WO2004083740A1

WO2004083740A1 - Instantaneous water heater

Info

Publication number: WO2004083740A1
Application number: PCT/EP2004/002548
Authority: WO
Inventors: Markus Helminger; Christian Lindert
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2003-03-21
Filing date: 2004-03-11
Publication date: 2004-09-30
Also published as: RU2333434C2; DE10312724B4; EP1608918A1; CN1761844A; RU2005128601A; CN100554809C; DE10312724A1

Abstract

The invention relates to an instantaneous water heater (D) comprising a heating module (H) provided with at least one assembly of heating bodies (K, K1, K2), a rotatable actuator (L) for preselecting a heating power, at least one stationary electric switching system (S), and a sliding system (A) which is linearly displaceable according to a flow and actuates the switching system (S). The inventive instantaneous water heater is characterised in that the sliding system (A) is rotatable and connected to the actuator (L), the switching system (S) is provided with only one switching element (3, 4, 3') for the assembly of heating bodies and the sliding system (A) is embodied in such a way that each heating power is pre-selectable only by adjusting the rotation position of the sliding system (A) with respect to the switching system (S) and can be called by the displacement of the sliding system.

Description

Heater

The invention relates to a water heater of the type specified in the preamble of claim 1.

In a known instantaneous water heater used in practice, two switching elements are provided for the flow-dependent call-up of the preselected heating output in the case of two individually activatable radiators, which are switched by the link system via a flow-dependent responsive actuating membrane. Since these switching elements are switched independently of the rotational position of the link system when the actuating diaphragm adjusts the link system linearly, the rotatable actuator for preselecting the heating output for two radiators has two additional microswitches that can be switched depending on the position of the switch, e.g. upstream in series. This means that each switching element switched by the actuating diaphragm receives current only if its associated microswitch has been switched via the actuator. If there are more than two radiators, even more switching elements or microswitches are required. The many electrical switching elements are expensive and require a considerable amount of wiring.

In a hot water heater known from DE 101 30 610 A, two microswitches are placed in the gate system for two heating circuits of the radiator arrangement. The link system has a switching cam with two ramps, which can only be moved vertically through the actuating membrane, each of which actuates a microswitch. The switching cam is operatively connected to the actuating diaphragm via a tappet. With the actuator designed as a rotary knob, the heating output can be preselected, for example in such a way that none or one or both heating circuits are switched on when water flows through. Since the two microswitches are switched with each actuation stroke of the actuating diaphragm, additional electrical switching systems are required for preselection. The invention has for its object to provide a water heater of the type mentioned, which is characterized by a minimal number of electrical switching elements, in particular microswitches, and a reduced wiring effort. Further, the water heater to be selectively operable with selectable heating power in steps or continuously with an electronic control system with pre-selectable heating power, wherein the ^'facilities of the water heater to allow both modes of operation selectively.

The object is achieved with the features of claim 1.

Since the setting system also preselects the heating power, which is then called up by the linear adjustment of the setting system, only one electrical switching element is required for each individually activatable radiator arrangement. This concept reduces the number of electrical switching elements to a minimum, and also the wiring effort, so that the instantaneous water heater can be manufactured cost-effectively. If the heating output is set in stages using individually activatable radiator arrangements, the link system, thanks to its design and depending on its set rotational position, leaves the switching element for a radiator arrangement that is not to be activated unactuated as soon as it is adjusted linearly in order to call up the preselected heating output. In the case of a radiator arrangement with one or at least two radiators which can be activated in parallel by means of power control electronics, the heating power on the power control electronics is set via the rotational position of the link system and is called up by the linear adjustment of the link system.

For a radiator arrangement with at least two separately activatable radiators, the link system has at least one switching element actuating surface running in the circumferential direction and at least one circumferential interruption. The switching element corresponding to the preselected heating power is actuated with the respective switching element actuation surface. With the circumferential interruption, the switching element not required for the preselected heating output is left unactuated. At its core, this means a special design of the setting for the heating output preselection, which works differently depending on the set rotary position when it is adjusted linearly to call up the selected heating output. Structurally simple, the link system has at least one switching cam arranged on a rotating body and delimited in the circumferential direction by the circumferential interruption. The switching cam carries the switching element actuating surface and a conical ramp surface on the outside in order to gradually actuate the respective switching element during the linear adjustment movement.

In view of the fact that even if the heating power is already called, i.e. with flow, a change in the heating power should be possible, a ramp is formed on at least one end of the switching element actuating surface pointing in the circumferential direction, thanks to which the switching cam during a rotary movement, e.g. in the sense of an increase in the heating power, the switching element which has not yet been actuated gradually, and does not go to the stop on the switching element during the rotary adjustment.

In terms of production technology, each switch cam is molded onto the outer edge of a radial flange of the rotating body in the manner of an apron. This measure results in optimum structural strength with minimal use of materials. Preferably, a rotary limiting projection can be formed on the switching cam and / or on the radial flange, which, for example, interacts with a counter projection formed on the heating module, in order to rule out an overturning of the link system, which can be difficult to undo, when the continuous-flow heater hood is removed.

In a preferred embodiment, two switching cams which are at least approximately diametrically positioned with respect to the axis of the rotating body, preferably microswitches, are provided with two switching cams of different lengths in the circumferential direction, separated from one another by two circumferential interruptions. A switching cam and a circumferential interruption are essentially the same length in radians. The first switching cam serves, for example, to actuate the first switching element in a rotational position, while the second switching cam cannot actuate the second switching element. The first switching cam, which can be longer than the second switching cam, continues to actuate the first switching element in another rotational position, even if the second switching cam also actuates the second switching element. The two circumferential interruptions either leave one non-actuated switching element or even both non-actuating switching elements unactuated, depending on the heating power set by the rotational position. By means of a head part with a socket on the rotating body, the link system can be easily connected to the actuator for preselecting the heating output.

In a particularly preferred embodiment, the rotating body is rotatably connected directly to an actuating membrane via a rotating coupling. The direct connection of the link system to the actuating membrane saves intermediate members, the rotary coupling allowing the required rotational positioning of the link system relative to the non-rotatable actuating membrane. A particularly simple and reliable rotary coupling is a threaded connection that is not tightened to the stop. The thread engagement creates the axially fixed connection and still allows the relative rotation of the rotating body. The threaded connection is easy to assemble and offers the advantages of relatively high resilience and freedom from play due to the expedient engagement based on several turns.

The rotary coupling can be formed with an external thread section at the free end of the rotating body and an internal thread section in a pressure plate of the actuating diaphragm. The actuating diaphragm is expediently guided in the setting direction and at the same time secured against rotation, so that it does not distort under a torque due to friction when the rotating body is rotated.

In terms of manufacturing technology, the rotating body with all the components arranged thereon, including the link system, is a one-piece injection-molded plastic part. Injection molding technology is particularly advantageous for a large series.

In order to achieve identical switching points regardless of the rotational position of the rotating body, the intersection edge between the switching element actuating surface and the ramp surface should run at least largely parallel to the thread pitch of the external thread section. If the rotating body is screwed further into the internal thread section during the pre-selection of the heating output, then the intersection edge moves back relative to the switching element so that the switching point of the switching element is not shifted. In view of the fact that the instantaneous water heater is optionally also provided with power control electronics in order to vary the heating power continuously, the head part of the rotating body can have end teeth on the outer circumference, and a further switching element actuating surface can be provided on an underside of the head part. With regard to the rotary coupling designed as a threaded connection between the rotating body and the actuating diaphragm, this further switching element actuating surface should run essentially parallel to the thread pitch in order to avoid an undesired shifting of the switching point even in this operating mode.

If, in a preferred embodiment, the instantaneous water heater is operated via a power control electronics which sets the heating output via a radiator or via at least two radiators which can then be activated in parallel, and has a rotary potentiometer and a switching element assigned to the radiator arrangement, then the rotary potentiometer can be connected to the spur gear via a gear wheel Coupled rotating body and the switching element to be aligned to the further switching element actuating surface that it can be switched independently of the rotational position of the rotating body by a linear actuating movement of the rotating body. With this equipment variant, too, only a single electrical switching element with simple wiring is required. From the outset, the link system is also designed for this equipment variant. Basically, this means that the instantaneous water heater is optionally equipped with equipment components for a step-by-step variable heating output or an infinitely variable heating output, and that different types of instantaneous water heaters can be created with a basic variant.

For safety reasons, in a preferred embodiment, in the heating module, a thermostat switch, preferably a bimetal switch is provided which interrupts the power supply at a un- ^'permissible overheating. For example, an electronically controlled instantaneous water heater can be created in the equipment variant with the power control electronics.

In order to enable the modular design to be convenient for the various equipment variants, it is advisable to use holding elements on the heating module that can be used to position the respective switching element and the power control electronics are molded relative to the backdrop system. Depending on the equipment, only the necessary holding elements are used, while the others remain free. To create the different equipment variants, no further modifications to the heating module itself are required.

Embodiments of the subject matter of the invention are explained with the aid of the drawing. Show it:

1 is a plan view of a water heater (with the hood removed),

Fig. 2 is an enlarged detail of Fig. 1, in a side view, partially in

Cut,

Fig. 3 is a plan view of the detail of Fig. 2, and

4 shows a section in the plane IV-VI in FIG. 2nd

A continuous-flow heater D shown in FIG. 1, for example a so-called shower heater SH for heating shower water, contains a heating module H as the main component, which is composed of plastic injection molded parts, of which an upper molded part 1 can be seen. The heating module H delimits an internal flow channel 2 in which an electric radiator arrangement K is mounted. An embodiment is shown with two separately switchable radiator arrangements K1 and K2 in order to obtain three heating output levels (none, one or all radiator arrangements switched on). More than two separately switchable radiator arrangements could also be provided. A further equipment variant contains a radiator arrangement or a plurality of radiator arrangements connected in parallel for a stepless change in heating output between no heating output and maximum heating output, for example via a power control electronics E, which sets the heating current.

In the equipment variant of the instantaneous water heater D shown in FIG. 1, the two radiator arrangements K1, K2 are connected to the first via an electrical switching system S. and second switching elements 3, 4 (eg microswitches) controlled. The switching elements 3, 4 are positioned stationary in holding elements 5a on the heating module H in alignment with a link system A. Each switching element 3 is arranged in the power supply of a radiator arrangement K1 or K2. The link system A is rotatably coupled to a rotatable actuator L (not shown in FIG. 1) for preselecting the heating output to be called up and also directly to an actuating membrane (not shown in FIG. 1) contained in a membrane socket 6 of the heating module H. This will be explained in detail with reference to FIGS. 2 to 4. The link system A can be rotated about an axis X by means of the actuator L and can be adjusted in the direction of the axis X by the actuating membrane from a passive position into a switching element actuating position. The actuation diaphragm responds to the flow in flow channel 2.

In the heating module H, a thermostat switch T, preferably a bimetal switch, can be positioned in the power supply, which appropriately taps the temperature of the water in the flow channel 2 where it is highest. If an overtemperature occurs, the thermostat switch cuts off the power supply.

For the already mentioned equipment variant with infinitely variable heating power, additional holding elements 5b are optionally provided on the heating module H for positioning, for example, a circuit board 25 of the power control electronics E in relation to the link system A and the actuator L.

2 to 4 show the switching elements 3, 4 positioned relative to the link system A. The main component of the link system A is a rotating body 9, the axis of which coincides with the axis X, and which has a rotary coupling designed as a threaded connection V directly with an actuating membrane M in the membrane socket 6 of the heating module H is connected. When there is a flow, the actuating diaphragm M performs a linear actuating movement, indicated by an arrow 7, against the force of a spring 26 in order to pull the link system A as a whole linearly downward in FIG the set heating position of the rotary body 9 to be called up.

The threaded connection V consists of an external thread section 21 at the lower free end of the rotating body 9 and an internal thread section 22 in a pressure plate 8 of the actuating diaphragm M. The threaded connection V is tightened over several full turns, but not to the stop, so that the rotating body 9 can be rotated in the threaded connection V in both directions. The actuating diaphragm M is expediently guided in the direction of the axis X by means of an extension 28 and secured against rotation.

A peripheral flange 10 is formed on the rotating body 9 and carries on its outer edge (FIGS. 2 and 4) two apron-shaped switching cams N1, N2 running in the peripheral direction. Each switching cam has an external, essentially cylindrical switching element actuating surface 12 and an inwardly inclined, e.g. conical, ramp surface 13. An inclined or rounded inward ramp 14 is also formed on an end of each switching element actuating surface 12 pointing in the circumferential direction. Two circumferential interruptions 16a, 16b are provided between the switching cams N1, N2 and limit the two switching cams N1, N2 in the embodiment shown (FIG. 4). One switching cam N1 is considerably longer in radians than the other switching cam N2. The circumferential lengths of the circumferential interruptions 16a, 16b essentially correspond to the lengths of the switching cams N1, N2 in radians. In an alternative embodiment, not shown, the at least one circumferential interruption 16a, 16b could be molded into the switching element actuating surface 12 of a single switching cam closed in the circumferential direction.

The purpose of the switching element actuating surfaces 12 is to actuate the respective switching element by pressing its switching element 3a or 4a when the actuating movement (arrow 7 ) took place. The purpose of the circumferential interruptions 16a, 16b is, depending on the selected rotational position of the link system A, to leave one or all of the switching elements 3, 4 unactuated when the link system A executes the linear actuating movement in the direction of arrow 7. The purpose of the ramp surface 13 is to actuate the switching element 3a or 4a gradually during the adjustment movement. The purpose of the ramps 14 is to be able to carry out a further rotary movement via the actuator L when the link system A has already been pulled down, in order to subsequently actuate one or all of the switching elements 3, 4. The switching elements 3, 4 do not necessarily have to be arranged diametrically as shown, but they could also be positioned closer to one another than shown. Then the configuration of the link system A would have to be modified accordingly. The link system A can also be modified if more than two switching elements should be provided.

In order not to change the switching points of the switching elements 3, 4 when the link system A is rotated in the threaded connection V, the intersecting edge 23 is advantageously arranged at an angle α essentially parallel to the thread pitch.

On the rotating body 9, for example on the radial flange 10 or directly on a switching cam N1 (as shown), a rotary stop 11 can also be formed, which interacts with a counter stop (not shown) on the heating module H, in order to prevent unwanted overturning when the device hood is removed.

2 to 4, for example, a rotational position is shown in which no heating power is called up. The two circumferential interruptions 16a, 16b are in front of the switching elements 3, 4. In order to set the first stages of the heating power, the link system A is rotated clockwise (arrow 15) via the actuator L in FIGS. 3 and 4 to a marked rotational position , in which the switching cam N1 is in front of the switching element 3, while the circumferential interruption 16b is in front of the other switching element 4. As soon as there is a flow, the actuating diaphragm M pulls the link system A down until the switching element 3 is actuated, while the switching element 4 remains unactuated. In order to set the next level of heating power, the link system A is rotated clockwise via the actuator L until the switching cam N1 is still in front of the switching element 3 and the switching element actuating surface 12 comes to rest on the switching cam N2 in front of the switching element 4. Then both switching elements 3, 4 are actuated.

At the upper end of the rotating body 9 a cup-shaped head part 27 is formed, which can have end teeth 19 on its approximately cylindrical outer surface 17 (FIG. 3) and has an upwardly open socket 18 for coupling with the actuator L. On the underside of the head part 27 there is a further switching element Actuating surface 20 is formed with a substantially radial orientation, which preferably extends over 360 ° at an angle relative to a plane perpendicular to the axis X, essentially parallel to the thread pitch of the external thread section 21.

The spur toothing 19 and the further switching element actuating surface 20 are provided for the equipment variant of the water heater, which is optionally equipped with power control electronics E, in which case the switching system S with the switching elements 3, 4 can be omitted.

The power control electronics E is positioned with the circuit board 24 on the holding elements 5b in relation to the link system A. The power control electronics E in this embodiment have an electrical switching element 3 ', e.g. a microswitch, with a switching element 3'a, which is aligned with the further switching element actuating surface 20. Furthermore, a variable voltage divider, for example a rotary potentiometer P, is provided, which can be rotated by the front toothing 19 via a toothed wheel 25. By turning the link system A clockwise (arrow 15) about the axis X, the heating power can be preselected using the rotary potentiometer P, which is called up when the link system A is adjusted in the direction of arrow 7 after actuation of the switching element 3 '.

Claims

claims

1. instantaneous water heater (D), in particular shower heater (SH), with a heating module (H) containing at least one electric radiator arrangement (K, K1, K2) in at least one flow channel (2), a rotatable actuator (L) for heating output Preselection, at least one stationary electrical switching system (S) and a flow-dependent linear setting system (A) for actuating the switching system and calling up the preselected heating power, characterized in that the setting system (A) is rotatable and coupled to the actuator (L) is that the switching system (S) per activatable radiator arrangement (K,

K1, K2) has a switching element (3, 4, 3 '), and that the link system (A) is designed such that by adjusting the rotational position of the link system (A) relative to the switching system (S), the respective heating power on the switching system (S ) can be selected and called up by adjusting the setting system (A).

2. instantaneous water heater according to claim 1, characterized in that the radiator arrangement (K, K1, K2) comprises at least two separately activatable radiators, and that the rotatable link system (A) in a set rotational position for maximum heating power at least one switching element running in the circumferential direction -Actuating surface (12) for actuating all switching elements provided

(3, 4) and at least one circumferential interruption (16a, 16b) in the switching element actuating surface (12), which in at least one other set rotational position for reduced or no heating power in the linear adjustment direction of the link system (A) on at least one of the or on all switching elements (3, 4), preferably at least on their switching element (s) (3a, 4a).

3. instantaneous water heater according to claim 2, characterized in that the link system (A) at least one on a rotating body (9) arranged in the circumferential direction by the circumferential interruption (16a, 16b) limited switching cams (N1, N2), which on the outside at least substantially cylindrical switching element actuating surface (12), and that with the switching element actuating surface (12) intersects a conical ramp surface (13) is in the setting direction of the link system (A) for actuating the switching system

(S) in the direction of the axis (X) of the rotating body (9) strives inward.

4. instantaneous water heater according to claim 2, characterized in that the switching cam (N1, N2) has at least one circumferentially facing end of the switching element actuating surface (12) a gradually decreasing in the direction of the axis (X) ramp (14), preferably on in the direction of rotation to set the maximum heating power at the front end.

5. water heater according to claim 3, characterized in that each switching cam (N1, N2) apron-shaped on the outer edge of a radial flange (10) of the

Rotary body (9) is integrally formed, and that, preferably, a rotation limiting projection (11) is formed on the switching cam (N1, N2) and / or on the radial flange (10).

6. Continuous-flow heater according to claim 2, characterized in that for two switching elements (3, 4) positioned at least approximately diametrically with respect to the axis (X), two switching cams of different lengths in the circumferential direction, separated from one another by two circumferential interruptions (16a, 16b) (N1, N2) are provided, and that a switching cam and a circumferential interruption each extend over essentially the same radian measure.

7. Continuous-flow heater according to claim 3, characterized in that the rotating body (9) has a head part (27) designed for coupling to the actuator (L) with a socket (18) open to a free end of the rotating body.

8. instantaneous water heater according to claim 3, characterized in that the rotary body (9) is rotatable via a rotary coupling and is directly connected to an actuating membrane (M), preferably by means of a threaded connection (V) not tightened to the stop.

9. instantaneous water heater according to claim 8, characterized in that at the other free end of the rotating body (9) an external thread section (21) and on a pressure plate (8) of the actuating membrane (M) an internal thread section (22) are provided.

10. Continuous-flow heater according to claim 3, characterized in that the rotating body (9) is a one-piece plastic injection molding.

11. Continuous-flow heater according to claims 3 and 9, characterized in that the intersecting edge (23) between the switching element actuating surface (12) and the ramp surface (13) extends at least largely parallel to the thread pitch (α) of the external thread section (21).

12. instantaneous water heater according to claim 7 and 9, characterized in that the head part (27) in its substantially cylindrical outer periphery (17)

Has spur toothing (19) and that on the rotating body (9), preferably on a radially to the axis (X) oriented bottom of the head part (27), an essentially flat, further switching element actuating surface (20) is provided, which, preferably, For example, runs essentially parallel to the thread pitch (α) of the external thread section (21) over 360 °.

13. Continuous-flow heater according to at least one of the preceding claims, characterized in that the heating element arrangement (K, K1, K2) comprises one or at least two radiators which can be activated in parallel, that power control electronics (E) are provided which have a rotary potentiometer (P ) and one of the

Radiator arrangement (K, K1, K2) has associated switching element (3 '), and that the rotary potentiometer (P) is coupled via a gear (25) to the spur toothing (19) of the rotating body (9) and the switching element (3') in this way the further switching element actuating surface (20) of the link system (A) is oriented such that it can be switched independently of the rotational position of the rotating body (9) by a linear actuating movement (7) of the rotating body (9).

14. instantaneous water heater according to at least one of the preceding claims, characterized in that in the heating module (H), preferably in the hot water outlet area, a between a mains connection and the respective switching element

(3, 4, 3 ') arranged thermostat switch (T), preferably a bimetal switch, is provided.

5. instantaneous heater according to at least one of the preceding claims, characterized in that on the heating module (H) optionally usable holding elements (5a, 5b) for positioning the respective switching element (3, 3 ') and the power control electronics (E) relative to the link system ( A) are molded.