JP2008522119A - Manufacturing method of heat exchanger - Google Patents

Abstract

The present invention is a method for producing a heat exchanger (10) for an air heater (12) for integrating into a housing for guiding air, the heat exchanger comprising a heat exchanger body (14) having a longitudinal axis. About. In accordance with the present invention, at least a portion of the heat exchanger body (14) is fabricated by die casting using two cores, the cores being in opposite mold release directions (40, 42) along the longitudinal axis. To be taken out.

Description

  The present invention relates to a method of manufacturing a heat exchanger for an air heater that includes a heat exchanger body having a longitudinal axis and is integrated into a housing that guides air.

  At present, auxiliary heaters that are operated with fuel for vehicles, in particular commercial vehicles, are mainly equipped separately from vehicle-specific heating-air conditioning units, also called vehicle air conditioners. Such an auxiliary heater is formed as an air heater used as an independent heater and / or a parking heater, for example.

For some time, attempts have been made to integrate air heaters into vehicle-specific heating-air conditioning units. This saves space and necessary components. An example of such a structure is shown in Patent Document 1.
DE 102 11 591 A1

  The location and structure of the air heater selected to integrate the air heater into the heating-air conditioning unit will affect the integration function, economy and safety. Accordingly, various problems associated with incorporating an air heater into a heating-air conditioning unit have been recognized and attempts have been made to provide solutions to this problem. This ultimately provides a good master plan.

  One problem is related to the large weight of the heat exchanger body, which is typically made by die casting technology. Based on the large weight, the housing that supports the vehicle heater, in particular, must be made quite sturdy.

  In the proposed design concept of a heat exchanger extending longitudinally in the axial direction, air flows around the heat exchanger perpendicular to this direction. Such air flow inevitably creates large vortices of air, thereby increasing flow loss. In order to solve this problem by increasing the space surrounding the heat exchanger, the entire space of the heating-air conditioner must be expanded. Therefore, there is a need for a solution that promotes heat exchanger flow conditions and heat transfer.

  Furthermore, in connection with the design philosophy of incorporating an air heater in a heating-air conditioner, there is a desire to continue to use the existing components of the air heater. Therefore, in order to be able to use the same design concept for different types of air heaters, attempts have been made to configure the heat exchanger as variable as possible. This desire for variability is also related to the production of heat exchangers.

  It is important that the air warmed by the heat exchanger flows around the heat exchanger and transfers heat from the combustion gases to the heat exchanger. This heat transfer should also be improved, which provides a great degree of freedom especially in the structure of the heat transfer.

  Another important requirement for the air heater is to arrange the air heater so that the combustion gases do not get into the air flowing around the air heater. In addition, the air used for combustion should be taken from the outside area of the vehicle. That is, it should not be taken out from inside the vehicle. Improvements regarding the positioning of the various connecting pipes of the air heater are also desirable.

  The problem underlying the present invention is to overcome the aforementioned problems, particularly by means of suitable solutions relating to the weight of the heat exchanger.

  This problem is solved by the features of the independent claims.

  Advantageous embodiments of the invention are described in the dependent claims.

  According to the present invention, in the method described at the beginning, at least a part of the heat exchanger body is manufactured by a die casting method using two cores, and the cores are arranged in an opposite mold release direction along the longitudinal axis. It is taken out. Thereby, in the case of a predetermined release taper surface, a predetermined surface state, and a predetermined material, the release force can be reduced. Finally, it is possible to manufacture a heat exchanger that is thin and has a light weight.

  This method is very advantageous if the heat exchanger core has an inner profile. In this case, the reduction according to the invention of the release force is very advantageous since the inner profile improves the release force.

  For example, if the inner profile comprises a longitudinally extending rib, the method of making the heat exchanger can be used. Such an inner profile increases the heat transfer inner surface of the heat exchanger, thereby reducing the overall space.

  It may be advantageous if the heat exchanger body and the heat exchanger bottom are made separately. If the heat exchanger bottom and the heat exchanger head are made separately from the heat exchanger body, the heat exchanger body can be made by the method according to the invention.

  For similar reasons, it is advisable to make the heat exchanger head separately. If such a heat exchanger head is present, its separate fabrication allows the use of the die casting method according to the present invention. However, the entire heat exchanger head can be omitted depending on the shape of the burner head or burner unit.

  In order to provide advantageous features, the features relating to the production of the heat exchanger according to the invention can be combined with a number of other characteristics of the production method of the heat exchanger, the air heater provided with the heat exchanger and the heat exchanger.

  The heat exchanger body may include a heat exchanger core and a heat transfer surface, and at least a part of the heat exchanger core and the component providing the heat transfer surface may be separately manufactured. Such a separately manufactured method is considered advantageous as a means of reducing weight and as a means of providing high variability with respect to the design and manufacturing method of the part.

  In this connection, it is particularly advantageous if the component providing the heat transfer surface is shrink-fitted and / or interference-fitted to the heat exchanger core. The heat exchanger head and the heat exchanger bottom are preferably hermetically connected to the heat exchanger core, preferably by welding, brazing, gluing and / or screwing, whereas they are formed, for example, in a disc shape Individual heat transfer surfaces can be shrink fit or interference fit to the heat exchanger core. Thereby, other methods can be provided for variations of the fabrication method.

  It can have a cross-sectional shape that facilitates reducing flow resistance.

  This can be achieved, for example, by having an elliptical cross-sectional shape.

  In another example, the cross-sectional shape is similar to the cross-sectional shape of an airplane wing.

  Furthermore, it may be advantageous if the cross-sectional shape is a spindle shape.

  The heat exchanger head can have a number of bars on its outer surface that provide a heat transfer surface. Such a large number of rods provides a very large surface area for transferring heat to the air to be warmed.

  In doing so, on the one hand, it may be advantageous if the heat exchanger body comprises a heat exchanger core and at least some of the numerous rods are attached to the heat exchanger core by separate parts.

  On the other hand, the heat exchanger body may include a heat exchanger core, and at least a part of a large number of bars may be formed integrally with the heat exchanger core. Depending on the design method of the rods that are attached to the heat exchanger core by separate parts or the design method of the rods that are integrally formed on the heat exchanger core, there are various advantages, for example on the one hand there are advantages on variability and on the other hand There is an advantage regarding simplification of the manufacturing method.

  The heat exchanger body may include a number of corrugated ribs on its outer surface that provide a heat transfer surface.

  In this connection, it is also possible that the heat exchanger body comprises a heat exchanger core, and at least some of the numerous corrugated ribs are attached to the heat exchanger core by separate parts or as separate parts.

  Similarly, the heat exchanger body may include a heat exchanger core, and at least some of the many corrugated ribs may be formed integrally with the heat exchanger core. Without fixing such heat transfer surfaces to the heat transfer core through screw connections or similar connections, individual, or multiple, transfer surface components or their entire set fitted may be welded, brazed, or baked. It is a good idea to fix by a fit or an interference fit.

  The heat exchanger body can be composed of a plurality of heat exchanger body modules. This enhances variability. This is because the individual heat exchanger body modules can be formed differently, in particular heat exchangers of different sizes can be produced.

  From the perspective of modular manufacturing, it is advantageous if at least some of the heat exchanger body modules are identical. In that case, especially in the case of the die casting method, a different mold is not required.

  There are other advantages associated with air heaters for integration into air guiding housings. The air heater includes a heat exchanger having a heat exchanger body, and the air heater further includes a flow guide element, the flow guide element being at least partially during combustion in a combustion chamber disposed within the heat exchanger. The generated hot gas is guided to the inside of the heat exchange body. Hot gas generated during combustion can be efficiently distributed inside the heat exchanger.

  In this context, it is advantageous if the flow guide element is formed like a thread, as a vane, as a serpentine part, as a baffle plate and / or as a perforated tube. This method and many other methods overall improve heat transfer.

  Furthermore, there are advantages associated with an air heater for integration into a housing that guides air. The air heater is provided with a heat exchanger, and in this case, a flange plate is provided, and the flange plate is provided with an exhaust gas exhaust pipe by using sealing elements provided between the air heater mounting point and the flange plate and between the air heater and the flange plate. Seal at least against the inside of the car. With such a funnel plate, the exhaust gas can be guided to the outside air through the shortest path possible. In this case, there is no danger of exhaust gas reaching the vehicle interior.

  In this connection, it is furthermore advantageous if the flange plate seals the combustion air supply pipe against the interior of the vehicle. Thereby, combustion air is taken out from the outer space of the vehicle.

  Furthermore, it is advantageous if the flange plate is provided with a penetration guide for the fuel supply pipe. Thereby, all connections carrying gas and liquid are arranged within the flange plate. This is advantageous for connecting the air heater to the overall design.

  The present invention is based on the recognition that an air heater can be incorporated in a heating-air-conditioning device of an automobile, in particular a commercial vehicle, in an economical manner and in a functionally suitable manner. This is in particular due to the high variability of the heat exchanger provided by the present invention and the positive characteristics of the heat exchanger in terms of weight.

  The invention will be described by way of example on the basis of a particularly advantageous embodiment with reference to the attached figures.

  In the following description of the figures, the same reference numerals indicate the same or similar components.

  FIG. 1 is a perspective view of the air heater 12. The air heater 12 includes a heat exchanger 10 attached to the burner unit 60 and a burner head 62. The burner head 62 includes a fan motor 64 and a control device 66, and the fan motor 64 and the control device 66 constitute important components of the combustion air fan unit 68. The burner head 62 is further provided with a pipe 56 for supplying combustion air. The burner unit 60 is provided with a fuel supply pipe 58 and an exhaust gas discharge pipe 54. A flange plate 48 is disposed in the exhaust gas discharge pipe 54, and the flange plate 48 has a notch for guiding through the fuel supply pipe 58 and the combustion air supply pipe 56. The function of the flange plate 48 will be described in detail with reference to FIG. The heat exchanger 10 attached to the burner unit 60 includes a rib structure on the outer surface, and the rib structure increases the area for transferring heat to the air flowing around the heat exchanger 10. The air heater 12 is preferably arranged such that with respect to the flow of air to be warmed, that air flows in and out of the heat exchanger 10 perpendicularly to the axis of the heat exchanger 10.

  FIG. 2 is a perspective view of the air heater 12 with the heat exchanger removed. In this figure, a burner head 62 and a burner unit 60 are shown. The burner unit 60 includes a burner pipe 70, and hot gas is generated by the formation of a flame in the burner pipe. This hot gas transfers its thermal energy to a heat exchanger 10 not shown in FIG. A number of holes 72 are drilled in the outer peripheral wall of the burner tube 70 to allow hot gas to reach the heat exchanger.

  FIG. 3 is a perspective view of the air heater 12 with the heat exchanger removed and the burner head and burner unit disassembled. As is apparent from this figure, the burner head 60 is connected to the burner unit 60 via flange joints 74 and 76. As is further apparent from this figure, the flange plate 48 is fixedly connected to the exhaust gas discharge pipe 54, while a through hole for the combustion air supply pipe 56 is provided in the flange plate.

  FIG. 4 is a perspective view of the heat exchanger 10. A rib structure providing a heat transfer surface 22 is shown.

  FIG. 5 is a perspective view of individual components of the heat exchanger 10. The heat exchanger 10 is formed by a plurality of parts. The heat exchanger includes a heat exchanger core 20, a part 24 having a heat transfer surface 22, a heat exchanger bottom 16, and a heat exchanger head 18. Depending on the design of the burner head 62 and / or the burner unit 60, the heat exchanger head 18 may be omitted. In order to improve heat transfer from the hot gas generated in the burner tube 70 to the heat exchanger 10, an inner profile 30 is provided in the heat exchanger core 20. The heat exchanger head 18 and the heat exchanger bottom 16 can be manufactured by various techniques such as deep drawing, die casting or cutting. The individual parts can be connected to each other by various connection techniques such as welding, brazing, bonding and / or screwing. Since combustion gas is generated in the heat exchanger 10, it is important to connect the heat exchanger head 18, the heat exchanger core 20, and the heat exchanger bottom 16 in an airtight manner. Within the scope of the present disclosure, the heat exchanger core is also referred to as the heat exchanger body 14 along with a component 24 secured thereto and having a heat transfer surface 22.

  FIG. 6 is a perspective view of the air heater 12 including the housing fixing member 74. The housing fixing member is disposed on the air heater. The air heater 12 can be fixed to the surrounding housing by the housing fixing member 74. The housing fixing member 74 is fixed to the air heater 12 via the heat exchanger head 18 and the heat exchanger bottom 16.

  FIG. 7 is a cross-sectional view of a heat exchanger core having an elliptical cross section. The heat exchanger core 20 has an inner profile 30. The finer the inner profile 30 is, the greater the surface area provided for heat transfer from the hot gas to the heat exchanger 10. The heat exchanger core 20 as shown in the figure can be manufactured by, for example, an extrusion method. This makes it possible to reduce the wall thickness, thereby reducing the weight on the one hand and increasing the heat transfer surface area on the other. In the heat exchanger core 20, fixing means for fixing other components, for example, a hole 76 is provided. The elliptical cross-sectional shape 32 of the heat exchanger 20 can improve the flow condition of the air to be warmed that flows around the heat exchanger 20. Since the heat exchanger bottom 16 is a part manufactured separately from the heat exchanger core 20, the manufacture of the heat exchanger core 20 is simplified.

  FIG. 8 is a cross-sectional view of a heat exchanger core having an airfoil cross section. FIG. 9 is a cross-sectional view of a heat exchanger core having a spindle-shaped cross section. The illustrated cross-sectional shapes, ie, the airfoil cross-sectional shape 34 and the spindle-shaped cross-sectional shape 30 are to be understood as other examples of shapes that facilitate flow around the heat exchanger 20.

  FIG. 10 is a perspective view of the heat exchanger 10 and a separate piece 24 for heat transfer. Each component 24 shown is manufactured separately from the heat exchanger core 20. The part 24 is already mounted on the heat exchanger core 20. These parts are secured on the heat exchanger core by shrink-fitting or interference-fitting individual or multiple parts fitted, or the entire set of parts.

  FIG. 11 is a perspective view of the heat exchanger. The illustrated heat exchanger 10 has a very large surface area to transfer heat to the air flowing around it. This is achieved by the heat transfer surface 22 being provided by a number of bars 26.

  FIG. 12 is a perspective view of the heat exchanger. Again, a very large heat transfer surface area is provided. This is because again a number of rods 26 are provided to provide this heat transfer surface 22. The inner profile 30 is visible inside the heat exchanger. In this embodiment, a portion of this inner profile follows the outer bar 26 or bar row. Both the rod 26 of the embodiment of FIG. 12 and the rod 26 of the embodiment of FIG. 11 can be attached from the outside to the heat exchange surface by separately manufactured parts, or extruded by deformation or cutting methods. It can be formed by reworking the molded product.

  FIG. 13 is a perspective view of the heat exchanger 10. The illustrated component 28 that provides the heat transfer surface 22 of the heat exchanger 10 is a corrugated rib that facilitates heat transfer.

  FIG. 14 is a perspective view of a plurality of identical heat exchanger body modules 38. This embodiment shown in the drawing is particularly important when the heat exchanger is manufactured by the die casting method without being manufactured by the extrusion method as described above. The die casting method has a drawback that the wall thickness is increased based on the taper surface for release. In the present embodiment, a plurality of heat exchanger body modules 38 are provided. In this case, each heat exchanger body module 38 has a short axial length. Therefore, the thickness can be determined based on the short taper surface for release.

  FIG. 15 is a cut perspective view of the heat exchanger 10. Based on this illustration, it is possible to describe another method capable of shortening the release taper surface. That is, the heat exchanger 10 manufactured as a die-cast part is provided with two cores that are removed in the two opposite mold release directions 40 and 42, so that the wall thickness can be similarly reduced.

  16, 17, and 18 are perspective views of the combustion tube 70. FIG. 17 is a perspective view of the combustion tube. FIG. 18 is a perspective view of the combustion tube. In order to distribute the hot gas generated during combustion as effectively as possible for good and uniform heat dissipation to the inside of the heat exchanger, the flow guide member is used to distribute the hot gas in the heat exchanger 10. It is expedient to guide towards the inner rib 30 and / or its inner wall. In FIG. 17, a spiral flow guide member 44 is shown. Similarly, the flow guide members can be formed in the form of vanes, meanders, baffle plates and perforated tubes. A perforated tube having a number of holes 46 in addition to the hole profile formed by the holes 72 is shown in FIG.

  FIG. 19 is a perspective view of the connection range of the air heater including the flange plate 48. The flange plate 48 serves to attach the air heater 10 to the vehicle body and / or the housing or other elements fixed to the vehicle. In order to supply exhaust gas and combustion air to the outer space and / or to take it out of the outer space, the flange plate 48 is sealed and mounted to the air heater 12 and to the mounting location, for example to the vehicle body. The sealing can be performed by a sealing ring, for example.

  The features of the invention disclosed above in the drawings and in the claims can be important for realizing the invention both individually and in any combination.

It is a perspective view of an air heater. It is a perspective view of the air heater which removed the heat exchanger. It is a perspective view of the air heater which removed the heat exchanger and decomposed | disassembled into the burner head and the burner unit. It is a perspective view of a heat exchanger. It is a perspective view of each component of a heat exchanger. It is a perspective view of the air heater which has arranged a housing fixing member. 2 is a cross-sectional view of a heat exchanger core having an elliptical cross section. FIG. 2 is a cross-sectional view of a heat exchanger core having an airfoil cross section. FIG. FIG. 3 is a cross-sectional view of a heat exchanger core having a spindle-shaped cross section. It is a perspective view of a heat exchanger and a separate heat transfer member. It is a perspective view of a heat exchanger. It is a perspective view of a heat exchanger. It is a perspective view of a heat exchanger. It is a perspective view of many same heat exchanger main body modules. It is a cutaway perspective view of a heat exchanger. It is a perspective view of a combustion pipe. It is a perspective view of a combustion pipe. It is a perspective view of a combustion pipe. It is a perspective view of the connection range of an air heater provided with a flange plate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Heat exchanger, 12 ... Air heater, 14 ... Heat exchanger main body, 16 ... Heat exchanger bottom part, 18 ... Heat exchanger head, 20 ... Heat exchanger core, 22 ... Heat transfer surface, 24 ... Heat transfer surface Parts (disc shape), 26 ... Parts having a heat transfer surface (bar), 28 ... Parts having a heat transfer surface (corrugated ribs), 30 ... Inner profile, 32 ... Oval cross section, 34 ... Airfoil crossing 36, spindle cross section, 38 ... heat exchanger body module, 40 ... mold release direction, 42 ... mold release direction, 44 ... bolt thread, 46 ... hole in perforated tube, 48 ... flange plate, 54 ... Exhaust gas guide 56, combustion air supply pipe, 58 ... fuel supply pipe, 60 ... burner unit, 62 ... burner head

Claims (4)

  In a method of manufacturing a heat exchanger (10) for an air heater (12) comprising a heat exchanger body (14) having a longitudinal axis and integrated into a housing for guiding air, the heat exchanger body (14) A method characterized in that at least a part is manufactured by a die casting method using two cores, and the cores are taken out in opposite mold release directions (40, 42) along the longitudinal axis.   The method of claim 1, wherein the heat exchanger core (20) comprises an inner profile (30).   The method of claim 2, wherein the inner profile comprises longitudinally extending ribs.   4. The method according to claim 1, wherein the heat exchanger body (14), the heat exchanger bottom (16) and the heat exchanger head are produced separately.

Images