EP1702184A1

EP1702184A1 - Refrigerating unit comprising an ultrasound-welded suction tube and a throttling tube

Info

Publication number: EP1702184A1
Application number: EP04804736A
Authority: EP
Inventors: Jürgen Eberle; Thomas Kranz; Werner Schmid
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2003-12-23
Filing date: 2004-12-08
Publication date: 2006-09-20
Also published as: CN100412469C; DE10360899A1; RU2006120460A; WO2005064246A1; RU2375650C2; US20080016904A1; CN1898508A

Abstract

The invention relates to a refrigerating unit comprising a suction tube (1) and a throttling tube (2) for refrigerant, whereby the throttling tube (1), at a fist location (A) on the suction tube (2), is inserted inside the suction tube (2) and is joined thereto. In addition, the throttling tube (1) and the suction tube (2) are joined to one another at a second location (B) on the suction tube (2) at which outer surfaces of the throttling tube (1) and of the suction tube (2) touch. According to the invention, the outer surfaces of the throttling tube (1) and of the suction tube (2) are joined to one another at the second location (B) by ultrasound welding. The invention also relates to a method for joining the throttling tube (1) and the suction tube (2).

Description

Description Refrigeration unit with ultrasonically welded suction and throttle tube

The present invention relates to a refrigeration device with a throttle pipe and a suction pipe for refrigerant. The throttle tube runs at least over part of its length in the interior of the intake manifold and emerges from the intake manifold to form an exit point. Furthermore, the throttle pipe and the suction pipe are connected to one another at a further, second point of the suction pipe, at which outer surfaces of the throttle pipe and the suction pipe touch. The invention further relates to a method for connecting the throttle and intake manifold.

In household refrigeration devices, the throttle tube is usually introduced into the interior of the intake pipe before entering an evaporator and is continued within the intake pipe to the evaporator. By means of heat exchange with the extracted, evaporated refrigerant in the intake pipe, this is intended to achieve a pre-cooling of the liquefied refrigerant guided in the throttle pipe. Usually, the intake manifold and the throttle tube are connected to one another in a liquid-tight and gas-tight manner by soldering at this first point of the intake manifold, at which the throttle tube is led into the interior of the intake tube. The material from which the throttle tube is made, usually copper or a copper alloy, is changed in its structure by soldering in such a way that the throttle tube would bend easily without further attachment. For this reason, the part of the throttle tube located outside the intake manifold is guided parallel to the intake manifold over a certain length before entering the intake manifold and fixed to the intake manifold with an adhesive tape. The tape is usually applied by hand.

Another possibility of fixing the throttle tube to the intake manifold would be to wind the throttle tube around the intake manifold. However, this could lead to undesirable noises.

The object of the present invention is to provide a refrigerator of the type mentioned, in which the throttle tube introduced into the intake manifold is protected in a simple and inexpensive manner from kinking at the entry point into the intake manifold.

The object is achieved with a refrigeration device according to claim 1 and a method for connecting the suction and throttle tube of a refrigeration device according to claim 7. The dependent claims relate to preferred configurations of the refrigerator.

Accordingly, a refrigeration device is provided with a throttle tube and a suction pipe for refrigerant, wherein the throttle pipe is inserted into and connected to the inside of the suction pipe at a first point of the suction pipe, and wherein the throttle pipe and the suction pipe at a further, second point of the intake manifold, on which outer surfaces of the throttle tube and the intake manifold touch, are connected to one another. According to the invention, the outer surfaces of the throttle tube and the intake manifold are connected to one another by ultrasonic welding at the second connection point of the intake and throttle tube.

The ultrasonic welding is usually done so that the outer surfaces to be connected by the suction and throttle tube are brought into contact with one another and excited with high-frequency ultrasound. The frequencies here can range from approximately 20,000 to 60,000 Hertz. The two surfaces of the intake and throttle tube rub against each other and heat up so much that their contact surfaces fuse together. As a rule, the ultrasonic energy is supplied to the pipes to be connected via a so-called sonode. The sonode amplifies the ultrasound generated, for example, by a piezo composite oscillator. A piezo composite transducer is usually made up of several piezoceramic perforated disks that are clamped together via metallic end pieces.

The welding of suction and throttling pipe by means of ultrasonic welding has the advantage that the heat required for welding is released in a short time and exclusively on the contacting surfaces of the two pipes. Other regions of the pipes are at most heated by the flow of heat from the contact area. They therefore remain much cooler than e.g. when soldering is possible. Therefore, the structure of the metallic material from which the intake manifold and the throttle tube are made, mostly copper or a copper alloy, is not significantly changed. The mechanical strength properties of the material are therefore not changed. It is also a very inexpensive connection technology. Furthermore, the throttle tube can be fixed automatically to the intake manifold by means of ultrasonic welding, which is not the case when fixing with the aid of an adhesive tape. This should still be done by hand. The elimination of the adhesive tape also saves material.

Preferably, the second point at which the outer surfaces of the throttle and intake manifold are connected to one another by means of ultrasonic welding is approximately 5 mm to 20 mm, in particular about 5 mm to 15 mm, more particularly about 10 mm, spaced from the first point at which the throttle tube enters the interior of the intake manifold.

The throttle tube can be guided into the interior of the intake manifold in a variety of ways. The suction pipe may have a puncture or an entry hole for the throttle pipe in its wall, for example. Furthermore, there is the possibility of providing a connection pipe which has a connection point on one side for an end of a first partial suction pipe and a throttle pipe and is therefore widened. The second partial intake manifold and the throttle tube are inserted into the expansion. Another possibility is to provide one of the partial suction pipes with a cover at one of its ends, which has an insertion hole for the second partial suction pipe and an entry hole for the throttle pipe. For example, in the case of expansion, the suction pipe has a larger diameter at the first point than at the second point.

By guiding the throttle tube in the suction tube immediately upstream of the evaporator, pre-cooling of the liquefied refrigerant conducted in the throttle tube to the evaporator is effected by means of heat exchange with the evaporated refrigerant discharged from the evaporator in the suction tube. Therefore, the second point, at which a part of the throttle tube located outside the intake manifold is fixed to the intake manifold by ultrasonic welding, is preferably downstream of the first point at which the throttle tube enters the intake manifold, with respect to the refrigerant flowing in the intake manifold entry.

[012] The refrigeration device according to the invention can, for example, be a refrigerator or freezer, for example for domestic use.

[013] The present invention also includes a method for connecting a suction pipe of a refrigeration device to a throttle pipe. The method has the following steps: leading the throttle tube out of the interior of the intake manifold at a first point of the intake manifold serving as an exit point; Connecting the suction pipe and the throttle pipe at the first point, in particular by soldering; Bringing an outer surface of a part of the throttle tube located outside the intake manifold into contact with an outer surface of the intake manifold at a second location of the intake manifold; Connect the suction pipe and the throttle pipe at the second point. The outer surfaces of the intake manifold and the throttle tube are connected to one another by ultrasonic welding. The method steps mentioned are preferably carried out in the order listed above. However, it is also possible to order them in a different order perform. For example, the throttle tube can first be inserted into the interior of the intake manifold, then the throttle tube can be fixed to the intake manifold by means of ultrasonic welding for later protection against kinking, and then the throttle tube and the intake manifold can be connected to each other at the entry point of the throttle tube, which is preferably done by soldering ,

Further features and advantages of the invention will become apparent from the following description of an embodiment with reference to the accompanying drawings. It shows:

1 shows a part of an evaporator 1 with a throttle tube 1 which supplies a refrigerant and a suction tube 2 which discharges the refrigerant, and the connection of the two tubes in front of the evaporator 1 in a sectional view.

1 shows a throttle pipe 1 and a suction pipe 2 of a refrigeration device according to the invention. The refrigerator itself is not shown because its structure is known to the person skilled in the art. The refrigerator can be a refrigerator, for example. The throttle tube 1 leads liquefied refrigerant to an evaporator 3 of the refrigeration device. It opens into a refrigerant line 4 of the evaporator 3, which, which cannot be seen from the detail shown, extends in a meandering manner over the entire surface of the evaporator 3. The end of the refrigerant line 4 opens into a connection section 5 of the evaporator 3, into which the suction pipe 2 is inserted and fastened. The suction pipe 2 leads the evaporated refrigerant away from the evaporator 3. The intake manifold 2 and the throttle tube 1 are each thin-walled tubes with an inner diameter of a few millimeters in the case of the intake manifold 2 and fractions of a millimeter in the case of the throttle tube 1.

In front of the evaporator 3, the throttle tube 1 enters the intake manifold 2 at a first point A of the intake manifold 2 and is continued up to the evaporator 3 in the intake manifold 2 until it ends in the connection section 5 of the evaporator 3. By guiding the throttle tube 1 in the intake manifold 2, the liquefied refrigerant guided in the throttle tube 1 is pre-cooled by heat exchange with the evacuated, evaporated refrigerant in the intake manifold 2. In the embodiment shown, the suction pipe 2 is formed from at least two partial suction pipes 9 and 10, which are connected to one another in a liquid-tight and gas-tight manner by a connecting pipe 11. The partial suction pipe 10 directly connected to the evaporator 3 is connected at one of its ends to the connecting pipe 11, which has a first point A, which is widened and has an outlet point for the throttle pipe. In the widening the partial suction pipe 9 and the throttle pipe 1 are introduced. The partial suction pipe 9 ends in the widening. The throttle tube 1 is continued up to the evaporator 3 in the partial intake manifold 10. The partial suction pipe 9 and the throttle pipe 1 are tightly connected to the partial suction pipe 10 by soldering at the widening of the connecting pipe 11.

Deviating from the figure shown, an embodiment is also conceivable in which the throttle tube 1 is inserted at point A of the intake manifold 2 through a puncture in the wall of the intake manifold 2 or the connecting tube 11 or an entry hole into the intake manifold 2 is. The suction pipe 2 could then be configured in one piece. It would also be conceivable to design the connecting pipe 11 at the first point A with a cover which has two through holes, one for inserting the partial suction pipe 9 and one for inserting the throttle pipe 1. The throttle pipe 1 and the suction pipe 2 would also come on in this case the entry point of the throttle tube 1 in the intake manifold 2 connected by soldering.

The intake manifold 2 and the throttle tube 1 are usually made of copper or a copper alloy. When soldering, the structure of the copper material is changed, which leads to an impairment of the strength properties of the copper material. The throttle tube 1 can therefore bend slightly under mechanical stress at the soldered entry point into the intake manifold 2. In order to prevent this, the throttle tube 1 is fixed at a further, second point B to the intake manifold 2 by means of ultrasonic welding. At this point B, the throttle tube 1 is located outside the intake manifold 2. In the embodiment shown, the second location B of the intake manifold 2 is thus downstream of the first location A of the intake manifold 2 with respect to the refrigerant guided in the intake manifold 2 the first point A and the second point B are spaced apart by approximately 5 mm to 20 mm, preferably approximately 5 mm to 15 mm and particularly preferably approximately 10 mm.

A connection of the throttle tube 1 and the intake manifold 2 at the two points A and B can be carried out, for example, as follows: The throttle tube 1 is led out of the interior of the intake manifold 2 at point A and connected to it by soldering. Thereafter, an outer surface of a part of the throttle tube 1 located outside the intake manifold 2 is brought into contact with an outer surface of the intake manifold 2 at point B, ie the throttle tube 1 is placed on the intake manifold 2. The contacting outer surfaces of throttle tube 1 and intake manifold 2 are connected to one another by ultrasonic welding. This is done by excitation with high-frequency ultrasound. The frequencies here can range from around 20 000 to 60,000 hertz. Excited by the ultrasound, the surfaces of the throttle tube 1 and the suction tube 2 rub against each other and heat up so strongly that their contact surfaces fuse with one another. As a rule, the ultrasonic energy is supplied via a so-called sonode. The sonode amplifies the ultrasound generated, for example, by a piezo composite oscillator. A piezo composite oscillator can be constructed from a plurality of piezoceramic perforated disks which are clamped together via metallic end pieces. The method steps described above for connecting throttle tube 1 and intake manifold 2 at points A and B can also be carried out in a sequence other than that described. For example, it is conceivable first to lead the throttle tube 1 out of the intake manifold 2 at point A, then to fix the throttle tube 1 at location B by ultrasonic welding on the intake manifold 2 and only then to close the throttle tube 1 and the intake manifold 2 at location A with one another solder.

Claims

Expectations

Refrigeration device with a suction pipe (2) and a throttle pipe (1), which extends at least with part of its length inside the suction pipe (2) and is led out from the suction pipe (2) to form an outlet part (A), wherein the throttle tube (1) and the intake manifold (2) are connected to one another at a second point (B) of the intake manifold (2) at which the outer surfaces of the throttle tube (1) and the intake manifold (2) touch, characterized in that the External surfaces of the throttle tube (1) and the suction tube (2) are connected to one another at the second point (B) by ultrasonic welding.

Refrigerating appliance according spoke 1, characterized in that the second point (B) is about 5 mm to 20 mm, preferably about 10 mm, from the first point (A) spaced.

[003] Refrigeration device according to claim 1 or 2, characterized in that the second point (B) is located downstream of the outlet point (A) with respect to the refrigerant flowing in the suction pipe (2).

Refrigerating appliance according to one of claims 1 to 3, characterized in that the outlet point (A) is provided on a connecting pipe (11) on which downstream both the suction pipe (2) and the throttle pipe (1) are liquid and gas tight is fixed.

Refrigerating appliance according to one of claims 1 to 3, characterized in that the suction pipe (2) in the region of the outlet point (A) has an expansion or a puncture for the throttle pipe (1).

Method for connecting a suction pipe (2) of a refrigeration device with a throttle pipe (1) comprising the following steps: leading the throttle pipe (1) out of the interior of the suction pipe (2) at an exit point (A) of the suction pipe (2); Connecting the suction pipe (2) and the throttle pipe (1) at the exit point (A), in particular by soldering; bringing an outer surface of a part of the throttle tube (1) located outside the intake manifold (2) into contact with an outer surface of the intake manifold (2) at a second location (B) of the intake manifold (2); Connecting the suction pipe (2) and the throttle pipe (1) at the second point (B); characterized in that the outer surfaces of the suction pipe (2) and the throttle pipe (1) at the second point (B) by ultrasonic welding be connected to each other.