JP2006118597A - Belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt type continuously variable transmission for suppressing an increase of force to be transmitted from a movable sheave to a fixed member. <P>SOLUTION: The belt type continuously variable transmission comprises a fixed sheave 11 movably mounted on a rotary member 7 in the axial direction, the movable sheave 12 movably mounted on the rotary member 7 in the axial direction, a belt 17 wrapped around the fixed sheave 11 and the movable sheave 12, a hydraulic pressure chamber forming member 37 mounted on the rotary member 7 to form a hydraulic pressure chamber 13A, and the fixed members 31, 36 provided on the rotary member 7 for positioning the hydraulic pressure chamber forming member 37 on the rotary member 7 in the axial direction. Herein, a restricting member 48 is provided for restricting the axial movement of the movable sheave 12 to prevent the contact of a cylindrical portion 60 of the movable sheave 12 directly or indirectly with the hydraulic pressure chamber forming member 37. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a belt-type continuously variable transmission that transmits power by winding a belt around a plurality of pulleys.

  In general, a belt-type continuously variable transmission is known as a continuously variable transmission disposed on the output side of a power source. An example of the belt-type continuously variable transmission is described in Patent Document 1. In Patent Literature 1, engine power is transmitted to drive wheels via a forward / reverse switching device, a continuously variable transmission, and a final reduction unit. The continuously variable transmission is a belt type continuously variable transmission and has a primary shaft and a secondary shaft. A primary pulley is attached to the primary shaft, and the primary pulley has a movable sheave and a fixed sheave. A secondary pulley is attached to the secondary shaft, and the secondary pulley has a movable sheave and a fixed sheave. A driving belt is wound around the primary pulley and the secondary pulley. Further, a primary hydraulic chamber and a secondary hydraulic chamber are provided, and the groove widths of both pulleys are changed by the operating pressure supplied to each hydraulic chamber, and the shift control is performed.

The secondary pulley will be specifically described. The secondary movable sheave is provided so as to be slidable along the secondary shaft. The outer edge side of the secondary movable sheave is extended in parallel in the axial direction toward the engine side of the secondary shaft, and a cylinder forming a secondary hydraulic chamber is formed. A plunger that forms the secondary hydraulic chamber is fixed. Specifically, a locking groove is provided on the outer periphery of the secondary shaft, and a ring-shaped cotter is attached to the locking groove. Further, a lock nut is attached to the secondary shaft, and the plunger is fitted and fixed between the cotter and the lock nut by tightening the lock nut. Further, the secondary hydraulic chamber is provided with a spring that constantly urges the secondary movable sheave and the plunger away from each other.
JP 2004-52815 A

  However, in the continuously variable transmission described in Patent Document 1, the movable sheave contacts the cotter, the cotter contacts the plunger, and the plunger contacts the lock nut. When a force in a direction that causes the movable sheave to move away from the fixed sheave is transmitted to the movable sheave, this force is transmitted from the movable sheave to the lock nut, which may increase the force transmitted to the lock nut.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide a belt-type continuously variable transmission capable of suppressing an increase in force transmitted from a movable sheave to a fixed member.

  In order to achieve the above object, the invention of claim 1 includes a fixed sheave attached to the rotating member so as not to move in the axial direction, and a movable sheave attached to the rotating member so as to be movable in the axial direction. A belt wound around the fixed sheave and the movable sheave, a hydraulic chamber constituting member that is attached to the rotating member and that forms a hydraulic chamber that applies a force in the axial direction to the movable sheave, and the rotating member In the belt-type continuously variable transmission that is provided and includes a fixing member that positions the hydraulic chamber constituent member in the axial direction of the rotating member, the cylindrical portion of the movable sheave and the hydraulic chamber constituent member are directly Alternatively, a restricting member for restricting the movement of the movable sheave in the axial direction is provided so as not to contact indirectly.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, a slidable portion is formed at a contact portion between the movable sheave and the hydraulic chamber constituent member in order to seal the hydraulic chamber in a liquid-tight manner. It is characterized by being.

  Furthermore, the invention of claim 3 is, in addition to the structure of claim 1 or 2, wherein the restriction member is an annular stopper attached to the rotating member and having a part cut away in the circumferential direction. It is characterized by.

  Furthermore, in the invention of claim 4, in addition to the structure of claim 2 or 3, the hydraulic chamber constituting member is provided with a cylindrical portion centering on an axis, and a seal ring is attached to the movable sheave. The slidable portion is formed by contacting the seal ring with the inner peripheral surface of the cylindrical portion.

  According to the first aspect of the present invention, when a force in the axial direction acts on the movable sheave, the movement of the movable sheave is restricted in the axial direction by the restricting member. It can suppress that it is transmitted to a fixing member via. Therefore, it is possible to suppress an increase in the force received by the fixing member.

  According to the second aspect of the invention, in addition to obtaining the same effect as the first aspect of the invention, a slidable portion is formed at the contact portion between the movable sheave and the hydraulic chamber constituting member, so that the hydraulic chamber is liquid tight. Sealed. Further, the force accompanying the movement of the movable sheave in the axial direction is transmitted from only the slidable portion to the hydraulic chamber constituent member.

  According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 1 or 2, the movable sheave comes into contact with the stopper, and the axial load is received by the stopper. The increase in force can be more reliably suppressed.

  According to the invention of claim 4, in addition to obtaining the same effect as that of the invention of claim 2 or 3, the seal ring and the cylindrical part slide in the axial direction, so that the slidable part changes to the hydraulic chamber constituent member. The transmitted axial force is small.

  Next, an embodiment of a belt type continuously variable transmission according to the present invention will be described with reference to the drawings. FIG. 2 is a conceptual diagram showing a power train of a vehicle Ve having a belt type continuously variable transmission and a control system of the vehicle Ve. In the vehicle Ve shown in FIG. 2, a fluid transmission device 3, a lock-up clutch 4, a forward / reverse switching mechanism 5, a belt type continuously variable transmission 6, and the like are provided in a power transmission path between the driving force source 1 and the wheels 2. Is provided. As the driving force source 1, for example, at least one of an engine or an electric motor can be used. In this embodiment, a case where an engine is used as the driving force source 1 will be described.

  Further, the fluid transmission device 3 and the lockup clutch 4 are provided in a power transmission path between the driving force source 1 and the forward / reverse switching mechanism 5, and the fluid transmission device 3 and the lockup clutch 4 are parallel to each other. Is arranged. The fluid transmission device 3 is a device that transmits power by the kinetic energy of the fluid, and the lockup clutch 4 is a device that transmits power by a frictional force.

  Further, the forward / reverse switching mechanism 5 is a device that selectively switches the rotation direction of the output member relative to the input member. The forward / reverse switching mechanism 5 includes a planetary gear mechanism (not shown), a clutch (not shown) for controlling the transmission state of power to the rotating element of the planetary gear mechanism, and rotation / stop of the rotating element of the planetary gear mechanism. And a brake (not shown) for controlling the motor. And it is comprised so that the engagement pressure of friction engagement apparatuses, such as a clutch and a brake, may be controlled by oil_pressure | hydraulic.

  The belt type continuously variable transmission 6 is provided in a power transmission path between the forward / reverse switching mechanism 5 and the wheels 2. The belt type continuously variable transmission 6 has a primary shaft 7 and a secondary shaft 8 arranged in parallel to each other. The primary shaft 7 is provided with a primary pulley 9, and the secondary shaft 8 is provided with a secondary pulley 10. The primary pulley 9 has a fixed sheave 11 fixed to the primary shaft 7 and a movable sheave 12 configured to be movable in the axial direction of the primary shaft 7. A groove M <b> 1 is formed between the fixed sheave 11 and the movable sheave 12. Further, a hydraulic servo mechanism 13 is provided for moving the movable sheave 12 in the axial direction of the primary shaft 7 so that the movable sheave 12 and the fixed sheave 11 approach and separate from each other. The hydraulic servo mechanism 13 has a hydraulic chamber 13A. The configuration of the hydraulic servo mechanism 13 will be described later.

  On the other hand, the secondary pulley 10 has a fixed sheave 14 fixed to the secondary shaft 8 and a movable sheave 15 configured to be movable in the axial direction of the secondary shaft 8. A V-shaped groove M <b> 2 is formed between the fixed sheave 14 and the movable sheave 15. In addition, a hydraulic servo mechanism 16 is provided that moves the movable sheave 15 in the axial direction of the secondary shaft 8 to bring the movable sheave 15 and the fixed sheave 14 closer to or away from each other. The hydraulic servo mechanism 16 has a hydraulic chamber 26. An endless belt 17 is wound around the primary pulley 9 and the secondary pulley 10 configured as described above.

  On the other hand, a hydraulic control device 18 for controlling the hydraulic servo mechanisms 13 and 16 and the lockup clutch 4 and the forward / reverse switching mechanism 5 of the belt type continuously variable transmission 6 is provided. Further, an electronic control device 52 as a controller for controlling the driving force source 1, the lockup clutch 4, the forward / reverse switching mechanism 5, the belt type continuously variable transmission 6, and the hydraulic control device 18 is provided.

  The electronic control unit 52 includes detection signals such as engine speed, accelerator pedal operation state, brake pedal operation state, throttle valve opening, shift position, primary shaft 7 rotational speed, and secondary shaft 8 rotational speed. Is entered. The vehicle speed is obtained based on the rotational speed of the secondary shaft 8. Various types of data are stored in the electronic control unit 52. Based on the signals input to the electronic control unit 52 and the stored data, the electronic control unit 52 controls the driving force source 1. A signal for controlling the belt-type continuously variable transmission 6, a signal for controlling the forward / reverse switching mechanism 5, a signal for controlling the lockup clutch 4, a signal for controlling the hydraulic control device 18, and the like are output.

  Examples of data stored in the electronic control unit 52 include a shift control map and a lockup clutch control map. This shift control map is a map for setting the gear ratio of the belt type continuously variable transmission 6 based on the vehicle speed, the accelerator opening, and the like. When an engine is used as the driving force source 1, it is possible to bring the actual engine speed closer to the target engine speed corresponding to the optimum fuel consumption curve by controlling the gear ratio of the belt-type continuously variable transmission 6. is there. In accordance with this, control is performed to bring the actual engine torque closer to the target engine torque. The lockup clutch control map is a map for setting the torque capacity of the lockup clutch 4 based on the vehicle speed, the accelerator opening, and the like.

  Next, the operation of the vehicle Ve shown in FIG. 2 will be described. The torque of the driving force source 1 is input to the forward / reverse switching mechanism 5 via either the fluid transmission device 3 or the lockup clutch 4. The torque output from the forward / reverse switching mechanism 5 is transmitted to the primary shaft 7 of the belt type continuously variable transmission 6. The torque of the primary shaft 7 is transmitted to the secondary shaft 8 via the belt 17. Then, the torque of the secondary shaft 8 is transmitted to the wheel 2 to generate a driving force.

  Here, the shift control of the belt type continuously variable transmission 6 will be described. First, based on the hydraulic pressure in the hydraulic chamber 13A, the thrust for moving the movable sheave 12 of the primary pulley 9 in the axial direction changes. Further, the thrust for moving the movable sheave 15 of the secondary pulley 10 in the axial direction is changed by the hydraulic pressure of the hydraulic chamber 26 of the hydraulic servo mechanism 16. The width of the groove M1 changes according to the operation of the movable sheave 12 in the axial direction, and the width of the groove M2 changes according to the operation of the movable sheave 15 in the axial direction.

  When the width of the groove M1 is adjusted as described above, the ratio between the winding radius of the belt 17 in the primary pulley 9 and the winding radius of the belt 17 in the secondary pulley 10 changes. As a result, the ratio of the rotational speed between the primary shaft 7 and the secondary shaft 8, that is, the gear ratio changes. Specifically, when the hydraulic pressure in the hydraulic chamber 13A is increased and the width of the groove M1 is reduced, the winding radius of the belt 17 in the primary pulley 9 is increased, and the gear ratio of the belt-type continuously variable transmission 7 is decreased. Shift as follows. On the other hand, when the hydraulic pressure in the hydraulic chamber 13A is reduced and the width of the groove M1 is widened, the winding radius of the belt 17 in the primary pulley 9 is reduced, and the gear ratio of the belt-type continuously variable transmission 6 is increased. Shift as follows.

  Further, when the width of the groove M2 is adjusted in accordance with this shift control, the clamping pressure acting on the belt 17 changes and the tension of the belt 17 changes. As a result, the capacity of torque transmitted between the primary shaft 7 and the secondary shaft 8 is controlled. Specifically, when the hydraulic pressure in the hydraulic chamber 26 is increased and the clamping pressure acting on the belt 17 is increased, the torque capacity increases. On the other hand, when the hydraulic pressure in the hydraulic chamber 26 is reduced and the clamping pressure acting on the belt 17 is weakened, the torque capacity is reduced. As described above, the torque capacity of the belt-type continuously variable transmission 6 changes as the clamping pressure acting on the belt 17 changes.

  Next, specific configuration examples of the primary pulley 9 and the hydraulic servo mechanism 13 will be described with reference to FIG. A casing 30 in which the belt type continuously variable transmission 6 is accommodated is provided, and a primary shaft 7 is rotatably held around an axis A <b> 1 by bearings 31 and 32 attached to the casing 30. The bearing 31 has an inner ring 33 and an outer ring 34. Further, an annular recess 30 </ b> A is formed in the casing 30, the outer ring 34 is fitted and fixed to the recess 30 </ b> A, and the inner ring 33 is attached to the primary shaft 7. A plate 70 is attached to the casing 30, and the outer ring 34 is sandwiched between the end face 30 </ b> B of the recess 30 </ b> A and the plate 70, and the casing 30 and the bearing 31 are positioned and fixed in the axial direction.

  On the other hand, a step 35 is formed on the primary shaft 7, and an inner ring 33 is disposed between the nut 36 attached to the primary shaft 7 and the step 35. By tightening the nut 36, the inner ring 33 is sandwiched between the step portion 35 and the nut 36, and the primary shaft 7 and the bearing 31 are positioned and fixed in the axial direction.

  A cylinder 37 is attached to the outer periphery of the primary shaft 7. The cylinder 37 is formed in an annular shape, and includes a disk-shaped inner portion 38, a connection portion 71 formed continuously on the outer periphery of the inner portion 38, a continuous outer peripheral end of the connection portion 71, and an axis line And a cylindrical portion 39 extending in the direction. The connection part 71 is inclined in the direction away from the bearing 31 in the axial direction as it goes outward. The cylinder 37 rotates integrally with the primary shaft 7, and the cylinder 37 is attached to the primary shaft 7 so that the primary shaft 7 and the cylinder 37 do not move relative to each other in the axial direction. The inner portion 38 and the inner ring 33 of the bearing 31 are in contact with each other with the cylinder 37 fixed to the primary shaft 7.

  The movable sheave 12 is disposed inside the outer cylindrical portion 39, and the movable sheave 12 includes an inner cylindrical portion 60 that extends in the axial direction, and a connecting portion that extends in the radial direction from one end of the inner cylindrical portion. 40 and an outer cylinder portion 41 formed continuously at the outer peripheral end of the connection portion 40. An annular rib 42 is formed on the outer periphery of the outer cylinder portion 41, and an annular mounting groove 43 is formed on the outer periphery of the rib 42. The outer diameter of the rib 42 is configured to be less than the inner diameter of the cylindrical portion 39, and the seal ring 44 is attached to the attachment groove 43. This seal ring 44 contacts the inner peripheral surface of the cylindrical portion 39 to form a seal surface S1. In this way, the hydraulic chamber 13A is formed between the movable sheave 12 and the cylinder 37, and the hydraulic chamber 13A is liquid-tightly held by the seal surface S1.

  On the other hand, an oil passage 45 is formed in the primary shaft 7 along the axial direction, and an oil passage 46 extending from the oil passage 45 in the radial direction is formed. The oil passage 46 is opened on the outer peripheral surface of the primary shaft 7. The inner cylindrical portion 60 of the movable sheave 12 is spline-fitted to the primary shaft 7, and the movable sheave 12 is movable in the axial direction of the primary shaft 7 and rotates integrally with the primary shaft 7. Therefore, a gap is formed in advance between the inner cylindrical portion 60 of the movable sheave 12 and the primary shaft 7. Further, an oil passage 47 that penetrates the inner cylinder portion 60 in the radial direction is provided, and the oil passage 46 and the hydraulic chamber 13 </ b> A are connected by the oil passage 47. Further, a stopper 48 is provided between the end portion on the bearing 31 side in the inner cylinder portion 60 and the inner portion 38 of the cylinder 37. The hydraulic servo mechanism 13 is configured by the cylinder 37, the hydraulic chamber 13A, the oil passages 45 and 46, and the like.

  The stopper 48 is formed in an annular shape, and is formed of a C-ring that is partially cut away in the circumferential direction. The stopper 48 is mounted in an annular mounting groove 49 provided on the outer periphery of the primary shaft 7. An annular holder 50 is attached to the outer periphery of the stopper 48. This holder 50 prevents "the stopper 48 from being enlarged and falling off from the primary shaft 7". In the state where the stopper 48 is mounted in the mounting groove 49 and the holder 50 is mounted, an axial gap L1 is formed between the inner portion 38 and the stopper 48 and the holder 50. The holder 50 is not in contact with the cylinder 37.

  The movable sheave 12 has an inclined surface 51, the fixed sheave 11 has an inclined surface 53, and a groove M 1 is formed between the inclined surface 51 and the inclined surface 53. The inclined surfaces 51 and 53 are inclined in such a direction that the width of the groove M1 increases as it is on the outer side. The fixed sheave 11 is integrally formed with the primary shaft 7. Furthermore, components such as the primary shaft 7, the movable sheave 12, the stopper 48, the cylinder 37, the bearing 31, and the nut 36 are made of a metal material.

  In the configuration of FIG. 1, the pressure oil is supplied to the hydraulic chamber 13A via the oil passages 45, 46, and 47, the pressure oil is discharged from the hydraulic chamber 13A, and the movable sheave 12 operates in the axial direction. The winding radius of the belt 17 in the groove M1 is controlled. Here, when the movable sheave 12 moves in the axial direction, the seal ring 44 and the cylindrical portion 39 slide. By the way, when the hydraulic pressure in the hydraulic chamber 13 </ b> A acts on the connecting portion 71 and the inner side portion 38 of the cylinder 37, an axial force acts in a direction in which the cylinder 37 is pressed against the bearing 31. 36.

  On the other hand, when the belt 17 is wound around the primary pulley 9, a region where the belt 17 contacts and a region where the belt 17 does not contact are generated in the circumferential direction of the movable sheave 12. In the region where the belt 17 is in contact, a reaction force corresponding to the thrust applied to the belt 17 is generated, and the movable sheave 12 is counterclockwise in FIG. A moment force F1 is generated which attempts to rotate in the direction. Here, when the moment force F <b> 1 is generated, the movable sheave 12 is elastically deformed, and a force is generated in a direction that brings the movable sheave 12 closer to the axial direction, more specifically, to the bearing 31. However, in this embodiment, since the stopper 48 that restricts the movement of the movable sheave 12 in the axial direction, that is, the movement of the movable sheave 12 in the direction approaching the inner portion 38 is provided, the movable sheave 12 acts on the movable sheave 12. The axial force is received by the stopper 48. Thus, in this embodiment, the axial force generated by the primary pulley 9 is received by being divided into two by the nut 36 and the stopper 48. On the seal surface S1, a frictional force is generated by sliding between the seal ring 44 and the cylindrical portion 39. Since the sliding direction is the axial direction, the axial force transmitted to the cylinder 37 by the sliding is Few.

  Therefore, substantially all of the axial force can be suppressed from being transmitted to the nut 36 via the bearing 31, and an increase in the load received by the nut 36 can be suppressed. Further, since the force in the axial direction can be received by the stopper 48, it is allowed to increase the amount by which the movable sheave 12 is tilted counterclockwise, and between the outer periphery of the primary shaft 7 and the inner periphery of the movable sheave 12. It is possible to design a predetermined gap (backlash) formed as large as possible. Furthermore, the nut 36 can be reduced in size. In this way, it is possible to reduce the manufacturing cost and reduce the size and weight of various components.

  The correspondence between the configuration described in this embodiment and the configuration of the present invention will be described. The primary shaft 7 corresponds to the rotating member of the present invention, the fixed sheave 11 corresponds to the fixed sheave of the present invention, and is movable. The sheave 12 corresponds to the movable sheave 12 of the present invention, the cylinder 37 corresponds to the hydraulic chamber constituting member of the present invention, the nut 36 and the bearing 31 correspond to the fixed member of the present invention, and the seal surface S1 is The stopper 48 corresponds to the restricting member of the present invention, the inner cylindrical portion 60 corresponds to the cylindrical portion of the present invention, and the hydraulic chamber 13A corresponds to the hydraulic chamber of the present invention. Equivalent to. In the embodiment shown in FIG. 1, the inner portion 38 of the cylinder 37 and the stopper 48 are not in contact with each other, that is, are not in direct contact with each other. It should be noted that some member (solid) is provided between the inner portion 38 of the cylinder 37 and the stopper 48, and this member is in contact with the inner portion 38 and the stopper 48. Such a configuration is not included in the “regulating member” of the present invention. In other words, the technical significance of the “regulating member” in the present invention is that the axial force transmitted to the regulating member is not transmitted to the hydraulic chamber constituting member.

  Although not shown in particular, a hydraulic servomechanism having a structure in which a piston that rotates integrally with the movable sheave and operates in the axial direction integrally with the movable sheave is provided and a seal ring is disposed between the piston and the cylinder is also provided. Are included in the configuration of the present invention. In this case, either a single piston type having one piston or a double piston type having two pistons may be used. Needless to say, in the case of the double piston type, there are two hydraulic chambers. As described above, the movable sheave according to the present invention includes not only the movable sheave alone but also a configuration in which other constituent members are attached to the movable sheave.

  In addition, this invention can also be used for the fixed sheave and the movable sheave constituting the secondary pulley. In this case, the secondary shaft 8 corresponds to the rotating member of the present invention, the movable sheave 15 corresponds to the movable sheave of the present invention, and the fixed sheave 14 corresponds to the fixed sheave of the present invention.

It is a fragmentary sectional view showing Example 1 of the belt type continuously variable transmission of this invention. It is a figure which shows an example of the power train of a vehicle which has a belt type continuously variable transmission which can apply this invention, and its control system.

Explanation of symbols

  6 ... Belt type continuously variable transmission, 7 ... Primary shaft, 11 ... Fixed sheave, 12 ... Movable sheave, 13A ... Hydraulic chamber, 17 ... Belt, 31 ... Bearing, 36 ... Nut, 37 ... Cylinder, 39 ... Cylindrical part, 44: Seal ring, 48: Stopper, S1: Seal surface.

Claims (4)

A fixed sheave attached to the rotating member so as not to move in the axial direction; a movable sheave attached to the rotating member so as to be movable in the axial direction; a belt wound around the fixed sheave and the movable sheave; A hydraulic chamber constituting member that is attached to the rotating member and forms a hydraulic chamber that applies the axial force to the movable sheave; and the hydraulic chamber constituting member that is provided on the rotating member and that is connected to the axis of the rotating member. In a belt-type continuously variable transmission including a fixing member that is positioned in a direction,
A belt type characterized in that a regulating member is provided for regulating movement of the movable sheave in the axial direction so that the cylindrical portion of the movable sheave and the hydraulic chamber constituting member do not contact directly or indirectly. Continuously variable transmission.   The belt-type continuously variable belt according to claim 1, wherein a slidable portion is formed at a contact portion between the movable sheave and the hydraulic chamber constituent member in order to liquid-tightly seal the hydraulic chamber. transmission.   3. The belt-type continuously variable transmission according to claim 1, wherein the regulating member is an annular stopper attached to the rotating member and having a part cut away in a circumferential direction. 4.   The hydraulic chamber component member is provided with a cylindrical portion centered on an axis, and a seal ring is attached to the movable sheave, and the sliding ring comes into contact with an inner peripheral surface of the cylindrical portion and slides. The belt-type continuously variable transmission according to claim 2 or 3, wherein a possible portion is formed.

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