JPH02138405A - Manufacture of v-shaped block for endless metal belt - Google Patents

Abstract

PURPOSE:To improve dimensional accuracy of receiving face in a V-shaped block with simple means by arranging interval between the receiving face for receiving inner circumferential face of an endless strip and inner face of a shaping hole to execute the shape-correction. CONSTITUTION:The V-shaped block 6 is composed of ferrous sintered body. At the time of correcting the shape of secondary raw material 62, the secondary raw material 62 is fitted into the shaping hole 45 with an upper punch 43. Both end faces (f) of the secondary raw material 62 is pressed while sandwiching with the upper and lower punches 43, 44 to correct inclined angle in both inclined surface 12 accompanied with spring back generated to the secondary raw material 6 after press-forming. In this pressing stage, as the center part 13a of both roller holding grooves 13 in the secondary raw material 62 is pressed at stronger than the press to the circumferential part, the receiving face 10 of the secondary raw material 62 is bulged and deformed. Then, the interval (d) at between the inner face 48 thereof and the bulge-deformed receiving face 10 is arranged so as not to bringing the receiving face 10 into contact with the faced inner face 48 in the shaping hole 45.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Application Field The present invention relates to a method for manufacturing a ■-shaped block for an endless metal belt used in continuously variable transmissions of vehicles, etc. It has a pair of inclined surfaces that are in sliding contact with the inner surface of the groove, and a receiving surface that is located between the two inclined surfaces and receives the inner circumferential surface of the endless strip. A metal ■-shaped block with a convex arc surface is manufactured (through compaction molding and compaction sintering using metal powder, a block with an inner slope and corresponding to the receiving surface is produced. Obtaining a primary material whose portion is formed into a flat surface, and then simultaneously pressing the inner inclined surface of the primary material with one mold to make the flat surface follow the concave arc-shaped molding surface of the other mold. to obtain a secondary material with the receiving surface formed therein, and then perform shape correction work by squeezing the inner inclined surface and both end surfaces of the secondary material adjacent to the receiving surface within the shaping hole of the shape correction mold. This invention relates to improvements in the manufacturing method of shaped blocks.

(2) Conventional technology The reason why the receiving surface is formed into a convex arc surface as described above is to prevent excessive tension from being applied to the endless strip when the endless metal belt slides on the V-pulley and rotates. However, when the secondary material is released from the mold after shaping the receiving surface, the secondary material undergoes springback, so that the angle of inclination of the inner inclined surface becomes slightly larger than that of the finished product.

Therefore, the above-mentioned shape correction work is required, but conventionally the shape of the shaping hole in the shape correction mold is formed slightly smaller than that in consideration of the springback of the finished product, and the inner surface facing the receiving surface is made flat. Forming and working. In this case, the inner surface of the shaping hole facing the receiving surface should preferably be a concave arc surface corresponding to the receiving surface, but if it is formed into a concave arc surface in order to release the ■-shaped block in the clamping direction after the straightening operation. Since the shaped block cannot be released from the mold, it is formed on a flat surface as described above.

(3) Problems to be solved by the invention However,
In the conventional method, the shape correction work is performed by bringing the inner surface of the shaping hole close to the receiving surface, so when the receiving surface bulges and deforms due to the pinching of both end surfaces, the receiving surface comes into pressure contact with the inner surface of the shaping hole. Following this, there is a problem in that the radius of the convex arc becomes larger than the set value.

An object of the present invention is to provide a method for manufacturing the V-shaped block that can solve the above problems.
The pulley has a pair of inclined surfaces that are in sliding contact with the inner surface of the V-groove, and a receiving surface that is located between the two inclined surfaces and receives the inner circumferential surface of the endless strip. In order to manufacture a metal ■-shaped block formed into a convex arc surface with the central portion as the apex, a green compact with an inwardly inclined surface and the receiving plate was formed through a compacting operation using metal powder and a compacting compact sintering operation. A primary material whose portion corresponding to the surface is formed into a flat surface is obtained, and then the inner inclined surface of the primary material is simultaneously pressed with one mold to mold the flat surface into a concave arc shape with the other mold. A secondary material having the receiving surface formed thereon is obtained by tracing the surface, and then both end surfaces of the secondary material adjacent to the inner inclined surface and the receiving surface are squeezed in a shaping hole of a shape correction mold. In the method for manufacturing a V-shaped block in which a shape correction operation is carried out by using the clamping pressure, the receiving surface is adjusted so that the receiving surface does not come into contact with the inner surface of the shaping hole opposite to the receiving surface when the receiving surface bulges and deforms due to the pinching pressure. The shape correction operation is performed with a space provided between the inner surface of the shaping hole and the inner surface of the shaping hole.

(2) Effects According to the shape correction work described above, the receiving surface does not follow the inner surface of the shaped hole, and therefore, the six arcs of the receiving surface have a set value or a radius close to it due to the spring bank after mold release.

(3) Embodiments In FIGS. 1 to 3, a belt transmission mechanism 1 used in a continuously variable transmission for a vehicle is connected between a driving pulley 2 rotating in the direction of the arrow and its driving boo IJ 2. It consists of a driven V-pulley 3 arranged at a predetermined interval, and an endless metal belt 4 stretched between the two pulleys 2 and 3.

The endless metal belt 4 includes a flexible endless strip 5 made of laminated thin steel plates, a plurality of metal ■-shaped blocks 6 arranged close to each other along the inner peripheral surface of the endless string 5, and each V-shaped block. A plurality of fully bent elastic stoppers 7 are attached to the X-shaped blocks 6 and attach the ■-shaped blocks 6 to the endless strips 5.
and a plurality of metal hollow one colas 8 interposed between the two adjacent two-shaped blowholes 6.

As clearly shown in FIGS. 4 to 7, the ■-shaped block roller is made of an iron-based sintered body, and includes a main body 9 and a receiving surface 10 of the main body 9 facing the inner circumferential surface of the endless strip 5. It consists of a pair of stopper mounting protrusions 11 which are protruded from both sides of the endless strip 5 and sandwich both side edges of the endless strip 5. The inner and outer surfaces of the main body 9 that are connected to the outer surfaces of both protrusions 11 are formed into inclined surfaces 12 so as to be in contact with the entire inner surfaces of the V-grooves g of the driving and driven pulleys 2 and 3; A roller holding groove 13 is formed on both end surfaces f adjacent to the receiving surface 1O, and has a substantially semi-circular cross section, which extends parallel to the generatrix of the circumferential surface of the endless strip 5, and is closed at both ends.

An engagement groove 14 extending in the circumferential direction of the endless strip 5 is formed at the base end of the outer surface of each protrusion 11, and a piece-shaped notch 15 is formed in each protrusion 11 from its distal end surface to reach the retaining groove 14. be done.

The stopper 7 includes a holding part 17 having a semi-annular bulging part 16 in the middle, and a pair of bent parts 18 extending from both ends of the holding part 17 at a substantially right angle to a plane including the bulging part 16 and facing each other.
and a pair of engaging portions 19 extending parallel to the plane from the tips of the double bent portions 18 and facing each other. The holding portion 17 engages both ends with the step portions of both notches 15 and faces the outer circumferential surface of the endless strip 5, and each bent portion 18 engages with the outer surface of each step portion, and further engages with the outer circumferential surface of the endless strip 5. The mating portions 19 engage with each of the engagement grooves 14 . As a result, the ■-shaped block 6 is assembled to the endless strip 5.

The endless metal belt 4 is assembled by assembling one V-shaped block 6 to the endless strip 5 using the stopper 7 as described above, and then inserting the hollow roller 8 between the roller holding grooves 13 of the adjacent ■-shaped blocks. Manufactured by interposing.

The receiving surface 10 is formed into a convex arcuate surface with the apex at the center in the endless strip winding direction shown by arrow A and in the direction orthogonal thereto.

As shown in FIG. 7, the receiving surface 101. Here, the first .
The radius of the six arcs a1 connecting the second edge el+eZ is the endless strip 50 that rotates around the minimum radius of both pulleys 2 and 3.
It is set to be smaller than the radius of curvature, which makes it an endless metal bell! -4 slides into contact with both pulleys 2 and 3 and rotates, thereby preventing excessive tension from acting on the endless string 5, thereby improving its durability.

Further, as shown in FIG.
3 located at the proximal end of 1. 6 connecting the fourth edge C101
The arc a2 has the function of bringing the endless strip 5 closer to the center of the receiving surface 10 when there is relative rotation between the endless strip 5 and the square block 6.

Furthermore, the first. Second edge else! is chamfered to be a convex arc surface with a smaller radius of curvature than the arc 6 a, and both edges eI+e! of the ■-shaped block 6 are chamfered. is adapted to smoothly slide into contact with the endless strip 5.

Next, a method for manufacturing the ■-shaped block 6 will be explained.

The manufacturing method includes a powder metallurgy process to obtain a primary material in which a portion corresponding to the receiving surface 10 is formed into a flat surface, and a press molding process to obtain a secondary material by forming the flat surface into a convex arc surface. ,
It consists of a shape correction process that adjusts the shape of the secondary material.

First, the powder metallurgy process will be explained with reference to FIG.

FIG. 8(C) shows a primary material 6I, in which the portion corresponding to the receiving surface 1O is formed as a flat surface 10a, and the first to fourth edges e, to e4 are at acute angles. ing. Except for these points, the primary material 61 has substantially the same shape as the ■-shaped block 6, so the same parts are given the same reference numerals.

FIG. 8(a) shows the compacted powder compacting operation, in which iron-based powder is charged into the cavity 21 of the outer mold 20, and then the punch 22 is inserted into the cavity 21 to compress the iron-based powder 1i11. The body 23 is molded.

FIG. 8(b) shows the sintering operation of the green compact 23.
3 is placed in the sintering furnace 24 and sintered by heating to produce a primary material 61 made of iron-based sintered body shown in FIG. 8(C).
get.

Next, the press molding process will be explained with reference to FIGS. 9 to 13.

The press molding device 25 has a pair of molds that can be opened and closed mutually, one of which is a press punch 26 that can be raised and lowered, and the other mold is a fixed mold that is disposed below the press punch 26. The die is 27.

9th. As clearly shown in FIG. 10, the die 27 has a rectangular holding hole 28 into which the primary material 6I can be inserted with its flat surface 10a facing downward, and a rectangular holding hole 28 that protrudes from the bottom of the holding hole 28 and has an upper end surface. A molding protrusion 30 formed on the concave arc-shaped molding surface 29 corresponding to the convex arc surface of the receiving surface 10, and a pair of punch guides 32 each opened in both inner walls 31 located on the short side of the holding hole 28. and has. Both end edges 33 of the concave arc shaped molding surface 29 located on both long sides of the holding hole 28. ．． 33M is formed into a concave arc surface with a radius smaller than the radius of curvature between both ends due to chamfering. In addition, the molding protrusion 3 is attached to the die 27.
A pair of through holes 34 are formed so as to sandwich 0, and a knockout pin 35 is slidably fitted into each of the internal through holes 34.

9th. As shown in FIG. 11, the press punch 26 includes a punch body 36 that is slidably fitted into the holding hole 28, and a pair of guide portions 37 that protrude from both sides of the punch body 36.
and a primary material 6. on the lower surface of the punch body 36. A recess 3 having a pair of inclined inner surfaces 38 capable of pressing both inclined surfaces 12 of
9 is open, and both guide portions 37 are slidably fitted into both punch guide grooves 32, respectively.

In the press punch 26 , a regulating member 40 is provided on the side surfaces of both guide portions 37 to abut on the upper surface of the die 27 and regulate the movement stroke of the press punch 26 .

In the press forming operation, as shown in FIG. 9, the press punch 26 is raised and separated from the die 27, and the primary material 6I is inserted into the holding hole 2 with its flat surface 10a facing downward. 10a is opposed to the concave arc-shaped molding surface 29 of the molding protrusion 30.

In this case, since the primary material 6I is guided to the holding hole 28, the flat surface Oa relative to the concave arc-shaped molding surface 29 is accurately positioned. In addition, both protrusions 11 are connected to the department store hole 34.
However, both knockout pins 35 are in the lowered position so that the tip end surface of each pin 35 is spaced apart from the lower end surface of each protrusion 11.

Next, the 12th. As shown in FIG.
is lowered to fit the punch body 36 into the holding hole 28 and both guide parts 37 into both punch guide grooves 32, respectively.
Both inclined inner surfaces 38 of the punch body 36 are aligned with both inclined surfaces 12 of the primary material 61, and the material 61 is pressed. As a result, the primary material 6 is deformed, and its flat surface 10a
is formed into the convex arc surface following the concave arc forming surface 29, and at the same time, the first . Edge 3 where the second edge el+et has a concave arc surface
3. ．． 33□ is formed into a convex arc surface and chamfered. Through the above steps, a secondary material 6□ is obtained.

In this case, since both inclined surfaces 12 are pressed by both inclined inner surfaces 38, the surface properties of these inclined surfaces 12 are improved, and the vicinity of these inclined surfaces 12 and receiving surface 10 is densified.

At this point, both regulating members 40 come into contact with the upper end surface of the die 27 to regulate the movement stroke of the press punch 26, so that dimensional changes in the secondary material 6□ due to overpressure are reliably prevented.

After forming, the press punch 26 is raised twice, and then both non-knockout pins 35 are raised to discharge the secondary material 6□ from the holding hole 28. With this discharge, the secondary material 6□ undergoes springback, and the inclination angle of both inclined surfaces 12 becomes slightly larger than that of the finished product.

In addition, secondary materials 6. Since it has approximately the same shape as the ■-shaped block roller, the same parts are given the same reference numerals.

Next, the shape correction process will be explained with reference to FIGS. 14 to 16.

The shape correction mold 41 includes an outer mold 42, an upper punch 43, and a lower bonder 44, and the upper and lower punches 43.4
4 is slidably fitted into a shaped hole 45 passing through the outer mold 42. The shaping hole 45 has a shape that allows the secondary material 6 □ to be forcefully fitted with both end surfaces thereof directed downward, and the upper and lower punches 43 and 44 are used to insert the secondary material 6□, respectively, downward. A protrusion 46 that fits into both roller retainers 13 of the cable member 61.
It is equipped with 47. In this case, in order to increase the clamping force on the center portion 13a (FIG. 14) of both roller holding grooves 13 than on the surrounding area, the portions of both protrusions 46, 47 corresponding to the center portion 13a are larger than the surrounding area. is also somewhat prominent.

Secondary material 6. In order to correct the shape of is compressed to correct the inclination angle of both inclined surfaces 12 due to the springback generated in the secondary rope material 6□ after press molding.

During the clamping process, the center portions 13a of both the cola holding grooves 13 in the secondary material 6□ are pressed more strongly than the periphery of the grooves, so that the receiving surface of the secondary material 6□ is compressed as shown by the chain line in FIG. 1
0 undergoes bulging deformation.

In the present invention, in order to prevent the receiving surface 10 from contacting the inner surface 48 of the shaped hole 45 facing the receiving surface 10 during the bulging deformation,
There is a gap GJ between the inner surface 48 and the receiving surface 10 which has undergone bulging deformation.
a exists.

The distance d is the length l between the inner surface 49 and the inner surface 49 opposite thereto, and the length l between the top of the receiving surface 10 and the outer surface 50 opposite thereto! This can be obtained by setting the difference Δl from 2 to be larger than the pressure during press molding.

When such shape correction work is performed, the receiving surface 10 is aligned with the shaped hole 4.
Therefore, due to the springback after demolding, the arc 6 of the receiving surface 10 has a radius at or close to the set value.

C9 Effects of the Invention According to the present invention, by employing an extremely simple method, it is possible to provide the ■-shaped block with improved dimensional accuracy of the receiving surface.

[Brief explanation of the drawing]

Figures 1 to 3 show the belt transmission mechanism, Figure 1 is an overall perspective view, Figure 2 is a partial perspective view of the endless metal belt, Figure 3 is a partial side view of the endless metal belt, and Figures 4 to 7. The figure shows a ■-shaped block, FIG. 4 is a perspective view showing the relationship between the ■-shaped block and the stopper, FIG. 5 is a side view of the V-shaped block, FIG. Figure 7 is a sectional view taken along the line ■-■ in Figure 6, and Figure 8 is an explanatory diagram of the powder metallurgy process for obtaining the primary material.
9 to 13 show the press molding process for obtaining a secondary material, FIG. 9 is a longitudinal cross-sectional view of the press molding device before operation, FIG. Fig. 11 is a partial perspective view of the press punch, Fig. 12 is a vertical sectional view of the press molding device during operation, Fig. 13 is a sectional view taken along the xm-xm line in Fig. 12, and Figs. 14 to 16 are the ■-shaped blocks. Fig. 14 is a sectional view of the outer mold, which corresponds to the sectional view taken along the line XrVXIV in Fig. 15; The figure is an explanatory diagram showing the relationship between the secondary material 1 and the shaping hole. d... Spacing, g...■Groove, 2, 3...Drive, driven ■Pulley, 5...Endless strip, 6...■shaped block, 6,. 6. ...1, secondary material, 10...receiving surface, 10a...flat surface, 12...slanted surface, 26...
Pressure punch (molding die), 27... die (molding die),
41... Shape correction mold, 45... Orthopedic hole, 48...
Inner surface Fig. 7 Fig. 5

Claims (1)

[Claims] The V-pulley has a pair of inclined surfaces that are in sliding contact with the inner surface of the V-groove, and a receiving surface that is located between the two inclined surfaces and receives the inner circumferential surface of the endless strip, and the receiving surface is arranged at least in the winding direction of the endless strip. In order to manufacture a metal V-shaped block formed into a convex arc surface with the central part as the apex, we performed a green compact molding operation using metal powder and a green compact sintering operation. A primary material whose portion corresponding to the receiving surface is formed into a flat surface is obtained, and then both inclined surfaces of the primary material are simultaneously pressed with one mold to form a concave arc shape of the other mold. 2. The receiving surface is molded by making it follow the molding surface.
In the method for producing a V-shaped block, the method includes obtaining a secondary material, and then performing a shape correction operation by squeezing both end surfaces of the secondary material adjacent to both inclined surfaces and the receiving surface in a shaping hole of a shape correction mold. A space is provided between the receiving surface and the inner surface of the shaping hole so that the receiving surface does not come into contact with the inner surface of the shaping hole that faces it when the receiving surface bulges and deforms due to the clamping pressure. A method of manufacturing a V-shaped block for an endless metal belt, which is characterized by performing work.