JP2008051154A - Belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt type continuously variable transmission, capable of suppressing increase in driving loss of an oil pump. <P>SOLUTION: In the belt type continuously variable transmission, a working fluid supply valve 70 permitting only supply of working fluid to a primary oil pressure chamber 55, and a control working fluid discharge valve 80 permitting or prohibiting discharge of working fluid from the primary oil pressure chamber 55 are disposed to rotate integrally with a primary pulley 50. A working fluid supply control device 130 for controlling a gear ratio, operates, when the gear ratio is fixed, an oil pressure generated by the control device 130 and controlled to an internal pressure P1 or less of the primary oil pressure chamber 55 by a clamping force control valve 134, to a side opposite to the oil pressure chamber side of each working fluid supply valve 70. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a belt type continuously variable transmission.

  In general, a vehicle has a transmission on the output side of the drive source in order to transmit a driving force from an internal combustion engine or an electric motor that is a drive source, that is, an output torque, to the road surface under an optimal condition according to the traveling state of the vehicle. Is provided. This transmission includes a continuously variable transmission that controls the gear ratio steplessly (continuously) and a stepped transmission that controls the gear ratio stepwise (discontinuously). Here, the continuously variable transmission includes two pulleys, namely a primary pulley to which driving force from a driving source is transmitted, a secondary pulley that changes and outputs output torque transmitted to the primary pulley, and the primary pulley. There is a belt-type continuously variable transmission configured by a belt that transmits a transmitted driving force to a secondary pulley. The primary pulley and the secondary pulley include a primary pulley shaft and a secondary pulley shaft, which are two pulley shafts arranged in parallel, and two movable sheaves (primary movable sheave, Secondary movable sheave), two fixed sheaves (primary fixed sheave, secondary fixed sheave) that face the two movable sheaves in the axial direction and form a V-shaped groove between the movable sheave and the belt, On the other hand, it is composed of a clamping pressure generating hydraulic chamber that generates a belt clamping pressure. The belt is wound around a V-shaped groove formed in each of the primary pulley and the secondary pulley.

  In this belt type continuously variable transmission, each movable sheave slides on each pulley shaft in the axial direction by each clamping pressure generating hydraulic chamber, and a V-shaped groove formed in each of the primary pulley and the secondary pulley. Change the width of. As a result, the contact radius between the belt, the primary pulley and the secondary pulley is changed steplessly, and the gear ratio is changed steplessly. That is, the output torque from the drive source is changed steplessly.

  As shown in Patent Document 1, for example, the clamping pressure generating hydraulic chamber is configured to press the movable sheave toward the fixed sheave by the hydraulic pressure of the clamping pressure generating hydraulic chamber to generate belt clamping pressure on the belt. . Here, in the belt type continuously variable transmission, there is a case where the movement of the movable sheave in the axial direction with respect to the fixed sheave is restricted, that is, the position of the movable sheave with respect to the fixed sheave in the axial direction is constant, and the gear ratio is fixed. In the conventional belt-type continuously variable transmission as shown in Patent Document 1, in order to keep the belt clamping pressure constant, it is necessary to keep the hydraulic pressure in the clamping pressure generating hydraulic chamber at a predetermined hydraulic pressure.

JP 2001-323978 A

  Therefore, in the conventional belt-type continuously variable transmission, it is necessary to supply hydraulic oil to the clamping pressure generating hydraulic chamber not only when the gear ratio is changed but also when the gear ratio is fixed. For this reason, it is necessary to operate the oil pump provided in the hydraulic oil supply control device. Further, the hydraulic oil is supplied from the hydraulic oil supply control device to the clamping pressure generating hydraulic chamber through an oil passage formed in a fixed member such as a case and a movable member such as a pulley shaft of the belt type continuously variable transmission. Is called. Therefore, in order to supply hydraulic oil to the clamping pressure generating hydraulic chamber even when the gear ratio is fixed, there is a possibility that the hydraulic oil leaks from the sliding portion between the fixed member and the movable member.

  Accordingly, the present invention has been made in view of the above, and an object thereof is to provide a belt type continuously variable transmission that can suppress an increase in driving loss of an oil pump.

  In order to solve the above-described problems and achieve the object, in the present invention, two pulleys and a driving force from a driving source wound around each pulley and transmitted to one pulley are transmitted to the other pulley. And a clamping pressure generating hydraulic chamber formed in each pulley and generating a belt clamping pressure with respect to the belt by hydraulic pressure, and an operation to one clamping pressure generating hydraulic chamber among the clamping pressure generating hydraulic chambers A hydraulic oil supply valve that allows only oil supply and rotates integrally with the one pulley, and controls whether to permit or prohibit the discharge of the hydraulic oil from the one clamping pressure generating hydraulic chamber, A belt-type continuously variable transmission comprising: a hydraulic oil discharge valve that rotates integrally; and hydraulic oil supply control means that supplies the hydraulic oil to at least each of the clamping pressure generating hydraulic chambers and controls a gear ratio, Hydraulic oil supply control Stage, when the fixed gear ratio, on the side opposite to the hydraulic chamber side of the working oil supply valve, characterized in that the action of the internal pressure below the hydraulic pressure of the one of clamping force generating hydraulic chamber.

  According to the present invention, when changing the gear ratio, the hydraulic oil supply control means supplies hydraulic oil to the clamping pressure generating hydraulic chamber or controls the hydraulic oil discharge valve to operate from the clamping pressure generating hydraulic chamber. Drain the oil. On the other hand, when the gear ratio is fixed (constant), the hydraulic oil discharge valve is controlled to prohibit the hydraulic oil from being discharged from the clamping pressure generating hydraulic chamber. That is, since the hydraulic oil supply valve only allows the hydraulic oil to be supplied to the clamping pressure generating hydraulic chamber, the hydraulic oil in the clamping pressure generating hydraulic chamber is held in the clamping pressure generating hydraulic chamber. . Therefore, even if the position of the movable sheave in the axial direction with respect to the fixed sheave is changed, the position of the movable sheave in the axial direction with respect to the fixed sheave can be maintained constant by changing the oil pressure in the one clamping pressure generating hydraulic chamber. Can do. Thus, in order to maintain the position of the movable sheave in the axial direction with respect to the fixed sheave, it is not necessary to supply hydraulic oil to the clamping pressure generating hydraulic chamber from outside the clamping pressure generating hydraulic chamber. The hydraulic oil can be prevented from leaking from the sliding portion. Thereby, an increase in driving loss of the oil pump can be suppressed.

  The hydraulic oil supply control means applies a hydraulic pressure equal to or lower than the internal pressure of one clamping pressure generating hydraulic chamber to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve when the transmission gear ratio is fixed. In comparison, the pressure difference between the hydraulic chamber side of the hydraulic oil supply valve, that is, the internal pressure of one clamping pressure generating hydraulic chamber, and the hydraulic pressure on the side opposite to the hydraulic chamber side of the hydraulic oil supply valve can be reduced. Therefore, due to the pressure difference between the internal pressure of one clamping pressure generating hydraulic chamber and the hydraulic pressure on the side opposite to the hydraulic chamber side of the hydraulic oil supply valve, the hydraulic pressure side of the hydraulic oil supply valve is changed from this one clamping pressure generation hydraulic chamber to the hydraulic chamber side. The amount of hydraulic fluid leaking to the opposite side can be reduced. As a result, the gear ratio when the gear ratio is fixed can be reliably maintained.

  According to the present invention, in the belt-type continuously variable transmission, the hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve is a hydraulic pressure generated by the hydraulic oil supply control means when the transmission ratio is fixed. It is characterized by being.

  According to this invention, the hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve, which is equal to or lower than the internal pressure of one clamping pressure generating hydraulic chamber, is the hydraulic pressure generated by the hydraulic oil supply control means when the gear ratio is fixed. To do. Here, the hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve only needs to be equal to or lower than the internal pressure of one clamping pressure generating hydraulic chamber, so that the hydraulic fluid is supplied to at least the belt-type continuously variable transmission. The hydraulic pressure that can be generated when the oil supply control means is fixed at the gear ratio can be used. Therefore, it is not necessary to further drive the oil pump that is currently generating any hydraulic pressure in the hydraulic oil supply control means in order to apply the hydraulic pressure to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve. Thereby, it is possible to improve the maintenance of the gear ratio when the gear ratio is fixed without changing the drive loss of the oil pump.

  According to the present invention, in the belt type continuously variable transmission, the hydraulic oil supply control means is configured such that when the transmission ratio is fixed, the hydraulic pressure generated by the hydraulic oil supply control means is an internal pressure of the one clamping pressure generating hydraulic chamber. When the pressure exceeds the hydraulic pressure, the hydraulic pressure generated by the hydraulic oil supply control means is controlled to be equal to or lower than the internal pressure of the one clamping pressure generating hydraulic chamber.

  Here, the hydraulic pressure generated by the hydraulic oil supply control means may exceed the internal pressure of one clamping pressure generating hydraulic chamber. Therefore, if the hydraulic pressure generated by the hydraulic oil supply control means is always applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve when the transmission ratio is fixed, the hydraulic oil supply control means may open. According to the present invention, when the hydraulic pressure generated by the hydraulic oil supply control means exceeds the internal pressure of one clamping pressure generation hydraulic chamber, the hydraulic oil supply control means controls the hydraulic pressure generated by the hydraulic oil supply control means. The hydraulic pressure generated by the control means, that is, the hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve is set to be equal to or lower than the internal pressure of one clamping pressure generating hydraulic chamber. Accordingly, when the transmission ratio is fixed, the hydraulic pressure generated by the hydraulic oil supply control means can always be applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve. The maintenance of the gear ratio when the gear ratio is fixed can be further improved.

  According to the present invention, in the belt-type continuously variable transmission, the hydraulic oil supply control means operates on a side opposite to the hydraulic chamber side of the hydraulic oil supply valve based on a leakage characteristic of the hydraulic oil supply valve. It is characterized by changing.

  Here, the leakage characteristic of the hydraulic oil supply valve varies depending on the hydraulic oil supply valve. For example, the hydraulic oil supply valve has a leakage characteristic in which the amount of hydraulic oil leaked by the hydraulic oil supply valve becomes a minimum at a predetermined pressure difference in the vicinity of 0, rather than the pressure difference between the hydraulic chamber side and the opposite side being 0. There is also. According to the present invention, the hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve is changed based on the leakage characteristic of the hydraulic oil supply valve, that is, the leakage amount is minimized based on the leakage characteristic of the hydraulic oil supply valve. The hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve can be changed with respect to the internal pressure of one clamping pressure generating hydraulic chamber so that the pressure difference between the hydraulic chamber side and the opposite side becomes. Therefore, by changing the hydraulic pressure that acts on the side opposite to the hydraulic chamber side of the hydraulic oil supply valve based on the leakage characteristics of the hydraulic oil supply valve, the hydraulic oil supply valve The amount of hydraulic oil leakage can be reduced. Thereby, maintenance of the gear ratio when the gear ratio is fixed can be improved.

  The belt type continuously variable transmission according to the present invention can prevent the hydraulic oil from being discharged from the clamping pressure generating hydraulic chamber when the transmission gear ratio is fixed, so that an increase in driving loss of the oil pump can be suppressed. . In addition, when the transmission gear ratio is fixed, a hydraulic pressure equal to or lower than the internal pressure of one clamping pressure generating hydraulic chamber is applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve, so that the transmission gear ratio when the transmission gear ratio is fixed is reliably maintained. Can do.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following Example. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or that are substantially the same. Here, an internal combustion engine (gasoline engine, diesel engine, LPG engine, etc.) is used as a drive source for generating a drive force transmitted to the belt type continuously variable transmission in the following embodiment, but the invention is not limited to this. Alternatively, an electric motor such as a motor may be used as a drive source.

  In the following embodiment, one pulley is a primary pulley and the other pulley is a secondary pulley. In the following embodiments, the hydraulic oil supply valve and the hydraulic oil discharge valve are arranged in the primary pulley shaft of the primary pulley. However, the hydraulic oil supply valve and the hydraulic oil discharge valve need only be able to rotate integrally with one of the pulleys, and are not limited thereto. is not. For example, the hydraulic oil supply valve and the hydraulic oil discharge valve may be arranged on the primary movable sheave, the primary fixed sheave, the primary partition wall, and the like.

  FIG. 1 is a skeleton diagram of a belt type continuously variable transmission according to the present invention. FIG. 2 is a cross-sectional view of the main part of the primary pulley when the transmission gear ratio is fixed. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 4 is a cross-sectional view taken along line BB in FIG. 5A and 5B are diagrams illustrating the torque cam. 6 and 7 are explanatory diagrams of the operation of the belt type continuously variable transmission when the gear ratio is changed. FIG. 8 is a diagram showing an operation flow of the control method of the belt type continuously variable transmission at the time of downshift. 9A and 9B are diagrams illustrating the state of the hydraulic oil supply valve when the transmission gear ratio is fixed.

  As shown in FIG. 1, a transaxle 20 is disposed on the output side of the internal combustion engine 10 that is a drive source. The transaxle 20 includes a transaxle housing 21, a transaxle case 22 attached to the transaxle housing 21, and a transaxle rear cover 23 attached to the transaxle case 22.

  A torque converter 30 is accommodated in the transaxle housing 21. On the other hand, inside the case constituted by the transaxle case 22 and the transaxle rear cover 23, a primary pulley 50 and a secondary pulley 60, which are two pulleys constituting the belt type continuously variable transmission 1 according to the present invention, The primary hydraulic chamber 55, the secondary hydraulic chamber 64, the hydraulic oil supply valve 70, the hydraulic oil discharge valve 80, and the belt 110 are accommodated. Reference numeral 40 denotes a forward / reverse switching mechanism, 90 denotes a final reduction gear that transmits the driving force of the internal combustion engine 10 to the wheels 120, 100 denotes a power transmission path, and 130 denotes hydraulic oil supply that is hydraulic oil supply control means according to the present invention. It is a control device.

  As shown in FIG. 1, the torque converter 30 serving as a starting mechanism increases or transmits the driving force from the driving source, that is, the output torque from the internal combustion engine 10 to the belt type continuously variable transmission 1 as it is. The torque converter 30 includes at least a pump (pump impeller) 31, a turbine (turbine impeller) 32, a stator 33, a lockup clutch 34, and a damper device 35.

  The pump 31 is attached to a hollow shaft 36 that can rotate around the same axis as the crankshaft 11 of the internal combustion engine 10. That is, the pump 31 can rotate about the same axis as the crankshaft 11 together with the hollow shaft 36. The pump 31 is connected to the front cover 37. The front cover 37 is connected to the crankshaft 11 via the drive plate 12 of the internal combustion engine 10.

  The turbine 32 is disposed so as to face the pump 31. The turbine 32 is disposed inside the hollow shaft 36 and is attached to an input shaft 38 that can rotate about the same axis as the crankshaft 11. That is, the turbine 32 can rotate about the same axis as the crankshaft 11 together with the input shaft 38.

  A stator 33 is disposed between the pump 31 and the turbine 32 via a one-way clutch 39. The one-way clutch 39 is fixed to the transaxle housing 21. A lockup clutch 34 is disposed between the turbine 32 and the front cover 37, and the lockup clutch 34 is connected to an input shaft 38 via a damper device 35. The casing formed by the pump 31 and the front cover 37 is a hydraulic oil supply portion of the belt-type continuously variable transmission 1, and hydraulic oil is supplied as a hydraulic fluid from the hydraulic oil supply control device 130.

  Here, the operation of the torque converter 30 will be described. The output torque from the internal combustion engine 10 is transmitted from the crankshaft 11 to the front cover 37 via the drive plate 12. When the lock-up clutch 34 is released by the damper device 35, the output torque from the internal combustion engine 10 transmitted to the front cover 37 is transmitted to the pump 31 and circulates between the pump 31 and the turbine 32. It is transmitted to the turbine 32 via oil. The output torque from the internal combustion engine 10 transmitted to the turbine 32 is transmitted to the input shaft 38. That is, the torque converter 30 increases the output torque from the internal combustion engine 10 via the input shaft 38 and transmits it to the belt type continuously variable transmission 1. In the above, the stator 33 can change the flow of hydraulic fluid circulating between the pump 31 and the turbine 32 to obtain a predetermined torque characteristic.

  On the other hand, when the lock-up clutch 34 is locked (engaged with the front cover 37) by the damper device 35, the output torque from the internal combustion engine 10 transmitted to the front cover 37 is directly not via hydraulic oil. It is transmitted to the input shaft 38. That is, the torque converter 30 transmits the output torque from the internal combustion engine 10 as it is to the belt type continuously variable transmission 1 via the input shaft 38.

  As shown in FIG. 1, the forward / reverse switching mechanism 40 transmits the output torque from the internal combustion engine 10 transmitted through the torque converter 30 to the primary pulley 50 of the belt type continuously variable transmission 1. The forward / reverse switching mechanism 40 includes at least a planetary gear device 41, a forward clutch 42, and a reverse brake 43.

  The planetary gear device 41 includes a sun gear 44, a pinion 45, and a ring gear 46.

  The sun gear 44 is spline-fitted to a connecting member (not shown). This connecting member is spline-fitted to the primary pulley shaft 51 of the primary pulley 50. Accordingly, the output torque from the internal combustion engine 10 transmitted to the sun gear 44 is transmitted to the primary pulley shaft 51.

  The pinion 45 meshes with the sun gear 44, and a plurality of (for example, three) pinions 45 are arranged around it. Each pinion 45 is held by a switching carrier 47 that is supported around the sun gear 44 so as to be able to revolve integrally. The switching carrier 47 is connected to the reverse brake 43 at its outer peripheral end.

  The ring gear 46 meshes with each pinion 45 held by the switching carrier 47 and is connected to the input shaft 38 of the torque converter 30 via the forward clutch 42.

  The forward clutch 42 is ON / OFF controlled by supplying hydraulic oil from the hydraulic oil supply control device 130 to a hollow portion (not shown) of the input shaft 38 that is a hydraulic oil supply portion of the belt type continuously variable transmission 1. Is. When the forward clutch 42 is OFF, the output torque from the internal combustion engine 10 transmitted to the input shaft 38 is transmitted to the ring gear 46. On the other hand, when the forward clutch 42 is ON, the output torque from the internal combustion engine 10 transmitted to the input shaft 38 is directly transmitted to the sun gear 44 without the ring gear 46, the sun gear 44, and the pinions 45 rotating relative to each other.

  The reverse brake 43 is ON / OFF controlled by supplying hydraulic oil from a hydraulic oil supply control device 130 to a brake piston (not shown) which is a hydraulic oil supply portion of the belt type continuously variable transmission 1. . When the reverse brake 43 is ON, the switching carrier 47 is fixed to the transaxle case 22 so that each pinion 45 cannot revolve around the sun gear 44. When the reverse brake 43 is OFF, the switching carrier 47 is released, and each pinion 45 can revolve around the sun gear 44.

  The primary pulley 50 of the belt-type continuously variable transmission 1 is one of the pulleys, and transmits the output torque from the internal combustion engine 10 transmitted through the forward / reverse switching mechanism 40 to the secondary pulley 60 through the belt 110. is there. As shown in FIGS. 1 and 2, the primary pulley 50 includes a primary pulley shaft 51, a primary fixed sheave 52, a primary movable sheave 53, a primary partition wall 54, and a primary hydraulic chamber 55.

  As shown in FIG. 2, the primary pulley shaft 51 is rotatably supported by bearings 111 and 112. The primary pulley shaft 51 is provided with a supply-side main passage 51a and a drive-side main passage 51b that are opened only at both ends in the axial direction.

  The supply-side main passage 51a is formed on the primary fixed sheave side, and the hydraulic oil supplied from the hydraulic oil supply control device 130 to the primary hydraulic chamber 55 that is one clamping pressure generating hydraulic chamber flows into the supply-side main passage 51a. The supply-side main passage 51a is provided between the primary movable sheave 53 and the primary pulley shaft 51 via a plurality of shaft-side communication passages 51c (three in this embodiment) formed in the vicinity of the tip portion. Communicating with

  Further, the drive side main passage 51b is formed on the side opposite to the primary fixed sheave side, and the hydraulic oil supplied from the hydraulic oil supply control device 130 to each drive hydraulic chamber 86 constituting each actuator flows in. The drive side main passage 51b is connected to each drive hydraulic chamber 86 (described in this embodiment) of the primary partition wall 54 via the shaft side communication passage 51d and the partition wall side communication passage 54d of the primary partition wall 54 (described later). 3 places).

  As shown in FIG. 2, the primary fixed sheave 52 is provided to rotate integrally with the primary pulley shaft 51 at a position facing the primary movable sheave 53. Here, the primary fixed sheave 52 is formed as an annular portion that protrudes radially outward from the outer periphery of the primary pulley shaft 51. That is, in this embodiment, the primary fixed sheave 52 is integrally formed on the outer periphery of the primary pulley shaft 51.

  As shown in FIG. 2, the primary movable sheave 53 includes a cylindrical portion 53a and an annular portion 53b. The cylindrical portion 53 a is formed around the same rotational axis as the primary pulley shaft 51. The annular portion 53b is formed so as to protrude radially outward from the end portion of the cylindrical portion 53a on the primary fixed sheave side. The primary movable sheave 53 has a spline 53c formed on the inner peripheral surface of the cylindrical portion 53a and a spline 51e formed on the outer peripheral surface of the primary pulley shaft 51. It is slidably supported in the axial direction. Between the primary fixed sheave 52 and the primary movable sheave 53, that is, between the surface of the primary fixed sheave 52 facing the primary movable sheave 53 and the surface of the primary movable sheave 53 facing the primary fixed sheave 52. A primary groove 110a having a shape is formed.

  Further, the primary movable sheave 53 is formed with an annular projecting portion 53d that projects in the other direction of the axial direction, that is, an annular projecting portion 53d that projects toward the primary partition wall, in the vicinity of the outer peripheral end of the annular portion 53b. Further, the cylindrical portion 53 a of the primary movable sheave 53 is formed with a primary hydraulic chamber 55 and a supply-side passage 53 e that communicates between the primary movable sheave 53 and the primary pulley shaft 51. The supply-side passage 53e has a cylindrical shape, and is formed at a plurality of locations on the circumference of the cylinder portion 53a at equal intervals (in this embodiment, three locations). Each supply-side passage 53e is formed with an annular valve seat step portion 53f that is closed by the valve body 71 of each hydraulic oil supply valve 70, respectively. The hydraulic fluid supplied from the hydraulic fluid supply control device 130 to the primary hydraulic chamber 55 flows into the supply-side passages 53e through the supply-side main passages 51a and the shaft-side communication passages 51c. That is, the supply-side passage 53 e supplies hydraulic oil to the primary hydraulic chamber 55.

  As shown in FIG. 2, the primary partition wall 54 is an annular member, and is arranged around the same rotational axis as the primary pulley shaft 51. The primary partition 54 is disposed so as to face the primary fixed sheave 52 in the axial direction with the primary movable sheave 53 interposed therebetween. The radially inner end of the primary partition wall 54 is fixed to the primary pulley shaft 51. Therefore, the primary partition 54 is provided so as to rotate integrally with the primary movable sheave 53.

  The primary partition wall 54 is formed with a discharge side passage 54a in the vicinity of the central portion in the radial direction so as to communicate both side surfaces facing each other in the axial direction. The discharge-side passage 54a has a cylindrical shape, and is formed at a plurality of locations on the circumference of the primary partition wall 54 at equal intervals (in this embodiment, three locations). Each discharge side passage 54a is formed with an annular valve seat protrusion 54b that is closed by a valve body 81 of each hydraulic oil discharge valve 80. Each discharge-side passage 54a is fixed by inserting a closing member 54c into one end thereof, that is, the end opposite to the primary fixed sheave side. Therefore, each discharge side passage 54 a is formed so that only the other end, that is, the end on the primary fixed sheave side, opens into the primary hydraulic chamber 55.

  In addition, a plurality of partition-side communication passages 54d and discharge passages 54e are formed in the primary partition 54 corresponding to the discharge-side passages 54a (three in this embodiment). As shown in FIG. 3, each partition-side communication passage 54d has one end communicating with the drive-side main passage 51b via the shaft-side communication passage 51d and the other end closed by a closing member 54f. ing. As shown in FIG. 2, each partition wall side communication passage 54d communicates with each discharge side passage 54a in the middle of the passage. Here, each partition wall side communication passage 54d opens to each drive hydraulic chamber 86 formed between each closing member 54c and each valve opening member 85 of each hydraulic oil discharge valve 80. There is no opening in each discharge space 87 facing the drive hydraulic chamber 86 across each valve opening member 85. That is, each partition wall side communication passage 54d communicates only with each drive hydraulic chamber 86 in each discharge side passage 54a. Accordingly, the hydraulic oil in the drive side main passage 51b that has flowed into the partition wall side communication passages 54d is supplied only to the drive hydraulic chambers 86, respectively.

  As shown in FIG. 4, the discharge passage 54 e has one end communicating with the discharge space 87 and the other end of the outer peripheral surface of the primary partition wall 54 constituting the primary hydraulic chamber 55. It opens as a discharge port in the excluded part. That is, the discharge side passage 54a discharges the hydraulic oil of the primary hydraulic chamber 55 from the discharge port to the transaxle 20 through the discharge passage 54e to the outside, in this embodiment. The cross-sectional area of the discharge port is the same in this embodiment. Therefore, when the hydraulic pressure of the hydraulic oil in each discharge space is the same, the discharge flow rate when the hydraulic oil from the primary hydraulic chamber 55 is discharged by each hydraulic oil discharge valve 80 becomes the same. Further, the discharge passage 54 e is in direct communication with the outside of the primary hydraulic chamber 55.

  The primary hydraulic chamber 55 is one clamping pressure generating hydraulic chamber, and as shown in FIG. 2, by pressing the primary movable sheave 53 toward the primary fixed sheave side, the primary pulley 50, that is, the V-shaped primary groove 110a. A belt clamping pressure is generated with respect to the belt 110 wound around the belt. The primary hydraulic chamber 55 is a space formed by the primary pulley shaft 51, the primary movable sheave 53, and the primary partition wall 54. Here, between the protrusion 53d of the primary movable sheave 53 and the primary partition wall 54 and between the cylindrical portion 53a of the primary movable sheave 53 and the primary pulley shaft 51, for example, a seal member S such as a seal ring is provided. ing. That is, the space formed by the primary pulley shaft 51, the primary movable sheave 53, and the primary partition wall 54 constituting the primary hydraulic chamber 55 is sealed by the seal member S.

  The primary hydraulic chamber 55 is supplied with hydraulic oil from the hydraulic oil supply control device 130 that has flowed into the supply-side main passage 51 a of the primary pulley shaft 51. In the primary hydraulic chamber 55, the primary movable sheave 53 is slid in the axial direction by the pressure of the hydraulic oil supplied from the hydraulic oil supply control device 130, that is, the internal pressure P1 of the primary hydraulic chamber 55, and the primary movable sheave 53 is primary fixed. It approaches or separates from the sheave 52. Thus, the primary hydraulic chamber 55 generates a belt clamping pressure with respect to the belt 110 by the internal pressure P1 of the primary hydraulic chamber 55, and changes the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52. Thus, the primary hydraulic chamber 55 mainly changes the gear ratio of the belt type continuously variable transmission 1.

  The secondary pulley 60 of the belt type continuously variable transmission 1 transmits the output torque from the internal combustion engine 10 transmitted to the primary pulley 50 by the belt 110 to the final reduction gear 90 of the belt type continuously variable transmission 1. As shown in FIG. 1, the secondary pulley 60 includes a secondary pulley shaft 61, a secondary fixed sheave 62, a secondary movable sheave 63, a secondary hydraulic chamber 64, a secondary partition wall 65, and a torque cam 66. Reference numeral 69 denotes a parking brake gear.

  The secondary pulley shaft 61 is rotatably supported by bearings 113 and 114. Further, the secondary pulley shaft 61 has a hydraulic oil passage (not shown) inside, and hydraulic oil supplied from the hydraulic oil supply control device 130 to the secondary hydraulic chamber 64 flows into the hydraulic oil passage.

  Secondary fixed sheave 62 is provided to rotate integrally with secondary pulley shaft 61 at a position facing secondary movable sheave 63. Here, the secondary fixed sheave 62 is formed as an annular portion that protrudes radially outward from the outer periphery of the secondary pulley shaft 61. That is, in this embodiment, the secondary fixed sheave 62 is integrally formed on the outer periphery of the secondary pulley shaft 61.

  The secondary movable sheave 63 has a spline (not shown) formed on the inner peripheral surface of the secondary movable sheave 63 and a spline (not shown) formed on the outer peripheral surface of the secondary pulley shaft 61. It is slidably supported on. Between the secondary fixed sheave 62 and the secondary movable sheave 63, that is, between the surface of the secondary fixed sheave 62 facing the secondary movable sheave 63 and the surface of the secondary movable sheave 63 facing the secondary fixed sheave 62. A secondary groove 110b having a shape is formed.

  The secondary hydraulic chamber 64 is the other clamping pressure generating hydraulic chamber, and as shown in FIG. 1, by pressing the secondary movable sheave 63 toward the secondary fixed sheave, the secondary pulley 60, that is, the V-shaped primary groove 110b. A belt clamping pressure is generated with respect to the belt 110 wound around the belt. The secondary hydraulic chamber 64 is a space formed by a secondary pulley shaft 61, a secondary movable sheave 63, and a disk-shaped secondary partition wall 65 fixed to the secondary pulley shaft 61. The secondary movable sheave 63 is formed with an annular protrusion 63 a that protrudes in one axial direction, that is, protrudes toward the final reduction gear 90. On the other hand, the secondary partition wall 65 is formed with an annular projecting portion 65a projecting in the other axial direction, that is, projecting to the secondary movable sheave 63 side. Here, a seal member (not shown) such as a seal ring is provided between the protrusion 63a and the protrusion 65a. That is, the space formed by the secondary movable sheave 63 and the secondary partition wall 65 constituting the secondary hydraulic chamber 64 is sealed by a seal member (not shown).

  The secondary hydraulic chamber 64 is supplied with hydraulic oil from the hydraulic oil supply control device 130 that has flowed into a hydraulic oil passage (not shown) of the secondary pulley shaft 61 via a hydraulic fluid supply hole (not shown). The hydraulic fluid is supplied to the secondary hydraulic chamber 64, and the secondary movable sheave 63 is slid in the axial direction by the pressure of the hydraulic fluid supplied from the hydraulic oil supply control device 130, that is, the internal pressure of the secondary hydraulic chamber 64, and the secondary movable sheave 63 63 is moved toward or away from the secondary fixed sheave 62. Thus, the secondary hydraulic chamber 64 generates a belt clamping pressure with respect to the belt 110 by the internal pressure of the secondary hydraulic chamber 64, and maintains a constant contact radius of the belt 110 with respect to the primary pulley 50 and the secondary pulley 60.

  As shown in FIG. 5A, the torque cam 66 includes a mountain-shaped first engagement portion 63 b provided in an annular shape on the secondary movable sheave 63 of the secondary pulley 60, and the first engagement portion 63 b and the secondary pulley shaft 61. And a plurality of disk-shaped discs arranged between the first engaging portion 63b and the second engaging portion 67a. The transmission member 68 is configured.

  The intermediate member 67 is formed integrally with the secondary partition wall 65 or fixed to the secondary partition wall 65 and supported by the bearings 113 and 115 so as to be relatively rotatable on the secondary pulley shaft 61 with respect to the secondary pulley shaft 61 and the secondary movable sheave 63. Has been. This intermediate member 67 is spline-fitted with the input shaft 101 of the power transmission path 100. That is, the output torque from the internal combustion engine 10 transmitted to the secondary pulley 60 is transmitted to the power transmission path 100 via the intermediate member 67.

  Here, the operation of the torque cam 66 will be described. When the output torque from the internal combustion engine 10 is transmitted to the primary pulley 50 and the primary pulley 50 rotates, the secondary pulley 60 rotates via the belt 100. At this time, since the secondary movable sheave 63 of the secondary pulley 60 rotates together with the secondary fixed sheave 62, the secondary pulley shaft 61, and the bearing 113, relative rotation occurs between the secondary movable sheave 63 and the intermediate member 67. Then, as shown in FIG. 5A, from the state where the first engaging portion 63b and the second engaging portion 67a approach each other, the first engaging portion as shown in FIG. The portion 63b and the second engaging portion 67a are changed to a separated state. As a result, the torque cam 66 generates a belt clamping pressure with respect to the belt 110 in the secondary pulley 60.

  That is, the secondary pulley 60 is provided with a torque cam 66 as a means for generating a belt clamping pressure with respect to the belt 110 in addition to the secondary hydraulic chamber 64 which is a clamping pressure generating hydraulic chamber. The torque cam 66 mainly generates belt clamping pressure, and the secondary hydraulic chamber 64 generates a shortage of belt clamping pressure generated by the torque cam 66. The secondary hydraulic chamber 64 may be the only means for generating the belt clamping pressure with respect to the belt 110 in the secondary pulley 60.

  As shown in FIG. 2, the hydraulic oil supply valve 70 allows only hydraulic oil to be supplied to the primary hydraulic chamber 55 that is a clamping pressure generating hydraulic chamber. That is, the hydraulic oil supply valve 70 prohibits the discharge of hydraulic oil from the primary hydraulic chamber 55. In this embodiment, the hydraulic oil supply valve 70 is a ball check valve, and is disposed in each supply-side passage 53e of the primary movable sheave 53. That is, the hydraulic oil supply valve 70 is arranged at a plurality of positions on the primary movable sheave 53 at equal intervals on the circumference (three positions in this embodiment). Each hydraulic oil supply valve 70 includes a valve body 71, a supply-side elastic member 72 that is a supply-side urging means, a disk member 73, and a locking member 74.

  Each valve body 71 is disposed closer to the primary hydraulic chamber than the valve seat step portion 53f of each supply side passage 53e, and has a diameter larger than the diameter of each valve seat step portion 53f. Each supply-side elastic member 72 is attached between each disk member 73 fixed to the supply-side passage 53e by each locking member 74 and each valve seat stepped portion 53f via each valve body 71. Each is arranged in a state of being energized. Each supply-side elastic member 72 generates a supply-side urging force in a direction in which each valve body 71 comes into contact with each valve seat stepped portion 53f. This supply-side urging force is generated by each valve body 71 in each valve seat. It acts on each valve body 71 as a pressing force in a direction in contact with the stepped portion 53f, that is, a valve closing direction. Each locking member 74 has a disc shape, and an opening for allowing hydraulic oil to pass therethrough is formed at the center thereof.

  Here, the hydraulic oil supply valve 70 is opposite to the primary hydraulic chamber side which is one clamping pressure generation hydraulic chamber across each hydraulic oil supply valve 70 of each supply side passage 53e, that is, the hydraulic pressure of each hydraulic supply valve 70. Valve opening direction acting on each valve body 71 by the hydraulic pressure on the opposite side to the chamber side (hereinafter simply referred to as “supply side hydraulic pressure P2”) (the direction in which each valve body 71 moves away from each valve seat step portion 53f) In the valve closing direction (the valve bodies 71 are in contact with the valve seat step portions 53f, respectively) acting on the valve bodies 71 by the internal pressure P1 of the primary hydraulic chamber 55 and the supply side biasing force of the supply side elastic member 72. The valve closed state is maintained as long as the pressing force in the direction) is not exceeded. The supply side hydraulic pressure P2 is generated by the hydraulic oil supplied by the hydraulic oil supply control device 130 to the side opposite to the hydraulic chamber side of each hydraulic supply valve 70.

  On the other hand, in the hydraulic oil supply valve 70, the pressing force in the valve opening direction acting on each valve body 71 by the supply side hydraulic pressure P2 is changed by the internal pressure P1 of the primary hydraulic chamber 55 and the supply side biasing force of the supply side elastic member 72. When the pressing force in the valve closing direction acting on the valve body 71 is exceeded, the valve body 71 moves in the valve opening direction with respect to the valve seat step portion 53f, and the hydraulic oil supply valve 70 is opened. That is, the hydraulic oil supply valve 70 is a check valve that opens only in the direction in which the hydraulic oil is supplied to the primary hydraulic chamber 55 from the outside. The internal pressure P1 of the primary hydraulic chamber 55 acts on each valve body 71, but acts in the valve closing direction. Therefore, even if the internal pressure P1 of the primary hydraulic chamber 55 increases, It does not leave the portion 53f. Therefore, the closed state of the hydraulic oil supply valve 70 is maintained, and the hydraulic oil in the primary hydraulic chamber 55 that is one clamping pressure generating hydraulic chamber is held in the primary hydraulic chamber 55.

  The hydraulic oil discharge valve 80 controls permission or prohibition of hydraulic oil discharge from the primary hydraulic chamber 55 which is one clamping pressure generating hydraulic chamber. In this embodiment, the hydraulic oil discharge valve 80 includes a ball-type check valve and an actuator, and is disposed in each discharge side passage 54 a of the primary partition wall 54. That is, the hydraulic oil discharge valves 80 are arranged at a plurality of positions on the primary partition wall 54 at equal intervals on the circumference (three positions in this embodiment). Each hydraulic oil discharge valve 80 includes a valve body 81, a discharge side elastic member 82 that is a discharge side urging means, a disk member 83, a locking member 84, a valve opening member 85, and a drive hydraulic chamber 86. And the discharge space 87.

  Each valve element 81 is disposed closer to the primary hydraulic chamber than the valve seat protrusion 54b of each discharge side passage 54a, and has a diameter larger than the inner diameter of each valve seat protrusion 54b. Each discharge side elastic member 82 is urged between each disk member 83 fixed to the discharge side passage 54a by each locking member 84 and each valve body protruding portion 54b via each valve body 81. Each is arranged in the state. Each discharge-side elastic member 82 generates a discharge-side urging force in a direction in which each valve body 81 comes into contact with each valve seat protrusion 54b, and this discharge-side urging force causes each valve body 81 to have a valve seat protrusion. It acts on each valve body 81 as a pressing force in a direction contacting 54b, that is, a valve closing direction. Each locking member 84 has a disk shape, and an opening for allowing hydraulic oil to pass therethrough is formed at the center thereof.

  The valve opening member 85 has a cylindrical shape and is supported on the opposite side of the primary hydraulic chamber side from the valve body protrusions 54b of the discharge side passages 54a so as to be slidable in the axial direction of the discharge side passages 54a. ing. A valve body pressing projection 85a is formed at one end in the axial direction of each valve opening member 85, that is, at the end on the primary hydraulic chamber side. The valve body pressing projections 85a are slid to the primary hydraulic chamber side by the pressing force to the primary hydraulic chamber side acting on the valve opening members 85 by the internal pressure P3 of the drive hydraulic chambers 86. By moving, the valve body pressing protrusions 85 a come into contact with the valve bodies 81. Then, the pressing force by which each valve opening member 85 presses each valve body 81 toward the primary hydraulic chamber side by the internal pressure P3 of the drive hydraulic chamber 86 causes the internal pressure P1 of the primary hydraulic chamber 55 and the discharge side elastic member 82 to be attached to the discharge side. When the pressing force to the side opposite to the primary hydraulic chamber acting on each valve body 81 due to the force is exceeded, each valve body 81 moves in the direction toward the primary hydraulic chamber with respect to the valve seat protrusion 54b, that is, in the valve opening direction. It moves and each hydraulic oil discharge valve 80 opens. That is, each hydraulic oil discharge valve 80 is a check valve that opens only in the direction in which the hydraulic oil is discharged from the primary hydraulic chamber 55 to the outside. Although the internal pressure P1 of the primary hydraulic chamber 55 acts on each valve body 81, it acts in the direction opposite to the primary hydraulic chamber side, that is, the valve closing direction, so the internal pressure P1 of the primary hydraulic chamber 55 increases. In addition, each valve element 81 does not separate from each valve seat protrusion 54b. Therefore, the closed state of the hydraulic oil discharge valve 80 is maintained, and the hydraulic oil in the primary hydraulic chamber 55 which is one clamping pressure generating hydraulic chamber is held in the primary hydraulic chamber 55. The hydraulic oil discharge valve 80 uses the internal pressure P3 of the drive hydraulic chamber 86 in order to control whether the hydraulic oil is discharged or allowed from the primary hydraulic chamber 55 which is one clamping pressure generating hydraulic chamber. However, the present invention is not limited to this, and rotational force such as a motor or electromagnetic force may be used.

  Each drive hydraulic chamber 86 is a hydraulic oil supply portion of the belt-type continuously variable transmission 1, and includes a valve opening member 85, an inner wall surface that forms the discharge side space 54 a of the primary pulley shaft 51, and an inside of the closing member 54 c. And wall surfaces. The hydraulic oil is supplied to the drive hydraulic chambers 86 from the hydraulic oil supply controller 130 via the drive-side main passages 51, the shaft-side communication passages 51d, and the partition-side communication passages 54d.

  Here, like the conventional belt-type continuously variable transmission, the hydraulic oil supply control device 130 is operated to the primary hydraulic chamber 55 in order to keep the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 constant. When oil is continuously supplied, the hydraulic oil having a predetermined pressure exists in the hydraulic oil supply path from the hydraulic oil supply control device 130 to the primary hydraulic chamber 55. The hydraulic oil supply path includes a plurality of sliding portions between the fixed member and the movable member. When the transmission gear ratio is fixed, hydraulic oil of a predetermined pressure is moved from the sliding portion to the outside of the hydraulic oil supply path. There was a risk of leakage. This fixing member is a member that does not rotate, slide, or the like among the members constituting the belt type continuously variable transmission 1. For example, a transaxle housing 21, a transaxle case 22, and a transaxle rear cover 23 of the transaxle 20. On the other hand, this movable member is a member that rotates, slides, etc. in the members constituting the belt type continuously variable transmission 1. For example, the primary pulley shaft 51 or the like. Therefore, the sliding portion includes, for example, a portion where the primary pulley shaft 51 rotates with respect to the transaxle housing 21, the transaxle case 22, the transaxle rear cover 23, and the like of the transaxle 20.

  However, in the belt type continuously variable transmission 1 according to the present invention, the hydraulic oil supply valve 70 and the hydraulic oil discharge valve 80 are disposed between the primary hydraulic chamber 55 and the sliding portion. That is, when the hydraulic oil supply valve 70 and the hydraulic oil discharge valve 80 are maintained in the closed state and the hydraulic oil is held in the primary hydraulic chamber 55, the primary hydraulic chamber 55, the hydraulic oil supply valve 70, and the hydraulic oil Between the discharge valve 80, there is no sliding portion between the fixed member and the movable member. Thereby, since it can suppress that hydraulic oil leaks from this sliding part, the increase in the drive loss of an oil pump can be suppressed.

  A power transmission path 100 is disposed between the secondary pulley 60 and the final reduction gear 90. The power transmission path 100 includes an input shaft 101 on the same axis as the secondary pulley shaft 61, an intermediate shaft 102 parallel to the input shaft 101, a counter drive pinion 103, a counter driven gear 104, and a final drive pinion 105. It is configured. The input shaft 101 and the counter drive pinion 103 fixed to the input shaft 101 are rotatably held by bearings 118 and 119. The intermediate shaft 102 is rotatably supported by bearings 116 and 117. The counter driven gear 104 is fixed to the intermediate shaft 102 and meshed with the counter drive pinion 103. The final drive pinion 105 is fixed to the intermediate shaft 102.

  The final speed reducer 90 of the belt-type continuously variable transmission 1 transmits the output torque from the internal combustion engine 10 transmitted through the power transmission path 100 from the wheels 120 and 120 to the road surface. The final reduction gear 90 includes a differential case 91 having a hollow portion, a pinion shaft 92, differential pinions 93 and 94, and side gears 95 and 96.

  The differential case 91 is rotatably supported by bearings 97 and 98. A ring gear 99 is provided on the outer periphery of the differential case 91, and the ring gear 99 is engaged with the final drive pinion 105. The pinion shaft 92 is attached to the hollow portion of the differential case 91. The differential pinions 93 and 94 are rotatably attached to the pinion shaft 92. The side gears 95 and 96 are meshed with both the differential pinions 93 and 94. The side gears 95 and 96 are fixed to the drive shafts 121 and 122, respectively.

  The belt 110 of the belt type continuously variable transmission 1 transmits the output torque from the internal combustion engine 10 transmitted through the primary pulley 50 to the secondary pulley 60. As shown in FIG. 1, the belt 110 is wound between a primary groove 110 a for the primary pulley 50 and a secondary groove 110 b for the secondary pulley 60. That is, the belt 110 is wound around the primary pulley 50 and the secondary pulley 60. Further, the belt 110 is an endless belt composed of, for example, a large number of metal pieces and a plurality of steel rings.

  The drive shafts 121 and 122 have side gears 95 and 96 fixed to one end thereof and wheels 120 and 120 attached to the other end thereof.

  The hydraulic oil supply control device 130 supplies hydraulic oil to a hydraulic oil supply portion that requires supply of hydraulic oil in a vehicle on which the belt type continuously variable transmission 1 and the internal combustion engine 10 are mounted. The hydraulic oil supply control device 130 supplies hydraulic oil to the primary hydraulic chamber 55, the secondary hydraulic chamber 64, the drive hydraulic chamber 86, and the like, and controls the hydraulic pressure to thereby change the gear ratio of the belt type continuously variable transmission 1. It is also what controls.

  The hydraulic oil supply part other than the drive hydraulic chamber 86 includes the above-described hydraulic oil supply part, the hydraulic oil supply part of the internal combustion engine 10 (for example, a stationary part or a dynamic part having a sliding surface with the dynamic part). Alternatively, there are a moving part having a sliding surface between stationary parts, a heated part, and a driving device driven by oil). Here, the hydraulic oil supply portion excluding the primary hydraulic chamber 55 and the drive hydraulic chamber 86 which are one clamping pressure generating hydraulic chamber is assumed to be another hydraulic oil supply portion (including the secondary hydraulic chamber 64).

  As shown in FIG. 2, the hydraulic oil supply control device 130 includes an oil pan 131, an oil pump 132, a pressure regulator 133, a pinching pressure regulating valve 134, and a pressing force regulating valve 135.

  The oil pump 132 sucks, pressurizes, and discharges the hydraulic oil stored in the oil pan 131. This oil pump 132 is connected to a pressure regulator 133. The hydraulic oil pressurized and discharged by the oil pump 132 is supplied to the pressure regulator 133. The oil pump 132 is disposed between the torque converter 30 and the forward / reverse switching mechanism 40 as shown in FIG. The oil pump 132 includes a rotor 132a, a hub 132b, and a body 132c. The oil pump 132 is connected to the pump 31 by a rotor 132a via a cylindrical hub 132b. The body 132c is fixed to the transaxle case 22. The hub 132b is spline-fitted to the hollow shaft 36. Therefore, the oil pump 132 can be driven because the output torque from the internal combustion engine 10 is transmitted to the rotor 132a via the pump 31. That is, the oil pump 132 increases the discharge amount of the discharged hydraulic oil, that is, the hydraulic pressure generated by the hydraulic oil supply control device 130 increases as the rotational speed of the internal combustion engine 10 increases.

  The pressure regulator 133 returns a part of the hydraulic oil on the oil pump side to the oil pan 131 when the hydraulic pressure on the downstream side of the pressure regulator 133, that is, on the oil pump side becomes equal to or higher than a predetermined hydraulic pressure. . The pressure regulator 133 is connected to a clamping pressure regulating valve 134 and a pressing pressure regulating valve 135. Further, the pressure regulator 133 is directly connected to another hydraulic oil supply portion through another pressure regulating valve (not shown) or without going through another pressure regulating valve. Accordingly, the hydraulic oil pressurized and discharged by the oil pump 132 is supplied to the clamping pressure regulating valve 134, the pressing pressure regulating valve 135, and other hydraulic oil supply parts via the pressure regulator 133.

  The clamping pressure regulating valve 134 regulates the pressure of the hydraulic oil supplied to the primary hydraulic chamber 55 which is one clamping pressure generating hydraulic chamber by controlling the valve opening degree. Thereby, the clamping pressure regulating valve 134 regulates the internal pressure P1 of the primary hydraulic chamber 55. That is, the clamping pressure regulating valve 134 controls the belt clamping pressure generated in the primary hydraulic chamber 55. The clamping pressure regulating valve 134 is connected to the supply side main passage 51 a of the primary pulley shaft 51. Accordingly, the hydraulic oil regulated by the clamping pressure regulating valve 134 is supplied to the primary hydraulic chamber 55 via the hydraulic oil supply valve 70. The hydraulic oil supply control device 130 includes another clamping pressure regulating valve (not shown) in addition to the clamping pressure regulating valve 134, and this clamping pressure regulating valve (not shown) is the hydraulic oil (not shown) of the secondary pulley shaft 61. Connected to the aisle. Accordingly, the hydraulic oil regulated by the clamping pressure regulating valve is supplied to the secondary hydraulic chamber 64 via the hydraulic oil passage (not shown).

  The pressing pressure regulating valve 135 regulates the pressure of the hydraulic oil supplied to each drive hydraulic chamber 86 by controlling the valve opening degree. Thereby, the pressing force regulating valve 135 regulates, that is, changes the internal pressure P <b> 3 of each drive hydraulic chamber 86. In other words, the pressing pressure regulating valve 135 controls the pressing force that presses each valve body 81 toward the primary fixed sheave side in the axial direction by each valve opening member 85 in each drive hydraulic chamber 86, and each hydraulic oil by each actuator. The discharge valve 80 is opened. The pressure adjusting valve 135 is connected to each drive hydraulic chamber 86 via the drive-side main passage 51 b of the primary pulley shaft 51. Accordingly, the hydraulic oil regulated by the pressing pressure regulating valve 135 is supplied to each drive hydraulic chamber 86.

  The hydraulic oil supply control device 130 is connected to an ECU (Engine Control Unit) 140 (not shown) that controls at least the operation of the internal combustion engine 10. Therefore, the hydraulic oil supply control device 130 regulates the clamping pressure regulating valve 134 that regulates the internal pressure P1 of the primary hydraulic chamber 55 and the internal pressure P3 of each drive hydraulic chamber 86 based on the control signal of the gear ratio from the ECU. At least the gear ratio of the belt-type continuously variable transmission 1 is controlled by controlling a pressing pressure regulating valve 135 and a clamping pressure regulating valve (not shown) that regulates the internal pressure of the secondary hydraulic chamber 64.

  Next, the operation of the belt type continuously variable transmission 1 according to the present invention will be described. First, general forward and reverse travel of the vehicle will be described. As shown in FIG. 1, when the driver selects the forward position by a shift position device (not shown) provided in the vehicle, the ECU 140 causes the forward clutch 42 to be moved by the hydraulic oil supplied from the hydraulic oil supply control device 130. The reverse brake 43 is turned on and the forward / reverse switching mechanism 40 is controlled. As a result, the input shaft 38 and the primary pulley shaft 51 are directly connected. That is, the sun gear 44 and the ring gear 46 of the planetary gear device 41 are directly connected, the primary pulley shaft 51 is rotated in the same direction as the rotation direction of the crankshaft 11 of the internal combustion engine 10, and the output torque from the internal combustion engine 10 is converted to the primary pulley. 50. The output torque from the internal combustion engine 10 transmitted to the primary pulley 50 is transmitted to the secondary pulley 60 via the belt 110 and rotates the secondary pulley shaft 61 of the secondary pulley 60.

  The output torque of the internal combustion engine 10 transmitted to the secondary pulley 60 is transmitted from the intermediate member 67 to the intermediate shaft 102 via the input shaft 101 of the power transmission path 100, the counter drive pinion 103 and the counter driven gear 104, thereby being intermediated. The shaft 102 is rotated. The output torque transmitted to the intermediate shaft 102 is transmitted to the differential case 91 of the final reduction gear 90 via the final drive pinion 105 and the ring gear 99, and the differential case 91 is rotated. The output torque from the internal combustion engine 10 transmitted to the differential case 91 is transmitted to the drive shafts 121 and 122 via the differential pinions 93 and 94 and the side gears 95 and 96, and to the wheels 120 and 120 attached to the ends thereof. The wheels 120 and 120 are rotated with respect to a road surface (not shown), and the vehicle moves forward.

  On the other hand, when the driver selects the reverse position by a shift position device (not shown) provided in the vehicle, the ECU 140 turns off the forward clutch 42 by the hydraulic oil supplied from the hydraulic oil supply control device 130 and the reverse brake 43. Is turned on, and the forward / reverse switching mechanism 40 is controlled. As a result, the switching carrier 47 of the planetary gear unit 41 is fixed to the transaxle case 22 and is held by the switching carrier 47 so that each pinion 45 only rotates. Accordingly, the ring gear 46 rotates in the same direction as the input shaft 38, and each pinion 45 meshed with the ring gear 46 also rotates in the same direction as the input shaft 38, and the sun gear 44 meshed with each pinion 45 becomes the input. It rotates in the opposite direction to the shaft 38. That is, the primary pulley shaft 51 connected to the sun gear 44 rotates in the direction opposite to the input shaft 38. As a result, the secondary pulley shaft 61, the input shaft 101, the intermediate shaft 102, the differential case 91, the drive shafts 121, 122, and the like of the secondary pulley 60 rotate in the opposite direction to the case where the driver selects the forward position. Goes backwards.

  Here, when the internal combustion engine 10 is controlled by the ECU 140, the oil pump 132 is driven by the driving force of the internal combustion engine 10 as shown in FIG. 4. When the oil pump 132 is driven, the hydraulic oil stored in the oil pan 131 is pressurized and discharged by the oil pump 132. The discharged hydraulic oil is supplied in a pressurized state to a hydraulic oil supply portion that requires hydraulic oil among the hydraulic oil supply portions.

  The ECU 140 also includes a map (for example, an optimal fuel consumption curve based on the engine speed and the throttle opening of the throttle valve) stored in the storage unit of the ECU 140 and conditions such as the vehicle speed and the accelerator opening of the driver. Based on the above, the gear ratio of the belt-type continuously variable transmission 1 is controlled via the hydraulic oil supply control device 130 so that the operation state of the internal combustion engine 10 is optimized. The control of the gear ratio of the belt type continuously variable transmission 1 includes changing the gear ratio and fixing the gear shift (gear ratio γ steady). The change of the gear ratio and the fixing of the gear ratio are performed by hydraulic oil from the hydraulic oil supply control device 130 by the hydraulic oil, the internal pressure P1 of the primary hydraulic chamber 55 of the primary pulley 50, the internal pressure of the secondary hydraulic chamber 64 of the secondary pulley 60, and the drive hydraulic chamber. This is done by controlling the internal pressure P3 of 86.

  The gear ratio is changed mainly by supplying hydraulic oil from the hydraulic oil supply control device 130 to the primary hydraulic chamber 55 or by discharging hydraulic oil from the primary hydraulic chamber 55 to the outside of the primary pulley 50. 53 slides in the axial direction of the primary pulley shaft 51, and the interval between the primary fixed sheave 52 and the primary movable sheave 53, that is, the width of the primary groove 110a is adjusted. As a result, the contact radius of the belt 110 in the primary pulley 50 changes, and the speed ratio, which is the ratio between the rotation speed of the primary pulley 50 and the rotation speed of the secondary pulley 60, is controlled steplessly (continuously). The gear ratio is fixed mainly by prohibiting the discharge of hydraulic fluid from the primary hydraulic chamber 55 to the outside of the primary pulley 50.

  In the secondary pulley 60, the belt 110 is sandwiched between the secondary fixed sheave 62 and the secondary movable sheave 63 by controlling the internal pressure of the secondary hydraulic chamber 64 with the hydraulic oil supplied from the hydraulic oil supply control device 130. The belt clamping pressure to be applied is adjusted. Thereby, the belt tension of the belt 110 wound around the primary pulley 50 and the secondary pulley 60 is controlled.

  The change of the gear ratio includes an upshift, that is, a gear ratio decrease change that decreases the gear ratio, and a downshift, that is, a gear ratio increase change that increases the gear ratio. Each will be described below.

  The gear ratio reduction change is performed by supplying hydraulic oil from the hydraulic oil supply control device 130 to the primary hydraulic chamber 55 and sliding (moving) the primary movable sheave 53 toward the primary fixed sheave side. As shown in FIG. 6, each hydraulic oil supply valve 70 is opened to allow the hydraulic oil to be supplied from the hydraulic oil supply control device 130 to the primary hydraulic chamber 55. Specifically, ECU 140 calculates a reduction gear ratio and a transmission speed, and outputs a control signal for the transmission ratio based on these to hydraulic fluid supply control device 130. The hydraulic oil supply control device 130 controls the clamping pressure regulating valve 134 and supplies the primary hydraulic chamber 55 so that the speed ratio of the belt-type continuously variable transmission 1 is reduced at the above speed. Increase oil pressure. Accordingly, the supply side hydraulic pressure P2 rises, and the pressing force in the valve opening direction that acts on each valve element 71 by this supply side hydraulic pressure P2 is the internal pressure P1 of the primary hydraulic chamber 55 and the supply side biasing force of each supply side elastic member 72. Thus, the pressing force in the valve closing direction acting on each valve body 71 is exceeded. Thereby, each valve body 71 moves in the valve opening direction, and each hydraulic oil supply valve 70 opens. That is, the hydraulic oil supply valve 70 allows the hydraulic oil to be supplied to the primary hydraulic chamber 55 that is one clamping pressure generating hydraulic chamber.

  When supply of hydraulic oil to the primary hydraulic chamber 55 by each hydraulic oil supply valve 70 is allowed, the pressure is adjusted by the clamping pressure regulating valve 134 of the hydraulic oil supply control device 130 as shown by an arrow C in FIG. The hydraulic fluid is supplied from the supply side main passage 51a to the primary hydraulic chamber 55 via the shaft side communication passage 51c and the supply side passage 53e. At this time, the hydraulic oil supply control device 130 closes the pressing pressure regulating valve 135 to stop the supply of hydraulic oil from the hydraulic oil supply control device 130 to the drive hydraulic chamber 86, or each drive hydraulic chamber 86. The internal pressure P3 of the drive hydraulic chamber 86 is applied to the valve body 81 via the valve opening member 85 by the internal pressure P3 of the drive hydraulic chamber 86. The pressure in the valve opening direction is the internal pressure P1 of the primary hydraulic chamber 55 and the discharge side elastic member 82. The hydraulic pressure of the hydraulic fluid supplied to each drive hydraulic chamber 86 is regulated so that the pressing force in the valve closing direction acting on each valve body 81 is not exceeded by the discharge side urging force. That is, each hydraulic oil discharge valve 80 maintains a closed state, and discharge of hydraulic oil from the primary hydraulic chamber 55 is prohibited. Therefore, the internal pressure P1 of the primary hydraulic chamber 55 is increased by the hydraulic oil supplied via each hydraulic oil supply valve 70, and the pressing force for pressing the primary movable sheave 53 toward the primary fixed sheave is increased. 53 slides to the primary fixed sheave side in the axial direction. As a result, the contact radius of the belt 110 in the primary pulley 50 is increased, the contact radius of the belt 110 in the secondary pulley 60 is decreased, the transmission ratio is decreased, and the reduced transmission ratio is obtained.

  The gear ratio increase is changed by discharging hydraulic oil from the primary hydraulic chamber 55 and sliding (moving) the primary movable sheave 53 to the side opposite to the primary fixed sheave side. First, as shown in FIG. 7, each hydraulic oil discharge valve 80 is opened to allow the hydraulic oil to be discharged from the primary hydraulic chamber 55. Specifically, ECU 140 calculates an increase gear ratio and a gear shift speed, and outputs a gear ratio control signal based on these to hydraulic oil request control device 130. The hydraulic oil supply control device 130 controls the pressing pressure regulating valve 135 and supplies it to each drive hydraulic chamber 86 so that the transmission ratio of the belt-type continuously variable transmission 1 is increased at the above-described transmission speed. Increase hydraulic oil pressure. Accordingly, the internal pressure P3 of each drive hydraulic chamber 86 rises, and the pressing force in the valve opening direction that acts on each valve element 71 via each valve opening member 85 by each drive hydraulic chamber 86 is the internal pressure of the primary hydraulic chamber 55. The pressing force in the valve closing direction acting on each valve body 81 is exceeded by P1 and the discharge-side biasing force of each discharge-side elastic member 82. Thereby, each valve body 81 moves in the valve opening direction, and each hydraulic oil discharge valve 80 opens. That is, the hydraulic oil is allowed to be discharged from the primary hydraulic chamber 55 which is one clamping pressure generating hydraulic chamber by each hydraulic oil discharge valve 80.

  When the hydraulic oil is allowed to be discharged from the primary hydraulic chamber 55 by each hydraulic oil discharging means 80, the hydraulic oil in the primary hydraulic chamber 55 flows into each discharge space 87 as shown by an arrow D in the figure. . The hydraulic oil that has flowed into the discharge space 87 is discharged to the outside of the primary pulley 50 via the discharge passage 54e. At this time, the hydraulic oil supply control device 130 closes the clamping pressure regulating valve 134 and supplies hydraulic oil from the hydraulic oil supply control device 130 to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70. Or a pressing force in the valve opening direction acting on each valve element 71 by the supply side hydraulic pressure P2 acts on each valve element 71 by the internal pressure P1 of the primary hydraulic chamber 55 and the supply side biasing force of each supply side elastic member 72. The supply side hydraulic pressure P2 generated by the hydraulic oil supplied to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70 is regulated so as not to exceed the pressing force in the valve closing direction. That is, each hydraulic oil supply valve 70 is kept closed, and the supply of hydraulic oil to the primary hydraulic chamber 55 is prohibited. Accordingly, when the hydraulic oil is discharged from the primary hydraulic chamber 55 via each hydraulic oil discharge valve 80, the internal pressure P1 of the primary hydraulic chamber 55 decreases, and the pressing force that presses the primary movable sheave 53 toward the primary fixed sheave side. Decreases and the primary movable sheave 53 slides in the axial direction on the side opposite to the primary fixed sheave side. Thereby, the contact radius of the belt 110 in the primary pulley 50 decreases, the contact radius of the belt 110 in the secondary pulley 60 increases, the transmission ratio is increased, and the increased transmission ratio is obtained.

  When the transmission gear ratio is fixed, the hydraulic oil is not supplied to the primary hydraulic chamber 55 and the hydraulic oil is not discharged from the primary hydraulic chamber 55, and the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 is constant. This is performed by restricting the movement of the movable sheave 53 with respect to the primary fixed sheave 52. When the transmission gear ratio is fixed, as shown in FIG. 2, the hydraulic oil supply valve 70 and the hydraulic oil discharge valve 80 are maintained in the closed state so that the hydraulic oil is supplied to the primary hydraulic chamber 55 and from the primary hydraulic chamber 55. Prohibit hydraulic fluid discharge.

  Hereinafter, the gear ratio fixed control will be specifically described. FIG. 8 is a diagram showing an operation flow of the speed ratio fixing control method for the belt type continuously variable transmission. First, as shown in FIG. 8, when the gear ratio fixing control is started via the hydraulic oil supply control device 130, the ECU 140 calculates the internal pressure P1 of the primary hydraulic chamber 55 (step ST1). Here, the ECU 140 calculates the hydraulic pressure P1 of the primary hydraulic chamber 55 based on, for example, the output torque of the internal combustion engine 10 and the gear ratio of the belt type continuously variable transmission 1. The internal pressure P1 of the primary hydraulic chamber 55 may be calculated based on the output of this pressure sensor by attaching a pressure sensor for detecting the internal pressure P1 of the primary hydraulic chamber 55 to the primary hydraulic chamber 55.

  Next, the ECU 140 controls the clamping pressure regulating valve 134 so that each hydraulic oil supply valve 70 maintains a closed state (step ST2). Here, the ECU 140 determines that each valve element 71 has a pressing force in the valve opening direction acting on each valve element 71 by the supply-side oil pressure P2 due to the internal pressure P1 of the primary hydraulic chamber 55 and the supply-side biasing force of each supply-side elastic member 72. The supply side hydraulic pressure P2 generated by the hydraulic oil supplied to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70 is controlled by the clamping pressure regulating valve 134 so as not to exceed the pressing force in the valve closing direction acting on the valve. To do. Thereby, the closed state of each hydraulic oil supply valve 70 is maintained. At this time, the ECU 140 controls the clamping pressure regulating valve 134 so that the supply side hydraulic pressure P2 becomes equal to or less than the calculated internal pressure P1 of the primary hydraulic chamber 55, that is, the internal pressure of one clamping pressure generating hydraulic chamber.

  Therefore, the hydraulic oil supply control device 130 opposes the supply side hydraulic pressure P2 below the internal pressure P1 of the primary hydraulic pressure chamber 55, which is one clamping pressure generating hydraulic pressure chamber, to the hydraulic pressure chamber side of each hydraulic oil supply valve 70 when the transmission ratio is fixed. Act on the side. In other words, the hydraulic chamber side of each hydraulic oil supply valve 70, that is, the internal pressure P1 of the primary hydraulic chamber 55 that is one clamping pressure generating hydraulic chamber, and the supply that is the hydraulic pressure opposite to the hydraulic chamber side of each hydraulic oil supply valve 70. The pressure difference ΔP (= P1−P2) with the side oil pressure P2 can be reduced.

  Next, the ECU 140 controls the pressure adjusting valve 135 such that each hydraulic oil discharge valve 80 maintains a closed state (step ST3). Here, the ECU 140 determines that the pressing force in the valve opening direction acting on each valve body 81 via each valve closing member 84 by the internal pressure P3 of each drive hydraulic chamber 86 is the internal pressure P1 of the primary hydraulic chamber 55 and each discharge side elastic member. The internal pressure P3 of each driving hydraulic chamber 86 generated by the hydraulic oil supplied to each driving hydraulic chamber 86 is set so that the pressing force in the valve closing direction acting on each valve body 81 by the discharge side urging force of 82 is not exceeded. The pressure is controlled by the pressure adjusting valve 135. Thereby, the closed state of each hydraulic oil discharge valve 80 is maintained.

  As described above, the hydraulic oil in the primary hydraulic chamber 55 is held by prohibiting the supply of the hydraulic oil to the primary hydraulic chamber 55 and the discharge of the hydraulic oil from the primary hydraulic chamber 55. Even when the gear ratio is fixed, the belt tension of the belt 110 changes, so that the contact radius of the belt 110 in the primary pulley 50 tends to change, and the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 may change. is there. As described above, since the hydraulic oil is held in the primary hydraulic chamber 55, if the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 is changed, the internal pressure of the primary hydraulic chamber 55 is changed. Although P1 changes, the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 is maintained constant. Accordingly, in order to keep the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 constant, it is not necessary to increase the internal pressure P1 of the primary hydraulic chamber 55 by supplying hydraulic oil to the primary hydraulic chamber 55. good. As a result, it is not necessary to drive the oil pump 132 included in the hydraulic oil supply control device 130 in order to supply the hydraulic oil to the primary hydraulic chamber 55 when the transmission gear ratio is fixed, thereby suppressing an increase in driving loss of the oil pump 132. can do.

  Further, in each hydraulic oil supply valve 70 in the valve-closed state, the valve element 71 closes the valve seat stepped portion 53f, thereby blocking the supply-side passage 53e. However, the amount of leakage increases as the pressure difference between one side and the other side of the valve body 71 that closes the valve seat step portion 53f increases. In the belt type continuously variable transmission 1 according to the present invention, it is conceivable that no hydraulic pressure is applied to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70, that is, the supply side hydraulic pressure P2 is set to 0. There is a concern that the pressure difference ΔP increases and the amount of leakage increases. Therefore, in the belt type continuously variable transmission 1 according to the present invention, by reducing the pressure difference ΔP, the pressure difference ΔP leaks from the primary hydraulic chamber 55 to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70. The amount of leaking hydraulic oil can be reduced. As a result, the gear ratio when the gear ratio is fixed can be reliably maintained.

  In the belt type continuously variable transmission 1 according to the present invention, the hydraulic pressure generated by the hydraulic oil supply control device 130 is regulated to the internal pressure P1 or less of the primary hydraulic chamber 55 by the clamping pressure regulating valve 134 when the transmission ratio is fixed. And used as the supply side hydraulic pressure P2. That is, the supply-side hydraulic pressure P2 uses a hydraulic pressure that can be generated at least when the hydraulic oil supply control device 130 that supplies hydraulic oil to the belt-type continuously variable transmission 1 is fixed at the gear ratio. Therefore, it is necessary to further drive the oil pump 132 that is currently generating an arbitrary hydraulic pressure in the hydraulic oil supply control device 130 in order to apply the hydraulic pressure to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70. Absent. Thereby, it is possible to improve the maintenance of the gear ratio when the gear ratio is fixed without changing the drive loss of the oil pump 132.

  Further, in the belt type continuously variable transmission 1 according to the present invention, when the hydraulic pressure generated by the hydraulic oil supply control device 130 exceeds the internal pressure P1 of the primary hydraulic chamber 55 when the transmission gear ratio is fixed, the hydraulic oil supply control device 130 is The generated hydraulic pressure exceeding the internal pressure P1 of the primary hydraulic chamber 55 is adjusted to be equal to or lower than the internal pressure P1 of the primary hydraulic chamber 55 by the clamping pressure regulating valve 134 and used as the supply side hydraulic pressure P2. Therefore, when the transmission ratio is fixed, the hydraulic pressure generated by the hydraulic oil supply control device 130 can always be applied as the supply-side hydraulic pressure P2. Thereby, maintenance of the gear ratio when the gear ratio is fixed can be further improved.

  The belt-type continuously variable transmission 1 according to the above embodiment uses a hydraulic pressure generated by the hydraulic oil supply control device 130 that exceeds 0 and is equal to or lower than the internal pressure P1 of the primary hydraulic chamber 55 as the supply-side hydraulic pressure P2. Is not limited to this. 9A and 9B are explanatory diagrams of the leakage characteristics of the hydraulic oil supply valve. As shown in FIG. 9A, in the hydraulic oil supply valve 70, a fine gap S is formed depending on the roundness of the valve body 71 and the processing accuracy of the valve seat step portion 53f. Therefore, if the valve body 71 and the valve seat step portion 53f are rigid bodies, there is a possibility that the hydraulic oil leaks from the primary hydraulic chamber 55 to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve 70 even if the pressure difference ΔP is zero. there were. Here, if the valve body 71 or the valve seat level difference part 53f is not a rigid body but an elastic body, it will deform | transform according to the force which acts. That is, as shown in FIG. 9-2, by pressing the valve body 71 that closes the valve seat step portion 53f in the valve closing direction, the valve body 71 or the valve seat step portion 53f is deformed, and a fine gap is formed. May be buried. Therefore, depending on the hydraulic oil supply valve 70, the hydraulic oil leakage amount by the hydraulic oil supply valve 70 has a leakage characteristic that becomes minimum at a predetermined pressure difference ΔP1 in the vicinity of 0, rather than setting the pressure difference ΔP to zero. There is a case.

  Therefore, for example, the hydraulic oil supply control device 130 may change the hydraulic pressure applied to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve based on the leakage characteristics of each hydraulic oil supply valve 70. Here, the ECU 140 applies the calculated internal pressure P1 of the primary hydraulic chamber 55 so that the pressure difference ΔP1 at which the amount of leakage is minimized based on the leakage characteristics of each hydraulic oil supply valve 70 when the speed ratio is fixed. The supply side hydraulic pressure P2 is changed. That is, the EUC 140 controls the supply side hydraulic pressure P2 generated by the hydraulic oil supplied to the side opposite to the hydraulic chamber side of each hydraulic oil supply valve 70 by the clamping pressure regulating valve 134 so that P1−P2 = ΔP1. To do. Therefore, by changing the supply side hydraulic pressure P2 based on the leakage characteristics of each hydraulic oil supply valve 70, the amount of hydraulic oil leaked from each hydraulic oil supply valve 70 regardless of the leakage characteristics of each hydraulic oil supply valve 70. Can be reduced. Thereby, maintenance of the gear ratio when the gear ratio is fixed can be further improved.

It is a skeleton figure of the belt type continuously variable transmission concerning this invention. It is principal part sectional drawing of the primary pulley at the time of gear ratio fixation. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a figure which shows a torque cam. It is a figure which shows a torque cam. It is operation | movement explanatory drawing of the belt type continuously variable transmission at the time of gear ratio change. It is operation | movement explanatory drawing of the belt type continuously variable transmission at the time of gear ratio change. It is a figure which shows the operation | movement flow of the gear ratio fixed control method of a belt-type continuously variable transmission. It is explanatory drawing of the leakage characteristic of a hydraulic-oil supply valve. It is explanatory drawing of the leakage characteristic of a hydraulic-oil supply valve.

Explanation of symbols

1 Belt type continuously variable transmission 10 Internal combustion engine (drive source)
20 Transaxle 30 Torque converter 40 Forward / reverse switching mechanism 50 Primary pulley 51 Primary pulley shaft 52 Primary fixed sheave 53 Primary movable sheave 54 Primary partition wall 55 Primary hydraulic chamber (one clamping pressure generating hydraulic chamber)
60 Secondary pulley 64 Secondary hydraulic chamber (the other clamping pressure generating hydraulic chamber)
DESCRIPTION OF SYMBOLS 70 Hydraulic oil supply valve 80 Hydraulic oil discharge valve 90 Final reduction gear 100 Power transmission path 110 Belt 120 Wheel 130 Hydraulic oil supply control device 131 Oil pan 132 Oil pump 133 Pressure regulator 134 Nipping pressure regulating valve 135 Pressure regulating valve 135

Claims (4)

Two pulleys,
A belt that is wound around each pulley and transmits a driving force from a driving source transmitted to one pulley to the other pulley;
A clamping pressure generating hydraulic chamber formed in each pulley and generating a belt clamping pressure with respect to the belt by hydraulic pressure;
A hydraulic oil supply valve that allows only hydraulic oil to be supplied to one of the clamping pressure generating hydraulic chambers among the clamping pressure generating hydraulic chamber, and rotates integrally with the one pulley;
A hydraulic oil discharge valve that controls permission or prohibition of discharge of the hydraulic oil from the one clamping pressure generating hydraulic chamber, and rotates integrally with the one pulley;
Hydraulic oil supply control means for supplying the hydraulic oil to at least each of the clamping pressure generating hydraulic chambers and controlling a gear ratio;
A belt type continuously variable transmission comprising:
The hydraulic oil supply control means applies a hydraulic pressure equal to or lower than an internal pressure of the one clamping pressure generating hydraulic chamber to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve when the transmission ratio is fixed. Continuously variable transmission.   2. The belt-type non-operating machine according to claim 1, wherein the hydraulic pressure applied to the side opposite to the hydraulic chamber side of the hydraulic oil supply valve is a hydraulic pressure generated by the hydraulic oil supply control means when the speed ratio is fixed. Step transmission.   The hydraulic oil supply control means generates hydraulic pressure generated by the hydraulic oil supply control means when the hydraulic pressure generated by the hydraulic oil supply control means exceeds the internal pressure of the one clamping pressure generating hydraulic chamber when the speed ratio is fixed. The belt type continuously variable transmission according to claim 2, wherein the pressure is controlled to be equal to or lower than the internal pressure of the one clamping pressure generating hydraulic chamber.   4. The belt according to claim 3, wherein the hydraulic oil supply control unit changes a hydraulic pressure applied to a side opposite to a hydraulic chamber side of the hydraulic oil supply valve based on a leakage characteristic of the hydraulic oil supply valve. Type continuously variable transmission.

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