CN1696585A - Liquid heat storage device for a domestic appliance, in particular a hot water generator - Google Patents

Abstract

The hot water tank of a domestic appliance, e.g. a boiler (2), has a deep and straight holder (40) in the tank wall (10) to take a thermostat (42). A straight and longitudinal gap (50) is formed in the wall (46) of the opening to stabilize the pressure injection molding tool used to form the opening.

Description

Liquid heat storage device for a domestic appliance, in particular a hot water generator

technical field

The invention relates to a liquid heat storage container for a domestic appliance, in particular a hot water generator, according to the preamble of claim 1 .

Background technique

German utility model patent G 82 09 111.0 U1 points out a liquid heat storage device, which has a storage container made of a material with good thermal conductivity, such as steel, and is welded on the outer surface of the container. Protective tube. Together, these are surrounded by a kind of insulating jacket.

DE-AS 1 259 902 indicates a temperature sensor in a recess on the outer side of a steam boiler water tube. The recess is V-shaped in cross section. A temperature sensor in the recess can be welded to the pipe and/or covered by a steel cover welded to the water pipe.

It is also known that a protective tube for accommodating a temperature-responsive element can protrude through a container flange into the liquid heat store. Here, however, the temperature-responsive element must be easily removable during assembly in the protective tube made of metal, also for exchanging the temperature-responsive element. This creates an air intermediate space between the temperature-responsive element and the inner wall of the protective tube, which leads to poor and uncontrollable heat transfer.

Contents of the invention

The object to be solved by the invention is to achieve a good thermal connection between a temperature-responsive element and the hot water region of the liquid heat store.

This object is achieved according to the invention by the features of claim 1 .

Advantages of the invention and advantageous developments according to the subclaims are the following: good heat transfer between the temperature response element and the hot water area of the liquid heat store due to the thinner wall of the receiving hole in the region of the temperature response element ; The temperature response element can be in good contact with the wall of the accommodating hole; the manufacturing cost is favorable; the installation is convenient; the number of components is small.

In a floating tube formed in a container in a pressure injection molding process - the tube forms the receiving hole, the thinness of the wall of the receiving hole is limited due to mold technology, because in the pressure injection molding process for The straightness of the mold mandrel (for example, a single-hole pin) required for the production of the receiving holes is affected by temperature and pressure influences during pressure injection molding. The thinner the hole wall, the greater the risk that the mold mandrel will be deformed into the region of the hole wall during injection molding and at the same time a leaky hole wall will be formed. According to the invention, the walls of the receiving bore can be made very thin, since the mold mandrel is connected to the injection molding tool through the longitudinal gap and is thus held in place so that it remains stable against thermal and pressure influences.

According to the invention, the temperature-reactive element is pushed into a specially adapted receiving opening in the wall of the heat storage container. In order to facilitate the access of the temperature-responsive element, the receiving opening is spread across the longitudinal gap. To this end, shoulders or projections can be provided on both sides of the longitudinal gap on the container wall, on which a tool can act to expand the longitudinal gap. After the temperature response element is installed in the holding hole, the expansion force of the container wall is reduced, so that the longitudinal gap and thus the holding hole can shrink to its natural size due to the spring elasticity of the container wall, so as to pass This tightly surrounds the temperature responsive element. A particularly large contact surface thus results between the temperature-responsive element and the container wall, which enables a particularly good and rapid heat transfer between the water region of the container and the temperature-responsive element.

According to an embodiment of the invention, the longitudinal gap of the receiving opening is located on an outer side of the container. The injection mold mandrel can thus be mechanically connected to an injection mold part on the outside of the container in a simple manner.

According to a further embodiment of the invention, an additional opening is provided parallel to the receiving opening, which is connected to the receiving opening via a longitudinal gap. An additional injection mold mandrel can thus be inserted into the additional hole, which is connected to the injection mold mandrel via the longitudinal gap in order to stabilize it. The additional hole wall is preferably located completely within the water region of the container. Due to this construction, the entire hole wall of the holding hole is located in the water region of the container, so that the temperature response element in the holding hole can be more hysteresis-free than in the above-mentioned construction (wherein the longitudinal gap is in an outer wall of the container) Find the water temperature more accurately.

According to a preferred embodiment of the invention, the hole wall is provided with heat transfer fins on its side facing the water region of the container. The action time and the accuracy of the temperature measurement or temperature response carried out by the temperature response element are thus improved.

The heat transfer fins preferably extend in the longitudinal direction of the receiving opening, since this makes it easier to separate the extrusion molding tool from the heat transfer fins after the extrusion molding has been completed.

According to the invention there is also provided a pressure injection molding method for producing a liquid heat reservoir of a domestic appliance, in particular a hot water generator, which is characterized in that a container wall is formed in the pressure injection molding process and at the same time A deep, straight, narrow receiving hole is formed in the container wall by means of a mold mandrel for accommodating a temperature-responsive element; Water-tight separation and good heat-conducting connection due to thin wall thickness; receiving hole has a receiving opening at one hole end on the outer side of a container for pulling out the mold mandrel and inserting the temperature response Component; the mold mandrel is stabilized by a mold part in the transverse direction of the mandrel during injection molding, and at the same time a linear longitudinal gap is formed in the wall of the accommodating hole along the longitudinal direction of the hole by this mold part. Starting next to the opening, the receiving hole wall surrounds the receiving hole by more than 180° in the circumferential direction of the hole up to a longitudinal gap.

These methods and the specific embodiments according to the claims again yield numerous advantages, which were explained above with reference to the liquid heat store.

Description of drawings

The present invention will be described below with reference to preferred embodiments as examples, but is not limited thereto. The accompanying drawings show:

Fig. 1: A vertical section through a liquid heat storage of a hot water generator according to the present invention;

Figure 2: A horizontal section along the II-II plane of Figure 1;

Fig. 3: vertical section through another embodiment of a liquid heat storage of a hot water generator according to the invention;

Figure 4: A horizontal section along plane IV-IV in Figure 3; and

FIG. 5 : A horizontal section according to FIG. 4 in another exemplary embodiment.

Detailed ways

The liquid heat storage 2 shown in Figures 1 and 2 is part of a hot water generator or boiler and contains an electric heating body 4 whose electrical terminals 4-1 and 4-2 are penetrated watertightly. 6 over a flange. The flange 6 is inserted into a hole 8 in a bottom wall 10 of the container 2 in a watertight manner.

The heat storage tank 2 consists of a tank bottom part 12 and a tank top part 14 which are connected to each other in a watertight manner on a parting surface 16 and are each produced by injection molding, for example of metal or preferably of plastic. A fresh water supply line 20 extends through the container top wall 18 almost all the way to the bottom wall 10 for supplying fresh, cold water on a common water pipe network. The hot water access pipe 24 passes through the container roof wall 18 only to reach immediately below the container roof wall 18 . By opening a cold water switch, fresh water is introduced into the container mouth through the fresh water inlet pipe 20 . Fresh cold water presses out the hot water corresponding to its amount from the hot water taking pipe 24 at this moment. Therefore, the container cavity 26 is normally pressureless and does not bear the entire pipeline water pressure of the water pipe network even when hot water is used. The water area of the container 2 extends upwards from the bottom wall 10 beyond the electric heating body 4 until reaching the hot water intake pipe 24 .

A protective tube 28 can also extend watertight through the flange 6 for accommodating a temperature response element 30 . The ends of the protective tube 28 located in the container interior 26 are closed watertight. From the end of the protective tube protruding from the container 2 on the flange 6, depending on the type of temperature-responsive element, there protrude connection lines 32, 34 or a liquid measuring line, to which a switch or regulator is connected. or temperature display or a fuse (not shown). When the temperature in the container interior 26 exceeds a predetermined safety value, a fuse disconnects the power supply line of the electric heater 4 in a known manner.

In the bottom wall 10 , a deep, linear, narrow receiving opening 40 is produced in the same injection molding process for receiving a further temperature-responsive element 42 . The temperature response element 42 can be added to or replace the temperature response element 30 of the protective tube 28 . Element 42 typically has a diameter of about 6mm.

The receiving opening 40 is separated from the water area 44 of the container 2 in a water-tight manner by a thin receiving opening wall 46 , but has a good heat-conducting connection. The receiving hole wall 46 is part of the container peripheral wall and is designed to be as thin as possible technically, and preferably thinner than the remaining container peripheral wall section 47 of the container lower part 12 and the base wall 10 .

The receiving hole 40 has a receiving opening 48 on the outside of the container at one end of the hole for the temperature response element 42 to be inserted into the receiving hole 40, and for the axial direction after the container lower part 12 together with the receiving hole wall 46 is made during pressure injection molding. Pull out a pressure injection mold mandrel.

A rectilinear longitudinal gap 50 is formed in the receiving hole wall 46 in the longitudinal direction of the hole, starting from the receiving opening 48 . The receiving hole wall 46 extends in the direction of the hole periphery as far as the longitudinal gap 50 exceeds 180° and is formed at the hole gap 50 by the adjacent edges 52 and 54 of the container peripheral wall section 47 of the container bottom part 12 .

During the production of the container lower part 12 , the receiving hole wall 46 is simultaneously formed by an extrusion mold mandrel inserted into the receiving hole 40 , which is stabilized by an extrusion mold part of the extrusion mold through the longitudinal gap 50 . After the lower housing part 12 has been produced in the extrusion molding process, this mold part together with the extrusion mold mandrel can be removed in the longitudinal direction of the receiving opening 40 . By making the pressure injection mold mandrel pass through the longitudinal gap 50 in the transverse direction in the receiving hole 40 and be held and thus stabilized, the receiving hole wall 46 in the container cavity 26 can be designed to be smaller than that of the container lower part 12. The remaining wall sections 47 are much thinner.

The temperature-responsive element 42 is preferably a temperature sensor, which is filled with a temperature-responsive liquid whose volume can vary strongly depending on the temperature, which acts via a measuring line 60 on a control element 62 arranged outside the container 2 . The control element 62 is preferably a switch or regulator in the circuit of the heating body 4 so as to open the circuit when a predetermined upper rating is exceeded and to switch on when it falls below a lower rating.

According to a further embodiment of the invention, the temperature response element 42 itself is a switch or regulator in the circuit of the heating body 4 or a thermometer for temperature display.

The receiving hole wall 46 is preferably provided with a plurality of heat conducting fins 64 inside the container. These heat conducting fins are preferably arranged in the longitudinal direction of the receiving opening 40 since they can be produced lighter by injection molding than transversely arranged heat conducting fins.

Those parts of the hot water generator shown in Figures 3 and 4 which correspond to those in Figures 1 and 2 are denoted by the same reference numerals and have the same functions as already described.

In the embodiment shown in FIGS. 3 and 4, a longitudinal gap 150 corresponding to the longitudinal gap 50 shown in FIGS. Bore 270 connects, and this additional hole is separated watertightly from the water region 44 of liquid heat storage device 2 by an additional hole wall 272, but has an inlet 274 on the outside of the same container as receiving opening 48 at one end of the hole , the inlet is separated from the receiving opening 48 only by a longitudinal gap 150 . The additional hole 270 is used to accommodate an additional mandrel of the injection mold, which is connected to the mold mandrel via the longitudinal gap 150 for the manufacture of the receiving hole 40, so that the mandrel is fixed radially so that the wall of the receiving hole can be made 46 is made very thin in the injection molding method, preferably much thinner than the container wall 56 of the container bottom part 12 . The additional hole wall 272 is preferably located at least partially in the container interior 26 . A part of the circumference of the additional hole wall 46 may be formed by the peripheral wall of the container, or connected to this wall. In the embodiment shown in FIGS. 3 and 4 , the additional hole wall 272 is at a radial distance from the peripheral wall of the container.

Another embodiment is shown in Figure 5 with only minor modifications. In order to improve workability, the wall thickness S ₂ of the receiving hole wall 46 is about 1 mm, which is thinner than the additional hole wall 272 . The additional hole wall thickness S ₁ is about 2.5 mm, contrary to that in FIG. 5 , the thickness of the peripheral wall 47 of the container is the same.

As an alternative to using a mold mandrel for the production of the receiving hole wall, local thinning of the container peripheral wall 47 as receiving hole wall 46 can also be achieved by other methods.

The invention can also be applied to other household appliances such as water boilers, washing machines, dishwashers and coffee makers.

Claims (15)

1. A liquid heat storage device for a furniture appliance, especially a hot water generator, characterized in that a receiving hole (40) is formed in a plastic container wall (10) for accommodating a temperature response element (42) The receiving hole ( 40 ) is separated watertightly from the water region ( 44 ) of the container ( 2 ) by a thin receiving hole wall ( 46 ), which is thinner than the container wall ( 10 ). 2. The liquid heat storage device according to claim 1, characterized in that, in the container (2), a linear receiving hole (40) is formed in the container wall (10) for placing the temperature response element (42); Furthermore, a rectilinear longitudinal gap (50) is formed in the receiving hole wall (46) for a mold mandrel. 3. The liquid heat store according to claim 1 or 2, characterized in that the container wall (10) and the receiving hole wall (46) are formed integrally with one another. 4. Liquid heat storage device according to one of the preceding claims, characterized in that the temperature element (42) rests at least mainly on the periphery against the inner surface of the receiving hole wall (46) for a good heat-conducting connection . 5. Liquid heat storage device according to one of the preceding claims, characterized in that the receiving hole (40) has a receiving opening (48) on the outside of a container at one end of the hole for inserting the temperature response element into the In the receiving hole (40). 6. The liquid heat storage device according to one of the preceding claims, characterized in that a linear longitudinal gap (50; 150) is formed in the wall of the receiving hole along the longitudinal direction of the hole, starting from the opening of the receiving opening (48). Next, wherein the receiving hole wall (46) surrounds the receiving hole (40) more than 180° in the circumferential direction of the hole up to the longitudinal gap (50; 150); Made in. 7. The liquid heat store according to claim 2, characterized in that the longitudinal gap (50) is located on an outer side of the container. 8. The liquid heat storage device according to claim 2, characterized in that the longitudinal gap (150) of the receiving hole (40) is connected in the transverse direction of the hole with a deep, linear additional Bore (270) is connected, and this additional hole is separated watertightly from the water area (44) of container (2) by an additional hole wall (272) and is in the same container outer surface at the end of an additional hole , That is, the place where the accommodation opening (48) of the accommodation hole (40) is located has an inlet (274), which is connected to the accommodation hole (40) through a longitudinal gap in the transverse direction of the hole. 9. Liquid heat storage according to one of the preceding claims, characterized in that the receiving hole wall (46) is provided with heat transfer fins (64) in the water region (44) of the container (2), wherein the heat transfer The tab (64) preferably extends parallel to the longitudinal direction of the receiving hole (40). 10. The liquid heat store as claimed in claim 1, characterized in that the receiving hole wall (46) has sections of different wall thicknesses (S ₁ , S ₂ ). 11. A pressure injection molding method for producing a liquid heat reservoir of a household appliance, in particular a hot water generator, characterized in that a container wall is produced in the pressure injection molding method and at the same time preferably by means of a mold core The rod forms a linear accommodation hole (40) in the container wall (10, 12, 47) for placing a temperature response element (42); here the accommodation hole ( 40) Water-tight separation from the water region (44) of the container (2) and a good heat-conducting connection through a thin wall thickness. 12. Press injection molding method according to claim 11, characterized in that the receiving hole (40) is provided with a receiving opening (48) on the outer side of a container at one end of the hole, for pulling out the mold core rod and using it When the temperature response element (42) is loaded into it; the mold mandrel is kept stable by a mold part in the transverse direction of the mandrel during pressure injection molding, and at the same time by the mold part in the hole wall (46) along the longitudinal direction of the hole A rectilinear longitudinal gap (50; 150) is formed which begins next to the receiving opening (48). 13. The injection molding method according to claim 11 or 12, characterized in that longitudinal gaps (50) are formed on the outside of a container. 14. The pressure injection molding method according to claim 11 or 12, characterized in that a deep, rectilinear additional hole (270) is formed parallel to the receiving hole (40) by means of an additional mandrel, the additional hole Watertightly separated from the water area (44) of the container (2) by an additional hole wall (272), but at the end of an additional hole on the same outer side of the container, that is, the accommodation of the receiving hole (40) Where the opening (48) is located, there is an inlet (274) in which an additional mandrel is connected to the mold mandrel of the receiving hole (40) through the longitudinal gap (150) of the receiving hole wall (46). 15. The injection molding method according to one of the preceding claims, characterized in that the receiving hole wall (46) is provided with heat transfer fins (64) in the water region (44) of the container (2) during the injection molding method, Wherein the heat transfer sheet (64) preferably extends parallel to the longitudinal direction of the receiving hole (40).

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