CN111426470A

CN111426470A - Method and device for checking a drive belt for a continuously variable transmission

Info

Publication number: CN111426470A
Application number: CN201911337702.8A
Authority: CN
Inventors: P·F·H·赫本; W·A·A·奈利斯; A·A·M·斯梅茨; M·施魏格
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2018-12-24
Filing date: 2019-12-23
Publication date: 2020-07-17
Also published as: JP2020101287A

Abstract

The invention relates to a method for checking a drive belt (50) for a continuously variable transmission, having a ring set (8) and a plurality of transverse segments (1) which are mounted in a row in the circumferential direction of the ring set (8), in which row at least two transverse segments (1) of a type (I, II) having a design which differs from one another are included. According to the invention, the checking method comprises the steps of detecting the actual sequence of the transverse segment types (I, II) in said row and comparing said actual sequence with a defined sequence.

Description

Method and device for checking a drive belt for a continuously variable transmission

Technical Field

The invention relates to a method and a device for checking a drive belt for a continuously variable transmission, in particular as a part or as a processing step in the overall manufacturing process of such a drive belt. Such drive belts are known, for example, from british patent No. GB1286777(a) and more recently international patent publication WO 2015/177372(a 1). Such known drive belt consists of a plurality of flexible annular metal strips or rings nested one within the other, i.e. stacked one on top of the other in a radial direction, as well as a plurality of metallic transverse segments arranged in a substantially continuous row along the circumference of such an annular group. The transverse segments each define a central opening defined between the base portion and the cylindrical portion by the base portion and two cylindrical portions of the transverse segments, the cylindrical portions each extending in a radially outward direction from a respective axial side of the base portion, the respective circumferential sections of the ring sets being received in the central openings while allowing the transverse segments to move circumferentially thereof. In order to accommodate the set of rings in the central opening, the latter is closed in a radially outward direction by respective axial extensions of at least one, possibly two, cylindrical portions. In particular, such an axial extension of the respective cylindrical portion extends partially over the set of rings towards the other, axially opposite cylindrical portion of the transverse segment, and is referred to hereinafter as the hook of the cylindrical portion.

Background

It should be noted that alternative measures and/or structures for accommodating the set of rings in the central opening of the transverse segment, i.e. alternatives with respect to such hooks, are known in the art, such as accommodating rings (see e.g. US 5123880) and closure pins (e.g. EP 0122064).

In a continuously variable transmission, a transmission belt is wrapped around and brought into frictional contact with two pulleys, which define V-shaped grooves of variable widths, respectively, in which respective portions of the transmission belt are held with variable radii. By changing the radius of the conveyor belt at the conveyor wheel, the speed ratio of the conveyor belt can be changed. Transmissions of this type are well known and are commonly used in the drive train of passenger cars and other motor vehicles.

In the description above and below, the axial, radial and circumferential directions are defined with respect to the drive belt when placed in an endless formation. The transverse segments have thickness direction and thickness dimension defined in the circumferential direction of the drive belt, height direction and height dimension defined in the radial direction of the drive belt, and width direction and width dimension defined in the axial direction of the drive belt. The thickness direction and the thickness dimension of the set of rings are defined in the radial direction of the drive belt, the width direction and the width dimension of the set of rings are defined in the axial direction of the drive belt, and the length direction and the length dimension of the set of rings are defined in the circumferential direction of the drive belt. The up-down direction and the up-and-down position are defined with respect to the radial or height direction.

According to WO 2015/177372, two types of transverse segments are included in the drive belt, which have different shapes of left and right cylindrical portions. In particular, according to WO 2015/177372, one of the two cylindrical parts of a transverse segment is provided with a hook, while the respective other cylindrical part thereof is provided with no hook or with a smaller-sized hook, the respective cylindrical part being designed to be arranged on the opposite side of the base part between the two types of transverse segments. Both types of transverse segments are included in the drive belt in a certain defined sequence or pattern, for example an alternating pattern. This prescribed sequence of transverse segment types should be followed when assembling the drive belt by mounting the transverse segments on the set of endless members, either manually or by machine. WO 2018/210456 provides another example of such a drive belt comprising two types of transverse segments having mutually different designs. In this case, the central opening extends further towards a first one of the transverse sections than towards its respective other axial side, which is located on the opposite side of the base portion between the two types of transverse sections. Obviously, more than two types of transverse segments may also be applied in the drive belt, depending on the intended technical effect of the drive belt.

Disclosure of Invention

In all these cases it is advantageous according to the invention to check the drive belt assembled thereby in connection with the detection of the sequence of transverse segment types in the row of transverse segments, i.e. to check whether the sequence of the respective type of transverse segments of the drive belt meets a prescribed sequence. If the assembled belt meets the prescribed sequence, it can be further processed and/or used. Otherwise, the drive belt will be rejected for use, or at least designated for disassembly. In particular, such a check is advantageous, since an incorrect transverse segment sequence often has an adverse effect on the technical performance of the drive belt in the transmission. Thus, according to the present disclosure, the manufacturing process of the drive belt comprises a processing step in which, by manual or automatic detection, the type of each transverse segment within a complete row of transverse segments of the assembled drive belt is identified. The actual sequence of the transverse segment and/or transverse segment type thus detected is compared with the specified desired sequence.

In the case of the drive belt known from WO 2015/177372, for example, different types of transverse segments can in principle be detected by determining and positioning the hook portion of one of said cylindrical parts, viewed from the radially outer side of the drive belt in a radially inward direction, and with respect to the left or right axial side of the respective transverse segment. This positioning can be done manually, i.e. visually, or automatically using imaging equipment (e.g. optical camera, 3D laser scanner, etc.) and image analysis software. In either case, the belt is rotated in its longitudinal direction, i.e. in an axial direction, relative to the examination position and/or the imaging device.

In the case of the drive belt known from WO 2018/210456, for example, different types of transverse segments cannot be detected from the outside of the drive belt, because the extension of the central opening of the transverse segment is covered by the hook of its cylindrical part. In this and similar cases, but in general it is also possible to facilitate the detection of different types of transverse segments as well, at least one of the two or more types of transverse segments is provided with a marking of a unique shape on or belonging to its outer circumferential surface. By means of such a marking, the type of each successive transverse segment within a complete row of transverse segments of the assembled drive belt can be easily and reliably detected as part of the transverse segment sequence check according to the invention.

Preferably, the markings of at least one type of transverse segment are in the form of recesses or protrusions in or on the circumferential surface. That is, in these cases, when the belt is illuminated by a light source as part of a transverse segment sequence inspection according to the present disclosure, the detectability of the markings is enhanced by the side walls of the recesses or protrusions that reflect light to the inspection location/imaging device or drop shadow. To maximize this detection enhancement, the sidewall is preferably oriented at an angle of 45 to 90 degrees relative to the adjacent portion of the circumferential surface. In particular, at an angle of about 90 degrees, the side walls of the marker will optimally cast a shadow, thereby optimally facilitating detection of the marker.

Preferably, the marking according to the invention is applied to the bottom of the transverse segment, which is located on the radially inner side of the drive belt, or to the side of the transverse segment, which is located on the axial side of the drive belt. In these cases, advantageously, a complete row of transverse segments of the assembled drive belt can be monitored from a single inspection or imaging device location, whereby the complete row can be captured with a single view and/or a single image. Thus, in these cases, it is advantageous that it is not necessary to rotate the imaging device with respect to the drive belt (or vice versa) to check a complete row of transverse segments thereof.

The present disclosure also relates to an apparatus for inspecting a drive belt, in particular for performing the above-discussed drive belt inspection method. The inspection apparatus according to the present disclosure is provided with at least a receiving member for holding the transmission belt, an imaging device for taking an image of a part or the whole of the transmission belt held by the receiving member, and a microcontroller, a microprocessor, or the like programmed to be able to process the image of the transmission belt taken by the imaging device. Preferably, such a drive belt inspection device is additionally provided with a light source. Preferably, the imaging device and, if present, the light source are located radially inside the drive belt or on an axial side of the drive belt. In the latter case, the light source is preferably located between the imaging device and the conveyor belt, with a light shield being arranged between the light source and the imaging device, so that a larger shadow is cast by the marking. However, if the imaging device is positioned radially outside the drive belt, the drive belt inspection device is additionally provided with a subassembly for rotating the drive belt relative to the imaging device or vice versa.

Drawings

The drive belt inspection method according to the present invention will now be further described with reference to the accompanying drawings, in which:

figure 1 is a simplified schematic side view of a transmission with two pulleys and a drive belt with a set of rings and a row of transverse segments arranged along the circumference of the set of rings;

figure 2 provides an example of a known drive belt comprising two transverse segment types/designs;

figure 3 schematically shows three possible embodiments of the marking of one of the transverse segment types of the drive belt shown in figure 2 according to the present disclosure;

FIG. 4 schematically shows a first embodiment of a drive belt inspection method according to the present disclosure; and

FIG. 5 schematically shows a second embodiment of the drive belt inspection method according to the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Fig. 1 schematically shows a central portion of a continuously variable transmission 51 used in a drive train of, for example, a passenger car, in a sectional view thereof. The transmission 51 is well known and includes at least a first variable pulley 52 and a second variable pulley 53. In the transmission system, a first pulley 52 is coupled to and driven by a prime mover, such as an electric motor or an internal combustion engine, and a second pulley 53 is coupled to and drives the driven wheels of the motor vehicle, typically through a plurality of gears.

The

transmission pulleys

52, 53 typically comprise a first conical pulley sheave fixed to the pulley shaft 54, 55 of the

respective pulley

52, 53 and a second conical pulley sheave axially displaceable relative to the respective pulley shaft 54, 55 and fixed to the pulley shaft 54, 55 only in the direction of rotation. The drive belt 50 of the transmission 51 is wound around the

pulleys

52, 53 and accommodated between their pulley sheaves. As shown in fig. 1, the trajectory of the drive belt 50 in the transmission 51 comprises two substantially straight portions ST and two curved portions CT, wherein the drive belt 50 is wrapped around a respective one of the two

transmission pulleys

52, 53. The drive belt 50 comprises an endless group 8 and a plurality of, for example about 400 (hundred), transverse segments 1 mounted on the endless group 8 in an at least substantially continuous row in the circumferential direction of the endless group 8. For the sake of simplicity, only a few of these transverse segments 1 are shown in fig. 1, said transverse segments 1 furthermore not being drawn to scale with respect to the diameter of the

pulleys

52, 53, for example.

In the drive belt 50, the transverse segments 1 are movable along the circumferential direction of the set of endless groups 8, the set of endless groups 8 typically consisting of a plurality of relatively thin and flexible endless metal bands or rings nested one within the other, i.e. stacked radially. During operation of the transmission 51, the transverse section 1 of the drive belt 50 can be driven by the first pulley 52 in its rotational direction by friction. These driven transverse segments 1 push the preceding transverse segment 1 in the circumferential direction of the set of endless belts 8 of the drive belt 50 and finally rotationally drive the second pulley 53 again by friction. In order to generate such friction (force) between the transverse segment 1 and the transmission pulleys 52, 53, the pulley sheaves of each

pulley

52, 53 are forced close to each other, thereby exerting a clamping force on the transverse segment 1 in the axial direction thereof. For this purpose, in general, electronically controllable and hydraulically acting shifting means (not shown) acting on the movable pulley sheaves of each

pulley

52, 53 are provided on the transmission 51. These moving means also control the respective radial positions R1 and R2 of the drive belt 50 at the drive pulleys 52, 53 and thus the speed ratio provided by the transmission 51 between the pulley shafts 54, 55.

In fig. 2, a known example of the transmission belt 50 is schematically shown. At the top of fig. 2, the drive belt 50 is shown in a sectional view, at the bottom of fig. 2, including only the front and side views of its transverse section 1. The transverse segment 1 is provided on either axial side thereof with side faces 12, which side faces 12 are in (frictional) contact with the transmission pulleys 52, 53 and are oriented at an angle to each other, which angle approximately matches the angle defined by the transmission pulleys 52, 53 between the transmission pulleys 52, 53. In practice, these side or pulley contact surfaces 12 are either corrugated by means of a macroscopic contour or have a rough surface structure (not shown), so that only the higher-lying portions or peaks of the corrugated contour or of the surface roughness are in contact with the transmission pulleys 52, 53. This particular feature of the design of the transverse segment 1 enables the friction between the drive belt 50 and the transmission pulleys 52, 53 to be optimized by allowing the cooling oil applied in the known transmission 51 to be accommodated in the lower portions or valleys of the corrugated profile or of the surface roughness.

Each transverse segment 1 of the drive belt 50 defines a base part 10 and two cylindrical parts 11, wherein the base part 10 extends mainly in the axial direction and the cylindrical parts 11 extend mainly in the radial direction from the respective axial side of the base part 10. Each transverse segment 1 extends in its thickness direction between a front surface 2 and a rear surface 3 thereof, which front surface 2 and rear surface 3 both face at least substantially in the circumferential direction of the drive belt 50. An opening 5 is defined centrally between the cylindrical portion 11 and the base portion 10 of each transverse segment 1, in which opening a circumferential section of the set of rings 8 is accommodated. A radially outward surface portion 15 of the base portion 10, which surface portion forms the radially inner boundary of the central opening 5, supports the ring element group 8 from the radially inner side, which surface portion is referred to hereinafter as support surface 15. This support surface 15 is generally convexly curved to facilitate a preferred centering alignment of the set of rings 8 during operation, i.e. rotation of the drive belt 50 in the transmission 51.

Both cylindrical portions 11 of the transverse segment 1 are provided with pegs 6 protruding in the thickness direction from the front surface 2 of the transverse segment 1 and with corresponding holes (not shown) in opposite sides of the respective cylindrical portion 11, i.e. in the rear surface 3 of the transverse segment 1. In the drive belt 50, the peg 6 of a first transverse segment 1 is received in the hole 7 of an adjacent second transverse segment 1. By this engagement of the peg 6 and the hole 7 of adjacent transverse segments 1, the transverse segments 1 are interlinked and aligned with each other in a row of transverse segments in the drive belt 50, at least in a virtual plane oriented perpendicular to the circumferential direction.

Also in the row of transverse segments 17 in the drive belt 50, at least a portion of the front surface 2 of a first transverse segment 1 abuts at least a portion of the rear surface 3 of an adjacent second transverse segment 1. The adjoining transverse segments 1 can be inclined relative to each other while being held in mutual contact at the convexly curved surface portion 4 of their front surface 3 and by means of the above-mentioned surface portion 4, which surface portion 4 is referred to as inclined edge 4 in the following. Below, i.e. radially inwards from such a tilting edge 4, the transverse segment 1 narrows, as can be seen in the side view of the transverse segment in fig. 2, to allow such a relative tilting without creating interference between the respective base portions 10 of adjacent transverse segments 1 below its tilting edge 4. It should be noted that in the embodiment of the transverse section 1 of fig. 2, the inclined edge 4 consists of two axially separated but radially aligned sections located in the cylindrical portion 11. However, the bevelled edge 4 may also be located partly or completely in the base part 10. Furthermore, although it is shown as a horizontal line in fig. 2, the upper slanted edge 4 has in practice an extension in the radial direction.

As shown in the front view of fig. 2, both, i.e. the left and right cylindrical portions 11 of the transverse section 1 are provided with respective hooks 13 extending in the axial direction over the central opening 5. These hooks 13 thus also partially close the central opening 5 in the radially outward direction to prevent or at least hinder the separation of the transverse segments 1 from the ring set 8 in the radially inward direction. In the shown example of the known drive belt 50, one cylindrical part 11-n of each transverse segment 1 is narrower radially inwards of its respective hook 13 than the other opposite wider cylindrical part 11-b. Furthermore, the drive belt 50 comprises two transverse sections 1 of type i, ii, of which the narrower and wider cylindrical parts 11; 11-n, 11-b are located on opposite axial sides of the transverse section 1 of each type i, ii, respectively. In particular, a transverse section 1 of a first type i is provided on the left side of its main portion 10 with a narrower cylindrical portion 11-n (i.e. as seen in its front view in fig. 2 and defined with respect to this front view), while for a transverse section 1 of a second type ii such a narrower cylindrical portion 11-n is located on the right side of the main portion 10. This particular design feature of its transverse section 1 is known to facilitate the assembly of the drive belt 50.

When assembling the drive belt 50, the two transverse segments 1 of type i, ii are mounted in their particular order on the set of endless elements 8. For example, a sequential, i.e. alternating sequence of two types i, ii of transverse segments 1 can be targeted in the row of transverse segments. According to the disclosure, after the transverse segments 1 have been mounted on the ring group 8, the particular actual sequence of the two transverse segments 1 of type i, ii in a complete row is detected and compared with the desired sequence. In addition, to facilitate detection of each type I, II beamTo the individual segments 1, at least one transverse segment 1 of this type i is provided with a uniquely shaped marking 16 on or belonging to its outer circumferential surface. In fig. 3, three examples 16 of such markings 16 are shown for a first transverse segment type i₁、16₂、16₃. In each of the examples shown thereof, the marking 16 is defined by a projection 16 of the general contour of the outer circumferential surface of the transverse segment 1, through which projection 16 passes₁Or through recesses 16 therein₂、16₃Is used to control the system. Preferably, however, the indicia 16 are recesses 16₂、16₃In order not to increase the weight of the transverse section 1. Likewise, the markings 16 may be selected to partially compensate for the asymmetry of the weight of the transverse section 1 with respect to the axial center of its main body portion 10. For example, at the projection 16₁In the case of (2), the mark 16 is preferably provided on one side of the narrower cylindrical portion 11-n, but in the recess 16₂In this case, the mark 16 is preferably provided on one side of the wider cylindrical portion 11-n.

It should be noted in particular that the transverse section 1 shown in fig. 2 and 3 serves only as an example of a possible design thereof. In fact, the design of the two types i, ii of transverse segments 1 can also be different by the axial extension of the respective left-hand and right-hand hook 13, in which case the additional marking 16 discussed above is not essentially necessary.

FIG. 4 illustrates a first embodiment of a drive belt inspection method according to the present disclosure. FIG. 4 shows a perspective view of the inspector or imaging device looking down on the belt 50 in a radially inward direction. In this example of the drive belt 50, both types I, II of its transverse section 1 are provided with projections 16 in the form of protrusions₁Indicia 16 in the form. In particular, in this embodiment, the markings 16, 16₁Provided on the hook 13 associated with the narrower cylindrical part 11-n of the respective transverse segment type i, ii of all transverse segments 1 of the drive belt 50.

The marking 16 applied to each transverse segment 1 in the drive belt 50 can be easily detected from the inspection position of fig. 4. By making the drive belt 50 rotate completely, a complete row of transverse segments 1 thereof passes the inspection position and the actual sequence of two types i, ii of transverse segments 1 can be reliably detected.

FIG. 5 illustrates a second embodiment of a drive belt inspection method according to the present disclosure. In fig. 5, the assembled drive belt 50 (however, the set of rings 8 is not shown to more clearly show each successive transverse segment 1 thereof) is held by a receiver 22 (which is shown in an exemplary manner as a flat surface 22), the optical camera 20 (or other type of imaging device) being positioned facing the axial side of the drive belt 50 at a distance that enables the camera 20 to take the entire drive belt 50 in a single image. In this example of the drive belt 50, one type i of the two types i, ii of the transverse section 1 thereof is provided with a recess 16 in the cylindrical portion 11 of the transverse section 1 of said one type i₂Indicia 16 in the form. The light source 21 is positioned between the camera 20 and the belt 50 so that the shadow is cast by the indicia 16 which enhances its detectability, whether manually or automatically by, for example, computer image analysis. Preferably, as shown in fig. 5, both the camera 20 and the light source 21 are centrally located with respect to the belt 50. In addition, it is preferable that the shield 23 is provided between the light source 21 and the image pickup device 20. This latter embodiment of the drive belt inspection method is preferred because it can be implemented and executed relatively easily and quickly, especially as compared to the embodiment shown in FIG. 4.

The present disclosure relates to and includes all features of the appended claims, except for all details of the foregoing description and accompanying drawings. Parenthetical reference signs in the claims do not limit their scope, but are provided merely as non-limiting examples of the corresponding features. The claimed features may be applied separately in a given product or a given process or method, as the case may be, but any combination of two or more such features may be applied therein.

The invention represented by the disclosure is not limited to the embodiments and/or examples explicitly mentioned herein, but also includes modifications, variations and practical applications thereof, especially those modifications, variations and practical applications which may occur to those skilled in the relevant art.

Claims

1. A method of checking a drive belt (50) for a continuously variable transmission, which drive belt has a set of rings (8) and has a plurality of transverse segments (1) which are mounted in a row in the circumferential direction of the set of rings (8), in which row at least two transverse segments (1) of a type (i, ii) of mutually different design are included, characterized in that an actual sequence of transverse segment types (i, ii) in the row is detected, which actual sequence is compared with a prescribed sequence.

2. An inspection method according to claim 1, wherein the actual sequence is detected after assembling the drive belt (50) by mounting the transverse segments (1) thereof on the set of endless groups (8) of the drive belt as part of the entire manufacturing process of the drive belt (50).

3. Inspection method according to claim 1 or 2, characterized in that the transverse segment (1) of at least one (I) of the two types (I, II) of transverse segments is provided with markings (16) on or belonging to its outer circumferential surface, the other types (II) of transverse segments (1) of the drive belt (50) being not provided with a specific said marking (16), the specific said marking (16) being used for identifying said at least one type (I) of transverse segment (1) upon detection of the actual sequence of transverse segment types (I, II) in said row.

4. Inspection method according to claim 3, characterized in that the marking (16) is a recess (16) located on the circumferential surface of the transverse segment (1)₂、16₃) Or a projection (16)₁) Preferably having a sidewall oriented at an angle of 45 to 90 degrees relative to an adjacent portion of the circumferential surface.

5. The inspection method according to claim 3 or 4, wherein the marking (16) is applied to a bottom of the transverse segment (1) on a radially inner side of the drive belt (50) or to a side of the transverse segment (1) on an axial side of the drive belt (50).

6. An inspection method according to claim 3, 4 or 5, wherein a transverse segment (1) of the drive belt (50) is provided with a base part (10) and with two cylindrical parts (11) which extend in a radially outward direction from a respective axial side of the base part (10), respectively, wherein the transverse segment (1) of the at least one type (I) is provided with a recess (16) in a portion of its circumferential surface at the cylindrical part (11) facing away from a respective other cylindrical part (11)₂) While the corresponding portion of the circumferential surface at the other cylindrical portion (11) is flat.

7. A device for checking a drive belt (50) for a continuously variable transmission, in particular for carrying out the checking method according to any one of the preceding claims, the drive belt has an endless set (8) of rings and has a plurality of transverse segments (1) which are mounted in a row in the circumferential direction of the endless set (8), in which row at least two transverse segments (1) of type (I, II) of mutually different design are included, characterized in that the device is provided with a receiving member (22) for holding the drive belt (50), an imaging device (20) for taking an image of a part or the whole of the drive belt (50) held by the receiving member, and a microcontroller, the microprocessor or the like is programmed to be able to process images of the conveyor belt (50) taken by the imaging device (20), preferably the device is additionally provided with a light source (21).

8. The inspection device according to claim 7, wherein the image pickup device (20) is located radially inside the transmission belt (50) when held by the receiving member.

9. The inspection device according to claim 7, wherein the imaging device (20) is located on an axial side of the drive belt (50) when held by the receptacle, the light source (21) preferably being located between the imaging device (20) and the drive belt (50), wherein the light shield (23) is arranged between the light source (21) and the imaging device (20).