JPS58119486A - Production of endless band for transmission v-belt - Google Patents

Abstract

PURPOSE:To correct the shape defects in weld zones and to apply residual compressive strains upon said zones by expanding a thin sheet material which is butt welded to an endless band in the circumferential direction thereof, subjecting the same to a thermal hardening treatment and pressurizing the projecting parts in the weld zones thereof. CONSTITUTION:A thin sheet material 7 is curved in the longitudinal direction thereof and both ends thereof are butted and are laser welded to an endless band. Such endless band is fitted to band expanding jigs 11, and adjusting screws 14 are rotated in one direction to displace both cylindrical half parts 12, 13 in mutually spacing directions relatively, whereby the material 7 is expanded and the peripheral length thereof is adjusted to a prescribed size. In this state, the material 7 is subjected to a thermal hardening treatment by hardening. Thereafter, the weld zones 15 of the material 7 are sandwiched between a pair of compressing jigs 16, 17 and are pressurized whereby the projecting shape defects in the zones 15 are corrected and residual compressive strains are applied upon the zones 15.

Description

[Detailed description of the invention] Ruto's steel endless band 1
It concerns the 5 laws.

This type of power transmission V-belt has a plurality of endless bands/a rlb, IC, as shown by B in Figs. 1 to 3, for example.
, ld in a layered manner, the laminated band /E surrounds the laminated band /E, and comes into frictional contact with its inner peripheral surface s (inner peripheral surface of the innermost endless band /d)... A large number of V-shaped blocks λ are arranged in a laminated band l without gaps in the longitudinal direction thereof.

Each V-shaped block is configured in a V-shape as shown in FIG.
By frictionally engaging the groove facing surfaces, the transmission V-belt 6 is passed between the pulleys 3 and q as shown in FIG. 1, and put into practical use.

Here, when the brima pulley 3 is rotationally driven, the result is -1.

This rotation is transmitted through the transmission V belt to the secondary rib □I7
is transmitted to μ, which rotates this boob in the corresponding direction,
The transmission V-belt 6 can perform a predetermined power transmission. The transmission mechanism shown in FIG. 1 includes both pulleys 3. 3. One of the flanges providing the groove wall is fixed, the other flange is movable in the axial direction, and the position of these movable flanges can be controlled. By making it possible to change the frictional engagement position of the V-shaped block 2 with respect to the V in the radial direction, a belt-type continuously variable transmission can be achieved.

By the way, conventionally, the endless band /a-/(l) was made by butt-welding both ends of a thin plate material by laser welding or electron beam welding.

However, the endless band made by this method has irregularities due to welding at the welding part, that is, shape defects, and the flatness is impaired. If the endless band is damaged and broken, or if the endless band is used with soft stool, the convex shape defect may catch on the V-shaped block 2 and damage it, or the endless band itself may break, etc. It was disadvantageous in this respect.

Therefore, the applicant previously proposed a thin plate material made into an endless material by butt welding according to the Tokusho Jyo St-A6973. I have developed a method of rolling the entire length to a predetermined thickness, but the endless band made by this method has difficulty in strictly controlling the Iθ of wall thickness and circumference, so it is necessary to laminate them. When a layered band is assembled, force may not be applied to all teno endless bands during use, and only a specific endless band may receive force, or each endless band may not be able to maintain its laminated state. However, the durability problem is difficult to solve.

In the Qo butt welding of the present invention, the endless thin plate material is heat-hardened in an expanded state using a band expansion jig to adjust the circumferential length, and then one butt weld is performed to +q thickness. A convex shape defect occurring on the surface of the plate material is corrected by pressurizing only the welded part, and this pressurization imparts residual compressive strain to the welded part. If this is done, the convex shape defects of the welded part of the endless band will be eliminated and its durability will be improved.Moreover, since the pressure applied for this purpose is only on the welded part, this pressure will be applied to the thickness and thickness of the endless band. By adjusting the circumferential length of the endless band using a band expansion jig, it is possible to strictly control the length and circumference of each endless band, with almost no effect on the same length, and the length of each endless band can be precisely controlled. After that, when a force is applied to a specific endless band, the N-layer light of the endless band becomes The purpose of this invention is to provide a method for manufacturing an endless band for use.

Hereinafter, the present invention will be explained in detail from a practical example G shown in the drawings.

In invention X, first, a thin steel plate 7 having the same thickness as the final plate thickness of the endless band is heated to 11. As shown in the figure, a length of Q is prepared, and the length of this thin plate material 7 is made to be equivalent to the developed length of the endless band. However, each endless band/
Since a□/d (i'1%/see Figures to Figures 3) is densely accumulated, the development length of each endless band is made longer by the thickness of the outer band. Furthermore, between adjacent endless bands, there are pulleys 3 and 3 as shown in FIG. It is necessary to curve along the intersecting arc of the
A certain amount of clearance should be set to eliminate interference between the endless bands, and the development length of each endless band should be determined by taking this clearance into consideration. Therefore, it goes without saying that the thin plates 7 for each endless band have different lengths, and that it is necessary to prepare thin plates 7 with different lengths corresponding to the number of layers of the endless band. Is the process of implementing the method of the present invention only for thin plate material corresponding to a specific endless band? I'll just say it to my brother.

The thin plate material 7 prepared in this way is curved in the longitudinal direction and brought into contact with each other along the recess r, as shown in the same <iu figure, and in this state, both ends of the thin plate material 7 are bent along the line t. Laser welding or electron beam welding. During this welding, the light beam is focused on the welding wire by the condensing lens 10, and the optical system of the light beam 9 and the thin plate material 7 are moved so that the focused light beam moves on the welding g resistance. By moving it, a predetermined butt and weld can be performed. In addition,
In the case of spacer beam welding, butt bath welding can also be performed in a similar manner using a viewing lens.

The thin plate material 7 thus welded by G straining is fitted into a band expansion jig shown in FIG. S, for example, as shown in the same figure. This jig/l consists of one cylindrical half/2゜13 and an adjustment screw/& for moving them toward or away from each other in the radial direction, and one end of the adjustment screw is a cylindrical half. Insert it into the half part /2 so that it can rotate freely, ・The other end is screwed into the cylindrical half part 13, and the hexagonal head /f a is integrally attached to these adjustment screws.
form. When the thin plate material 7 is fitted, the hexagonal head/11
By engaging the tool with a and rotating the adjustment screw /F E in one direction, both cylindrical halves /2 and /3 are adjusted by the screw action.
are relative/displaced in the direction of moving away from each other. Thus, the circumferential length of the thin plate 7 can be set to the final specified length (the final required length of the endless band) by adjusting the screwing adjustment of the thin plate 7. Dimensions can be adjusted.

In this state, the thin plate material 7 is heat-hardened by quenching to give the thin plate material 7 a predetermined hardness required by the endless band. During this heat treatment, the thin plate material 7 is kept in an expanded state by the band expansion jig/l, so that the cylindricity (flatness) etc. of the thin plate material 7 is prevented from being impaired due to thermal distortion during quenching. can. □The advantage is that the thin plate material 7 has uneven shape defects on both sides of the welded portion 15 due to the butt welding, and the convex shape defects particularly impair the durability as an endless band as described above. Therefore, in the present invention, the welded part /3'E is □ as shown in Fig. 6.
A pair of compression jigs #: , 17 are placed in between and pressurized, thereby correcting the convex shape defect and eliminating it.
This pressurization imparts residual compressive strain to the welded portion 15. Therefore, in order to completely eliminate the convex shape defect, the method for correcting such a shape defect is to compress the welded part 13 using compression jigs /4 and /7, as shown in FIG. Since it has to be carried out over the thickness of the board, a step/g is created at the boundary between the compressed and uncompressed areas. Unless this level difference/g is kept to a certain level, it will cause stress to be concentrated in this area during use as an endless band, resulting in disadvantages in terms of strength in addition to the shape defect mentioned above. Therefore, the compression of the welded part /3 using the compression jig /, <', /7 needs to be carried out while taking into consideration the correction of the convex shape defect and the formation of the step /g.

In this emphasis, Cat
A shot peening method using a hard ball or hard glass ball/9 as shown in the figure is more preferable.

This shot peening is performed by applying the pedestal 2D to the welded part 3 of the thin plate material 7 from one side, and colliding the other side with the ball 19 blown out at high speed from the nozzle. Correct to eliminate convex shape defects on the sides. Next, the convex shape defect on the above-mentioned side surface of the welded part 15 is also eliminated by the colleague G. As a result, it is possible to correct shape/shape defects on both sides of the bath contact part/S, and also to fix defects in the welded part. The residual compressive strain can be given accordingly.

This shot peening can almost eliminate the convex shape defect with the maximum height H that existed as shown in Figure 9 (ω), but the concave shape as shown in Figure 9 (b). It is hardly effective against defects.1 However, since concave shape defects do not affect the durability of the endless band, there is no need to correct them with this shape defect removal method, and this method is
This is useful because only the problematic convex shape defect can be corrected intensively without producing the step 1.1' as shown in the figure.

Note that shot peening leaves some unevenness as shown in Figure 9 (b), but these unevenness are due to stress in the endless band. This is not a problem at all because it is not so large that it rarely occurs, and it does not have a negative impact on the durability of the endless band.

After completing each of the above treatments, the thin plate material 7 is sequentially sliced into rounds of a predetermined width to obtain an endless band (endless band la in the illustrated example) as shown in Figure 1, and finally the endless band is completed. let

Note that this round cutting does not necessarily need to be performed at this stage, and may be performed at any stage, such as immediately after the butt welding of the thin plate material 7 or immediately after the quenching. Further, the width of the thin plate material 7 may be made to correspond to the width of the endless band so that this round cutting operation is not necessary.

As mentioned above, the inventive method is to butt weld a thin plate material 7fr on both ends, heat harden it in an expanded state using a band expansion jig l/ to adjust the circumference, and then butt weld the thin plate material. A convex shape defect on the surface of the weld lS? This is corrected by pressurizing only the welded part 15, and this pressurization gives residual compressive strain to the welded part to create an endless band, so the convex shape defect from the endless band welded part 15 is eliminated, and this shape defect is eliminated. It is possible to prevent the deterioration of durability of the endless band that would otherwise occur due to this, and since the pressure applied for this purpose is only on the welded part IS, this pressure has almost no effect on the thickness and circumference of the endless band. Band expansion jig.

The circumference of the endless band can be adjusted using //, so the dimensions of each endless band can be strictly controlled. It no longer collapses.

It is possible to improve the durability of the endless band.

In addition, in the present invention, since residual compressive strain is applied to the welded part /3 by pressurization, the following effects can be obtained. That is, the center line A in FIG. 1O shows how the stress applied to the welded portion of the endless band manufactured by the conventional method changes during the use of the endless band as shown in FIG. 1. The solid line AOa portion indicates that the welded portion is the pulley 3. The slack lateral line between the ridges (
The tension applied to this welded part when the welded part is located at the lower straight part in Fig. Part 0 is the tension applied to this welded part when the welded part is located at the tension side line part (upper straight part in Figure 1) between pulleys 3 and 17,
The d part is the bending tensile stress applied to the welded part when the welded part is in the position where it is engaged with the drive pulley 3.The difference in width of the b part and d part is opposite to that in Fig. 1, but the pulley 3. This is due to the difference in the frictional engagement arc diameter of the transmission V-belt B with respect to the belt. By the way, according to the method of the present invention, residual compressive strain is imparted to the weld zone /j by the above-mentioned pressurization.
As shown by the dashed line B in Figure O, the trend is similar to that of the solid line A, but there is an overall decrease. Therefore, the welded part 15 of the endless band made by the method G of the present invention has a reduced stress peak, and fatigue failure of the welded part that occurs at this peak is prevented, and the durability of the endless band is improved.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a transmission V-belt having an endless spunt as a component to be produced by the method of the present invention, being passed between pulleys, and Figs. A front view showing two examples of a V-shaped block as an element, a perspective view showing a butt welding method for a thin plate material that is an endless band material, and a diagram showing a band expansion treatment used in carrying out the method of the present invention. Partially cutaway front view of the tool, Figures 6 and 7
The figure is an explanatory diagram of the welding part pressurizing step in the method of the present invention,
The figure is an explanatory diagram showing another example of the same pressurizing process, FIG. FIG. 2 is a diagram showing changes in stress applied to a welded portion of an endless band made by the conventional method in comparison with changes in stress applied to a welded portion of an endless band made by a conventional method. l... Laminated band, 1aNld... Endless band, C... V-shaped block, 3. l...Pulley, 6.
...Transmission V-belt, 7...Thin plate material, g...Butt welding line, 9゛...Light ray, 10...Condensing lens, /l.
...Band expansion jig, 15...Welded part, /4, /
7... Compression jig, 19... Hard ball, 〃...11゛ pedestal, 2/... Nozzle. Patent applicant: Nissan Motor Co., Ltd. Representative Patent Attorney: Hidetoshi Sugimura, Patent Attorney
Written by Oki Sugimura＋＋＋
To the door~ - ~ノ 1 no arm＼
shidan, 謔, descendant, qtada

Claims (1)

[Claims] 1. In an endless band for a power transmission V-belt made by butt welding both ends of thin plate materials, the dimensions of the length of the band length are adjusted using a band expansion jig for the endless thin plate material that has been made endless by the butt welding. Heat cured in the expanded state,
After that, 1... occurred on the surface of the thin plate material due to the butt welding.
A method for using an endless band for a power transmission V-belt, characterized in that a convex shape defect is corrected by pressurizing only the welded portion, and at the same time, residual compressive strain is imparted to the welded portion by this pressurization. 2. The above-mentioned pressurization is performed by shot peening using a hard ball or a hard glass ball.
A method for manufacturing an endless band for a power transmission V-belt according to item 1. 3. The device according to claim 1, wherein the pressurization is performed by clamping using a pair of compression jigs. ■A-a method of endless band for dynamic belt. 1