JP5948600B2 - Metal belt for continuously variable transmission and design method for metal belt for continuously variable transmission - Google Patents

Description

  The present invention relates to a metal belt for a continuously variable transmission and a method for designing a metal belt for a continuously variable transmission.

  Conventionally, a block-type metal belt disclosed in Patent Document 1 below and a metal belt for continuously variable transmission manufactured by a manufacturing method disclosed in Patent Document 2 have been provided. These prior arts are intended to suppress the noise level generated when a metal belt for a continuously variable transmission provided in the past is used in a continuously variable transmission.

  In the prior art disclosed in Patent Documents 1 and 2 below, a number of elements used in the metal belt for continuously variable transmissions are configured with a plurality of types having different thicknesses, thereby attempting to reduce the noise level. ing. Specifically, in the prior art disclosed in Patent Document 1 below, elements having different thicknesses are randomly arranged to form an annular shape. Moreover, in the prior art of the following Patent Document 2, the belt formed in an annular shape is divided into a circumferential first half part and a second half part, and the thickness of the element constituting the first half part and the thickness of the element constituting the second half part are determined. It is supposed to be different.

Japanese Patent No. 2532253 Japanese Patent No. 4557704

  The present inventors examined the noise suppression effect of the prior art metal belts disclosed in Patent Documents 1 and 2 and found that it was a little more than a conventional metal belt in which all elements had the same thickness. It was found that the noise level decreased. However, the metal belt of the prior art has an insufficient effect of suppressing the noise level, and there is a demand for providing a metal belt for continuously variable transmission that has a further noise suppressing effect. There is also a need to provide a design method that can easily and accurately design a metal belt for a continuously variable transmission having a high noise suppression effect.

  Therefore, the present invention has an object to provide a metal belt for continuously variable transmission having a high noise suppressing effect and a method for designing the metal belt for continuously variable transmission.

The metal belt for continuously variable transmission of the present invention provided to solve the above-described problem is a metal for continuously variable transmission formed by arranging a plurality of types of elements having different thicknesses along an endless annular body. a belt, a plurality of the first equal-thickness element group of plate thickness thick the element arranged above the continuously along an endless annular body along the thickness thin the element in the endless annular body There are a plurality of second same-thickness element groups arranged continuously, and each of the first same-thickness element group and the second same-thickness element group is 1% or more with respect to the total length of the endless annular body. der having a length of is, wherein the first equal-thickness element group and the second equal-thickness element groups with different lengths are characterized by being arranged alternately.

As in the present invention, the second arranged the thick element a first thin elements of equal-thickness element group and the plate thickness in continuously along the endless member which is continuously arranged along an endless annular body Each of the same-thickness element groups has a length of 1% or more with respect to the total length of the endless annular body, and the first same-thickness element group and the second same-thickness element group have different lengths. The metal belt for a continuously variable transmission can be provided by dispersing the noise generation peak and reducing the amplitude by alternately arranging them, and suppressing the noise generated in the continuously variable transmission to a minimum. it can.

Moreover, the design method of the metal belt for a continuously variable transmission of the present invention provided to solve the same problem is formed by arranging a plurality of kinds elements of which thickness is different along the endless member, a plate A plurality of first same-thickness element groups in which thick elements are continuously arranged along the endless annular body, and second elements in which thin plate elements are continuously arranged along the endless annular body. has a plurality of thicknesses element group, wherein each of the equal-thickness element group, said to have a 1% or more in length with respect to the entire length of the endless annular body, said first of said second same the same thickness element group A method for designing a metal belt for continuously variable transmission, wherein the thick element groups are alternately arranged with different lengths, and the arrangement of the first same thickness element group and the second same thickness element group Array derivation to derive what is assumed as The noise for deriving the noise generation level when a metal belt for continuously variable transmission having the arrangement is used for a predetermined continuously variable transmission for a part or all of the arrangement derived in the arrangement deriving step. An derivation step and an array of the same thickness element groups of the first same thickness element group and the second same thickness element group corresponding to the lowest noise generation level derived in the noise derivation step are derived. And a sequence selection step to perform.

  According to the method for designing a metal belt for continuously variable transmission according to the present invention, it is possible to easily derive an optimal arrangement of elements having the same thickness for dispersion of noise generation peaks and reduction in amplitude. Become. This makes it possible to easily and accurately design a continuously variable transmission metal belt capable of minimizing noise generated in the continuously variable transmission.

  ADVANTAGE OF THE INVENTION According to this invention, the design method of the metal belt for continuously variable transmission with the high noise suppression effect and the said metal belt for continuously variable transmission can be provided.

(A) is a front view which shows the state which mounted | wore the pulley of the continuously variable transmission with the metal belt for continuously variable transmission which concerns on one Embodiment of this invention, (b) is the metal belt for continuously variable transmission of (a). (C) is a front view which shows the metal belt for continuously variable transmission of (a). (A), (b) is explanatory drawing which shows the concept of the design method at the time of designing the metal belt for continuously variable transmission shown in FIG. 1 from a viewpoint of noise reduction, (c) is an example of the simulation result of a noise generation state It is a graph which shows. (A)-(e) is a graph which shows the simulation result of the noise generation state in the metal belt for continuously variable transmissions concerning a comparative example. (A) is a graph which shows the relationship between the amplitude and appearance frequency of the noise in the metal belt for continuously variable transmission which concerns on this embodiment and a comparative example, (b) is the noise in the metal belt for continuously variable transmission of this embodiment. It is a graph which shows the simulation result of an occurrence state.

  Next, a continuously variable transmission metal belt 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1A, the continuously variable transmission metal belt 10 is used in a state of being wound around two pulleys P1 and P2 constituting the continuously variable transmission. As shown in FIG. 1 (b), the continuously variable transmission metal belt 10 includes a plurality of elements 20 with respect to a hoop 12 (endless annular body) formed by laminating a plurality of metal plates into an annular shape. It is formed by mounting in a state of being connected. The number of the elements 20 constituting the continuously variable transmission metal belt 10 may be any number, but in the present embodiment, about 400 elements 20 constitute the continuously variable transmission metal belt 10.

  The element 20 is composed of a steel plate. As shown in FIG. 1B, the element 20 includes a body portion 22 that contacts the pulleys P1 and P2 of the continuously variable transmission, and a head portion 26 connected to the body portion 22 via a pillar portion 24. Have Saddle portions 28 for receiving the hoops 12 are formed on both sides of the pillar portion 24 and between the body portion 22 and the head portion 26.

  In the present embodiment, as the element 20, a plurality of types having different plate thicknesses are used. Specifically, as shown in FIG. 1C by distinguishing the presence / absence of hatching, two types of elements 20 are used, one having a thick plate and the other having a thin plate. The thickness t of the element 20 may be anything, but the thickness t of the thick element 20 (hereinafter also referred to as “element 20a”) is 1.5 [mm]. The thin element 20 (hereinafter also referred to as “element 20b”) has a thickness t of 1.4 [mm]. Further, the elements 20a and 20b are the same except for the structure except for the thickness t.

The continuously variable transmission metal belt 10 is characterized by the arrangement structure of the elements 20a and 20b described above. Specifically, the continuously variable transmission metal belt 10 includes a plurality of elements 30 having the same thickness in which the elements 20 (20 a, 20 b) having the same thickness t are continuously arranged along the hoop 12. That is, the same-thickness element group 30 (hereinafter also referred to as “same-thickness element group 30a”) configured by continuously disposing the thick plate elements 20a and the thin plate element 20b are continuously disposed. The metal belt 10 for a continuously variable transmission is configured by the same thickness element group 30 (hereinafter, also referred to as “same thickness element group 30b”) configured as described above. The same-thickness element groups 30a and 30b have different lengths and are arranged alternately in the circumferential direction of the continuously variable transmission metal belt 10.

  Further, the same thickness element group 30a, 30b described above has a length of 1% or more with respect to the entire length of the hoop 12. In other words, each same-thickness element group 30a, 30b is configured by continuously arranging at least five elements 20a, 20b. Therefore, the continuously variable transmission metal belt 10 does not change the plate thickness t of the elements 20 (20a, 20b) in a short cycle one after another in the circumferential direction of the hoop 12 as in the prior art. It changes at a cycle.

  Next, a design method for designing the continuously variable transmission metal belt 10 from the viewpoint of noise reduction will be described in detail with reference to the drawings. When the continuously variable transmission metal belt 10 is operated by being wound between the pulleys P1 and P2 of the continuously variable transmission, the element 20 enters the pulleys P1 and P2 and is detached from the pulleys P1 and P2. Due to the collision, vibration noise is generated. This noise corresponds to the frequency at which the element 20 passes a predetermined point.

  Under such knowledge, as shown in FIG. 2A, the shock wave generated when the element 20 collides with the pulleys P1 and P2 can be equated with a sine wave, and according to the change in the thickness t of the element 20 Assuming that the wavelength of the sine wave changes, the position and magnitude of the peak frequency for noise generated in the metal belt 10 for continuously variable transmission can be determined by performing analysis by Fourier analysis (FFT). It can be derived as shown in FIG. Therefore, the arrangement of the same thickness element groups 30a and 30b that minimizes noise when used in a continuously variable transmission can be derived by the following design procedure.

<Design procedure of metal belt 10 for continuously variable transmission>
The continuously variable transmission metal belt 10 can be designed from the viewpoint of noise reduction by executing an array derivation process, a noise derivation process, and an array selection process. The design of the continuously variable transmission metal belt 10 can be performed using a computer in which a design program for executing the above-described steps is installed.

  The arrangement deriving step is a step of deriving what is assumed as the arrangement of the same thickness element groups 30a and 30b. In this step, it is desirable to execute the array derivation process under the setting that the element groups 30a and 30b having the same thickness include at least n elements 20a and 20b (an integer equal to or greater than 5). By carrying out the arrangement deriving step in this way, variations in the arrangement of the same-thickness element groups 30a and 30b and the quantity of the elements 20a and 20b constituting each of the same-thickness element groups 30a and 30b are derived.

  The noise deriving step generates noise when the continuously variable transmission metal belt 10 having this arrangement is used in a predetermined continuously variable transmission with respect to the arrangement of the same thickness element groups 30a and 30b derived in the arrangement deriving step. This is a process of deriving a level. In the noise derivation process, the noise generation level may be derived for all of the arrays derived in the array derivation process, but only some of the arrays are excluded, such as excluding arrays that are clearly assumed to be high in noise. The generation level of noise may be derived.

The noise derivation step is executed in accordance with the assumptions and derivation methods described in (1) to (3) below.
(1) The noise generated in the continuously variable transmission metal belt 10 is assumed to be vibration generated by a collision with the pulleys P1 and P2, and the vibration waveform is assumed to be a sine wave having an amplitude of 1 (see FIG. 2A). ).
(2) It is assumed that the wavelength of the sine wave assumed in the above (1) corresponds to the thickness t of the elements 20a and 20b. That is, it is assumed that the wavelength of the sine wave that makes noise changes depending on the thickness t of the elements 20a and 20b (see FIG. 2B).
(3) In accordance with the arrangement of the same-thickness element groups 30a and 30b derived in the arrangement deriving step, sine waves having wavelengths corresponding to the thickness t of the elements 20a and 20b are arranged in a line. As a result, a waveform (noise waveform) corresponding to noise generated when the continuously variable transmission metal belt 10 is made to make one round is formed (see FIG. 2B).
(4) A Fourier analysis (FFT) is performed on the noise waveform corresponding to one round of the continuously variable transmission metal belt 10 derived in (3) (see FIG. 2C).

  When the noise derivation process is executed as described above, the noise generated when the continuously variable transmission metal belt 10 makes a round between the pulleys P1 and P2 is derived as a relationship between the order and the amplitude. Here, the order is the ratio of the frequency of noise generated with respect to the input rotational speed. More specifically, assuming that the thickness t of all the elements 20 is the same, when the metal belt 10 for continuously variable transmission is rotated once between the pulleys P1 and P2, the element 20 is compared with the pulleys P1 and P2. When the impact sound (noise) for n times is generated by the collision, the order is n-th order. In the present embodiment, as the element 20, two types (elements 20a and 20b) having different thicknesses t are used. Therefore, when the overall length of the continuously variable transmission metal belt 10 is L and the thicknesses of the elements 20a and 20b are A and B, respectively, the impact sound that is outstanding in the L / A and L / B orders. (Noise) may occur.

  Subsequently, an example of a result obtained by the noise derivation process described above will be described. First, the continuously variable transmission metal belts 100 to 104, which are comparative examples of the continuously variable transmission metal belt 10 of the present embodiment, will be described. When the noise generation state is simulated by the noise derivation process for the continuously variable transmission metal belts 100 to 104, the results shown in FIGS. 3A to 3E are obtained.

  Specifically, the continuously variable transmission metal belt 100 is composed of all elements 20 having the same thickness t, that is, all elements 20 composed of only one of the elements 20a and 20b. is there. When a noise generation simulation by the noise derivation process is executed for the continuously variable transmission metal belt 100, a steep peak as shown in FIG. In the case of the continuously variable transmission metal belt 101 in which the elements 20a and 20b having different thicknesses t are alternately arranged, a peak appears at a predetermined order position as shown in FIG. In this state, it is assumed that a large noise is generated at a substantially constant period.

  Further, the continuously variable transmission metal belt 102 is configured such that the first half of the circumferential direction is configured by only one of the elements 20a and 20b and the second half is configured by only the other of the elements 20a and 20b. In this case, when a noise generation simulation by the noise derivation process is executed, two peaks appear as shown in FIG. Since the height (amplitude) of each peak is lower than that of the continuously variable transmission metal belts 100 and 101 of FIGS. 3A and 3B, noise generated at each order position is low. However, two noises are generated while the continuously variable transmission metal belt 102 makes one round, which is not a preferable noise generation state.

  The continuously variable transmission metal belt 103 is formed by randomly arranging elements 20a and 20b having different thicknesses t as exemplified in the prior art. When a noise generation simulation by the noise derivation process is executed for this, a result that a noise generation state as shown in FIG. 3D is obtained is obtained. In this case, as in the case shown in FIGS. 3 (a) and 3 (b), a steep peak appears and the noise becomes conspicuous. Further, the continuously variable transmission metal belt 104 is obtained by changing the blending ratio of the elements 20a and 20b between the first half and the second half in the circumferential direction as in the above-described prior art. When a noise generation simulation by the noise derivation process is executed, two peaks appear as shown in FIG. The noise generation state shown in FIG. 3 (e) is the same as that shown in FIG. 3 (c) described above and cannot be said to be a preferable noise generation state.

  On the other hand, when a simulation is performed on the relationship between the order of noise and the amplitude when the elements 20a and 20b are arranged in an arrangement corresponding to the continuously variable transmission metal belt 10 shown in the present embodiment, FIG. The result shown in is obtained. As described above, in the continuously variable transmission metal belt 10, noise generated when the continuously variable transmission is driven does not have a peak characteristic (periodicity), and the amplitude thereof is small.

  When the simulation of the noise generation state is completed when the elements 20a and 20b (the same thickness element groups 30a and 30b) are variously changed in the noise derivation process as described above, the program for designing the metal belt 10 for continuously variable transmission is completed. Thus, the sequence selection process is performed. The array selection step is a step of deriving an array of the same-thickness element groups 30a and 30b corresponding to the lowest noise generation level derived in the noise deriving step. More specifically, the arrangement of the same-thickness element groups 30a and 30b having no peak and no amplitude in the noise assumed to be generated when the continuously variable transmission is driven is that of the metal belt 10 for the continuously variable transmission. Selected as

  The continuously variable transmission metal belt 10 created by deriving and selecting the optimum arrangement of the same thickness element groups 30a and 30b as described above was rotated between the pulleys P1 and P2 of the continuously variable transmission. Regarding the noise in the case, the relationship between the amplitude and noise level (noise level) and the occurrence frequency was examined, and the result shown in FIG. 4A was obtained. 4A, when compared with the results of the above-described comparative example continuously variable transmission metal belts 103 and 104, the continuously variable transmission metal belt 10 has an amplitude and Both noise levels are reduced. Therefore, like the metal belt 10 for continuously variable transmission, the same-thickness element groups 30a and 30b having a length of 1% or more with respect to the entire length of the hoop 12 are optimally derived in accordance with the design procedure described above. By arranging in an array, it is possible to achieve dispersion of noise generation peaks and reduction in amplitude.

  In addition, according to the above-described design method of the continuously variable transmission metal belt 10, it is possible to easily derive an optimal arrangement of elements having the same thickness in order to disperse noise generation peaks and reduce the amplitude. it can. As a result, the continuously variable transmission metal belt 10 capable of minimizing noise generated in the continuously variable transmission can be easily and accurately designed, and the effort and cost required for the design can be minimized. .

  The metal belt for continuously variable transmission of the present invention can be suitably used in a vehicle equipped with a CVT.

10 Metal belt for continuously variable transmission 12 Hoop 20 Element 30 Same thickness element group P1, P2 Pulley

Claims (2)

A metal belt for continuously variable transmission formed by arranging a plurality of types of elements having different thicknesses along an endless annular body,
A plurality of first same-thickness element groups in which the thick elements are continuously arranged along the endless annular body;
A plurality of second same-thickness element groups in which the thin elements are continuously arranged along the endless annular body;
Wherein the first respective same thicknesses element group and the second equal-thickness element group of state, and are not having more than 1% of the length over the full length of the endless annular body,
The metal belt for continuously variable transmission, wherein the first same-thickness element group and the second same-thickness element group are alternately arranged with different lengths . A plurality of first same-thickness element groups formed by arranging a plurality of types of elements having different thicknesses along an endless annular body and continuously arranging the elements having a large plate thickness along the endless annular body. A plurality of second same-thickness element groups in which the elements having a thin plate thickness are continuously arranged along the endless annular body, the first same-thickness element group and the second same-thickness element alternating each group is the so have a 1% or more in length with respect to the entire length of the endless annular body, varies the first equal-thickness element group and the second equal-thickness element group and the length A method for designing a metal belt for a continuously variable transmission arranged in
An array derivation step for deriving what is assumed as an array of the first same-thickness element group and the second same-thickness element group ;
A noise deriving step for deriving a noise generation level when a metal belt for continuously variable transmission having the arrangement is used for a predetermined continuously variable transmission for a part or all of the arrangement derived in the arrangement deriving step; ,
An array selection step of deriving an array of the first same-thickness element group and the second same-thickness element group corresponding to the lowest noise generation level derived in the noise derivation step. A method for designing a metal belt for a continuously variable transmission.