JP4736366B2 - Endless belt manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing an endless belt for transmission used in a belt-type continuously variable transmission, and more particularly to a technology for manufacturing an endless belt with improved silence.

  One type of continuously variable transmission (CVT) is a belt-type continuously variable transmission that transmits torque by winding an endless belt between two pulleys arranged in parallel shafts. In a continuously variable transmission using an endless belt, the position where the endless belt winds around the pulley wall surface from the center of the rotating shaft by changing the distance between the conical wall surfaces of a pair of pulleys (primary pulley and secondary pulley) on the parallel rotating shaft Speed change (change in the rotation ratio between the primary pulley and the secondary pulley) is realized by changing the distance up to (that is, the radius of rotation when the endless belt is wound around the pulley, hereinafter referred to as pitch circle radius). For example, if the pitch circle radius on the primary side is reduced and the pitch circle radius on the secondary side is increased, the gear ratio becomes the deceleration side. Conversely, if the pitch circle radius on the primary side is increased and the pitch circle radius on the secondary side is reduced, the gear ratio is Increase speed side. As a result, torque is transmitted from the primary pulley to the endless belt on the driving side and from the endless belt to the secondary pulley on the driven side at a position where the endless belt wraps around the pulley wall surface.

  There are various types of belt-type continuously variable transmissions of this type. One of them is a joint pin of a link constituting an endless belt, which is used as an engaging means with a pulley. There is a type in which the belt travels and torque is transmitted by intermittently contacting the pulley wall surface.

  As described above, in the type in which the pin contacts the pulley and transmits torque, noise is generated by vibration due to the impact of the contact each time the pin contacts the pulley. It is known that the noise has a peak in the frequency corresponding to the period in which the pin contacts the pulley (the reciprocal of the period) and the harmonic frequency. This is thought to be due to the fact that the periodic impact on the pulley due to the contact of the pin becomes a vibration source, and the pulley and the belt itself vibrate.

  Therefore, a technique for arranging pins of different lengths on a belt at random (pin random) is known in the past as a countermeasure against vibration. Further, the length of the pair of pins formed by the two pins is made the same, and a pair of pins having different lengths in one pair and another pair of pins (in this case, all the pins come into contact with the pulley), and these are not used. A technique of regularly arranging on a belt is also known. By arranging pins with different lengths for each group as in this technique, noise can be reduced by shifting the tamming in which the pins are engaged with the pulleys.

As another technology, the length of the pair of pins is different (the longer one is called a torque transmission pin and the shorter one is called a strip pin). There is a technique in which only a long torque transmission pin is brought into contact with a pulley to transmit torque (see Patent Document 1).
Japanese Patent Laid-Open No. 8-31725

  In the above-mentioned conventional technology, in the case of a pair of pins having the same length, since all the pins are in contact with the pulley, at the time of production, the same length pins are extracted as a pair from different length pins. It is necessary to assemble (pin sorting work is required). Also, the pair of pins must be approximately equal in length. In general, the type in which a pair of pins come into contact with a pulley needs to align the length of a pair of pins to several μm or less, and when one pair of pins and another pair of pins have different lengths (pin random However, even if the difference between the lengths of a pair of pins can be several tens of μm, the difference in the lengths of all pairs of pins needs to be several μm or less. Therefore, it is necessary to strictly manage the dimensional tolerance, such as installing equipment with high machining accuracy capability or sorting and aligning two pins with a length difference of several μm or less by pin sorting. .

  In addition, when assembling torque transmission pins having different lengths based on the technique described in Patent Document 1, it is necessary to mix long and short pins at a predetermined ratio with respect to one belt. A step of counting the number of torque transmission pins for each belt, that is, counting the necessary number of torque transmission pins for each belt and preparing the belt after assembling the belt, is required. In addition, a management process is required in which a necessary number of long and short torque transmission pins are sorted for each belt.

  In view of the problems of the prior art as described above, the present invention eliminates the need for high-performance equipment with high processing accuracy and pin counting and sorting, thereby improving the productivity of the endless belt for transmission, The main object is to provide an endless belt manufacturing method capable of reducing belt noise.

In the present invention, a number of link plates are connected to each other by a pair of two pins, a torque transmission pin that transmits torque by bringing one end of the pair of pins into contact with a pulley, and a pair of pins In the endless belt manufacturing method for manufacturing an endless belt that uses a strip pin that does not contact the pulley with the other end, the torque transmission pin is the same with a dimensional tolerance coarser than that of a pin of a type in which a pair of pins contact the pulley. The manufacturing process includes a step of manufacturing as a pin having a different length, and a step of inserting the manufactured torque transmission pin into the insertion hole of the link plate.
More specifically, the dimensional tolerance is between several tens of μm to several hundreds of μm.
In any of the above cases, the link plate may be composed of at least two types of link plates having different lengths (pitch lengths) between connecting portions by the pair of pins.

According to the configuration of the present invention, the dimensional tolerance management of the pin can be facilitated by greatly reducing the dimensional tolerance of the torque transmission pin. In addition, endless belts having different torque transmission pin lengths can be manufactured by utilizing the dimensional tolerance variation. By providing a torque transmission pin with a dimensional tolerance of several tens to several hundreds of μm on the endless belt, the period when the torque transmission pin sequentially contacts (engages) the pulley due to the difference in length is slightly shifted. Can do. Thereby, the period when a torque transmission pin contacts a pulley can be distributed. Therefore, it is possible to reduce noise having a peak at a frequency (reciprocal of the cycle) corresponding to this cycle, which occurs when the torque transmission pin is engaged with the pulley at a constant cycle. Therefore, in the present invention, an endless belt excellent in silence can be easily manufactured by increasing the dimensional tolerance of the torque transmission pin.
In addition, when the link plate is composed of at least two types of link plates having different lengths between the connecting portions by a pair of pins, an endless belt having pins having different lengths in addition to noise reduction by a plurality of pitch lengths. Thus, an endless belt excellent in silence can be efficiently manufactured.

  The present invention is an endless belt having a torque transmission pin that makes a pair of pins contact with a pulley and a strip pin that does not make contact with the pulley, wherein the pulley torque is transmitted from the torque transmission pin to the link plate via the strip pin. It is particularly effective when applied to. By applying to this type, when the endless belt is wound around the pulley, the relative rotation of the link plate connected to the link plate that is engaged with the pin that previously contacts the pulley is not restricted. Thus, the belt vibration can be substantially reduced, so that the effect of the application of the present invention can be exhibited more effectively. In this type of endless belt, one pin (strip pin) of a pair of pins is short enough not to contact the pulley, so a torque transmission pin with a large dimensional tolerance can be used as a strip pin without taking into account variations in its length. The endless belt can be assembled as a pair, and the manufacturing process of the endless belt with reduced noise due to belt vibration can be facilitated.

  1 and 2 show an endless belt according to application of the first embodiment. 1 shows a partial side surface of the belt, and FIG. 2 shows a belt plane viewed from the circumferential direction. The endless belt 1 has a number of link plates 2 endlessly formed by two pairs of pins 31 and 32. It consists of a chain belt connected to In this example, the pins 31 and 32 are engaged with the adjacent link plates 2 so as not to rotate relative to each other, and are capable of rolling with each other. As shown in FIG. 2, even if the pin 31 contacts the pulley, the pin 32 is shorter than the pin 31 to the extent that it does not contact the pulley. Here, the pin 31 that contacts the pulley is called a torque transmission pin, and the pin 32 is called a strip pin. The pin length means the length in the vertical direction of the pins 32 and 31 in FIG.

  A pair of pins 31 and 32 in the endless belt is sequentially bitten between conical surfaces as opposed wall surfaces of the pulley by winding the belt 1 around the pulley (not shown) as a torque transmission pin. Torque is transmitted between the pulley and the endless belt 1. That is, in this example, as shown in the left side of FIG. 1, the state where the pulley is engaged with the pulley, the torque transmission pin 31 a immediately after the endless belt 1 traveling in the direction indicated by the arrow in FIG. While the link plate 2a is fixed to the pulley, the pin 32a paired with the torque transmission pin 31a is not constrained to rotate by not contacting the pulley. The link plate 2b locked to 32a is in a freely rotatable state. This relationship holds for all subsequent pins and link plates. Since the link plate before being wound around the pulley is free as described above, the vertical vibration of the belt (vibration in the inner and outer circumferential directions of the annular belt) is reduced.

  On the premise of the belt configuration described above, the present invention is applied to the manufacture of at least one of the pair of pins 31 and 32, that is, the torque transmission pin 31, and the incorporation into the link plate 2. First, in order to manufacture the torque transmission pin 31 as a pin having a different length, in this embodiment, the torque transmission pin 31 is manufactured by a common manufacturing process with a rough dimensional tolerance.

  FIG. 3 shows the relationship between the manufacturing tolerance of a conventional pin (denoted as a normal dimensional tolerance in the figure) and the manufacturing tolerance of a pin according to this embodiment (denoted as a dimensional tolerance in the present invention in the figure). In the figure, the vertical line in the center indicates the dimensional design value of the pin length. In general, for a type in which a pair of pins is in contact with a pulley, it is necessary to align the length of the pair of pins to several μm or less with respect to the dimension design value. Even when different (in the case of random pins), even if the difference between the lengths of a pair of pins can be several tens of μm, the difference in the lengths of all pairs of pins is several μm. Because it is necessary to make the following, it is necessary to introduce equipment with high processing accuracy capability, or to sort and align two pins with a length difference of several μm or less by pin sorting work. It is necessary to manage strictly. On the other hand, in the present embodiment, a manufacturing method is adopted in which a dimensional tolerance is about several tens to several hundreds μm, which is much larger than a normal dimensional tolerance.

  If the dimensional tolerance exceeds several hundred μm, the variation in the contact timing (pin contact cycle) when the torque transmission pins are sequentially engaged with the pulley due to the variation in the length of the pins becomes too large. If the pin contact cycle is too large, the previous torque transmission pin will move in the circumferential direction of the pulley as the pulley rotates from when one torque transmission pin is engaged until the next torque transmission pin is engaged. growing. As a result, the vibration of the belt in the radial direction of the pulley increases, and the noise reduction effect is reduced. When the dimensional tolerance is less than several tens of μm, the timing of meshing with the pulley does not change so much, and the meshing occurs with a substantially constant period, and noise having a peak at a frequency corresponding to this period is generated. The effect will be reduced.

  Since the pins obtained by the above manufacturing method are different in length to the extent that they cannot be regarded as the same length, without considering the difference in the length of the pins from the container in which those pins are stored. The extracted pin is inserted into the insertion hole of the link plate as a torque transmission pin (without requiring a pin management process based on the difference in length). This process completes an endless belt with different torque transmission pin lengths.

  In the case of this embodiment, more specifically, one of a pair of two pins, that is, only the torque transmission pin is manufactured by the above method, and combined with a strip pin of a fixed length that is separately manufactured shorter than the shortest torque transmission pin. It is intended to be assembled into a pair of pins and inserted into the insertion holes of the link plate.

  In addition, when assuming application of the present invention to an endless belt of a type in which two pins having the same cross-sectional shape form a pair and the pair of pins are in contact with the pulley, particularly distinguish between the torque transmission pin and the strip pin. Alternatively, it is possible to adopt a manufacturing method in which the pins are manufactured in a single manufacturing process, and the pins taken out without considering the difference in pin length are incorporated into the link plate as a pair. In this case, when the endless belt is wound around the pulley, the longer pin of the pair of combined pins is engaged with the pulley as a power transmission pin. And since the belt width direction lengths of the pins are not uniform for each pin, the power transmission pin is not caught in the pulley at a constant cycle, and an endless belt excellent in silence is realized.

  According to the first embodiment, it is possible to easily manage the dimensional tolerance in manufacturing the pin by greatly reducing the dimensional tolerance of the torque transmission pin. In addition, it is possible to manufacture pinless endless belts that randomly include pins that differ in length to the extent that noise reduction effect can be achieved by utilizing variation in dimensional tolerances, making it easy to make endless belts with excellent silence. Can be manufactured.

  FIG. 4 is a flowchart showing a specific belt manufacturing process in this embodiment. As shown in the drawing, the link plate, the torque transmission pin, and the strip pin as the components of the endless belt are manufactured in separate process steps S1 to S3, respectively.

  Among the manufactured parts, the link plate is prepared as it is in the belt assembly line as shown in step S11. Similarly, strip pins are also prepared in the assembly line as shown in step S13. Similarly to these, torque transmission pins are prepared by being housed in one container in the belt assembly line as shown in step S12. As a result, in the container, torque transmission pins which are longer than the strip pins but have different lengths are mixed.

  Next, as shown in step S21, the number of torque transmission pins required for one endless belt is extracted from the container without considering the difference in pin length. Similarly, as shown in step S22, the required number of strip pins for one endless belt is extracted from another container. The extraction in these steps does not require counting. Finally, in step 31, the torque transmission pin and the strip pin are paired and inserted into the insertion hole of the link plate.

  According to the first embodiment, in the process of manufacturing an endless belt, it is possible to omit the step of counting and preparing pins having different lengths necessary for each belt, and productivity is improved. Note that, depending on the structure of the manufacturing facility, the torque transmission pin and the strip pin may be individually inserted into the insertion holes of the link plate.

  In addition, since all the strip pins in Example 1 have the same length and shape, it is not necessary to manage the number for each belt, and when the belt is assembled, the torque transmission pins mixed in long and short lengths are accommodated. The torque transmission pin and strip extracted from the container may be combined and inserted into the link plate.

  Example 1 described above is to manufacture an endless belt that randomly includes pins having different lengths so as to achieve a noise reduction effect by making the lengths of the pins in the belt width direction different. Furthermore, the noise reduction effect can be further improved by making the length between the connecting portions by the pair of pins of the link plate different (referred to as link random).

  According to the second embodiment, noise is distributed with respect to the basic pitch length by link random, and further fine noise is distributed by pin random. In addition to the quietness, an endless belt having different lengths of pins can efficiently produce an endless belt with excellent quietness.

  In the third embodiment, two types of torque transmission pin lengths as design values are manufactured and assembled with increased dimensional tolerances. As shown in FIG. 5, two types of torque transmission pins having significant design dimensional differences as design values 1 and 2 are manufactured with large dimensional tolerances. Then, torque transmission pins having two dimensional design values are mixed at a predetermined ratio. A set of the mixed torque transmission pins is prepared in the assembly line in step S12 of FIG. Thereafter, the belt is assembled in the same manner as in the step of FIG. In FIG. 5, the torque transmission pin with a short design value is shown so that the intersecting ranges do not overlap each other for the long torque transmitting pins, but this does not prevent the intersecting ranges from overlapping each other.

  According to this embodiment, two types of torque transmission pins having different design dimension values are arranged on the endless belt with a predetermined ratio of torque transmission pins having a large dimensional tolerance (several tens to hundreds of μm). It becomes. In addition to randomness due to differences in dimensional design values, randomness of torque transmission pins due to large dimensional tolerances is added, and noise dispersion is achieved by having more complicated randomness, resulting in superior quietness. The belt can be easily manufactured.

It is a partial side view which shows the connection structure of the endless belt which concerns on application of this invention. It is the fragmentary top view which looked at the same endless belt from the peripheral surface direction. It is a figure explaining the tolerance of the torque transmission pin of the endless belt which concerns on Example 1. FIG. 3 is a flowchart showing a manufacturing process of Example 1. It is a figure explaining the tolerance of the torque transmission pin of the endless belt which concerns on Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endless belt 2 Link plate 21 Insertion hole 31 Torque transmission pin 32 Strip pin

Claims (3)

A large number of link plates are connected to each other by a pair of two pins, and both ends of one of the pair of pins are brought into contact with the pulley to form a torque transmission pin and the other of the pair of pins is a pulley. In an endless belt manufacturing method for manufacturing an endless belt as a strip pin that is not brought into contact with
Manufacturing the torque transmission pin as a pin having a different length by the same manufacturing process in which a dimensional tolerance is rougher than a dimensional tolerance of a pin of a type in which a pair of pins are in contact with a pulley ;
Inserting the manufactured torque transmission pin into the insertion hole of the link plate;
A process for producing an endless belt, comprising:   2. The method of manufacturing an endless belt according to claim 1, wherein the dimensional tolerance is between several tens of micrometers and several hundreds of micrometers.   3. The method of manufacturing an endless belt according to claim 1, wherein the link plate is composed of at least two types of link plates having different lengths between connecting portions by the pair of pins.

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