Continuously variable transmission

Abstract

To secure minimum traveling performance by preventing a chain from being cut off.SOLUTION: A continuously variable transmission has a chain which is looped over a primary pully and a secondary pulley and which is made of a plurality of elements. The plurality of elements include a first element having a first engagement part, and a second element having a second engagement part. In a normal state of the chain in which none of the plurality of elements is broken, the first and second engagement parts are separated from each other. In an abnormal state of the chain in which any of the plurality of elements is broken, the first and second engagement parts are brought into contact with each other.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a continuously variable transmission.

Background Art

[0002] A continuously variable transmission has a primary pulley provided on an input shaft and a secondary pulley provided on an output shaft. The continuously variable transmission also has a chain or belt wound around the primary pulley and the secondary pulley (see Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, although the chain of the continuously variable transmission has sufficient strength, if the chain breaks by any chance, the vehicle cannot run. Therefore, even when any of a plurality of elements constituting the chain breaks, it is required to prevent the chain from breaking and ensure the minimum running performance.

Means for Solving the Problems

[0005] According to the present disclosure, a continuously variable transmission has a primary pulley provided on an input shaft and a secondary pulley provided on an output shaft. The continuously variable transmission has a chain composed of a plurality of elements wound around the primary pulley and the secondary pulley. The plurality of elements includes a first element having a first engagement portion and a second element having a second engagement portion. In a normal state of the chain in which none of the plurality of elements is broken, the first engagement portion and the second engagement portion are separated from each other. In an abnormal state of the chain in which any one of the plurality of elements is broken, the first engagement portion and the second engagement portion are in contact with each other.

Advantages of the Invention

[0006] According to the present disclosure, in an abnormal state of a chain in which any one of a plurality of elements is broken, the first engagement portion of the first element and the second engagement portion of the second element are in contact with each other. Thereby, chain breakage can be prevented, and minimum running performance can be ensured.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Figure 13

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or substantially the same configurations and elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0009] <Embodiment 1> <Power Unit> FIG. 1 is a view showing an example of a vehicle 11 equipped with a continuously variable transmission 10 according to an embodiment of the present disclosure. As shown in FIG. 1, the vehicle 11 has a power unit 15 including an engine 12, a torque converter 13, a forward and reverse switching mechanism 14, and a continuously variable transmission 10. A rear wheel output shaft 16 of the power unit 15 is connected to a wheel 19 via a propeller shaft 17 and a differential mechanism 18. Note that the illustrated power unit 15 is a power unit for rear-wheel drive, but is not limited thereto, and may be a power unit for all-wheel drive or front-wheel drive.

[0010] FIG. 2 is a diagram showing an example of the power unit 15 and the control system 20. As shown in FIG. 2, the engine 12 has a throttle valve 21, an injector 22, etc. In order to control the throttle valve 21 and the injector 22, an engine control unit 23 is connected to the throttle valve 21 and the injector 22. Further, in order to control the continuously variable transmission 10, the forward and reverse switching mechanism 14, etc., the power unit 15 has a valve body 24 composed of an electromagnetic valve or the like. An oil pump 25 is connected to the valve body 24, and the hydraulic oil pumped from the oil pump 25 is supplied to the continuously variable transmission 10 etc. via the valve body 24. Also, in order to control the continuously variable transmission 10 etc. via the valve body 24, a transmission control unit 26 is connected to the valve body 24.

[0011] <Continuously variable transmission> FIG. 3 is a diagram showing the continuously variable transmission 10. In FIG. 3, the continuously variable transmission 10 shown in FIG. 2 is shown with its orientation changed. As shown in FIG. 3, the continuously variable transmission 10 has a primary pulley 40 provided on the primary shaft (input shaft) 31, a secondary pulley 50 provided on the secondary shaft (output shaft) 32, and a chain 60 wound around the primary pulley 40 and the secondary pulley 50. As shown in FIG. 2, the engine 12 is connected to the primary shaft 31 via the forward and reverse switching mechanism 14 and the torque converter 13. Also, the wheels 19 are connected to the secondary shaft 32 via the rear wheel output shaft 16, the propeller shaft 17, and the differential mechanism 18. The forward and reverse switching mechanism 14 for switching the rotation direction of the primary pulley 40 is composed of a forward clutch, a reverse brake, a planetary gear train, etc. not shown.

[0012] As shown in FIG. 3, the primary pulley 40 has a fixed sheave 41 fixed to the primary shaft 31 and a movable sheave 42 attached to be axially movable with respect to the primary shaft 31. Further, the secondary pulley 50 has a fixed sheave 51 fixed to the secondary shaft 32 and a movable sheave 52 attached to be axially movable with respect to the secondary shaft 32. The movable sheave 42 is attached to the primary shaft 31 via a ball spline, and the movable sheave 52 is attached to the secondary shaft 32 via a ball spline.

[0013] On the back side of the movable sheave 42, a drum 43 fixed to the primary shaft 31 is arranged. A primary oil chamber 44 is partitioned between the drum 43 and the movable sheave 42, and the valve body 24 is connected to the primary oil chamber 44 via an oil passage 45 in the primary shaft 31. Also, on the back side of the movable sheave 52, a disk 53 fixed to the secondary shaft 32 is arranged. A secondary oil chamber 54 is partitioned between the disk 53 and the movable sheave 52, and the valve body 24 is connected to the secondary oil chamber 54 via an oil passage 55 in the secondary shaft 32. By regulating the hydraulic oil supplied to the primary oil chamber 44 and the secondary oil chamber 54 by the valve body 24, the two movable sheaves 42, 52 can be moved to control the groove width of the pulleys 40, 50.

[0014] That is, by widening the groove width of the primary pulley 40, the winding diameter of the chain 60 around the primary pulley 40 is reduced, and the winding diameter of the chain 60 around the secondary pulley 50 is increased. Thereby, the transmission ratio of the continuously variable transmission 10 can be controlled to the low side. On the other hand, by narrowing the groove width of the primary pulley 40, the winding diameter of the chain 60 around the primary pulley 40 is increased, and the winding diameter of the chain 60 around the secondary pulley 50 is reduced. Thereby, the transmission ratio of the continuously variable transmission 10 can be controlled to the high side. In this way, by controlling the groove widths of both pulleys 40 and 50 to change the winding diameter of the chain 60, the transmission ratio of the continuously variable transmission 10 can be steplessly controlled.

[0015] The illustrated mission control unit 26 can control the primary pressure of the hydraulic oil supplied to the primary oil chamber 44 and the secondary pressure of the hydraulic oil supplied to the secondary oil chamber according to the following procedure example. The mission control unit 26 calculates a target transmission ratio R1 based on the vehicle speed and the accelerator opening, and calculates a hydraulic pressure ratio (Pp / Ps) between the target primary pressure Pp and the target secondary pressure Ps corresponding to the target transmission ratio R1. Further, the mission control unit 26 calculates a target primary pressure Pp for controlling the pulley groove width toward the target transmission ratio R1 by multiplying the target secondary pressure Ps by the hydraulic pressure ratio (Pp / Ps). Note that the mission control unit 26 calculates a target secondary pressure Ps for generating a clamping force corresponding to the transmission torque of the chain 60 based on the input torque to the primary shaft 31 and the target transmission ratio R1.

[0016] <Control System> As shown in FIG. 2, the vehicle 11 has a control system 20 composed of a plurality of electronic control units in order to control the power unit 15. The vehicle 11 has the engine control unit 23 and the transmission control unit 26 described above as the electronic control units constituting the control system 20, and also has a vehicle control unit 70 that outputs control signals to the control units 23 and 26. These control units 23, 26, and 70 are communicably connected to each other via an in-vehicle network 71. The vehicle control unit 70 sets operation targets for the engine 12, the continuously variable transmission 10, etc. based on input information from various control units 23, 26 and various sensors described later. Further, the vehicle control unit 70 generates control signals corresponding to the operation targets of the engine 12, the continuously variable transmission 10, etc., and outputs these control signals to the engine control unit 23 and the transmission control unit 26.

[0017] Connected to the vehicle control unit 70 are a vehicle speed sensor 72 that detects the vehicle speed, which is the traveling speed of the vehicle 11, an accelerator sensor 73 that detects the accelerator opening, which is the operation amount of the accelerator pedal, and a brake sensor 74 that detects the operation state of the brake pedal. Also connected to the vehicle control unit 70 are a primary rotation sensor 75 that detects the primary rotation speed Np, which is the rotation speed of the primary pulley 40, and a secondary rotation sensor 76 that detects the secondary rotation speed Ns, which is the rotation speed of the secondary pulley 50. Further, connected to the vehicle control unit 70 are a power switch 77 for performing a start operation and a stop operation of the control system 20, and a warning lamp 79 provided on the meter panel 78.

[0018] FIG. 4 is a diagram showing an example of the basic structure of the electronic control units 23, 26, and 70. As shown in FIG. 3, the electronic control units 23, 26, and 70 include a microcontroller 82 in which a processor 80, a main memory 81, and the like are incorporated. A predetermined program is stored in the main memory 81, and the program is executed by the processor 80. The processor 80 and the main memory 81 are connected to each other so as to be communicable. Note that a plurality of processors 80 may be incorporated in the microcontroller 82, or a plurality of main memories 81 may be incorporated in the microcontroller 82.

[0019] Further, the electronic control units 23, 26, and 70 include an input circuit 83, a drive circuit 84, a communication circuit 85, an external memory 86, and a power supply circuit 87. The input circuit 83 converts a signal input from various sensors into a signal that can be input to the microcontroller 82. The drive circuit 84 generates a drive signal for a device such as the valve body 24 described above based on a signal output from the microcontroller 82. The communication circuit 85 converts a signal output from the microcontroller 82 into a communication signal directed to another electronic control unit or the like. Further, the communication circuit 85 converts a communication signal received from another electronic control unit or the like into a signal that can be input to the microcontroller 82. Furthermore, the power supply circuit 87 supplies a stable power supply voltage to the microcontroller 82, the input circuit 83, the drive circuit 84, the communication circuit 85, the external memory 86, and the like. Programs and various data are stored in the external memory 86 composed of a nonvolatile memory or the like.

[0020] <Chain structure> FIG. 5 is a diagram showing a partial section of the chain 60 from the side. FIG. 5 shows a partial section of the chain 60 and also shows the link plates 61 and 62 constituting the chain 60 alone. FIG. 6 is a cross-sectional view showing a partial section of the chain 60 along VI-VI of FIG. 5. The dashed-dotted line shown in FIG. 6 indicates the positions of the sheave surfaces 41a, 42a, 51a, and 52a of the pulleys 40 and 50.

[0021] As shown in FIGS. 5 and 6, the chain 60 has a plurality of link plates (elements) 61, 62 and a plurality of locker joints (elements, joints) 63 that connect the plurality of link plates 61, 62 to each other. That is, the chain 60 is composed of a plurality of elements, and the plurality of elements are composed of a plurality of link plates 61, 62 and a plurality of locker joints 63.

[0022] The plurality of link plates 61, 62 are composed of a first link plate 61 including a base plate 65 and an engagement pin 66, and a second link plate 62 including a base plate 67 and a frame 68. The locker joint 63 is composed of a pair of locker pins 64. As shown in FIGS. 3 and 6, the end faces of the locker joint 63 are in contact with the sheave surfaces 41a, 42a, 51a, 52a of the pulleys 40, 50.

[0023] As shown in FIGS. 5 and 6, the first link plate (first element) 61 has a base plate 65 in which an opening 65a for accommodating the locker joint 63 is formed, and an engagement pin 66 that protrudes from both surfaces of the base plate 65. The engagement pins (first engagement portions, first convex portions) 66 located at both ends of the base plate 65 protrude in the thickness direction of the base plate 65 toward the second link plate 62. The second link plate (second element) 62 has a base plate 67 in which an opening 67a for accommodating the locker joint 63 is formed, and a frame 68 provided so as to overlap both surfaces of the base plate 67. The stoppers (second engagement portions, second convex portions) 69 located at both ends of the frame 68 protrude in the thickness direction of the base plate 67 toward the first link plate 61. The engagement pin 66 of the first link plate 61 is separated from the stopper 69 of the second link plate 62.

[0024] <Breaking of the locker joint> Figures 7 and 8 are diagrams showing a comparison between the normal state and the abnormal state of the chain 60. The same parts as in FIG. 5 are shown in FIG. 7, and the same parts as in FIG. 6 are shown in FIG. 8. The normal state of the chain 60 is a state in which none of the rocker joints 63 are broken. The abnormal state of the chain 60 is a state in which any one of the rocker joints 63 is broken. In the following description, in order to clarify the target rocker joint 63, first link plate 61, and second link plate 62, they will be described with reference numerals 61X, 62X, 63Xa, and 63Xb different from the above-mentioned reference numerals 61, 62, and 63. The arrow D1 shown in FIGS. 7 and 8 indicates the moving direction of the chain 60.

[0025] As shown in FIGS. 7 and 8, if, by some unexpected factor, the rocker joint 63Xa breaks, the connection state between the first link plate 61X and the second link plate 62X by the rocker joint 63Xa is released. As a result, as shown by the arrow α1 in FIGS. 7 and 8, the rocker joint 63Xb moves the first link plate 61X, but the engagement pin 66 of the first link plate 61X contacts the stopper 69 of the second link plate 62X. That is, even when the rocker joint 63Xa breaks, the first link plate 61X does not come off from the second link plate 62X, and it is possible to prevent chain breakage and ensure a minimum running performance.

[0026] As shown by the reference numeral α2 in FIG. 8, the first link plate 61X located on the outermost side in the chain width direction is provided with an engagement pin 66 protruding outward in the chain width direction. By providing the engagement pin 66 protruding outward in the chain width direction in this way, the gap between the first link plate 61X and the sheave surfaces 41a, 42a, 51a, and 52a can be narrowed. Thereby, the movement of the first link plate 61X in the chain width direction can be suppressed, and the first link plate 61X can be prevented from coming off from the second link plate 62X.

[0027] <Detection of chain abnormality> As shown in FIGS. 7 and 8, when the rocker joint 63Xa breaks, the chain 60 will extend by the dimension L1. Therefore, the control system 20 executes abnormality detection control for detecting an abnormal state of the chain 60 based on the actual gear ratio. Here, FIG. 9 is a flowchart showing an example of the execution procedure of the abnormality detection control. Each step of the abnormality detection control shown in FIG. 9 is a step executed by the processor 80 constituting the control system 20. Further, the abnormality detection control is control that is executed by the control system 20 at a predetermined cycle after the control system 20 is activated by the operation of the power switch 77.

[0028] As shown in FIG. 9, the control system 20 proceeds to step S10 and calculates a target gear ratio R1 based on the vehicle speed and the accelerator opening. The control system 20 proceeds to step S11 and calculates an actual gear ratio R2 based on the primary rotational speed Np and the secondary rotational speed Ns. The control system 20 proceeds to step S12 and determines whether the absolute value of the difference between the target gear ratio R1 and the actual gear ratio R2 is equal to or less than a predetermined threshold value Rx. Then, when the control system 20 determines in step S12 that the absolute value of the difference between the target gear ratio R1 and the actual gear ratio R2 exceeds the threshold value Rx, it proceeds to step S13, outputs an abnormal signal, and turns on the warning lamp 79. That is, when the absolute value of the difference between the target gear ratio R1 and the actual gear ratio R2 exceeds the threshold value Rx, there is a possibility that the rocker joint 63Xa has broken and the chain 60 has stretched. Therefore, the control system 20 outputs an abnormal signal and turns on the warning lamp 79. When the rocker joint 63Xa breaks and the chain 60 stretches, depending on the gear ratio and load at the time of joint breakage, the actual gear ratio R2 may change to the higher side than the target gear ratio R1, and the actual gear ratio R2 may change to the lower side than the target gear ratio R1.

[0029] When the control system 20 determines in step S12 that the absolute value of the difference between the target gear ratio R1 and the actual gear ratio R2 is less than or equal to the threshold value Rx, it proceeds to step S14 and determines whether the actual gear ratio R2 is greater than or equal to the minimum gear ratio Rmin and less than or equal to the maximum gear ratio Rmax. Then, in step S13, when the actual gear ratio R2 is less than the minimum gear ratio Rmin on the high side or the actual gear ratio R2 is greater than the maximum gear ratio Rmax on the low side, the control system 20 proceeds to step S13, outputs an abnormal signal, and turns on the warning lamp 79. That is, when the actual gear ratio R2 is outside the gear shift range between the minimum gear ratio Rmin and the maximum gear ratio Rmax, there is a possibility that the rocker joint 63Xa is broken and the chain 60 is stretched. Therefore, the control system 20 outputs an abnormal signal and turns on the warning lamp 79. The gear shift range between the minimum gear ratio Rmin and the maximum gear ratio Rmax is the gear shift range that can be obtained during normal operation when the rocker joint 63Xa is not broken.

[0030] In this way, by turning on the warning lamp 79 related to the chain 60, the control system 20 prompts the driver to enter the maintenance factory. As a result, the inspection and maintenance of the continuously variable transmission 10 can be carried out early, and the continuously variable transmission 10 can be appropriately protected. Also, when an abnormal state of the chain 60 is detected, in order to protect the continuously variable transmission 10 by reducing the input torque to the continuously variable transmission 10, the control system 20 may reduce the engine torque by applying an output limit to the engine 12.

[0031] <Embodiment 2> <Chain Structure> The examples shown in FIGS. 5 and 6 are chain structures assuming breakage of the rocker joint 93, but are not limited thereto, and may be chain structures assuming breakage of the link plates 61 and 62. Here, FIG. 10 is a view showing a partial section of a chain 90 provided in a continuously variable transmission according to another embodiment of the present disclosure from the side. FIG. 10 shows a partial section of the chain 90 and also shows the link plates 91 and 92 constituting the chain 90 alone. Further, FIG. 11 is a cross-sectional view showing a partial section of the chain 90 along line XI-XI of FIG. 10. The dashed-dotted line shown in FIG. 11 indicates the positions of the sheave surfaces 41a, 42a, 51a, and 52a of the pulleys 40 and 50.

[0032] As shown in FIGS. 10 and 11, the chain 90 has a plurality of link plates (elements) 91 and 92 and a plurality of rocker joints (elements, joints) 93 that connect the plurality of link plates 91 and 92 to each other. That is, the chain 90 is composed of a plurality of elements, and the plurality of elements are composed of a plurality of link plates 91 and 92 and a plurality of rocker joints 93.

[0033] The plurality of link plates 91 and 92 are composed of a main plate 91 disposed at the center in the chain width direction and sub-plates 92 disposed at both ends in the chain width direction. The rocker joint 93 is composed of a pair of rocker pins 94. As shown in FIG. 11, the end faces of the rocker joint 93 are in contact with the sheave surfaces 41a, 42a, 51a, and 52a of the pulleys 40 and 50.

[0034] As shown in FIGS. 10 and 11, an opening (first opening) 95 for accommodating the rocker joint 93 is formed in the main plate 91. Further, an opening (second opening) 96 for accommodating the rocker joint 93 is formed in the subplate 92. The length dimension Lb of the opening 96 in the subplate 92 is larger than the length dimension La of the opening 95 in the main plate 91. That is, the opening 96 in the subplate 92 is formed larger than the opening 95 in the main plate 91.

[0035] The opening 96 formed in the subplate 92 has an inner peripheral surface 96a on one side in the longitudinal direction and an inner peripheral surface 96b on the other side in the longitudinal direction. Further, the inner peripheral surface (first engaging portion) 96a of the opening 96 formed in the subplate (first element) 92 faces the outer peripheral surface (second engaging portion) 97 of the rocker joint (second element) 93. Similarly, the inner peripheral surface (first engaging portion) 96b of the opening 96 formed in the subplate (first element) 92 faces the outer peripheral surface (second engaging portion) 97 of the rocker joint (second element) 93. Note that the inner peripheral surface 96a of the opening 96 is separated from the outer peripheral surface 97 of the rocker joint 93, and the inner peripheral surface 96b of the opening 96 is separated from the outer peripheral surface 97 of the rocker joint 93.

[0036] <Break of the main plate> FIGS. 12 and 13 are diagrams showing a comparison between the normal state and the abnormal state of the chain 90. The same parts as those in FIG. 10 are shown in FIG. 12, and the same parts as those in FIG. 11 are shown in FIG. 13. The normal state of the chain 90 is a state in which none of the main plates 91 are broken. Further, the abnormal state of the chain 90 is a state in which any one of the main plates 91 is broken. In the following description, in order to clarify the target main plate 91, subplate 92, and rocker joint 93, they will be described with reference numerals 91X, 92X, 93Xa, and 93Xb different from the above-mentioned reference numerals 91, 92, and 93. Further, the arrow D1 shown in FIGS. 12 and 13 indicates the moving direction of the chain 90.

[0037] As shown in FIGS. 12 and 13, if the main plate 91X breaks due to an unexpected factor, the connection state of the rocker joints 93Xa and 93Xb by the main plate 91X is released. As a result, as shown by the arrow β1 in FIGS. 12 and 13, the rocker joint 93Xa moves in a direction away from the rocker joint 93Xb. However, since the outer peripheral surface 97 of the rocker joint 93Xa and the inner peripheral surface 96a of the sub-plate 92X are in contact with each other, and the outer peripheral surface 97 of the rocker joint 93Xb and the inner peripheral surface 96b of the sub-plate 92X are in contact with each other, the distance between the rocker joints 93Xa and 93Xb is restricted by the sub-plate 92X. That is, even when the main plate 91X breaks, the connection state of the rocker joints 93Xa and 93Xb is maintained by the sub-plate 92X, so that it is possible to prevent the chain from breaking and ensure the minimum running performance.

[0038] As shown in FIGS. 12 and 13, when the main plate 91X breaks, the chain 90 extends by the dimension L2. Therefore, the control system 20 detects the abnormal state of the chain 90 based on the actual gear ratio by executing the above-described abnormality detection control shown in FIG. 9. Thereby, when the main plate 91X breaks, the warning lamp 79 regarding the chain 90 can be lit, and the driver can be urged to enter the maintenance factory. In addition, since the inspection and maintenance of the continuously variable transmission 10 are carried out at an early stage, the continuously variable transmission 10 can be appropriately protected.

[0039] <Other modification examples> The present disclosure is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist thereof. In the example shown in FIG. 6, all of the link plates constituting the chain 60 are constituted by the first link plate 61 and the second link plate 62, but the present disclosure is not limited thereto. For example, a part of the link plates constituting the chain 60 may be constituted by the first link plate 61 and the second link plate 62. Further, in the example shown in FIG. 11, the main plate 91 is disposed at the center in the chain width direction, and the sub-plates 92 are disposed at both ends in the chain width direction, but the present disclosure is not limited thereto. For example, the main plates 91 may be disposed at both ends in the chain width direction, and the sub-plates 92 may be disposed at the center in the chain width direction. Further, the sub-plates shown in FIG. 11 may be incorporated into the chain structure shown in FIG. 6, and the first link plate 61 and the second link plate 62 shown in FIG. 6 may be incorporated into the chain structure shown in FIG. 11.

[0040] In the illustrated example, one rocker joint 63 is constituted by a pair of rocker pins 64, but the present disclosure is not limited thereto. For example, one rocker joint 63 may be constituted by one rocker pin 64, or one rocker joint 63 may be constituted by three or more rocker pins 64. Further, in the foregoing description, the control system 20 is constituted by a plurality of electronic control units, but the present disclosure is not limited thereto, and the control system 20 may be constituted by one electronic control unit. Further, in the foregoing description, the warning lamp 79 is lit based on the abnormal signal issued from the control system 20, but the present disclosure is not limited thereto, and the warning lamp 79 may be blinked. Further, based on the abnormal signal issued from the control system 20, a warning sound may be generated from a buzzer, and the warning content may be displayed on a display.

Description of Reference Numerals

[0041] 10…Continuously variable transmission, 20…Control system, 31…Primary shaft (input shaft), 32…Secondary shaft (output shaft), 40…Primary pulley, 50…Secondary pulley, 60…Chain, 61, 61X…First link plate (element, first element, link plate), 62, 62X…Second link plate (element, second element, link plate), 63, 63Xa, 63Xb…Rocking joint (element, joint), 64…Rocking pin, 66…Engagement pin (first engagement part, first convex part), 69…Stopper (second engagement part, second convex part), 80…Processor, 81…Main memory, 90…Chain, 91, 91X…Main plate (element, link plate), 92, 92X…Sub plate (element, first element, link plate), 93, 93Xa, 93Xb…Rocking joint (element, second element, joint), 94…Rocking pin, 95…Opening (first opening), 96…Opening (second opening), 96a, 96b…Inner peripheral surface (first engagement part), 97…Outer peripheral surface (second engagement part), R1…Target transmission ratio, R2…Actual transmission ratio, Rx…Threshold value, Rmin…Minimum transmission ratio, Rmax…Maximum transmission ratio

Claims

1. A primary pulley provided on an input shaft, A secondary pulley provided on an output shaft, A chain wound around the primary pulley and the secondary pulley and consisting of a plurality of elements, And having, The plurality of elements include a first element having a first engaging portion and a second element having a second engaging portion, In the normal state of the chain in which none of the plurality of elements is broken, the first engaging portion and the second engaging portion are separated from each other, In the abnormal state of the chain in which any one of the plurality of elements is broken, the first engaging portion and the second engaging portion are in contact with each other, A continuously variable transmission.

2. In the continuously variable transmission according to claim 1, The plurality of elements are composed of a plurality of link plates and a plurality of joints connecting the plurality of link plates to each other, The plurality of link plates include a first link plate that is the first element and a second link plate that is connected to the first link plate via the joint and is the second element, The first engaging portion is a first convex portion protruding in the thickness direction of the first link plate, The second engaging portion is a second convex portion protruding in the thickness direction of the second link plate, A continuously variable transmission.

3. In the continuously variable transmission according to claim 1, The plurality of elements are composed of a plurality of link plates and a plurality of joints connecting the plurality of link plates to each other, The plurality of link plates include a main plate having a first opening for accommodating the joint and a sub-plate formed larger than the first opening and having a second opening for accommodating the joint, The first engaging portion is the inner peripheral surface of the second opening formed in the sub-plate that is the first element, The second engaging portion is the outer peripheral surface formed on the joint that is the second element and facing the inner peripheral surface, A continuously variable transmission.

4. In the continuously variable transmission according to any one of claims 1 to 3, It has a control system including a processor and a memory connected to be communicable with each other, The control system outputs an abnormal signal when the difference between the target transmission ratio and the actual transmission ratio exceeds a threshold value, A continuously variable transmission.

5. In the continuously variable transmission according to any one of claims 1 to 3, A control system having a processor and a memory communicably connected to each other, wherein the control system outputs an abnormal signal when an actual gear ratio is less than a minimum gear ratio or when the actual gear ratio is greater than a maximum gear ratio. A continuously variable transmission.

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