Flow measuring device

A flow measuring device, especially for coolant guided through injection molds, is provided. The flow measuring device has a coolant inlet, a coolant outlet leading to an injection mold, a shut-off valve disposed between the coolant inlet and the coolant outlet, a flow meter having an inlet for receiving coolant from the injection mold and an outlet, a flow control valve disposed upstream of the outlet of the flow meter, and a common control mechanism for the shut-off valve and the flow control valve.

BACKGROUND OF THE INVENTION 
The present invention relates to a flow measuring device, especially for 
coolant guided through injection molds. 
Flow measuring devices are always required when the quantity of flow of a 
fluid through an apparatus, for example the quantity of a coolant through 
an injection mold, is to be controlled or regulated. 
Commercially available flow measuring devices for coolant guided through 
injection molds have a complicated construction, have an impractical 
construction with respect to their various connections, and require 
separate controls for a generally available shut-off valve, which is 
disposed upstream of the injection mold, and for a flow control valve, 
which is disposed downstream of a flow meter that is a part of the flow 
control valve. 
It is therefore an object of the present invention to provide a flow 
measuring device that has a simple and easy to understand construction, 
the connections of which are grouped in a logical and space-saving manner 
and require no separate control of the valves that are present on the flow 
measuring device. 
SUMMARY OF THE INVENTION 
Starting from this objective it is proposed with a flow measuring device of 
the aforementioned type having a coolant inlet and a coolant outlet to the 
injection mold that pursuant to the present invention there be provided a 
shut-off valve between the coolant inlet and the coolant outlet, a flow 
meter having an inlet for coolant coming from the injection mold and an 
outlet adjacent the coolant inlet, a flow control valve ahead of the 
outlet that is adjacent to the coolant inlet, and a common control means 
or mechanism for the shut-off valve and the flow control valve. In this 
connection, the coolant inlet can preferably be disposed adjacent to the 
outlet, the shut-off valve adjacent to the flow control valve, and the 
common control mechanism in or on a valve block. 
In this way, the connections for the coolant are disposed very close to one 
another on the valve block, so that in a logical and space-saving manner 
the connection to a coolant supply line, a coolant return line, a 
connecting line from the valve block to an injection mold, and a return 
line from the injection mold can be established in a simple manner. 
It is particularly advantageous if the coolant inlet and the outlet 
disposed adjacent thereto be disposed in the valve block as parallel 
through-bores that extend from one side face to the parallel other side 
face, since then several valve blocks having aligned and sealed bores can 
be bolted together at their adjoining side faces. 
From each of these bores, respective parallel bores can branch off 
perpendicularly, with one leading to the coolant inlet and the other 
establishing the connection to the flow meter and accommodating the 
shut-off valve and the flow control valve, which are preferably disposed 
coaxially on a shaft that is perpendicular to the bores. 
The flow meter can preferably be a float element flow meter having a 
conical, vertical tube that at least in a portion as viewed in the 
longitudinal direction is transparent and graduated, with a float element 
being disposed in the tube; the upper end of the tube is disposed in a 
sealed manner in the valve block ahead of the flow control valve, and the 
lower end is detachably held by a carrier that is connected to the valve 
block, with the inlet for the coolant that comes from the injection mold 
being disposed directly at the lower end of the tube. 
A particularly straightforward and easy to seal off embodiment of the 
shut-off valve and of the flow control valve can have coaxially disposed, 
rotatable plugs, whereby for better control of the fluid flow through the 
flow control valve, the flow cross-section of the shut-off valve can be 
greater than that of the flow control valve. 
In addition to this measure, or in place of the different flow cross 
sections, is also possible for the opening cross-section of the shut-off 
valve to increase more rapidly than does that of the flow control valve 
upon actuation of the common control mechanism. 
The simplest common control mechanism can comprise a shaft that is coaxial 
to the plugs, by means of which the plugs can be coupled together, whereby 
these plugs can be simultaneously opened and closed by a control knob 
either directly or accompanied by the interposition of a gear arrangement. 
In order to achieve a state where the shut-off valve constantly exposes a 
cross-sectional area of such a magnitude that the pressure loss in the 
shut-off valve is negligible relative to that in the flow control valve, 
it is also possible for the shut-off valve and flow control valve to be 
coupled together in such a way that first the shut-off valve and 
thereafter the flow control valve are opened. 
This can be achieved, for example, by a cam control for the shut-off valve 
and for the flow control valve that can preferably be embodied in such a 
way that an axially displaceable, driveable wheel is disposed on the 
coaxial shaft between the two plugs, whereby this wheel is provided on 
each side face with a cam-like elevation that cooperates with 
corresponding abutments on the valve block; the elevations are offset 
relative to one another by at least 90.degree. in such a way that upon 
rotation the wheel is axially shifted in the direction of the shut-off 
valve or in the direction of the flow control valve and then by means of 
driver means that can be coupled thereby either the plug of the shut-off 
valve or the plug of the flow control valve is rotated. 
The cam-like elevations can be disposed on the side faces of the wheel in 
such a way that first the shut-off valve is coupled with the wheel, while 
the flow control valve is uncoupled, so that a first rotation of the 
wheel, for example by 90.degree., effects the complete opening of the plug 
of the shut-off valve, whereafter the wheel is uncoupled from the shut-off 
valve and is coupled with the flow control valve, as a result of which a 
further rotation of the wheel effects the sensitive controllable opening 
of the flow control valve. 
In particular, the driver means can comprise driver discs that are fixedly 
disposed on the shaft that is connected with the plug, on both sides of 
the base, with each driver disc having an axially parallel bore on each 
side of the wheel and axially parallel coupling pins that can be brought 
into and out of engagement with one or the other of the bores by the axial 
displacement of the wheel. 
If these coupling pins are spring mounted in an axially parallel bore in 
the wheel, the wheel can be axially shifted by the cam-like elevations 
without jamming occurring between the driver discs. 
In order to be able to drive the wheel in a simple manner, it can be 
embodied as a gear wheel and can be rotated by a pinion on an axially 
parallel shaft by means of a control knob. The width of the gear wheel 
must then exceed the width of the pinion approximately by the axial path 
of displacement toward both sides. 
For the particularly sensitive control of the quantity of flow through the 
flow control valve, at least the opening in the plug of the flow control 
valve or the passage opening in the valve housing can have an elliptical 
cross-sectional area with the small axis extending in the direction of the 
axis of rotation and the major axis extending perpendicular thereto.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The inventive flow measuring device has a valve block 2 that is provided 
with holes 1 in order to fasten together a number of valve blocks 2, or in 
order to fasten non-illustrated cover plates and/or a carrier plate 9 with 
side surfaces of the valve block 2. 
The valve block 2 has a through-bore 19 that extends from one side surface 
to the other and forms a coolant outlet. Disposed parallel thereto is a 
further through-bore 20 that forms a coolant inlet. Branching off from the 
bores 19, 20 are perpendicular bores 46, 47 that also extend parallel to 
one another and that form receiving means for a spherical plug or stopcock 
3 of a shut-off valve and for a spherical plug or stopcock 8 of a flow 
control valve. 
The spherical plugs 3, 8 are held in the bores 46, 47 by means of sleeves 
4, 5, and are sealed by means of O-rings 16. 
The axis of rotation of the spherical plugs 3, 8 extends perpendicular to 
the center lines 46, 47. Disposed coaxial to this axis of rotation is a 
shaft 6 that by means of projections 30 illustrated in FIG. 3 engages in 
corresponding slots in the spherical plugs 3, 8 and in this manner 
establishes a fixed coupling between the spherical plugs 3, 8. The shaft 6 
is also sealed in its bore by an O-ring 16. 
A further shaft 18, which is coaxial to the axis of rotation of the 
spherical plugs 3, 8 engages via its projection into a slot in the 
spherical plug 8 and is guided out of the front side of the valve block 2, 
where it ends in a control knob 7. An O-ring seal 16 is disposed on the 
shaft 18. 
To ensure that the shaft 18 is protected against axial displacement, the 
control knob 7 is provided with detents that interengage corresponding 
projections on the valve block 2. 
In this embodiment, the spherical plug 8 of the flow control valve is 
actuated directly by the control knob 7 via the shaft 18 and in so doing 
at the same time takes along the spherical plug 3 of the shut-off valve 
via the shaft 6. 
Since the cross-sectional area of the opening 23 in the spherical plug 3 of 
the shut-off valve is larger than the cross-sectional area of the opening 
27 in the spherical plug 8 of the flow control valve, the cross-section of 
flow passage of the shut-off valve is in every position so much greater 
than the cross-section of flow passage of the flow control valve that it 
is possible to control the quantity of flow of the fluid by means of the 
flow control valve without this being affected by the pressure loss in the 
shut-off valve. 
The carrier plate 9 serves as a holding means for the flowmeter which is in 
the form of a conical, transparent tube 15, the upper end of which is 
inserted into a bore ahead of the sleeve 4 in the valve block 2, and is 
sealed by means of an O-ring 16. At the bottom end, the tube 15 is 
provided with detents 24 into which engage a locking pin 10 that is 
displaceable by means of a spring 11 and is mounted on the carrier plate 
9. 
Lugs 14 are disposed on the carrier plate 9, with the height of the lugs 
corresponding to the width of valve block 2 and being provided with holes 
1 by means of which, as already described in conjunction with the valve 
block 2, a number of flow measuring devices can be placed next to one 
another and interconnected. The tube 15 is centered between the lugs 14 by 
means of a flange 25. 
Disposed at the free, lower end of the tube 15 are a thermometer 13 as well 
as a coolant inlet, which is embodied as a fastening fitting 22 and serves 
for receiving coolant coming from a non-illustrated injection mold. 
Instead of connecting the coolant line that comes from an injection mold 
directly to the fastening fitting 22, an electronic flow regulator 12, 
which is illustrated by dashed lines, can also be interposed. 
The coolant that comes from a non-illustrated coolant source is connected 
to the coolant inlet 20, flows through the bore 46, the opening 23 and the 
spherical plug 3, and from there passes via a coolant outlet 21 to a 
non-illustrated injection mold. From there, the warmed-up coolant flows 
through the inlet 22 into the tube 15. This tube 15 has a conical 
configuration and contains a float element 26 that in conformity with the 
quantity of flow and the thereby resulting flow velocity is raised by the 
coolant and remains at a height or position in the tube 15 that is 
proportional to the quantity of flow. The tube 15 can be provided with a 
scale that can be calibrated to the quantity of flow of the coolant. 
To achieve a particularly sensitive adjustment of the quantity of flow, a 
spherical plug 28 for the flow control valve can be provided (FIG. 2), 
whereby it has an opening 29 with an elliptical cross-sectional area, the 
small axis extending in the direction of the axis of rotation of the 
spherical plug 28 and the major axis extending perpendicular thereto. 
Pursuant to the specific embodiment illustrated in FIG. 2, disposed on a 
coaxial shaft 18 that is coupled with the spherical plug 28 is a gear 
wheel 32 that meshes with a pinion 31. This pinion is rotated by the 
control knob 7. The control knob 7, together with the pinion 31, are 
disposed in a cover 17 that is screwed or adhesively connected to the 
valve block 2. 
By means of the gearing 31, 32, a rotation of the control knob 7 by about 
300.degree. corresponds to a rotation of the spherical plugs 3, 28 of 
about 90.degree.. This, in conjunction with the opening 29 that has an 
elliptical cross-sectional area in the spherical plug 28, results in the 
ability to very finely adjust the flow control valve. 
The embodiment illustrated in FIG. 4 is embodied in such a way that with a 
rotation of the control knob 7 the spherical plug 3 of the shut-off valve 
is first opened, and only thereafter is the spherical plug 8 of the flow 
control valve actuated. This is achieved by a cam control means that is 
disposed between shaft stubs 60 that drive the spherical plug 3 and the 
spherical plug 8. The shaft stubs 60 are kept spaced apart by means of a 
coaxial shaft 33 of smaller diameter, yet without being rotatably coupled 
by this shaft 33. 
Disposed on the shaft 33 is an axially displaceable gear wheel 34, one side 
face 35 of which has disposed thereon a cam-like elevation 36 and the 
other side face 37 of which has disposed thereon a cam-like elevation 38. 
Disposed in the valve block 2 are integral, spaced-apart abutments 39, the 
spacing of which corresponds to the width of the gear wheel 34 plus the 
height of the cam-like elevations 36, 38. 
Rotatably disposed on each shaft stub 60 is a driver disc 40, each of which 
is provided with an axially parallel bore 41. Disposed in the gear wheel 
34 are axially parallel coupling pins 42 that project out of the side 
faces 35, 37 and can be brought into engagement with the bores 41. The 
coupling pins 42 are acted upon by a compression spring 43. 
Meshing with the gear wheel 34 is a further gear wheel 44 that is disposed 
on an axially parallel shaft 45 and can be rotated by means of a control 
knob 7. 
The cam-like elevations 36, 38, the bores 41 in the driver discs 40, and 
the coupling pins 42 in the gear wheel 34 are disposed in such a way that 
when the control knob is rotated, and hence the gear wheel 34 is initially 
shifted toward the right, the appropriate coupling pin 42 comes into 
engagement with the corresponding bore 41 in the driver disc 40 and the 
spherical plug 3 is rotated into the opening position illustrated in FIG. 
4. When this opening position is achieved, the gear wheel 34 is shifted to 
the left by the cam-like elevation 36, which now together with the gear 
wheel 34 is disposed between the abutments 39, so that in the illustrated 
manner the coupling pin 42 engages in the bore 41 of the driver disc 40, 
while the coupling pin 42 disengages from the driver disc 40 of the 
spherical plug 3, so that now the spherical plug 8 can open and be brought 
into the position illustrated in FIG. 4 without the spherical plug 3 of 
the shut-off valve having to thereby move. 
Since with the use of spherical plugs 3, 8 a rotation of only about 
90.degree. is necessary from the completely closed into the completely 
open position and vice versa, the cam-like elevations 36, 38 on the side 
faces 35, 37 of the gear wheel 34 are disposed in such a way that the 
uncoupling of the spherical plug 3 and the coupling of the spherical plug 
8 are effected after a rotation of about 90.degree.. After a further 
rotation of about 90.degree. the spherical plug 8 is then completely 
opened, so that during this second portion of the rotation a sensitive 
adjustment of the quantity of flow by means of the spherical plug 8, which 
could have an opening with an elliptical cross-sectional area as 
illustrated in FIG. 3, can be achieved. The difference in diameter between 
the opening 23 in the spherical plug 3 and the opening 27 in the spherical 
plug 8 contributes to the fact that there can be no effect of the control 
of the quantity of flow from the shut-off valve having the spherical plug 
3. 
The present invention is not limited to a shut-off valve and a flow control 
valve having spherical plugs, but rather other valves having rotatable 
plugs or also cam-controlled check valves can be used where the cams for 
the shut-off valve are embodied in such a way that a rapid opening and 
closing is effected, while the cam for the flow control valve can have a 
slowly rising ramp that effects a gradual opening for the control of the 
flow by the flow control valve. 
The inventive flow measuring device can be used particularly advantageously 
in conjunction with the apparatus for selectively acting upon molds for 
processing synthetic material with a liquid or a pressurized gas pursuant 
to German Patent 42 42 024. 
The present invention is, of course, in no way restricted to the specific 
disclosure of the specification and drawings, but also encompasses any 
modifications within the scope of the appended claims.