C-C, and (e) showing a shut-off
valve for the lubricant feed.
[0057] FIG. 13 shows a cross section through a metering device
according to the invention, with a reservoir and one respective
metering pump according to the invention from FIG. 12 and FIG. 15,
in a stacked arrangement.
[0058] FIG. 14 shows another possible mounting block fitting with
the pump block from FIG. 9, with two receptacles for pump blocks
(a) in a top view of the mounting block, (b) in a side view of the
mounting block, (c) in a longitudinal section through the two side
walls of the mounting blocks along the plane A-A, (d) in a cross
section through the plane B-B, (e) in a cross section through the
plane C-C, and (f) in a cross section through the plane D-D.
[0059] FIG. 15 shows a schematic cross section of yet another
advantageous embodiment of a mounting block fitting with the pump
block from FIG. 9, with receptacles for two pump blocks and with a
connector for a reservoir and a shut-off valve.
IMPLEMENTATION OF THE INVENTION
[0060] The examples given below are being provided in order to
better illustrate the present invention but are not intended to
limit the invention to the features disclosed therein.
[0061] FIG. 3 shows a schematic view of an advantageous embodiment
of a metering pump according to the invention. The metering pump
comprises a substantially cylindrical pump block 10 that is
arranged in an appropriately shaped mounting block 30.
[0062] The pump block 10 contains the actual pneumatic pump device
that corresponds to the pump device from FIG. 1 in terms of its
functional principle. A cylindrical metering chamber 12 is arranged
in the pump body 10 in the direction of the longitudinal axis 101
that is closed on one side with a stop valve 131 and is connected
on the other side to a feed duct system 11. A metering piston 14 is
arranged so as to be slidable along the longitudinal axis and is
operated by a pneumatic actuator device 16. The pneumatic actuator
device 16 comprises an actuator piston 163 operationally connected
to the metering piston 14 that is arranged so as to be slidable in
the longitudinal direction in an actuator cylinder 162. The
actuator cylinder 162 is connected to a feed duct system 17 for the
pneumatic medium. Without the pressurization of the actuator, a
return spring 161 presses the actuator piston in the actuator
cylinder into the home position (as shown).
[0063] If pressure is applied to the actuator cylinder 162, then
the actuator piston 163 and the metering piston 14 move to the
right, and the viscous lubricant located in the metering chamber 12
is pressed through the stop valve 131 into the pump duct 13 and the
lubricant delivery line 45. In the example shown, the lubricant
delivery line 45 is connected in a sealing manner to the pump block
10 via a corresponding threaded connection piece 451.
[0064] After the end of the pressure pulse, the return element 161
moves the metering piston 14 to the left again back into the home
position. The stop valve 131 closes, and liquid continues to flow
from the feed duct system 11 into the chamber 12.
[0065] A knob 165 is provided on the longitudinal-side end of the
actuator 16 with which the actuator can be manually operated. The
position of the metering piston in relation to the actuator piston
163 can be adjusted in the longitudinal direction in order to
adjust the effective stroke within the metering chamber. The
metering piston extended beyond the actuator piston is provided
with an external thread that is screwed into a corresponding
internal thread of the actuator piston. By turning the knob 165,
the metering piston moves relative to the actuator piston.
[0066] The mounting block 30 has a cuboid outer shape. The metering
pump, analogously to the one-piece metering pumps according to FIG.
1, can therefore be assembled in a stacking manner. A cylindrical
hollow space is provided within the mounting block in alignment
with the longitudinal axis 101 that serves as a receptacle 31 for
the cylindrical pump block 10. A first longitudinal-side opening
312 serves as an insertion opening for the pump block 10 into the
mounting block 30. A second longitudinal-side opening 313 enables
access to the convection for the delivery line delivery line
45.
[0067] Two circumferential flutes 33, 36 are arranged in the
mounting block 30 on the inner wall 311 of the receptacle 31. These
flutes or grooves or recesses are connected to a third 32 or fourth
35 feed duct system arranged in the mounting block. In the example
shown, the cuboid mounting block 30, on two opposing walls 302,
303, has two openings of the third feed duct system 32 for the
liquid to be pumped. Likewise, two corresponding openings of the
fourth feed duct system 35 are provided for the pneumatic medium.
The openings of the third and fourth feed duct systems are arranged
such that, when equivalent metering pumps according to the
invention are placed in a stacked arrangement, the mutually
corresponding openings of adjacent metering pumps lie one over the
other. O-rings 104 or other suitable sealing means are arranged in
corresponding circular recesses 103 and ensure a sealing connection
between the individual metering pumps.
[0068] In the depicted embodiment, the position of the recesses 33,
36 in the lateral surface 311 of the receptacle 31 is selected such
that, in the assembled metering pump 1, the openings 111, 111',
171, 171' of the first feed duct system 11 and of the second feed
duct system 17 lie on the lateral surface 15 of the pump block 10
on the corresponding flutes 33, 36 on the inner wall 311. When seen
in the longitudinal direct ion 101, sealing elements 331, 331' or
361, 361' are arranged on both sides of the openings 111, 111' and
171, 171' circumferentially around the cylindrical cover 15 of the
pump block 10. In the example shown, these are O-rings that are
arranged in corresponding recesses on the lateral surface 15. The
abovementioned sealing elements ensure a sealing connection between
the first 11 and third 32 feed duct system or the second 17 and
fourth 36 feed duct system. This results in a continuous feed duct
system 11, 31, 32 within the metering pump 1 for the liquid to be
delivered, as well as a continuous feed duct system 17, 35, 36 for
the pneumatic fluid.
[0069] One great advantage of such a configuration of the metering
pump 1 according to the invention is the fact that the pump block
can be mounted in any position in the mounting block in relation to
the rotational position around the longitudinal axis 101.
Independently of the rotational alignment of the pump block 10, a
continuous connection is ensured via the grooves 33, 36. This
facilitates the installation of the pump block 1 of a metering pump
1 according to the invention that need substantially only be pushed
into the receptacle of the mounting block until reaching the
longitudinal-side stop 314.
[0070] The housing cover 15 of the pump block 10 and the receptacle
31 of the mounting block 30 advantageously have as little backlash
as possible. Consequently, the sealing rings and their mounting
grooves can be dimensioned such that the sealing rings are
plastically deformed as little as possible in an assembled metering
pump and have a commensurately longer service life. In practice,
the manufacturing tolerance of the cover 15 and receptacle 31 is
advantageously set at 5 micrometers or less. Accordingly, such
precise dimensioning also necessitates careful handling of the pump
block cover 15 during transport and assembly.
[0071] FIG. 4 shows a section from a stack 42 of inventive metering
pumps 1, 1 a according to FIG. 3, in cross section through the feed
duct system 11 for the lubricant. As can be seen, the pump block 10
is arranged in one metering pump 1 such that the first feed duct
system 11 is aligned with the third feed duct system 32. In the
other metering pump 1a, in contrast, the pump block 10a is rotated
with respect to the mounting body mounting body 30a. Nonetheless,
the first feed duct system 11a is connected to the third feed duct
system 32a via the circumferential groove 33a. The orientation of
the pump blocks 10 is not relevant to the function of the metering
pump.
[0072] Such a metering pump according to the invention further
makes it possible to quickly and efficiently change out those parts
of the pump having moveable parts and therefore requiring
maintenance without having to break down a metering device 4
consisting of several stacked metering pumps, as is the case with
the prior art. The supply of lubricant and the pneumatics must
merely be interrupted temporarily and the delivery lines
disconnected. The pump block is then removed from the mounting
block and a new pump block with fresh sealing elements is inserted.
Upon connection of the delivery line and opening of the feed lines,
the metering device can immediately be put back into operation. The
removed pump block can then be subsequently inspected or repaired
separately.
[0073] The inventive configuration of the metering pump also offers
the advantage that existing metering devices can be retrofitted
with inventive metering pumps if they are compatible in terms of
the dimensioning of the mounting blocks and the connection
elements. When breaking down a lubricant metering device according
to the prior art (like in FIG. 2, for example), a defective
metering pump can be replaced by a metering pump according to the
invention. If it needs to be checked later, it is no longer
necessary to break the stack down, however, but rather the pump
block is merely exchanged.
[0074] In an alternative configuration, the first feed duct system
of the pump block could also be embodied as a blind hole instead of
as a continuous hole. A single opening that is connected to the
groove is substantially sufficient in order to ensure the feeding
of lubricant into the metering chamber. However, the use of a
continuous duct offers the advantage that the ventilation functions
better upon the initial filling of the metering pump.
[0075] In the example shown in FIG. 12 of a metering pump according
to the invention, the pump block 10 is not fixed in the
longitudinal direction 101, which is also not necessary, since no
forces occur in the longitudinal direction between the pump block
and the mounting block. The longitudinal-side stop 314 ensures
correct positioning. In another version, however, fixing means 34
can be provided in order to attach the pump positively and/or
nonpositively in the mounting block. For example, a cap nut or
similar means can be provided at the first opening 312 in order to
block the pump block in the receptacle 31.
[0076] Likewise, the pump block and mounting block can be provided
with a bayonet coupling mechanism, or the pump block is secured
with a Seeger ring.
[0077] FIG. 5 shows another possible variant for the fixation of
the pump block 10 in the mounting block 30, in a longitudinal
section through the rear end of the metering pump. In this
exemplary embodiment, the connection piece 451 is provided with a
continuous external thread that is screwed into the pump block on
one end. Also arranged on the external thread is a nut 452 that is
supported on the rear end of the mounting block, thus fixing the
pump block in a positive manner in the receptacle of the mounting
block.
[0078] FIG. 6 shows an embodiment of a metering pump 1 according to
the invention in which a screw 341 is provided in a slotted hole
343 in the side wall of the mounting block 30 that is capable of
engaging in a circumferential groove 342 in the pump block provided
for this purpose in order to positively fix the longitudinal
position of the pump block 10 in the receptacle 31. FIG. 6 shows a
cross section in the area of the actuator cylinder 162 through the
circumferential fixing groove 342. Such a solution is especially
advantageous, since it is space-saving and cost-effective. The
groove 342 makes it possible to mount the pump block in the
mounting block without exact angular orientation.
[0079] The fixing screw 341 is advantageously made of a stable
plastic or a soft metal. This is sufficient for the positive
fixation. At the same time, if the pump block is not inserted
completely into the mounting block, the fixing screw 341 is
prevented from being pressed into the cylindrical cover and
deforming and damaging the latter. Since a screw 341 made of
plastic or soft metal has a lower hardness than the cylindrical
cover of the pump block, the screw is deformed instead.
[0080] FIG. 7 shows a schematic view of a variant of a metering
pump according to the invention in which the circumferential
grooves are arranged on the cylindrical cover 15 of the pump block.
Such a variant offers the advantage over the embodiment from FIG. 2
that the mounting body is simpler to manufacture.
[0081] FIG. 8 shows another advantageous embodiment of an inventive
metering pump 1 in which a third 51 and a fourth 52 circumferential
groove are arranged on the lateral surface 311 of the receptacle
31. The third groove 53 is connected to a pump duct 13' arranged in
the side wall of the mounting block 30 for the lubricant to be
pumped, which pump duct 13' is connected to the delivery line (not
shown). The pump duct 13 in the pump body opens on two sides toward
the groove 51. Such a configuration of the metering pump 1 makes it
possible to arrange the connection for the delivery line on the
mounting block 30 instead of on the pump block 10. Accordingly,
when the pump block 10 is changed out, the delivery line 45 no
longer needs to be disconnected, which further simplifies the
exchange.
[0082] The fourth groove 52, in turn, is connected to a vent duct
53 in the side wall of the mounting blocks 30, which is open to the
outside. The pump block 10 has one or more holes 54 that open on
the lateral surface 15 toward this fourth groove 53 and are
connected to the volume opposite the pressurized side of the
cylinder 162. This offers the advantage that the actuator piston
163 always works against external pressure, so no relevant
counterpressure occurs when the piston moves, and no warming
occurs. In an advantageous variant, the groove 53 can
simultaneously be used as a fixing groove 342 for a fixing screw
341 as shown in FIG. 6.
[0083] The vent ducts 53, 54 are connected in a sealing manner by
sealing elements 521, 521' circumferentially arranged on the cover
15, the sealing elements 521', 331 being identical. Analogously,
the sealing elements 511, 511' connect the delivery channels 13',
13. An opening in the longitudinal-side end of the mounting block
serves to ventilate the interior of the mounting block upon
insertion of the pump block.
[0084] FIG. 9 shows the pump block 10 of another advantageous
embodiment of an inventive metering pump 1 which has a similar
construction as the metering pump from FIG. 8. The openings of the
feed duct 11 for the liquid, of the feed duct 17 for the
pressurized air, of the vent duct 54 and of the pump duct 13 are
arranged on a line. The individual sealing elements are not shown
so that the corresponding grooves in the cover 15 of the pump block
362, 362', 522, 512 are visible. Only one sealing element is
provided for the pump duct 13 and is arranged in the groove 512. As
will be explained below in relation to FIG. 10, this is sufficient
for the seal, since the longitudinal-side end of the receptacle of
the mounting block 30 has a closed design.
[0085] The depicted pump block 10 can be built into a mounting
block 30 according to FIG. 10, for example. In this example, the
vent duct 53 and the pump duct 13' open toward a first side wall
301 of the mounting block. The feed duct 35 for the pressurized air
is arranged parallel to the feed duct 32 for the lubricant but does
not run through the longitudinal axis 101, but rather intersects
tangentially with the groove 36. A branch 35' of the feed duct 35
opens toward a second side wall 301' of the mounting block 30. A
feed line of a pressurized air pulse generator can be connected to
the corresponding connection opening. The corresponding air pulse
can thus be forwarded via the feed duct 35 to the adjacent metering
pumps. If the connection 35' is not needed, for instance because
the pressurized air pulse is being delivered from another metering
pump, then the opening 35' can be tightly sealed off by means of an
appropriate closure element (not shown).
[0086] Another advantage of the depicted mounting block 30 is an
advantageous, novel connection 41 of the individual metering pumps
into a stack. For this purpose, two T-shaped recesses 416 are
provided on both side walls for a clip 412. The corresponding clip
412 is shown in FIG. 11. In order to positively and nonpositively
connect two metering pumps stacked one on top of the other, the
clip 412 is screw-connected with both mounting blocks 30.
Corresponding holes 419 and threaded holes 418 are provided on the
mounting block and on the clip. Here, the clip is advantageously
dimensioned such that, upon screwing, force is applied in the
longitudinal direction of the clip which braces the two mounting
blocks against each other. Accordingly, the clamping bolts used in
the prior art can be omitted, which reduces the space requirements
of a lubricant metering device according to the invention compared
to the prior art.
[0087] If the external dimensions of such a metering pump according
to the invention are appropriately selected, however, then it is
also compatible with the conventional attachment system with
clamping bolts, so existing lubricant metering devices can be
retrofitted, for example, with individual metering pumps according
to the invention.
[0088] FIG. 12 shows a special variant of such a mounting block 30.
This mounting block has on its upper wall 302 a connector 431 for a
corresponding connection element (not shown) of a lubricant supply
unit. This connector is connected to a feed duct that is arranged
tangentially to the groove 36, it being possible to reversibly
interrupt this connection by means of a stop valve in the form of a
shut-off valve 44.
[0089] FIG. 13 shows such an inventive metering device 4 with a
lubricant supply unit with reservoir 43, as well as one inventive
metering pump 1, 1a from FIG. 12 and FIG. 15 in a stacked
arrangement. The reservoir 43 is a reservoir that is substantially
known from the prior art for minimum-quantity cooling lubrication,
with appropriate venting and filtering devices, etc., which need
not be discussed here in further detail. A feed line 46 leads to a
connection piece 432 that is screwed into the corresponding
connection opening 431 of a metering pump 1 according to FIG. 15.
Das shut-off valve 44 separates the reservoir 43 from the feed duct
system 32. A second metering pump 1a according to FIG. 12 is
connected to the first metering pump 1 by means of two clips 412.
In turn, this second metering pump 1a is sealed on its lower wall
303 with a closure block 414. In the example shown, this closure
block is screwed into corresponding holes 314 of the metering pump
1a. Alternatively, clips can also be used.
[0090] During normal operation, the shut-off valve 44 is constantly
open. When a pump block needs to be exchanged, then the shut-off
valve 44 is closed after the pressure pulse generators (not shown)
are shut off. The pump block can be removed without having to empty
the lubricant feed duct system 32. After insertion of the new pump
block, the valve 44 must only be opened again and the metering
device 4 according to the invention is again ready for
operation.
[0091] Another variant of such a mounting block 30 is disclosed in
FIG. 14. In this advantageous embodiment, the mounting block 30 has
two receptacles 31, 31a for two pump blocks. Each of the two
receptacles 31, 31a has its own connector 35' for the pressurized
air feed. Accordingly, the pressurized air can be [supplied] via
one of these two connectors, the other being sealed. Both
connectors can also be sealed, so that the pressurized air feed is
provided by an adjacent mounting block via the feed duct system
35.
[0092] Accordingly, such a mounting block 30 can also be
implemented with a connector 431 for the lubricant feed, as shown
in FIG. 15.
[0093] In another advantageous embodiment, a special connection
block is provided for the lubricant feed in which a connection
opening 431 for a feed duct system 32 is provided that can be
closed by a shut-off valve 44. Analogously to the mounting blocks
discussed above, the feed duct system can be connected to the feed
duct system from additional mounting blocks. Accordingly, such an
advantageous connection block offers special advantages not only
for metering devices with inventive metering pumps, but also for
metering devices with cuboid-shaped metering pumps according to
FIG. 2. In both cases, such an inventive connection block makes it
possible to change out metering pumps without having to remove the
lubricant container, given that the supply is disconnected using
the shut-off valve 44.
[0094] The content of all of the documents cited in this
application constitutes, by reference, an integral component of the
disclosure.
[0095] The disclosed specific embodiments are not intended to limit
the scope of the present invention. For the person skilled in the
art, various possible variations and modifications in addition to
the disclosed examples follow from the above description and the
drawings that also fall under the scope of protection of the
claims.
LIST OF REFERENCE SYSTEM
[0096] 1, 1a, 1b, 1c metering pump
[0097] 10, 10a pump block
[0098] 101 longitudinal axis
[0099] 102, 102' side wall
[0100] 103 recess for sealing element
[0101] 104 sealing element, sealing ring
[0102] 11, 11 a first feed duct system for liquid
[0103] 111, 111' opening
[0104] 12 metering chamber, metering cylinder
[0105] 13, 13' pump duct
[0106] 131 stop valve
[0107] 132 return spring of the stop valve
[0108] 14 metering piston
[0109] 141 front end of the piston
[0110] 142 axis of the metering piston
[0111] 15 housing cover, housing
[0112] 16 actuator device
[0113] 161 return element, return spring
[0114] 162 cylinder of the pneumatic actuator device
[0115] 163 piston of the pneumatic actuator device
[0116] 164 adjustment threads for metering piston position
[0117] 165 rotating knob, manual operation
[0118] 17 second feed duct system for pressurized air
[0119] 171, 171' opening
[0120] 21 liquid, lubricant
[0121] 22 pressurized air, pneumatic medium
[0122] 30, 30a, 30b mounting block
[0123] 301, 301' side wall
[0124] 302 upper wall
[0125] 303 lower wall
[0126] 304 blind hole with internal threads
[0127] 31, 31a receptacle
[0128] 311 wall of the receptacle
[0129] 312 insertion opening
[0130] 313 second opening
[0131] 314 stop
[0132] 32, 32a third feed duct system for liquid
[0133] 321, 321' opening
[0134] 33 first circumferential groove for liquid
[0135] 331, 331' sealing element, sealing ring
[0136] 332, 332' recess for sealing element
[0137] 34 fixing means
[0138] 341 screw
[0139] 342 groove
[0140] 343 threaded hole
[0141] 35, 35', 35a fourth feed duct system for pressurized air
[0142] 351, 351' opening
[0143] 36 second circumferential groove for pressurized air
[0144] 361, 361' sealing element, sealing ring
[0145] 362, 362' recess for sealing element
[0146] 4 lubricant metering device
[0147] 41 connection means
[0148] 410 clamping bolts
[0149] 411 nut
[0150] 412 clip, bracket
[0151] 413 clamping plates
[0152] 414 closure block
[0153] 415 connection block
[0154] 416 recess for clip, bracket
[0155] 418 blind hole with internal threads
[0156] 419 hole
[0157] 42 pump stack
[0158] 421 axis of the pump stacks
[0159] 43 reservoir
[0160] 431 mounting opening for connection element
[0161] 432 connection element
[0162] 44 shut-off valve
[0163] 441 mounting opening for shut-off valve
[0164] 45 delivery line for the lubricant
[0165] 451 connection piece delivery line
[0166] 452 nut
[0167] 46 feed line
[0168] 51 third circumferential groove
[0169] 511, 511' sealing element, sealing ring
[0170] 512, 512' recess for sealing element
[0171] 52 fourth circumferential groove
[0172] 521, 521' sealing element, sealing ring
[0173] 522, 522' recess for sealing element
[0174] 53 vent duct
[0175] 54 vent duct
* * * * *