WO2015137822A1

WO2015137822A1 - A heater assembly

Info

Publication number: WO2015137822A1
Application number: PCT/NO2015/050048
Authority: WO
Inventors: Pål SANDØY
Original assignee: Defa As
Priority date: 2014-03-13
Filing date: 2015-03-10
Publication date: 2015-09-17
Also published as: NO20140329A1; WO2015137818A1

Abstract

A heater assembly for heating a fluid, particularly in a vehicle or vessel comprises at least one heater housing (1) having a heating element (7) arranged and a fluid inlet (4a) and a fluid outlet (4b). The fluid inlet and the fluid outlet are connected via one or more fluid channels (6a,b) in thermal connection with the heating element (7). At least one of the fluid inlet and the fluid outlet comprises a removable connection stub (18; 18') having a first end with means (21, 22, 34) for releasable connection to the inlet or outlet. The connection stub may be a bidirectional connection stub (18''') with two similar and opposite ends with similar connection portions (40a, 40b) configured for releasable connection to a fluid inlet (4a; 36) or a fluid outlet (4b; 38). The bidirectional connection stub allows for the interconnection of a plurality of heater housings (1a, 1b, 1c), as well as a circulation pump (35).

Description

A HEATER ASSEMBLY

Field of the invention

The invention concerns heating devices and ancillary equipment and components, especially for use in heating a unit, such as an engine, in a vehicle or vessel. More specifically, the invention concerns a heating assembly for such heating devices, equipment and components, as specified in the preamble of claim 1.

Background of the invention

Heating devices for engines for various vehicles or vessels are well known. The purpose of these is to pre-heat the engine by direct or indirect heating of the engine oil or cooling liquid (coolant), such that it starts easier in cold weather and will reduce fuel consumption / exhaust gas related to cold-starting the engine. Similar heating devices for other mechanical units in a vehicle or a vessel, such as gearbox, hydraulics system, transmission, are also well known. For the sake of simplicity, the term "engine heater" will mainly be used in the following, even if these also may be used for heating other mechanical units as mentioned above.

There are different kinds of engine heaters, among others such that heat the engine coolant. A variant of such engine heaters comprises a container having a heating element inside. The container has an inlet opening and an outlet opening such that the engine coolant hose may be cut and the hose ends be coupled to these openings. The engine heater is thereby a part of the engine cooling circuit, and the coolant flowing through the container is heated by the heating element and circulates in the engine cooling circuit. This type of engine heater is often referred to as a "hose heater."

EP 1 793 103 A describes an engine heater having a container with a thermostat- controlled, electrical, heating element and connection stubs for coolant inlet and outlet.

EP 2 462 339 Al also describes an engine heater with such a container with connection stubs for hoses, where the heating element is a PTC element ("Positive Temperature Coefficient"). US 5 408 960 describes an engine heater with a container with an electric, thermostat- controlled, heating element and a pump which drives the coolant in the cooling circuit. The container has connection stubs for coolant inlet and outlet.

Engine heaters with other types of heating elements are also known.

What the known engine heaters of this type have in common, is that their connection stubs for inlet and outlet, respectively, are configured for the hoses for which they are to be connected.

Figure 1 shows an engine heater 51 of a type which is known in the art, comprising a container 52 (holding a heating element; not shown), and electric socket 53 (for supplying power to the heating element), as well as an inlet stub 56 and an outlet stub 55 for coolant. The stubs are slick pipe stubs (often referred to as "nipples") and provided with a respective flange 57, 54 at their outer ends. On assembly, the cooling system rubber hoses are entered onto the respective flanges and fastened with hose clamps (not shown) or similar fastening means. The flange ensures that the fastening means, and thus the hoses, do not slide off the stubs unintentionally. The engine heater may also comprise attachment means (not shown) such that it may be attached to the engine or other component.

An engine heater may only be installed in a cooling system if it does not compromise the cooling circuit. The engine heater itself must of course be tight and dimensioned for the pressures and temperatures it may become exposed to. It is equally important that the couplings between the engine heater and the cooling system hoses are completely tight. This is achieved, already during the design and production process, by adapting the engine heater inlet and outlet stubs to the cooling hose design (e.g. hose quality and diameter) on the engine for which it is designed. There are several hose dimensions in use today, and car and/or engine manufacturers has begun designing custom-made hoses and pipes. Consequently, different variants of engine heaters must be produced, adapted to the hoses of the individual engine.

The engine compartment in modern cars is often very compact and cramped, so there is little space for placing and mounting an engine heater when it is to be fitted into the existing cooling circuit. Often, in such cramped environments it can be difficult to ensure that the connected are mounted appropriately and correctly, for example with a correct angle and at the correct location in the cooling circuit. It is, for example, not uncommon that the mechanic cuts and removes too short a portion of the cooling hose when the engine heater is fitted, which may result in the remaining cooling hose being bent and hence may restrict liquid flow after the engine heater has been installed.

The invention provides solutions which remedies at least some of the deficiencies of the prior art, and offer in addition further advantages.

Summary of the invention

The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

It is provided a heater assembly for heating a fluid, particularly in a vehicle or vessel, comprising at least one heater housing having a heating element and a fluid inlet and a fluid outlet; wherein the fluid inlet and the fluid outlet are connected via one or more fluid channels in thermal connection with the heating element; characterized by at least one connection stub having a first end with means for releasable connection to the fluid inlet or fluid outlet.

In one embodiment, the connection stub comprises a second, free, end adapted for connection to a hose or to a component in the cooling circuit.

In one embodiment, the heater assembly comprises a transition piece configured for the housing at the fluid inlet or fluid outlet and comprising connection means for connection to said first end of the connection stub. In one embodiment, the transition piece is releasably configured for the housing.

In one embodiment, the releasable connection stub is a bidirectional connection stub, having two similar and opposite ends with similar connection portions configured for releasable connection to a fluid inlet or a fluid outlet.

The heater assembly may further comprise a plurality of heater housings fluidly and releasably interconnected via a respective plurality of connection stubs. In one embodiment, the heater assembly comprises a circulation pump having at least one fluid opening with configured for releasable connection to a connection stub. The circulation pump may be fluidly interconnected to a heater housing via a bidirectional connection stub.

In one embodiment, the connection stub has an angle different from 0° with respect to a longitudinal axis. The angle may be 45° or 90°. The connection stub may be U-shaped or V-shaped.

The housing is preferably of a heat conducting material and the connection stub is preferably of a thermally insulating material.

In one embodiment, the connection stub is rotatably connected to the housing.

An advantage of the invention is that the heating device may be configured with different replaceable connection stubs. The replaceable connection stubs can be configured at installation of the heating device (e.g. by sending more connection stubs than strictly speaking are necessary), or they may be configured at the manufacturing plant. The connection stubs may be specific for each car manufacturer, in that they fit with the manufacturer's quick coupling (on the engine) in the one end, and the engine heater at the other end.

Brief description of the drawings

The above and other characteristics of the invention will become clear in the following description of preferential forms of embodiment, given as a non-restrictive examples, with reference to the attached drawings, where:

Figure 1 is an illustration of an engine heater of a known type;

Figure 2 is a perspective view of an embodiment of the heating device according to the invention;

Figure 3 is a perspective view of the heating device shown in figure 2, seen mainly from an end;

Figure 4 is a perspective view of the heating device shown in figure 2, onto which are connected removable connection stubs according to the invention; Figure 5 shows a vertical section along the longitudinal axis C in figure 4;

Figure 6 is an enlargement of the portion D in figure 5, seen from a different perspective;

Figure 7 is a perspective view of a replaceable stub according to the invention;

Figure 8 is a perspective view of a second embodiment of the replaceable stub according to the invention, in a mounted state on a transition piece;

Figure 9 is a sectional view (longitudinal section) of the connection stub shown in figure 8;

Figure 10 corresponds to figure 8, but shows the stub in a connected, unlocked state, where the locking element is removed;

Figure 11 is a perspective view of the transition piece;

Figure 12 is a perspective view of the removable connection stub shown in figures 8-10;

Figure 13 is a perspective view of another embodiment of the removable connection stub;

Figures 14 and 15 are perspective views of a circulation pump and an embodiment of the connection stub, in a disconnected state (figure 14) and a connected state (figure 15);

Figure 16 is a perspective view of a circulation pump and an embodiment of a bidirectional the connection stub; in a disconnected state;

Figures 17 and 18 are perspective views of a circulation pump, a heater and a bidirectional removable connection stub, in a disconnected state (figure 17) and a connected state (figure 18);

Figure 19 is a schematic drawing of a plurality of heaters and a circulation pump, interconnected in series via removable bidirectional stubs; and Figure 20 is a schematic drawing of a heater and a circulation pump,

interconnected in series a via removable bidirectional stub having a U-shape.

Detailed description of preferential embodiments

In this description terms such as "upper", "lower", "inner", "outer", "vertical",

"horizontal", "forward", "rear", etc. occur. The terms are used with reference to the device according to the invention, as it is presented in the figures.

Figure 2 shows an embodiment of the heating device according to the invention, in a state where the replaceable stubs are not mounted. A mainly tubular-shaped housing 1 has a first fluid opening 4a and a second fluid opening 4b and internal channels that allow fluid flow between the fluid openings. Each of the fluid openings may be connected to respective hoses (not shown) via removable and replaceable connection stubs in a manner which is described below, such that the heating device is an integral part of for example a coolant circuit in a combustion engine. It should be understood that fluid may flow in either one or the other direction through the housing. Which one of the fluid openings 4a,b being the inlet opening and the outlet opening, respectively, therefore depends on the application of the heating device and is without consequence for the invention as such. The housing 1 is preferably of a material having good thermal conductivity. A suitable material is aluminium.

The housing 1 has in the illustrated embodiment a mainly circular cross-section, and has a base 17 to which a cover 2 is attached in a manner which is known per se, e.g. by means of screws 8 through a flange 9 on the cover. The figure also shows a gasket 10 between the flange 9 and the base 17. In the cover is also a socket 3 for connection to electrical wires (not shown) in a connection chamber 27 (see figure 5) for connection to a heating element. The socket 3 is aligned with the housing longitudinal axis, which is advantageous for installation and servicing.

Figure 3 shows that the housing, between the fluid openings 4a,b, comprises to separated fluid conduits 6a,b. Each fluid conduit 6a,b is defined by a respective inner portion of the housing wall (which in the illustrated embodiment is circular-arc shaped) and a respective inner partition wall (only partition wall 12b is shown in figure 3) which in the illustrated embodiment extends between a housing upper portion and a housing lower portion. Between the partition walls is a chamber 13 (see also figure 5). The partition walls are interconnected at their leading edges and trailing edges by respective end walls 5a. The end walls 5a are preferably rounded or streamline-shaped in order to reduce fluid drag and resulting loss of pressure when fluid flows through the housing.

Figure 4 shows the heating device as illustrated in figure 2, but having connected to it an embodiment of the removable and replaceable connection stubs 18. The connection stubs have respective flanges 19 at their free ends, which are connectable to the cooling system hoses. An advantage with such replaceable connection stubs is that the free ends may be dimensioned and shaped such that they fit different hose dimensions and/or couplings (i.e. the flanges may be substituted by other geometries and connection mechanisms, such as quick-couplings). The same heating device may thus be used with different hose systems, such as manufacturer-specific dimensions and/or couplings, merely by replacing the connections stubs 18.

Figure 5 shows that the heating device has a chamber 13 which is configured for reception of a heating element 7, in the illustrated embodiment a so-called PTC element. PTC elements ("Positive Temperature Coefficient") are as such well known and need therefore not be described in detail here. It should be understood that other heating elements (possibly in combination with thermostat) may be used. The PTC element 7 is connected to the socket 3 via wires (not shown). The connection stubs 18 have respective internal channels 29 such that a fluid connection is formed with the above- mentioned fluid openings 4a,b.

Figure 6 shows how the connection stub 18 is mounted to the housing. In the illustrated embodiment, the connection stub has a ring flange 22 and an O-ring 21 arranged in a groove 34 on the stub. The O-ring seals against the internal wall of the fluid opening 4a and a locking ring 20 keeps the connection stub 18 in place in the axial direction. The connection stub is thus rotatably connected to the housing. A removable support bushing 37 arranged at the inner end of the connection stub 18 provides an abutment member for the connection stub against the heater. The support bushing 37 is preferably made of a metal, such as stainless steel, and serves to stabilize interface between the connection stub and the heater housing. The connection stub preferably is made of a thermoplastic material (e.g. PPS, PPA), or other material having thermally insulating properties, while the heater housing is made of a heat-conducting material, preferably a metal (such as aluminium).

Figure 7 shows the connection stub 18, disconnected from the heating device. The ring flanges 22 and groove (for O-ring) 34 are designated the connecting portion 40.

Another embodiment of the connection stub 18' according to the invention will now be described with reference to figures 8-12.

In this embodiment, the connection stub 18' has an angle of 90°, such that the internal fluid channel 29' changes direction with 90° with respect to the fluid opening 4a'.

The connection stub 18' is connected to a transition piece 30 and is held in place by a flexible clip 28. The transition piece 30 is in the illustrated embodiment configured with an end 31 for assembly in a housing on a heating device (not shown in figure 8). It shall be understood that the transition piece 30 may be a separate part as shown in figures 8- 11, or be fixedly integrated (i.e. a part of) the heating device housing.

The connection stub 18' is held in place in the transition piece 30 by the clip 28 passing through slits 32 in the transition piece and into a groove 34' which is defined by two raised ring portions 33. The connection stub is thus connected to the transition piece 30 - and thus to the heating device housing. In the illustrated embodiment, the connection piece is rotatable around the longitudinal axis C. An O-ring 21 ensures sealing between the connection stub 18' and the transition piece 30. In figure 12, the raised portions 33 and groove 34' are designated the connecting portion 40.

Figure 13 illustrates yet another embodiment of the connection stub 18" according to the invention, which has an angle of 45°, such that the internal fluid channel 29 also has an angle of 45°. Connection stubs having such angle provides a considerable flexibility when assembling heaters, associated pumps, etc. in an engine compartment. The 45° connected stub may for example be connected to the heater or pump in a similar fashion as described above with reference to the 90° connection stub.

It should be understood that the connection stubs according to the invention may have other angles than those shown here. The connection stub may have any geometrical shape, adapted to the use. The connection stub may also have other types of connection portions than those illustrated here. The connection stub may also have a length which renders hoses superfluous. For example, the connection stub may be considerably longer than the illustrated embodiment, and may thus be connected directly to the next component in the cooling circuit. The connection stub according to the invention is preferably made of thermally insulating materials, such as a thermoplastic material (e.g. PPS, PPA).

In certain cases it is advantageous or necessary to incorporate a pump in the cooling circuit. The pump operates when the heater operates, and contributes to enhancing fluid flow though the heater, and hence the heating efficiency. Such circulation pump 35 is shown in figure 14 (Required electrical connections for the pump motor are not shown). The circulation pump 35 comprises housing with a first fluid opening 36 (coolant inlet or outlet) and second fluid opening 38 (coolant outlet or inlet). The second fluid opening 38 is configured for reception of a connection stub 18 having a connecting portion 40, in a manner similar to one of those described above with reference to the heater. For example, the connection stub 18 may be connected to the second fluid opening 38 in a similar manner to that described above with reference to figures 8 - 12, using a locking clip 28'. Figure 14 shows the connection stub 18 disconnected from the pump 35, while figure 15 shows the connection stub 18 when connected to the pump 35 (locking clip 28' not in place).

Figure 16 shows yet another embodiment of the invented connection stub 18"'. This bidirectional connection stub 18"' has two similar ends; i.e. it is symmetrical about a central collar 39 and thus has two opposite connecting portions 40a, 40b, one at each end of the connection stub. The connection portions 40a,b and their corresponding interfaces in the housing fluid opening are as described above, and need therefore not be described further here.

One advantage of the bidirectional connection stub 18"' is that it allows components in the coolant circuit to be coupled in series, in a highly compact manner. An example is illustrated in figures 17 and 18, showing a circulation pump 35 and heater housing 1 and a bidirectional connection stub 18"'. Figure 17 shows the heater, pump and connection stub in a disconnected state, while figure 18 shows the circulation pump 35 and the heater housing 1 fluidly interconnected via the bidirectional connection stub 18"' (only one locking clip 28' in place in figure 18).

Figure 19 illustrates an advantage of the removable bidirectional stub. In some instances it is required of desirable to have several heaters, each independently controlled and with different power output, connected in series in the coolant circuit. In figure 19, three heaters with housings la, lb, lc are interconnected in series via two bidirectional stubs 18"', and a circulation pump 35 is connected in series to the heater housing lc via a bidirectional connection stub 18"'. In principle, a plurality of heaters and pumps may be interconnected in this fashion. The bidirectional stub provides for a compact, efficient and reliable assembly and obviates the need for interconnecting hoses.

As mentioned above with reference to figures 8 - 13, the connection stub may have angles of 45° and 90° with respect to the longitudinal axis. In fact, the connection stub, including also the bidirectional stub, may have any angle, including U-shape and V- shape. This is illustrated schematically in figure 20, where a heater 1 and a circulation pump 35 are interconnected via a U-shaped bidirectional connection stub 18"". This configuration is useful for installation in a tight engine compartment, where the pump and heater may be connected before the assembly is lowered into the engine

compartment.

Even though the invention has been described with reference to an engine heater and a pump for a cooling fluid, it should be understood that is suitable for assembly to other units, particularly in a vehicle or a vessel, and for other fluids (gases and/or liquids) than coolant.

Even though the invention has been described with reference to a circular cross-section, it should be understood that the removable connection stubs may be used on other housings with other cross-sections. The invention is also not limited to a heating device using PTC elements.

Claims

1. A heater assembly for heating a fluid, particularly in a vehicle or vessel, comprising at least one heater housing (1) having a heating element (7) and a fluid inlet (4a) and a fluid outlet (4b); wherein the fluid inlet and the fluid outlet are connected via one or more fluid channels (6a,b) in thermal connection with the heating element (7); characterized by at least one connection stub (18; 18'; 18"; 18"'; 18"") having a first end with means (21, 22, 34, 40) for releasable connection to the fluid inlet or fluid outlet.

2. The heater assembly of claim 1, wherein the connection stub (18; 18'; 18") comprises a second, free, end (19) adapted for connection to a hose or to a component in a cooling circuit.

3. The heater assembly of claim 1 or claim 2, further comprising a transition piece (30) configured for the housing at the fluid inlet or fluid outlet and comprising connection means (28, 32) for connection to said first end of the connection stub.

4. The heater assembly of any one of claims 1-3, wherein the transition piece (30) is releasably configured for the housing.

5. The heater assembly of claim 1, wherein the releasable connection stub is a bidirectional connection stub (18"'; 18""), having two similar and opposite ends with similar connection portions (40a, 40b) configured for releasable connection to a fluid inlet (4a; 36) or a fluid outlet (4b; 38).

6. The heater assembly of claim 1 or 5, further comprising a plurality of heater housings (la, lb, lc) fluidly and releasably interconnected via a respective plurality of connection stubs (18"'; 18"").

7. The heater assembly of claim 1, 5 or 6, further comprising a circulation pump (35) having at least one fluid opening (38) with configured for releasable connection to a connection stub (18; 18'; 18"; 18"'; 18"").

8. The heater assembly of claim 7, wherein the circulation pump (35) is fluidly interconnected to a heater housing (lc) via a bidirectional connection stub (18"'; 18"").

9. The heater assembly of any one of the preceding claims, wherein the connection stub (18'; 18"; 18"") has an angle different from 0° with respect to a longitudinal axis (C).

10. The heater assembly of claim 9, wherein said angle is 45° or 90°.

11. The heater assembly of claim 9, wherein the connection stub is U-shaped or V- shaped.

12. The heater assembly of any one of the preceding claims, wherein the housing (1) is of a heat conducting material and the connection stub (18) is of a thermally insulating material.

13. The heater assembly of any one of the preceding claims, wherein the connection stub is rotatably connected to the housing.