JPH01139727A - Manufacture of remelting chilled camshaft - Google Patents

Abstract

PURPOSE:To easily form a surface hardened layer of uniform depth by bringing a stylus of a camshaft into contact with a specific cam profile and applying high-density energy to the surface of a cam sliding part by a uniform linear reciprocating motion. CONSTITUTION:A camshaft 3 is horizontally held by means of holding members 5, 6 and rotated, and high-density energy, such as laser beam, is applied to a cam 4, by which remelting chilling is applied to the surface 4a of a cam sliding part to form a surface hardened layer. In a method for manufacturing the above remelting chilled camshaft, a copying cam 1 consisting of an isosceles triangle having a base circle part as the base and also having a cam lift corresponding to the irradiation breadth of the above high-density energy at the vertex is provided and rotated in the direction of an arrow 9. A copying stylus consisting of a roller 7 at the end of the camshaft 3 is brought into contact with the above cam lift part. By this method, the high-density energy is scanned across the surface of a cam sliding part by a uniform linear reciprocating motion to easily uniformize the hardening depth of the above surface, by which a remelting chilled camshaft having superior quality can be obtained at a low cost.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a remelted chill camshaft,
Specifically, the depth of the surface hardened layer is made uniform by remelting and chilling the scanning movement of the irradiated area by high-density energy such as laser beam, TIG arc, plasma arc, electron beam, etc. on the surface of the cam sliding part of the camshaft. The following describes a method for manufacturing a remelted chill camshaft with uniform linear reciprocating motion.

[Conventional technology]

Conventionally, laser beam, TIG arc, plasma arc,
When forming a hardened layer by remelting and chilling the surface of the cam sliding part of the camshaft by irradiating high-density energy such as an electron beam, By moving the camshaft or high-density energy irradiation device using a slider crank mechanism, etc., the irradiation area with high-density energy is reciprocated relatively in the cam width direction on the cam sliding surface of the camshaft. It was common practice to scan using

However, when applying high-density energy to the surface of the cam sliding part of the camshaft using such a slider crank mechanism, the scanning movement of the irradiated area due to the high-density energy causes a sign as shown in Figure 11. Because of the curved motion, the scanning speed of the area irradiated by high-density energy is fast at the center of the cam width on the surface of the cam sliding part of the camshaft, and conversely, at both ends of the cam width on the surface of the cam sliding part of the camshaft. The scanning speed of the irradiated area by high-density energy becomes slow, and as shown in Figure 12, the depth of the hardened surface layer formed on the surface of the cam sliding part of the camshaft due to remelting and chilling becomes uneven. There were drawbacks.

Furthermore, when attempting to secure a uniform surface hardening layer depth by remelting and chilling by irradiating high-density energy onto the surface of the cam sliding part of the camshaft using such a slider crank mechanism 1, etc., It is necessary to increase the scanning speed of the irradiated area with high-density energy, and in this case, there is also the disadvantage that the depth of the hardened surface layer formed on the surface of the cam sliding part of the camshaft becomes extremely shallow due to remelting and chilling. Ta.

Furthermore, if an attempt is made to form a deep surface hardening layer at the center of the cam width on the surface of the cam sliding part of the camshaft, at both ends of the cam width on the surface of the cam sliding part of the camshaft,
The surface hardening N formed by re-melting and chilling may become excessively deep or the corners may fall off, so-called "melt droop".
At present, it is not possible to produce remelted chill camshafts of sufficient quality and cost.

[Problem to be solved by the invention]

In view of the current state of the conventional technology as described above, the problems of the present invention can be summarized as follows. In the method of forming a surface hardening layer on the surface of the cam sliding part of the camshaft, since the scanning motion of the irradiated area by high-density energy on the surface of the cam sliding part of the camshaft is a sine curve motion, the surface of the cam sliding part of the camshaft is At the center of the cam width, the scanning speed of the area irradiated by high-density energy is fast (on the contrary, at both ends of the cam width on the cam sliding surface of the camshaft, the scanning speed of the area irradiated by high-density energy is slow, This means that it has been difficult to equalize the depth of the hardened surface layer formed by remelting and chilling the surface of the cam sliding part of the camshaft by irradiating it with density energy.

Therefore, the technical problem of the present invention is to make the scanning motion of the irradiated area by high-density energy with respect to the surface of the cam sliding part of the camshaft into a uniform linear reciprocating motion. To facilitate uniformity of the depth of a hardened surface layer formed by remelting and chilling on the surface of a cam sliding part, thereby ensuring excellent quality and cost of a remelting chilled camshaft.

[Means to solve the problem]

In view of the problems in the conventional technology, the present invention provides means for solving the problems in the conventional technology by applying high-density energy such as a laser beam, TIG arc, plasma arc, electron beam, etc. to the cam of the camshaft. A method for manufacturing a remelted chill camshaft in which a surface hardening layer is formed on the surface of a cam sliding part of a camshaft by irradiating the surface of the sliding part to remelt and chill it, the method comprising: An isosceles triangle with the pace circle in the cam as the base and the cam lift corresponding to the irradiation width by high-density energy on the surface of the cam sliding part of the camshaft as the apex is defined as the relative relationship between the camshaft and the area irradiated by high-density energy. When the profiling cam is moved perpendicularly to the reciprocating direction, the locus drawn by the contact point between the equilateral part of the above-mentioned isosceles triangle and the profiling stylus installed on the camshaft or the high-density energy irradiation device is calculated as follows: By driving a camshaft or a high-density energy irradiation device following a cam profile formed in accordance with the rotation angle, scanning motion of the irradiation area by high-density energy against the surface of the cam sliding part of the camshaft is achieved. This method consists of a method for manufacturing a remelted chill camshaft characterized by constant linear reciprocating motion.

[Effect]

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 3 shows a cam profile of the copying cam 1 for making the scanning movement of the irradiated area by high-density energy into a uniform linear reciprocating movement on the cam sliding part surface 4a of the camshaft 3 according to the method of the present invention. There is.

In the present invention, the copying cam 1 has a predetermined base circle 1a large enough to accommodate at least one cam lift part 1b, and has a base circular portion of the copying cam 1 as its base, and a cam sliding portion of the camshaft 3. An isosceles triangle whose apex is the cam lift corresponding to the irradiation width by high-density energy on the moving part surface 4a is moved perpendicular to the direction of relative reciprocating movement between the camshaft 3 and the irradiation area by high-density energy. In some cases, a cam is formed in which the locus drawn by the contact point between the equilateral part of the isosceles triangle and the camshaft 3 or a copying stylus disposed on a high-density energy irradiation device corresponds to the rotation angle of the copying cam l. The profile is created by driving the camshaft 3 or the copying stylus of a high-density energy irradiation device to follow the copying cam 1 having the cam profile drawn as described above, and by the rotation of the copying cam l. The camshaft 3 or the high-density energy irradiation device can perform reciprocating motion along the equilateral part of the isosceles triangle, that is, a uniform linear reciprocating motion, and the cam of the cam sliding portion surface 4a of the camshaft 3 By remelting and chilling in the width direction, a uniform hardened surface layer 4b as shown in FIG. 5 can be formed.

Next, FIG. 4 shows a cam of the camshaft 3 formed by driving the camshaft 3 or a high-density energy irradiation device using the copying cam 1 having the above-described cam profile according to the method of the present invention. It shows the scanning motion of the irradiated region by high-density energy on the sliding part surface 4a, and it is understood that the scanning motion of the irradiated region by high-density energy is a uniform linear reciprocating motion.

FIG. 5 shows that the scanning motion of the irradiated area by high-density energy on the surface 4a of the cam sliding portion of the camshaft 3 is made into a uniform linear reciprocating motion, so that the surface of the cam sliding portion 4a of the camshaft 3 is A cross-sectional view of the cam 4 is shown when a surface hardening layer 4b is formed by remelting and chilling, with the scanning motion of the irradiated area by density energy being a uniform linear reciprocating motion.

In FIG. 5, 4 indicates a cam, and 4b indicates a hardened surface layer formed by irradiating high-density energy according to the method of the present invention.

As is clear from FIG. 5, by making the scanning motion of the irradiated area by high-density energy with respect to the cam sliding part surface 4a of the camshaft 3 into a uniform linear reciprocating motion as shown in FIG. It is understood that the depth of the hardened surface layer 4a formed by irradiating the surface 4a of the cam sliding portion of No. 3 with high-density energy and remelting and chilling is made uniform.

Note that the copying cam l may be a temporary cam having the outer shape of the cam profile as described above, or may be a temporary cam having the cam profile as described above in the groove shape formed in the plate member 2, the cylindrical member, etc. It may also be a so-called grooved cam.

However, when performing uniform linear reciprocating motion at high speed, it is desirable to use a grooved cam from the viewpoint of followability of a camshaft or a copying stylus of a high-density energy irradiation device.

〔Example〕

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

In the following embodiments, the same or equivalent parts will be given the same reference numerals and the explanation will be omitted.

(First Example) FIGS. 1 and 2 show the cam sliding part surface 4a of the camshaft 3 produced by the method of manufacturing a remelted chill camshaft of the present invention.
In contrast, a first embodiment is shown in which a hardened surface layer 4b is formed by remelting and chilling.

FIG. 1 shows the cam sliding portion of the camshaft 3 by fixing the high-density energy irradiation device and causing the camshaft 3 to reciprocate at a constant speed as shown in FIG. 4 using a direct drive method. An example is shown in which a hardened surface layer 4b is formed on the surface 4a by remelting and chilling.

In the direct drive system shown in FIG. 1, the camshaft 3 is held by the holding members 5 and 6 of the camshaft 3, and one end of the holding member 6 is held by a holding member (not shown) and is A roller 7 that rotates and moves as a stylus is provided, and when a high-density energy irradiation device 8 such as a TIG arc torch is fixed, the camshaft 3 is rotated in the direction of the arrow 9 by the copying cam 1. A hardened surface layer 4b is formed on the surface 4a of the cam sliding part of the camshaft 3 by remelting and chilling by reciprocating the cam in a straight line at a constant speed in 10 directions.

In addition, in the link drive system shown in FIG. 2, a cam profile of a temporary cam-like copying cam 1 whose external shape is a cam profile is copied by a copying pin 11 as a copying stylus provided at one end of the link member 12. By doing so, the link member 12 and the link member 15 are rotatably provided through the pin hole 13 into which a supporting member (not shown) is inserted, and are arranged on the other end side of the link member 15 in the link member 12 and the link member 15 connected by the fixing pin 14. The cam sliding portion surface 4 of the camshaft 3 is irradiated with high-density energy from a high-density energy irradiation device 8 such as a TIG torch (not shown) installed.
A hardened surface layer 4b is formed by remelting and chilling.

(Second Example) FIG. 6 is a diagram showing a second example of manufacturing a remelted chill camshaft by the method of the present invention.

In FIG. 6, the frame 21 is slidable in the direction of arrow 10, and a motor 24 for rotationally driving a holding member 6 that holds one end of the camshaft 3 is disposed at one end of the frame 21, and another motor 24 is disposed at the other end. A holding member 5 is provided and the roller 2
2 is rotatably fixed to the frame 21, and the copying cam 23a is rotationally driven by a motor 25.

Then, the roller 22, which is a stylus, copies the groove 26 of the copying cam 23a, causing the frame 21 to move back and forth in a straight line at a constant speed.

In addition, in FIG. 6, the camshaft 3 is rotated by the motor 24 while being held by the holding members 6 and 5,
On the other hand, the copying cam 23a is rotated by the motor 25, the roller 22 copies the groove 26 of the copying cam 23a, and the frame 2
The camshaft 3 rotates while reciprocating in the direction of the arrow 10, and is irradiated with high-density energy by a high-density energy irradiation device such as a TIG (not shown) which is in a fixed state. Then, the surface 4a of the cam sliding portion of the camshaft 3 is remelted and chilled to form a hardened surface layer 4b.

As mentioned above, the speed pattern of the uniform linear reciprocating motion is determined by the groove shape of the copying cam 23a, and since there is almost no play between the roller 22 and the groove 26, the roller 22 accurately copies the groove shape of the copying cam 23a. The uniform linear reciprocating motion of the camshaft 3 reliably moves at the set speed.

Moreover, since the shape of the groove 26 of the copying cam 23a can be processed into any shape, the speed pattern of the uniform linear reciprocating motion can be arbitrarily set.

FIG. 8 is a developed view of the copying cam 23a shown in FIG.

(Third Example) FIG. 7 is a diagram showing a third example of manufacturing a remelted chill camshaft by the method of the present invention.

In FIG. 7, the method of holding the camshaft 3 is similar to that in FIG. 6, in which the copying cam 23b has a cam profile formed by a groove on a disk.

The copying cam 23b is rotated by the motor 25, and the groove 26 of the copying cam 23b is followed by the roller 22, causing the frame 21 to reciprocate linearly at a constant speed.

Since the groove width of the groove 26 is almost equal to the roller width of the roller 22 and there is almost no backlash, the uniform linear reciprocating motion of the camshaft 3 is at the same speed as the uniform linear reciprocating motion of the groove shape of the copying cam 23b. Reliably repeated.

FIG. 9 shows the groove shape of the disc-shaped copying cam 23b shown in FIG.

FIG. 10 shows a high-density energy irradiation device 8 such as a TIG torch by rotating the cam 4 of the camshaft 3 in the direction of arrow 28.
Fig. 6 shows a locus 27 of the irradiated area with high-density energy when the cam 23b is moved in the direction of the arrow 29 in order to follow the shape of the copying cam 23b while being linearly reciprocated at a constant speed in the direction of the arrow 1o. FIG. 8 is a detailed view showing the operating state of the high-density energy irradiation device in manufacturing the remelted chill camshaft of FIG. 7;

As is clear from the above, according to the second and third embodiments, the scanning movement of the irradiated area by high-density energy with respect to the cam sliding portion surface 4a of the camshaft 3 is performed by the copying cams 23a, 23b, etc. By using a grooved cam, uniform linear reciprocating motion with a targeted speed pattern can be reliably performed, so the hardening depth of the surface hardened layer 4b can be made uniform, and the quality of the remelted chill camshaft is stabilized. It is.

In the second and third embodiments described above, the camshaft 3 is moved linearly and reciprocally at a constant speed. It goes without saying that the same effect can be obtained even if the linear reciprocating motion is performed at a constant speed.

[Effects of the Invention] As is clear from the above, according to the method for manufacturing a remelted chill camshaft according to the present invention, the scanning movement of the irradiated area by high-density energy on the surface of the cam sliding part of the camshaft is performed in a uniform straight line. The reciprocating motion facilitates uniformity of the depth of the hardened surface layer formed by remelting and chilling the surface of the cam sliding part of the camshaft by irradiating high-density energy. The shaft has the advantage of being able to ensure excellent quality and cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a method for manufacturing a direct drive type remelted chill camshaft, which is one of the first embodiments of the method of the present invention. FIG. 2 is a diagram showing a method for manufacturing a link-driven remelted chill camshaft, which is one of the first embodiments of the method of the present invention. FIG. 3 is a diagram showing a cam profile of a copying cam for making the scanning movement of the irradiated area by high-density energy into a uniform linear reciprocating movement according to the method of the present invention. FIG. 4 is a diagram showing the scanning motion of the irradiated area with high-density energy on the surface of the cam sliding part of the camshaft according to the method of the present invention. FIG. 5 is a cross-sectional view of a cam remelted and chilled by the method of the present invention. FIG. 6 is a diagram showing a method for manufacturing a remelted chill camshaft according to a second embodiment of the method of the present invention. FIG. 7 is a diagram showing a method for manufacturing a remelted chill camshaft according to a third embodiment of the method of the present invention. FIG. 8 is a developed view of the copying cam used in the second embodiment. FIG. 9 is a plan view of the copying cam used in the third embodiment. FIG. 1O is a diagram showing a state in which high-density energy is irradiated to the surface of the cam sliding part of the camshaft according to the method of the present invention. FIG. 11 is a diagram showing a scanning movement of an irradiated area by high-density energy using a conventional slider crank mechanism. FIG. 12 is a cross-sectional view of a cam that has been remelted and chilled by a conventional method. 1. ~----- Copying cam. la----Base circle. lb-m-...cam profile. 2--Rotation axis. 3-.-Camshaft. 4-...cam. 4a・～・・・・Cam sliding part surface. 4b---Surface hardening layer. 5.6...-----Holding member. 7.---... Laura. 8 - - High density energy irradiation device. 9--・One rotation direction. 10------Movement direction. 11-111--Copy pin. 12-------Link member. 13--- Pin hole. 14--Fixing pin. 15...--Link member. 21-・-・-・frame. 22------One roller. 23 a, 23 b --- one copy cam. 24.25...---Motor. 26.--groove. 27-.-Trajectory of irradiated area by high-density energy. 28--Rotation direction of the camshaft. 29--... Movement direction of the high-density energy irradiation device. Applicant Toyota Motor Corporation Figure 3 Figure 5 236 Figure 7 Figure 8 Figure 9 Figure 12

Claims (1)

[Claims] 1. By irradiating the surface of the cam sliding part of the camshaft with high-density energy such as a laser beam, TIG arc, plasma arc, or electron beam to remelt and chill the surface,
A method for manufacturing a remelted chill camshaft in which a surface hardening layer is formed on the surface of a cam sliding part of a camshaft, the method comprising: forming a surface hardened layer on the surface of a cam sliding part of a camshaft, the base circle part of a copying cam having a predetermined base circle being the base; When the isosceles triangle whose apex is the cam lift corresponding to the irradiation width by high-density energy on the surface is moved perpendicular to the direction of relative reciprocating motion between the camshaft and the irradiation area by high-density energy, the above two The trajectory drawn by the contact point between the equilateral part of the equilateral triangle and the camshaft or the copying stylus installed on the high-density energy irradiation device is made to follow the cam profile formed in accordance with the rotation angle of the copying cam, A remelting chill cam characterized in that by driving a camshaft or a high-density energy irradiation device, the scanning motion of the irradiated area by high-density energy against the cam sliding part surface of the camshaft is made into a uniform linear reciprocating motion. How to manufacture the shaft. 2. The method for manufacturing a remelted chill camshaft according to claim 1, wherein the cam profile of the copying cam has the outer shape of a plate cam. 3. Claim 1 in which the cam profile of the copying cam is constituted by a groove shape formed in a plate member, a cylindrical member, etc.
A method for manufacturing a remelted chill camshaft as described in .