JPH01103235A - Laser beam shrink fitting - Google Patents

Abstract

PURPOSE:To realize shrink fitting with high precision by locally irradiating the laser beam onto the minutely bent parts of a press part or molded part and executing shrink fitting. CONSTITUTION:When an internal part 2 is fitted into an outer part 3, the internal part 2 is inserted into the outer part 3, and the minutely bent parts 4,... are adjusted to the positions of the fitting recessed parts 5,.... Then, if necessary, a force is applied so that the minutely bent parts 4,... are shifted to the fitting recessed parts 5,... by using an auxiliary jig 6. Then, the laser beam 9 irradiated from a laser oscillator 8 by using a laser radiation device 7 is controlled by a light collecting lens 10, and irradiated onto a dividing mirror 11, and the light is divided and locally irradiated to each minutely bent part 4,.... The minutely bent parts 4,... in plastic deformation are softened by the irradiation of the laser beam 9, and spread outside by the return force, and automatically fitted into the fitting recessed parts 5,..., and shrink fitting is completed. Since, the heating for the whole of the part is suppressed, thermal deformation and the generation of strain are prevented, and shrink fitting with high precision is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for laser shrink-fitting a minutely bent portion of, for example, a press part or a molded part.

(Conventional technology) Conventionally, when shrink-fitting an internal part to an external part for press parts, molded parts, etc., a shrink-fitting method using high-frequency heating or a burner is used to heat and expand the entire outer periphery of the internal part. This allows for a secure fit with external parts.

However, such a shrink fitting method using high-frequency heating has the problem that when the member is a hardened part, the hardness of the hardened part decreases, and distortion occurs due to heating the whole part.

Additionally, in the past, a method was used in which a minute bend was formed in a part of a press part or a molded part, and the minute bend was heated with a high frequency or a burner to shrink-fit, but even with this method, Because it takes time to heat up, the overall temperature of the heated parts rises, causing thermal deformation and changes in hardness, making it impossible to achieve high-precision shrink fitting.

(Problems to be Solved by the Invention) As described above, the conventional shrink fitting method has problems in that it is difficult to deform parts, change hardness, and cause distortion, making it impossible to perform highly accurate shrink fitting.

This invention was made in view of these conventional problems, and it achieves highly accurate shrink fitting by locally irradiating a laser beam to the micro-bending portions of pressed parts and molded parts to perform shrink fitting. The purpose of the present invention is to provide a laser shrink fitting method that can realize the following.

[Structure J of the Invention (Means for Solving Problems) The laser shrink fitting method of the present invention involves forming a minute bending portion in one of an external component or an internal component, and fitting the internal component to the external component. At the same time, the micro-bending portion is irradiated with a laser beam to slightly extend the bending portion, or the portion is pressed and bent for shrink-fitting.

In addition, in the laser shrink fitting method of the present invention, when laser irradiation is applied to the micro-bending portion, mechanical force is applied to the jig in the direction of shrink-fitting the micro-bending portion, thereby making it more reliable. Shrink fit can be performed.

(Example) Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a laser shrink fitting apparatus 1 using an embodiment of the invention, in which an internal part 2, such as a pressed part, is fitted onto an external part 3. A portion of the side surface of the internal component 2 has minute bending portions 4, 4 . for shrink fitting.・・・
・is formed. In the external component 3, fitting recesses 5.degree. 5, .

In the case of this embodiment, there are further minute bending portions 4, 4°...
the fitting recesses 5, 5. An auxiliary jig 6 is used to securely fit into the fitting recess 5. By pressing the auxiliary jig 6, each minute bent portion 4 moves in the direction of the fitting recess 5. .

The laser irradiation device 7 used for shrink fitting is, for example, 1
Using a kWCO laser, a laser beam 9 emitted from a laser oscillator 8 is focused by a condensing lens 10, and a splitting mirror 11 is used to collect each micro-bending portion 4, 4 . Splits the light so that it irradiates...

In this embodiment, the splitting mirror 11 has a quadrangular pyramid shape in order to separate light into four directions.

Therefore, when fitting the internal component 2 into the external component 3, the internal component 2 is first inserted into the external component 3, and the minutely bent portions 4, 4. ... to the position of the fitting recess 5, 5°... Subsequently, each micro-bending portion 4, 4 . ... into the fitting recesses 5, 5. ...Apply force to move it to the side.

Next, using the laser irradiation device 7, the laser beam 9 emitted from the laser oscillator 8 is focused by the condensing lens 10 and irradiated onto the splitting mirror 11, where it is separated and separated into the respective micro-bending portions 4, 4, . ...is locally irradiated.

Due to the irradiation with this laser beam 9, the minutely bent portions 4, 4, which had been plastically deformed. ... expands outward due to the force of softening and returning to its original state, and the fitting recesses 5, 5. It will automatically fit into ... and the shrink fit will be completed.

If the auxiliary jig 6 is used during this shrink fitting, each small bent portion 4, 4. ...is further expanded to the outside, making the shrink fit even stronger.

Here, even if the internal parts 2 are made of hardened steel, the irradiation by the laser beam 9 is short and local, so there is no overall temperature rise and the cooling time is fast, so there is no decrease in hardness or heat No deformation occurs.

Furthermore, since the external component 3 is not heated at all, no deformation occurs and a highly accurate shrink fit can be achieved.

FIG. 2 shows another embodiment of the present invention, in which the inner part 2 is shrink-fitted to the outer part 3 without using the auxiliary jig 6. In this case, the minute bending portion 4 that has been plastically deformed due to the irradiation with the laser beam 9
,4. ... tries to return to its original shape due to thermal expansion and expands outward, causing the fitting recess 5.5. I got caught up in...
Can be shrink fit.

FIG. 3 further shows an embodiment of the pond, in which the external part 3 has fitting recesses 5, 5. ... is not provided, and each micro-bending portion 4, 4. is plastically deformed. By irradiating the laser beam 9 on ..., each micro-bending portion 4゜4, ... is firmly attached to the inner surface of the external component 3 due to the force of expanding outward, and shrink fitting can be achieved. be.

FIG. 4 shows the micro-bending portions 4, 4°... of the internal part 2 and the fitting recesses 5°5, . . . formed by holes in the external part 3.
・This shows an embodiment in which the laser beam 9 is irradiated from the outside when shrink-fitting.

Even if the laser beam 9 is irradiated from the outside in this way, each minute bending portion 4, 4. ... is locally heated and tries to return to its original state and spreads outward, causing the fitting recesses 5, 5 .・・・
・They fit tightly together.

FIG. 5 shows still another embodiment, in which internal parts 21
F! I have fitting recesses 5, 5. ... are provided, and minute bending portions 4, 4... are provided on the external component 3 side. ..., and the laser beam 9
from the outside to each micro-bending portion 4, 4. . . while irradiating each minute bent portion 4° 4, . It is shrink-fitted by pushing it into...

Incidentally, reference numeral 13 denotes a spring that applies a force for the auxiliary jig 12 to press into the minutely bent portion 4.

(Specific Example) Next, a specific example of the laser shrink fitting method performed using the apparatus 1 shown in FIG. 1 will be described.

A 1kW CO2 laser was used as the laser beam 9, and a 15-inch focal length was used as the condenser lens 9.
As the divided mirror 11, a copper diamond-cut mirror was adopted.

The internal part 2 is made of hardened steel and has a hardness of Rc60, and has minute bending parts 4, 4. . . . cannot be mechanically deformed in the direction of return. External parts 3
are parts with similar hardness, and the fitting recesses 5.5.・・・
・ was used.

Each minute bending portion of the laser beam 9 4.4. The spot to be irradiated is approximately 3IIll to 41111, and 250
Controlled to the strength of W.

Micro-bending portion 4, 4. ...The temperature is about 400℃~15
As the temperature rises to 00°C, the plastically deformed portion expands outward, forming the fitting recesses 5, 5. I got stuck in...
These minute bending portions 4, 4. An auxiliary jig 6 was used to help spread...

After the shrink fit is completed, the small bent portions 4, 4 are rapidly cooled by the self-cooling effect unique to the laser. There was almost no decrease in hardness, and a strong shrink fit was achieved.

[Effects of the Invention j As described above, according to the present invention, the micro-bending portion is irradiated with a laser beam to soften the plastically deformed portion and bring it into close contact with the mating part. A fit is possible. Moreover, since the laser beam is applied locally, the entire part is not heated, and highly accurate shrink fitting can be achieved without causing thermal deformation or distortion.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing a shrink fitting device used in one embodiment of the present invention, FIG. 2 is a partially cutaway perspective view showing another embodiment of the present invention, and FIG. FIG. 4 is a partially cutaway perspective view of still another solid line embodiment of the present invention; FIG. 5 is a partially cutaway perspective view of yet another embodiment; FIG. It is.

Claims (2)

[Claims] (1) Form a minute bend in either the external component or the internal component, fit the internal component into the external component, and irradiate the minute bend with a laser beam to slightly extend or push the bend. A laser shrink fit method characterized by bending and shrink fitting. (2) Laser shrinkage according to claim 1, characterized in that when laser irradiation is applied to the minutely bent portion, mechanical force is applied by a jig in a direction to shrink fit the minutely bent portion. method.