JPS63293116A - Manufacture of camshaft - Google Patents

Abstract

PURPOSE:To form a cam surface having desired depth of chill and high shape accuracy, by irradiating the surface of a cam part in which guide plates having normal cam profiles are provided to both side faces, respectively, with high- density energy heat and by carrying out chill forming by means of a pressure jig guided by the above guide plates. CONSTITUTION:A camshaft stock 1 is formed by casting into the prescribed shape, and a pair of guide plates 12 is stuck to both side faces of the cam part 10. The guide plates are composed of steel plates which previously have normal cam-profile shapes and in which through holes 12a are formed according to the diameter of the shaft 1, which are cast integrally with the stock 1 at the time of casting the stock 1. The cam surface 11 of the stock 1 supported and rotated in an A direction is remelted by means of a laser beam 21 applied from a laser beam machine 2, and the remelted zone is subjected to chill forming by means of a pressure roller 3 provided to the position right after the laser-irradiated zone and guided by respective peripheries of the guide plates 12.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to testing the manufacturing capacity of camshafts.

More specifically, the present invention relates to improving surface characteristics such as wear resistance by remelting the surface of the cam portion using high-density energy heat to form a chill hardened layer.

(Prior art and its problems) When remelting and chilling the cam S surface using high-density energy heat, a laser beam, electric beam, TIG arc, etc. is irradiated onto the desired area on the cam surface to target the area. This high-density energy heat irradiation may cause flow holes or thermal cracks in the remelted area, or may cause significant unevenness on the surface. -1
As disclosed in Japanese Patent No. 19615, when remelting and chilling using high-density energy swallow irradiation, the area is pressed and molded using a pressing roller immediately after melting, thereby preventing blowholes and cracks and improving surface smoothness. It is proposed that it be secured.

However, in melting by high-density energy heat irradiation as described above, #! from the center of the axis! When the surface of the cam 1, which has a non-circular profile that changes gradually, is to be processed, the irradiation angle, irradiation distance, and even irradiation time change depending on the irradiation area, so the total amount of energy applied to the irradiation area changes.

Therefore, if the amount of melt increases more than necessary and the suppression treatment is performed immediately after melting, the melted part will flow and deform, requiring post-processing. There are some issues that may make it difficult. Furthermore, if the amount of irradiation energy is reduced to reduce the amount of melting in order to maintain the cam shape, it becomes impossible to form a necessary chill hardened layer over the entire surface of the cam portion.

(Eleventh Object of the Invention) In view of the circumstances as described in 1-1, the present invention provides a method for manufacturing a camshaft that can form a cam portion surface having a desired chill depth with high shape accuracy. purpose.

(Structure of the Invention) Therefore, in the method for manufacturing a camshaft according to the present invention, high-density energy heat is applied to the cam portion with a guide plate having a regular cam profile shape installed on the inner surface of the cam portion of the camshaft J-shaped member. The surface is irradiated and melted, and the melted area is chill-molded into a predetermined shape by a pressing jig guided by the peripheral edge of the guide plate.

That is, by guiding a pressing tool for suppressing the surface of the cam part in a re-melted state along the periphery of a pair of guide plates having a regular cam profile shape, the cam shape is changed by flow deformation of the excessively melted part. A chilled hardened layer of a required depth is formed on the surface of the cam part while preventing deformation, maintaining the cam shape with high precision, and ensuring surface smoothness.

The above-mentioned pair of guide plates may be formed by pre-forming a high melting point member such as a steel plate into a regular cam profile shape, and then casting it into the inner surface area of the cam part during casting of the camshaft material and fixing and integrating it. , 14 is pressed against the inner surface of the cam part from the side during the melt-chill process. In addition, if a ceramic guide plate is adopted, it can be configured so that it is cast into the inner surface area of the cam part when manufacturing the camshaft material #PI, fixed and integrated, and removed from the camshaft after the internal melting and chilling process is completed. You can also do it.

(Embodiment of the Invention) FIG. 1 shows an example of remelting and chilling the cam surface 11 of a camshaft material 1 by carrying out the method of the present invention. The cam surface 114:+9 of the camshaft profile l, which is supported and rotated in the direction of arrow A in FIG. 11 by a rotation mechanism (not shown), is melted, and the melted surface is remelted by the suppression roller 3 installed immediately after the laser irradiation area. This indicates the state in which the

Cam shirt I to be subjected to remelting chill treatment [Shape 1 is
It is obtained by casting the composition shown in Table 1 into a predetermined shape, and the cam portion 10 is r& shaped with a profile shape as shown in Figure 6 and a cam width of 171 mm. Further, a pair of guide plates 12 and 1 are provided on both sides of the cam portion 10.
2 is fixed. Each guide plate 12 is made of a steel plate having an outer shape that matches the regular cam profile shape and a shell through hole 12a that matches the diameter of the shaft of the camshaft L in the center thereof, as shown in the second figure. It is made of aluminum and is cast into the body when the camshaft material l is cast.

Attached Table 1 (wt Atsushi) Laser processing LA2 is a 5KW class GO2 laser processing machine, and is set at 8N to irradiate the laser beam 21 from the vertical direction to the central axis of the camshaft material l.
The beam 21 is irradiated onto the cam surface 11 of the camshaft J-shaped member l within the width of the interval between the guide plates 12 and 12.

The suppression roller 3 includes an arm 32 elastically supported by a pressing mechanism (not shown), and a free roll 31 of ceramic (Si3N4) tJ stretched in the axial direction between a pair of guide plates 12.
The guide plate 12-
The guide is regulated by the peripheral edge 12as12a of 12.

Therefore, the irradiation conditions of the laser beam j by the laser processing machine 2 indicated by L are as shown in Attached Table 2, the pressing force by the pressure roller 3 indicated by L is 3 to 5 kgf, the force is 11 shakt, and the cam surface 11 of the A-shaped member 1 is After remelting and chilling the product, measure the cam width of the cam nose, cam lift, and base circle, and measure the cam width at the center and edge of the cam and the cam width of the cam nose. The results of investigating the amount of dimensional change due to treatment are shown in Attached Table 3.

In addition, Comparative Example 1 in Attached Table 3 is a case where the guide plate 12-12 is used and the shape is re-melted and chilled with the force 11 shaft in condition B without IHL, and Comparative Example 2 is when the guide plate 12-1 is
2 is used in the same manner as in this example, but when the force 11 shaft end-formed material is re-melted and chilled under the same conditions without applying pressure by the pressure roller 3, comparative example 3 is the same as the guide plate 12.
・Simply remelt using the laser processing machine 2 without using the 12 or the pressure roller 3! This figure shows the results of measuring the modified acids when I&I was applied under the same conditions.

As is clear from Attached Table 3, when the remelting and chilling treatment according to the method of the present invention is performed, the cam nose part, cam lift part,
In contrast, in Comparative Example 1, the chilling process was completed while maintaining the normal cam profile shape without causing any deviation in the base circle area (see Figure 3). The molten part protrudes to both ends of the cam surface under pressure by the pressure roller 3, and the entire size becomes smaller on average (see Figure 4). Although the protrusion to the base is stopped, the shape changes to a raised shape at the center due to the surface tension during melting (see Figure 5).In addition, in the case of Comparative Example 3, the center of the base is raised due to the gravitational action and surface tension. A significant bulge occurs in the center of the circle, causing the largest dimensional deformation.

That is, in the case of one embodiment of the method of the present invention, the free roll 31 is controlled to be guided down by the peripheral edge 12a-12a of the guide plate 12-12.

This product effectively prevents the occurrence of "protrusion of the cam surface toward the end side due to pressure and the swelling of the center part due to surface tension" and successfully performs remelting and chilling processing while maintaining the cam shape with high precision. It is. Therefore, in both Comparative Examples 1-2 and 3, the post-processing and the 80% processing time required for that are almost unnecessary, simplifying the work process and the installation and materials. It was possible to achieve a significant saving in consumption V.

In addition, in the case of the embodiment of the method of the present invention, a chill hardened layer of the required depth was formed over almost the entire cam surface, whereas in the case of Comparative Example 1, it was shallow overall; In cases 2 and 3, the depth of the chill hardening layer varies greatly depending on the location,
From this point of view as well, in the case of the comparative example, post-processing, which is almost unnecessary in the method of the present invention, and setting of the additive margin associated therewith are important and indispensable conditions.

(Effects of the Invention) As described above, according to the camshaft manufacturing method according to the present invention, guide plates having a regular cam profile shape are installed on both sides of the cam part of the camshaft material, and the end edges By controlling the downward guidance of the pressing jig, the generation of blowholes, thermal cracks, and unevenness in the remelting castle caused by the irradiation of high-density melon energy heat can be prevented, and smoothness can be maintained. The aim is to prevent deformation of the cam profile due to the pressing action of a pressing jig, the action of gravity, etc., and to form a chill hardened layer with high shape accuracy. Therefore, post-processing and setting of machining margins for post-processing, which were conventionally indispensable, are almost unnecessary, contributing to simplification of work processes and significant savings in material consumption.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a state in which a cam surface is remelted and chilled according to an embodiment of the present invention, Fig. 2 is a perspective view showing an example of a guide plate, and Fig. 3 is a perspective view showing a remelting and chilling process according to the present invention. Process F [A perspective view showing the results; Figure 4 is a perspective view showing the results of remelting and chilling in Comparative Example 1; Figure 5 is a perspective view showing the results of remelting and chilling in Comparative Example 2; Figure 6 is a perspective view showing the results of remelting and chilling in Comparative Example 2; FIG. 3 is a cam profile diagram before melting treatment. l...Camshaft material 2...Laser processing 2 machines 3...Press I roller 11...Cam surface 12...Guide plate Patent applicant Matsuta Co., Ltd. Figure 1 Figure 3 Peng District 4. 8 Figure 6 Tail Figure 5

Claims (1)

[Claims] With guide plates having a regular cam profile shape installed on both sides of the cam part of the camshaft material, high-density energy heat is irradiated onto the surface of the cam part to melt it, and the cam part is guided to the peripheral edge of the guide plate. A method for manufacturing a camshaft, comprising chill-molding the melted region into a predetermined shape using a pressing jig.