Metal working – Means to assemble or disassemble – Heat exchanger
Patent
1993-11-22
1994-12-06
Cuda, Irene
Metal working
Means to assemble or disassemble
Heat exchanger
29727, 29723, 29890047, B23P 1500
Patent
active
053698762
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to apparatus for and to a method of inserting U-shaped heat exchanger tubes in a heat exchange core.
U-shaped heat exchanger tubes are often referred to as hairpin tubes. These tubes are used to conduct a liquid medium through a heat exchanger and are used where the heat exchanger has a manifold on one end only. The liquid flows along one limb of the U-shaped tube to the far end of the heat exchanger core, and then flows back through the other limb to the manifold. The manifold may be divided into a number of different sections.
The invention is particularly, but not exclusively, applicable to heat exchanger cores as used in motor vehicles. In many such heat exchangers, the core is formed by a stack of thin fins which have holes pierced in them through which tubes can pass. The tubes have to be inserted through the holes in each fin in order to assemble the heat exchanger. In a subsequent manufacturing stage (which is no concern of the present invention) the tubes are expanded outwardly into intimate, thermally conducting, contact with the fins.
BACKGROUND TO THE INVENTION
Heat exchangers are known where straight heat exchanger tubes are used and it is known to insert such tubes automatically.
British patent specification 2 157 985 shows a system for threading U-shaped tubes into a heat exchanger core, but this requires the use of lacing rods which are introduced from below through the holes in the core, and which guide the leading ends of the U-shaped tubes. This is shown in FIGS. 10, 11, 12 and 13 of British patent specification 2 157 985.
European patent specification 0 126 457 also describes a system for inserting U-shaped tubes into a heat exchanger, but in this case the tubes are moved horizontally into holes in the heat exchanger, and are merely supported from below during the insertion process.
SUMMARY OF THE INVENTION
According to the present invention, there is provided apparatus for inserting U-shaped heat exchanger tubes in a heat exchanger core, the apparatus comprising a track which includes a pair of parallel channels for receiving the limbs of the tubes and for guiding the limbs on three sides of a slide for pushing the tubes along the track and into a heat exchanger core, and restraining means for closing the fourth side of the channels to guide the limbs, the restraining means being adapted to move out of the track as the head of the tube and the slide pass along the track.
The restraining means preferably comprises at least one tongue which can be inserted into the track, between the channels, to locally close the fourth side of the channels. For example, if the U-shaped tubes are 750 mm long, there may be three tongues forming the restraining means.
It is preferred if each tongue only moves out of the track at the last minute before the head of the tube and the slide reach the location of the tongue. The tongues will therefore move out of the track sequentially as the tube moves along the track.
It is also preferred if the restraining means are moved out of the track by a component which moves with the slide. This ensures that correct sequencing is achieved.
The tongues may comprise a leading end part which is introduced into the track, and a rear end part which is engaged by a retractor mechanism. The tongue is preferably biased into its position in the track and is moved out of the track, against the biasing force, by the retractor mechanism. The retractor mechanism may be a rod connected to the top of the slide which makes contact with each tongue a short distance ahead of the position of the slide, to withdraw each tongue from the track.
The apparatus preferably also includes a magazine in which tubes are collected, with the surfaces of the next tube to be inserted forming one wall of the channel and acting as a guide on one side of the channel for guiding the limbs of a tube which is being inserted, and means for feeding the next tube into the track as soon as a preceding tube has been pushed out of the track.
The apparatus may a
REFERENCES:
patent: 4202085 (1980-05-01), Vollmer
patent: 4221534 (1980-09-01), Rethy
patent: 4380868 (1983-04-01), Hall
patent: 4698904 (1987-10-01), Nozawa et al.
patent: 4734969 (1988-04-01), Currie et al.
patent: 5003691 (1991-04-01), Millinan et al.
patent: 5220722 (1993-06-01), Millinan
Coppiellie Raymond L.
Cuda Irene
Ford Motor Company
May Roger L.
LandOfFree
Apparatus for inserting U-shaped tubes in a heat exchanger core does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for inserting U-shaped tubes in a heat exchanger core, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for inserting U-shaped tubes in a heat exchanger core will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-206103