Thermal measuring and testing – Temperature measurement – Combined with diverse art device
Reexamination Certificate
1999-05-14
2001-10-09
Gutierrez, Diego (Department: 2859)
Thermal measuring and testing
Temperature measurement
Combined with diverse art device
C073S714000, C073S753000, C374S179000
Reexamination Certificate
active
06299349
ABSTRACT:
The invention concerns a pressure and temperature sensor, in particular for detecting a pressure and temperature condition in a cavity of an injection molding apparatus or the like.
Sensors of that kind are used in particular when measuring the internal pressure in a tool in an injection molding apparatus, the pressure of molten material in pressure chambers of a corresponding installation being directly or indirectly detected.
During such an injection molding procedure an internal pressure pattern which is dependent on a respective state in the process obtains in the pressure chamber (cavity)—from a sharp rise after the beginning of the injection procedure by way of a more or less shallow pressure drop during the post-pressure phase down to atmospheric pressure. In that respect in particular parameters of a plastic material to be injected, the injection rate or the temperature conditions in the interior influence the configuration of that curve. Therefore, it is precisely in relation to high-precision parts that accurate reproducible measurement of the pressure conditions in an injection molding pressure cavity is an important consideration in order to be able to aid and support the complex control procedures which are necessary to achieve an optimum result.
In that respect it has been found desirable to be able to measure the temperature in the internal cavity, in addition to the pressure therein. More specifically, such an additional parameter would then make it possible to support and aid in particular still further control procedures which are pressure-neutral and to that extent cannot be monitored and controlled by pressure measurement alone.
It is known in that respect for temperature detection to be additionally provided in the internal cavity in locally separate relationship from a conventional pressure sensor in order to acquire that further control parameter.
Besides the mechanical and structural complication and expenditure which however is inevitably necessary for that purpose (thus for example a second access would have to be provided to the pressure chamber), pressure and temperature measurement values from such an arrangement also mean that the temperature is measured at a different location from a respective pressure. Particularly in the event of severely non-homogenous conditions in the internal space therefore there can potentially be incorrect measurements and, as a result thereof, malfunctions.
Therefore the object of the present invention, in particular for parameter detection in an internal space of injection molding apparatuses, is to provide a sensor of the general kind set forth for pressure and temperature detection, which is also easily suitable at low cost for conventionally existing injection molding apparatuses that are only designed for pressure measurement, and which permits locally interrelated pressure and temperature measurement.
Advantageously, the thermoelectric detector element which is directly fitted into the pressure body permits local detection of the temperature directly at the location of pressure measurement without additional precautions having to be taken in the pressure chamber or for example without the diameter of a sensor having to be increased. The invention also advantageously provides that arranging for temperature detection in the pressure body itself and thus in the immediate vicinity of the temperature source means that it is possible to implement quickly reacting, short-time temperature detection which is necessary in particular for process operations which themselves are relatively short.
Advantageous developments of the invention are claimed in the appendant claims.
Thus in a particularly preferred feature the pressure body is of a circular cross-section and is dimensioned for use in openings of a diameter for example of 4 mm, which are already present for conventional pressure sensors. That makes it possible for existing injection molding installations to be converted in a particularly simple fashion.
It has also proven to be advantageous to use flat crystal elements in the form of wafers as detector elements as that makes it possible to optimize the electrical pressure signal.
Choosing the thermoelectric sensor element in the form of a casing or jacket-type thermocouple element also permits complete capacitive screening which is appropriate in particular in regard to the adjacent pressure detection.
In accordance with a preferred development moreover the thermocouple element is designed to be exposed in the pressure-application surface. That makes it possible further to minimize the thermal response time.
In order to provide for contact-sure contacting which is however nonetheless simple to produce in respect of a pressure and temperature sensor according to the invention, it is particularly appropriate for the contact device to be in the form of a coaxial plug connection, in which case it can preferably also be of multi-shell structure—corresponding to the number of electrical poles to be taken out of same—, or a shell of a plurality of poles is used for contacting purposes.
REFERENCES:
patent: 3062052 (1962-11-01), Kolb
patent: 3439356 (1969-04-01), Kinzer
patent: 3605495 (1971-09-01), Krause et al.
patent: 4563902 (1986-01-01), Kohnlecher
patent: 4765751 (1988-08-01), Pannone et al.
patent: 4788871 (1988-12-01), Nelson et al.
patent: 4797007 (1989-01-01), Elmore, III
patent: 4984905 (1991-01-01), Amano et al.
patent: 5163321 (1992-11-01), Perales
patent: 5231880 (1993-08-01), Ward et al.
patent: 5315876 (1994-05-01), Glassey et al.
patent: 5385200 (1995-01-01), Yuki et al.
patent: 5578993 (1996-11-01), Sitabkhan
patent: 5702592 (1997-12-01), Suri et al.
patent: 5975842 (1999-11-01), Jensen et al.
patent: 6062087 (2000-05-01), Vovan
patent: 6090318 (2000-07-01), Bader et al.
patent: 6147437 (2000-11-01), Matsumoto et al.
patent: 0845400 (1989-09-01), None
patent: 40 10 609 A1 (1990-10-01), None
patent: 42 25 879 A1 (1993-02-01), None
patent: 2182775 (1987-05-01), None
patent: 11077780 (1999-03-01), None
patent: 0932311 (1982-05-01), None
patent: 1509650 (1989-09-01), None
Ein Sensor für Druck und Temperatur, Messtechnik, Elektronik 16/Aug. 7, 1987, XP-002058653.
Nier Ekkehart
Steinel Heinrich Wolfgang
Carter & Schnedler, P.A.
Gutierrez Diego
Steinel AG
Verbitsky Gail
LandOfFree
Pressure and temperature sensor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressure and temperature sensor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressure and temperature sensor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2617688