JP2018501448A - Endless metal band with a coated surface, drive belt with the endless metal band, and method of forming the drive belt - Google Patents

Abstract

An endless metal band (44) for a drive belt (3), the drive belt (3) comprising at least one set (31) comprising a plurality of endless metal bands (44) stacked on each other; A plurality of transverse elements (32) attached to the band set (31), the transverse element (32) being provided with a notch (33), the notch accommodating the band set (31). In order to do so, it extends between the front main surface (39) and the rear main surface (38) of the transverse element (32), the notch (33) being the radius of the band set (31) Connected radially inward to the radially outwardly directed support surface (42) of the transverse element (32) in sliding frictional contact with the radially inner surface (51) of the innermost endless metal band (44i) The And has, endless metal band for a driving belt (3) (44). According to the present invention, the radially inner side surface (51) of the endless metal band (44) is at least partially provided with an abrasive coating (50).

Description

  The present invention relates to a drive belt for use with a continuously variable transmission, wherein the continuously variable transmission has two variable pulleys, each pulley defining a circumferential V-groove. The drive belt is provided with an endless carrier, which typically consists of two band sets, each band set having at least one, but usually a plurality of, mutually stacked flexible The drive belt is further provided with a plurality of metal transverse elements that are arranged on the endless carrier and are slidable relative to the endless carrier. Each transverse element is provided with one or more notches, each notch accommodating a respective band set. A drive belt of this type is known from EP-A-0014013.

  When describing the direction with respect to the drive belt and / or the transverse element of the drive belt, it is always assumed that the transverse element is in an upright position as shown in the front view of FIG. In FIG. 2, the circumferential direction or length direction L of the drive belt is perpendicular to the drawing plane. The horizontal direction or the width direction W is the left-right direction in the plane of FIG. 2, and the radial direction or the height direction H is the vertical direction in the plane of FIG.

  During operation of the drive belt in the transmission, the transverse element is pressed against the inner surface of the endless carrier at least at the position of the transmission pulley, in which case the bottom surface of the notch of the transverse element corresponds to each band set of the endless carrier. It is in intimate contact with the radially inner surface of the radially innermost band, in particular sliding friction contact. Hereinafter, the bottom surface of the notch is also referred to as a saddle surface. In this technical field, it has been proposed to design the saddle surface with a convex curvature as seen in the width direction of the transverse element, ie between the front side and the rear side of the transverse element. With respect to such convex curvature, the art reduces (hertz) contact stress between the transverse element and the endless carrier, and reduces (local) bending angle and stress of the endless metal band, thereby Several effects are obtained, such as the drive belt can be loaded higher and / or longer until it fails and friction losses are reduced, thereby improving the operating efficiency.

  However, current methods of manufacturing transverse elements are cut out of a base material sheet or strip in the same front-to-back direction with a precision stamping process step. Simultaneously with the cutting, the convex curve cannot be provided on the saddle surface. Therefore, in this technical field, several methods have been proposed in which the saddle surface is first cut out as a flat surface, and then the saddle surface is reshaped so as to have a convexly curved shape. In particular, for example, European Patent Application Publication No. 0231985, European Patent Application Publication No. 1366855, US Pat. No. 4,281,483, Japanese Patent Application Laid-Open No. 61-152362, Japanese Patent Application Laid-Open No. 2014-145423, etc. For this purpose, several grinding methods have been proposed in the art for this purpose. These known grinding methods unfortunately increase the complexity and cost of manufacturing the transverse element.

  The problem of the present disclosure is to provide a cost-effective alternative to the known process of providing a convex curvature on the saddle surface of a transverse element.

  According to the present disclosure, the above-described object is achieved by providing a coating with abrasive properties on the radially inner side of the endless carrier, i.e., on the radially inner side of the radially innermost band of the band set of the endless carrier. Is done. With such an abrasive coating, during the operation of the drive belt in the transmission, the transverse element is pressed against the radially inner surface of the endless carrier band in the radially outward direction, between which relative movement or Combined with the fact that a speed difference exists, the saddle surface of the transverse element is polished. The degree of such polishing is proportional to the contact force between the transverse element and the endless carrier, and therefore at least initially during operation of the drive belt in the transmission, the saddle surface at the tightest curved portion of the drive belt The highest on the front and rear sides of the. Thus, the abrasive coating of the endless carrier causes the saddle surface of the transverse element to be ground into a convexly curved shape, which in this case is preferably an additional component to be included in the production of the transverse element for this purpose. No process steps are necessary.

  Of course, it is still possible to include such polishing of the saddle face of the transverse element as one process step in the overall drive belt manufacturing process. For this purpose, after the drive belt is assembled, it is attached to two pulleys, wound around them, and a clamping force is applied to the drive belt by the pulleys so that the transverse element of the drive belt is against the inner surface of the endless carrier. The pulley and the drive belt are rotating during the time to perform the polishing process. Only then is the drive belt attached to the continuously variable transmission and not used.

  Once the convex curved shape is formed on the saddle surface, it is preferable to stop polishing the saddle surface and thus prevent subsequent removal of material from the saddle surface. To that end, according to the present disclosure, the abrasive coating of the endless carrier is a consumable product and is itself worn, for example, by interaction with the saddle surface. Another option is to use an abrasive coating that dissolves in the lubricant applied to the transmission. In this case, the abrasive coating typically consists of relatively hard abrasive particles embedded in a relatively soft matrix that can be (gradually) dissolved.

  Furthermore, according to the present disclosure, it is preferable that the polishing rate of the saddle surface is not too high. If the polishing rate is too high, the size of the polished particles will be too large and / or too much heat will be generated during the polishing process. Furthermore, the higher the polishing rate, the less predictable the end result of the polishing process, and the lower the consistency. The polishing rate is clearly determined in part by the properties of the abrasive coating. For example, the hardness, size and number of abrasive particles in the coating will all affect the polishing rate of the saddle surface in the transmission obtained with this coating. However, according to the present disclosure, a particularly preferred solution has been found in that the abrasive coating is provided only on a portion of the radially inner surface of the radially innermost band. The abrasive coating may be applied, for example, in the form of one or more strips extending in the width direction of the band.

  Further, according to the present disclosure, it is preferred that the other surfaces of the bands of the band set (i.e., the non-radially inner surface of the radially innermost band of the band set) are relatively smooth. In particular, these other surfaces do not have abrasive coatings or surface shapes as known from EP00140113 and are currently universally applied to drive belts. More particularly, the so-called Ra surface roughness value according to the ISO standard for these other band surfaces is preferably 0.1 microns or less. That is, it is observed that a relatively smooth surface with a minimum Ra roughness value is also obtained for the saddle surface apart from the convex curved shape of the saddle surface. Such a smooth surface is known to be suitable if it applies relatively little frictional force to the radially innermost band, in which case the friction between the bands of the band set itself is also small.

  The above novel considerations and technical concepts will be described using an exemplary embodiment of a drive belt with reference to the drawings.

It is a perspective view which shows roughly the continuously variable transmission which has the drive belt which drive | works on two pulleys. It is sectional drawing which shows the well-known drive belt seen in the circumferential direction of the drive belt. It is the figure which looked at the transverse element of the well-known drive belt toward the width direction. FIG. 4 is an enlarged view of FIG. 3 showing aspects of the design and manufacture of the transverse element underlying the present disclosure. 1 is a perspective view schematically illustrating a first embodiment of a flexible endless metal band according to the present disclosure. FIG. FIG. 6 is a perspective view schematically illustrating a second embodiment of a flexible endless metal band according to the present disclosure. FIG. 6 is a perspective view schematically illustrating a plurality of alternative embodiments of a flexible endless metal band according to the present disclosure.

  A drive belt 3 is shown in the schematic diagram of the continuously variable transmission of FIG. The drive belt 3 runs on two pulleys 1, 2 and includes an endless band set 31, which is substantially adjacent to the transverse element 32 arranged over the circumference of the band set 31. Supports the column. The drive belt 3 and the pulleys 1 and 2 are in frictional contact, and the conical discs 4 and 5 of the pulleys 1 and 2 are biased against each other, thereby applying a clamping force to the drive belt 3. ing. In the position shown, the upper pulley 1 rotates faster than the lower pulley 2. By changing the distance between the two conical discs 4, 5 forming each pulley 1, 2, the so-called running radius R of the drive belt 3 on each pulley 1, 2 can be changed, resulting in The speed difference between the two pulleys 1 and 2 can be changed as desired. This is a known format for transmitting power between the input shaft 6 and the output shaft 7 of the transmission, and there is a continuously variable rotational speed ratio between the input shaft 6 and the output shaft 7.

  In FIG. 2, the drive belt 3 is shown in a cross section facing the circumferential direction L thereof. FIG. 2 shows an embodiment of the drive belt 3 provided with two band sets 31 each shown in a sectional view. The band set 31 supports and guides a plurality of transverse elements 32 of the drive belt 3. One of the transverse elements 32 is shown in front view in FIG. The transverse element 32 and the band set 31 of the drive belt 3 are typically made of metal, usually steel. The band set 31 holds the drive belt 3 together, and in this particular embodiment consists of five individual endless bands 44. These endless bands 44 are stacked concentrically with each other to form a band set 31. In practice, the band set 31 often has more than five endless bands 44. The transverse element 32 can move or slide along the longitudinal direction L of the band set 31 so that when a force is transmitted between the transmission pulleys 1, 2, this force is at least partially pressed against each other. Transmitted by the transverse elements 32 which are pushed against each other in the forward direction in the direction of rotation of the drive belt 3 and pulleys 1, 2.

  Two cutouts 33 are provided in the transverse element 32 which is also shown in a side view in FIG. These notches are arranged opposite to each other and open towards the opposite side of the transverse element 32. Each notch 33 accommodates one of the two band sets 31. The first portion or body portion 34 of the transverse element 32 extends radially inward of the band set 31, or in the height direction H, below the band set 31. The second part or neck part 35 is located between both band sets 31 and at the same (radial) height as the band set 31, and the third part or head part 36 of the transverse element 32 is It extends radially outward or above the band set 31 in the height direction H. The lower side or the radially inner side of each notch 33 is defined by a so-called support surface 42 of the body portion 34 of the transverse element 32. The support surface 42 faces radially outward or upward as viewed in the general direction of the head portion 36. The support surface 42 is in contact with, or supported by, the radially inner peripheral surface of the band set 31, that is, the radially inner surface of the innermost band 44 i in the radial direction.

  The lateral side surfaces 37 of the body part 34 of the transverse element 32 that are in contact with the pulley discs 4, 5 are oriented at an angle Φ with respect to each other, this angle being between these discs 4, 5. Corresponds at least approximately to the angle of the V-shape.

  The first or rear major surface 38 of the transverse element 32 facing the circumferential direction L of the drive belt 3 is substantially flat, while the second or front major surface of the transverse element 32 facing the opposite side. The surface 39 is provided with a so-called rocking or tilting edge 18. Above the oscillating edge 18 in the height direction H, the transverse element 32 has a substantially constant thickness as viewed in side view, but below the oscillating edge 18 in the height direction H, the body The portion 34 tapers toward the bottom surface of the transverse element 32. The oscillating edge 18 is usually provided in the form of a slightly rounded section of the front main surface 39 of the transverse element 32. In the drive belt 3, the straight part of the drive belt 3 extending between the pulleys 1, 2 and the curved part of the drive belt 3 located between the conical pulley disks 4, 5 of the transmission pulleys 1, 2. In both cases, the front major surface 39 of the transverse element 32 contacts the rear major surface 38 of the adjacent transverse element 32 at the position of the oscillating edge 18.

  The transverse element 32 is further provided with a protrusion 40 on the front main surface 39 and a hole 41 on the rear main surface 38. The protrusions 40 and the holes 41 of the two adjacent transverse elements 32 in the drive belt 3 are the same as the protrusions 40 of the first transverse element 32 of the adjacent transverse elements 32 and the holes 41 of the second transverse element 32. Are engaged with each other so as to be at least partially inserted into each other. In this case, the relative displacement and / or rotation between the two adjacent transverse elements 32 is limited to the gap provided between the projection 40 and the hole 41.

  In this technical field, a convex curve in the circumferential direction L of the drive belt 3 is used to limit the contact stress introduced into the radially innermost band 44 i by contacting the transverse element 32. It is known to provide the support surface 42. The curvature radius Rs of such a curve is typically adapted or selected to be less than or equal to the minimum travel radius R of the drive belt 3 in the pulleys 1 and 2.

  The transverse element 32 is cut from the strip-like base material by a cutter that moves through the material in the defined circumferential direction L of the drive belt 3. In principle, this cutting process provides a predetermined contour in the cutter moving direction, for example, the convex curve in the circumferential direction L of the drive belt 3 on the surface formed therein, such as the support surface 42. It is not possible. Thus, the support surface 42 is initially formed without the convex curvature as shown in the left and middle of FIG. 4 which is a side view of the transverse element 32 and a partially enlarged view thereof. The convex curvature of the support surface 42 of the final product transverse element 32 shown on the right side of FIG. 4 is thus further processed by additional process steps in the overall manufacturing process of the final product transverse element 32. Need to be shaped. Some examples of such additional process steps are provided primarily by techniques relating specifically to grinding the edges of the support surface 42.

  According to the present disclosure, the known process steps forming the support surface 42 of the transverse element 32 can be advantageously omitted from the entire transverse element manufacturing process. Instead, according to the present disclosure, a coating 50 with abrasive properties is applied to the radially inner side 51 of the radially innermost band 44 i of the band set 31. In FIG. 5, such a feature is schematically shown in a perspective view of the innermost band 44i.

  Such an abrasive coating 50 is combined with the fact that during the operation of the drive belt 3 in the transmission there is a relative movement or speed difference between the transverse element 32 and the band set 31 in the circumferential direction of the drive belt 3, The saddle surface 42 of the element 32 is ground so as to have a convexly curved shape.

  Further, according to the present disclosure, in a particularly preferred embodiment of the innermost band 44i, the abrasive coating 50 is provided in the form of a strip. This strip traverses the entire width of the radially inner surface 51 but only traverses a (small) portion of the circumferential length of the radially inner surface 51. This embodiment of the innermost band 44i is shown in FIG. With such a strip-shaped width, the polishing rate of the saddle surface 42 can be defined in advance. In addition, such a strip shape allows a harder and / or more wear resistant material to be used as the coating without an excessive wear rate of the support surface 42.

  Additionally, it may be desirable if the polishing rate of the saddle surface 42 is changed along the width of the saddle surface 42. For example, to improve contact lubrication between the saddle surface 42 and the radially inner surface of the innermost band 44i, the side surface of the saddle surface 42 may be less polished or not polished at all. . If not polished at all, the abrasive coating 50 may only be applied to the widthwise central portion of the innermost band 44i, as shown as one possible embodiment 50a in FIG. In the case of less polishing, the abrasive coating 50 is shaped to narrow toward the axial side from the central portion in the width direction of the innermost band 44i, as shown as two possible embodiments 50b and 50c in FIG. It may be provided. Optionally, polishing may be particularly required on the lateral side of the saddle surface 42. In such a case, the abrasive coating 50 is provided in a shape that widens from the central portion in the width direction of the innermost band 44i toward the axial direction, as shown as one possible embodiment 50d in FIG. May be. Yet another option is that one lateral side of the saddle surface 42 is each more polished than the other lateral side, but in such a case, the abrasive coating 50 is shown in FIG. As shown as one possible embodiment 50e, it may be provided only on one axial side of the innermost band 44i. Optionally, the abrasive coating 50 may extend across the entire width of the innermost band 44i, but may taper in the width direction. For example, as shown in FIG. 7 as one possible embodiment 50f, the abrasive coating 50 is provided in a trapezoidal shape.

  The present disclosure relates to and includes all features of the appended claims in addition to all the details of the foregoing description and the accompanying drawings. Reference signs in parentheses in the claims do not limit the scope of the claims, but are provided merely as an unconstrained example of each feature. The features recited in the claims can optionally be applied separately in any product or method, but any combination of two or more of these features can also be applied.

  The invention represented by this disclosure is not limited to the embodiments and / or examples explicitly mentioned in the specification, but to its amendments, modifications and practical applications, particularly within the reach of those skilled in the art. Some are also included.

Claims (9)

An endless metal band (44) for a drive belt (3), the drive belt (3) comprising at least one set (31) comprising a plurality of endless metal bands (44) stacked on each other; A plurality of transverse elements (32) mounted in a slidable manner on the band set (31), each transverse element (32) being provided with a notch (33), To accommodate the band set (31), it extends between the front main surface (39) and the rear main surface (38) of the transverse element (32) at the position of the notch (33). The transverse element (32) has a radially outwardly facing support surface (42) that contacts the radially inner surface (51) of the radially innermost endless metal band (44i) of the band set (31). )But Is kicked, the endless metal band for a driving belt (3) (44),
The radially inner side surface (51) of the endless metal band (44) is at least partially provided with an abrasive coating (50), that is, at least partially provided with a layer having abrasive properties. Endless metal band (44) for drive belt (3), characterized in that   The endless metal band (44) of claim 1, wherein the radially inner surface (51) of the endless metal band (44) is completely covered by the abrasive coating (50).   The abrasive coating (50) is optionally provided in one or more isolated spots, bands, or other shapes that extend across the entire width of the radially inner surface (51) of the endless metal band (44). The endless metal band (44) of claim 1, wherein:   The endless metal band (44) according to any of the preceding claims, wherein the abrasive coating comprises relatively hard abrasive particles embedded in a relatively soft matrix that is soluble in a lubricant. A drive belt (3) comprising at least one set (31) comprising a plurality of endless metal bands (44) stacked on each other, and a plurality of slidably attached to the band set (31) A transverse element (32), each transverse element (32) being provided with a notch (33), said notch being adapted to receive said band set (31), said transverse element (32) Of the band set (31) extending between the front main surface (39) and the rear main surface (38) of the transverse element (32) at the position of the notch (33). In the drive belt (3), provided with a radially outwardly facing support surface (42) in contact with the radially inner side surface (51) of the direction innermost endless metal band (44i),
Drive belt (3), characterized in that said radially innermost endless metal band (44i) is an endless metal band (44) according to any one of claims 1 to 4.   A radially outer surface (51) of the radially innermost endless metal band (44i) and a radially inner surface of the outer endless metal band (44) of the band set (31) of the drive belt (3). The drive belt according to claim 5, wherein the radially outer surface is provided as a smooth surface having an ISO standard Ra surface roughness value of 0.1 μm or less. A method of forming a drive belt (3), wherein the drive belt (3) comprises at least one set (31) comprising a plurality of endless metal bands (44) stacked on each other, and the band set (31). A plurality of transverse elements (32) attached in a slidable manner to the transverse elements (32), each of which is provided with a notch (33), the notches being provided with the band set (31). Is extended between the front main surface (39) and the rear main surface (38) of the transverse element (32) and at the position of the notch (33) the transverse element (32 ) Is provided with a radially outward support surface (42) that contacts the radially inner surface (51) of the radially innermost endless metal band (44i) of the band set (31). Have A method of forming a drive belt (3),
The radially innermost endless metal band (44i) is an endless metal band (44) according to any one of claims 1 to 4,
The drive belt (3) wound around and in frictional contact with the two rotating pulleys (1, 2) is operated, and the two rotating pulleys have two conical discs (4, 5), respectively. The conical discs (4, 5) define a circumferential V-groove between the discs, and the V-groove has a predetermined circumferential direction of the drive belt (3). Method for forming the drive belt (3), in which the part is located.   Method for forming a drive belt (3) according to claim 7, wherein the abrasive coating (50) is designed to be consumed during operation, for example by (mechanical) wear and / or (chemical) dissolution.   Before being actuated, the support surface (42) extends substantially linearly at least in its main part between the front main surface (39) and the rear main surface (38) of the cross member. 9. A method of forming a drive belt (3) according to claim 7 or 8, wherein:

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