JPS58107287A - Cold press welding method - Google Patents

Abstract

PURPOSE:To join a Cu pipe and an Al plate in a tight contact state in the stage of joining the Cu pipe and the Al plate by inserting a bar-like die having a porjecting line into the pipe then placing the plate on the pipe and grasping both under pressure with a hydraulic device. CONSTITUTION:A die 6 having a linear projection 10 is inserted into the hollow part of a Cu pipe 5 by facing the projection 10 upward. The pipe 5 is placed and fixed in a flat circular groove 4 provided in a lower support 3 by means of positioning members 7 in both end parts. Thereafter, an Al plate 15 to be joined on the pipe 5 is placed and further an upper support 11 provided with a punch 13 is placed thereon. The pipe 5 and the plate 15 are grasped under pressure by means of the linear projection 14 provided to the preceding end of the punch 13 and the linear projection 10 of the die 6 by a hydraulic device, whereby the pipe 5 and the plate 15 are cold press welded. The bending of the plate 15 in the direction of an arrow 18 is prevented by anti-cambering bodies 16, whereby the joined part of the Cu pipe and the Al plate having a good tight contact stage is formed.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a cold pressure welding method, and more particularly to a cold pressure welding method in which a pipe body and a plate body are brought into contact with each other and the contact portions are linearly joined.

Technical background of the invention and its problems Recently, solar heat collecting plates have been manufactured in large quantities as part of solar heat utilization. As shown in Figure 1, this solar heat collecting plate is composed of a circular copper tube (1) and an aluminum plate body (2) to which the circular tube (1) is joined by caulking. The solar heat collected by the body (2) is transferred to the circular tube (1
) Heat is absorbed by a heat transfer medium such as water circulating inside. However, when the circular tube (1) and the plate (2) are joined by caulking, the circular tube (1) and the plate (2) are only in mechanical contact. ) to the circular tube (2) has a limit. In particular, when a solar heat collection plate is housed in a vacuum container to increase heat collection efficiency, the amount of heat conduction is extremely small and it cannot function as a heat exchanger. Therefore, in the past, a method has been implemented in which the circular tube (1) and the plate (2) are brought into contact with each other and the contact portion is linearly high-frequency resistance welded. However, according to this method, a weak intermetallic compound such as CuAl is generated in the weld, and the weld becomes brittle. Moreover, during use of the solar heat collector plate, the temperature of the welded part changes periodically within the range of approximately 120 to 20'0°C, and the welded part undergoes repeated expansion and contraction, so the welded part is subject to alternating tensile and compressive forces. It has the disadvantage that cracks occur very easily starting from intermetallic compounds.

OBJECTS OF THE INVENTION The present invention provides a cold press welding method that increases the amount of heat conduction from a plate to a tube and can join the tube so that the joint has sufficient mechanical properties. A rod-shaped lower mold with a linear protrusion inside is inserted, and the tube into which the lower mold is inserted is inserted into the fixing groove provided on the support body. After fitting the plate body so as to face the protrusion, the pipe contact portion of the plate body is cold-welded in a linear manner.

Embodiment of the Invention In the cold welding method in this embodiment, a cold welding apparatus whose main parts are shown in FIGS. 2 and 3 is used. A linear fixing #1I (41) with a semicircular cross section is provided on the upper surface of the lower support (3) which serves as a base.
) is the outer diameter of t! They are now equal. Further, at both ends of the fixing groove (4), there are positioning parts (7), (7) having a rectangular cross section that protrude from both end surfaces of a lower mold (6) that is inserted into a circular tube (5), which will be described later. Positioning to fit /13 (8),
(The lower mold 61 is a cylindrical body (9) having an outer diameter smaller than the inner diameter of the circular tube (5) as shown in FIGS. 3 and 4, and a cylindrical body ( 9) protrudes parallel to the axis of the cylindrical body (9).
a linear protrusion α0) with a height approximately corresponding to the difference between the outer diameter of the cylinder (5) and the inner diameter of the circular tube (5), and the above-mentioned positioning portion ( Furthermore, an upper support member [υ] is provided above the lower support member (3) so as to face the lower support member (3).This upper support member ( lυ is moved forward and backward in the direction of the arrow α2 by a hydraulic device (not shown).Then, the upper support body αυ is fixed #1 (4).
A rectangular rod-shaped upper U-shaped column parallel to the fixing groove (4) and having a substantially rectangular cross section is attached directly above the fixing groove (4). The surface of this upper mold uken facing the lower mold (3) has a rock-shaped protrusion as described later.
The upper support member αυ has a rectangular rod-shaped warp stopper body αb whose cross section is rectangular and parallel to the upper mold moat on both sides of the upper mold.
l, u61 have been added. These warp prevention bodies +1
1i1. The height of the Lie is approximately equal to the height of the upper mold 0.

Next, to describe the cold welding method in this embodiment, first, the lower die (6) is inserted into the hollow part of the circular tube (5), and the linear protrusion aQ of the lower die (6) is opposed to the upper die. Fit the positioning part (force, positioning groove + 8), (81) of the lower mold (6) so that the lower half of the circular tube (5) is in close contact with the fixing groove (4). After that, the plate body α is attached to the circular pipe (5) so that the pressure welding part α7) (see Fig. 5) at the center of the plate body 1 comes into contact with the planned cold welding position of the circular pipe (5). 5) Place it on top of the upper support (1
1) by operating the hydraulic system to lower the lower support (3).
) As shown in Figure 6, the circular pipe (5) and plate body (15)
are cold welded. At this time, a good bonding state can be obtained at a deformation rate of around 70%. Note that during cold welding, the plate Q5) tries to bend in the direction of the arrow in FIG.
Warpage prevention body d1. Since fll contacts the plate 1i5), bending deformation is prevented. In this way, the circular pipe (5) and the plate body 9 are continuously joined at the pressure contact part, and when the plate body a is a solar heat collecting plate, the heat collected by the plate body (summer 9) is smoothly and smoothly connected. The tube (5) conducts 114J.Especially when the plate (1) which is a solar heat collecting plate and the circular tube (5) are housed in a vacuum container, 114J is effective.Also, when welded Because fragile intermetallic compounds are not generated, the circular tube (5) and plate (15)
Cold pressure welding has better bonding strength than welding.

In addition, as shown in FIGS. 7 and 8, in accordance with other embodiments, a plurality of linear or comb-shaped pressure welding portions are arranged at regular intervals along a straight line. Cold pressure welding may be performed. This case also has the same effect as the above embodiment, but there is a part between the four welded parts whose cross-sectional area is not reduced by cold welding (-), which improves the bending resistance. , the mechanical strength such as tensile resistance is improved.In the case of joints, the T part that holds the circular pipe (5) and the plate body (15) is formed without cold welding the pressure welding parts u and... at once. Support (3
) may be sent in a direction perpendicular to the plane of the paper in the second drawing, and the parts may be cold-welded one by one. In this case, one advantage is that the length of the upper mold can be shortened. Furthermore, the present invention is not limited to the production of solar heat collecting plates as in the above embodiments, but can be applied to any cold press welding of tubes and plates. In this case, the material combination of the pressure-welding members to be joined is not limited to a combination of aluminum and copper, but may also be a combination of aluminum and aluminum, copper and copper, or copper and iron. Further, the shape of the tube is not limited to a circular tube, and may be an elliptical tube or a tube with a rectangular cross section.

Effects of the Invention According to the cold pressure welding method of the present invention, the remarkable effects listed below are achieved.

(1) Cold welding creates a completely continuous bond at the pressure interface between the plate and tube, so if the plate and tube are a heat exchanger such as a solar heat collector, The amount of heat conducted from the plate to the tube increases significantly compared to when the plate and the tube are in mechanical contact, for example, by caulking. In particular, heat 9: A ringing sound is heard in the container where the utensil is housed in a vacuum container.

(2) Unlike #welding, brittle intermetallic compounds are not generated, so the joint strength is higher than that of welding, and it will not break even under severe conditions where tensile and compressive forces are applied alternately. , reliability as a heat exchanger is improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part showing a conventional joining method, FIG. 2 is a cross-sectional view of a main part showing cold welding by a cold pressure welding method according to an embodiment of the present invention, and FIG. -X-ray cross-section if1 and FIG. 4 are views showing the end of the lower die used in the cold welding method shown in FIGS. 2 and 3, and FIG. 5 is a cold welding method according to an embodiment of the present invention. FIG. 6 is a plan view showing a press-welded area on a plate body cold-welded by this method; FIG. Figure and @8
The figure is a plan view showing a press-welded portion on a plate body cold-welded by a cold-pressure welding method according to another embodiment of the present invention. (1): Circular tube (tubular body), (6I: lower type, αI: linear projection, t1 moat upper type, d4): lll1! protuberance, 1151
S plate body. Figure 1

Claims (1)

[Claims] A cold pressure welding method characterized by having the following configuration. (B) A method in which a rod-shaped lower mold with projections provided along a straight line in the longitudinal direction is inserted into the hollow part of the tube, and the projections of the lower mold are brought close to the inner surface of the tube.(B) A method in which the lower mold is Method of bringing the plate into contact with the planned cold welding position on the outer surface of the inserted tube (c) Corresponding to the protrusion of the lower die mentioned above and the protrusion of this lower die