JPS5828038B2 - Friction welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly involves rotating either one of two members to which an acid solution is to be applied, and utilizing the rotational friction heat of the abutting surfaces of the members and Calo pressure in the direction of the rotational axis. The present invention relates to a friction welding method for joining the above members.

In the friction welding method, the temperature rise between the outer and inner centers of the butt friction surfaces is greater on the outside where the frictional energy is greater, and deformation due to friction occurs from a relatively early stage. The prominent Paris becomes larger.

However, as Paris grows larger, it has the following disadvantages:

In other words, the machining process to remove the paris takes time.In particular, the paris is affected by heat during fermentation and becomes much harder than the material, so the time required to remove the paris takes up most of the total machining time. In some cases, it occupies .

Furthermore, due to the large twist, the fiber structure that is generated parallel to the longitudinal direction of the material is pushed and bent in the direction parallel to the joint surface at the joint surface of both members, resulting in a drawback of low toughness.

A way to solve these drawbacks at the same time would be to reduce the tension, that is, the pressure, but conventional methods either reduce the friction time or reduce the thermal pressure.

However, in both cases, the difference in temperature between the inside and outside of the friction surface becomes large, causing another problem in that a safe temperature for bonding cannot be obtained.

In order to eliminate such drawbacks of the conventional friction welding method, the present invention cools the abutting surfaces of the joining members that are frictionally rotating against each other from the outside, and also oxidizes the inside and outside of the abutting surfaces almost simultaneously. Provided is a friction welding method characterized in that force-rotation welding is performed when the liquid temperature is reached.

Embodiments of the method of the present invention will be described in detail with reference to the drawings.

1, one of the members 1.1 to be joined is attached to the rotary chuck 7 and the other to the fixed chuck 8, and the abutting friction surfaces 1, 1 are abutted, and the abutting friction between the two members 1, 1 is A hollow ring 3 for cooling is provided on the outer periphery of the surfaces 1, 1,
During a certain period of time during friction, a cooling body 6 is injected from a plurality of small holes 5 inside the cooling body passage 4 of the hollow ring 3 to forcibly cool the outside of the friction surface.

However, by using such a cooling method, a phenomenon different from that of the conventional method occurs in addition to the temperature of the friction surface as explained below. A very small joint is obtained.

Changes in the rotational speed N, Calo pressure P, temperature T, and twisting margin δ of the joining members during the entire acid solution process of the method of the present invention shown in FIG. 3 will be explained while comparing with the conventional method shown in FIG. 4.

In Sunzu 3rd fixation and 4th figure, 3-a figure and 4
- Figure a is a graph of the relationship between time t and rotation speed N, Figures 3-b and 4-b are graphs of the relationship between time t and pressing force P,
ph is the caloric pressure, Pu is the upset pressure, Figure 3-c and 4-0 are graphs of the relationship between time t and temperature T of the friction surface, Ti is the inner temperature of the friction surface, and To is the temperature of the friction surface. Outside temperature, Figures 3-d and 4-d are graphs of the relationship between time t and twisting force δ, where δh indicates the force behind friction and δU indicates the force behind upset, respectively. Figure a, 31b
As shown in the figures and 4-b, the conditions for the rotational speed N and 77[] pressure P are the same in the method of the present invention as in the conventional method.

According to the method of the present invention, one member starts rotating and three
- When the rotational speed N reaches a certain value as shown in Fig. 3-a, the Ikekata member advances due to the Karo pressure Ph shown in Fig. 3-b, and both members come into contact and generate frictional heat.

After a while, a cooling body is ejected to cool the area around the friction surfaces of both members from the outside, and as shown in Figure 3-'c, the temperature To on the outside of the friction surfaces becomes extremely lower than the temperature Ti on the inside center. , In addition, as shown in Figure 3-d, δh rather than friction hardly occurs because the deformation resistance on the outside is large.

In contrast, in the conventional method, the temperature T on the outside of the friction surface is lower than the temperature Ti on the inside of the friction surface, as shown in Figure 4-0.

is always high, and as shown in the truncated 4-d diagram, both δh from friction and δU from upset are large, and the gap at the joint is large.

In this state, the time for the inside temperature to reach a sufficiently high temperature is to 1.
This continues for a certain period of time, and at time t, the jetting of the cooling body is stopped.

Then, as shown in Figure 3-0, the temperature To on the outside of the friction surface rapidly rises and approaches the temperature Ti on the inside.

As a result, a slight amount of friction δh occurs as shown in Figure 3-d.

Then, when the temperature distribution on the friction surface becomes uniform, that is, To=Ti, the rotation of the rotating member is stopped by the brake, and an upset pressure Pu is applied to complete the joining.

Note that depending on the type of component to which the acid solution is applied, To=T is not necessarily true.
It does not have to be i, and the pressure bonding may be performed when the temperature distribution of the abutting surfaces reaches the acid solution temperature almost simultaneously.

At this time, the upset δU occurs, but the friction δh is extremely small compared to the conventional method, so the total loss δ is also extremely small.

In other words, a joint with a small Paris can be obtained.

Furthermore, since the supply of the cooling body is stopped slightly before the upset pressure Pu is applied, there is no difference in temperature between the inside and outside of the friction surface, making it possible to join at an appropriate temperature.

As described above, according to the welding method of the present invention, a sound joint can be obtained by shifting the burrs to a smaller size, reducing the mechanical man-hours required to remove the burrs, and the fiber composition of the material can also be changed at the joining surface. The toughness of the joint is also improved because it is extremely unlikely to be pressed and bent.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the welding method of the present invention, and FIG. 2 is a side view of an acid liquid joint made by the welding method of the present invention, both of which partially show the cut portion. FIGS. 3 and 4 are charts showing changes in the rotational speed N, pressing force P, temperature T, and twisting width δ in the welding method of the present invention and the conventional method. DESCRIPTION OF SYMBOLS 1... Joining member, 1... Butt friction surface, 2... Butt friction surface, 3... Hollow ring for cooling, 4... Cooling body passage, 5... Small hole, 6... Cooling liquid, 7... Rotating chuck, 8... Fixed chuck.

Claims (1)

[Claims] 1. A friction welding method characterized by cooling the abutting surfaces of joining members that are frictionally rotating against each other from the outside, and performing force-pressure welding when the inside and outside of the abutting surfaces reach welding temperatures almost simultaneously. .