JP2006275154A - Pulley structure of continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for surely receiving hydraulic pressure reaction applied to a plunger. <P>SOLUTION: A secondary pulley 21 has a fixed sheave 21a fixed to a secondary shaft 14, and a movable sheave 21b arranged on the secondary shaft 14 oppositely to this sheave. A hydraulic fluid chamber is partitioned on the back face side of the movable sheave 21b by the plunger 26 fitted to the secondary shaft 14. The secondary shaft 14 is formed with a shaft part 61 for supporting the fixed sheave 21a, a shaft part 62 for supporting the movable sheave 21b adjacently to this shaft part, and a shaft part 63 for supporting the plunger 26 adjacently to this part, and the shaft parts 61 and 62 are formed thinner than a fitting hole 91 of the plunger 26. The plunger 26 can be installed from the shaft part 61 side, and since a stopper 64 for positioning the plunger 26 can be integrally formed in the shaft part 63, rigidity of the stopper 64 can be easily enhanced, and the hydraulic pressure reaction applied to the plunger 26 can be received. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pulley structure for a continuously variable transmission that includes a fixed sheave and a movable sheave facing the fixed sheave.

  A continuously variable transmission (CVT) mounted on a power transmission system of a vehicle includes a primary pulley provided on a primary shaft, a secondary pulley provided on a secondary shaft, and a drive belt stretched around these pulleys. The gear ratio is continuously controlled by changing the winding diameter of the drive belt around the pulley. Each of the primary pulley and the secondary pulley includes a fixed sheave and a movable sheave facing the stationary sheave, and a shell member such as a plunger that divides the hydraulic oil chamber is assembled to the back side of the movable sheave. By controlling the supply of hydraulic oil to this hydraulic oil chamber, the movable sheave can be moved back and forth to control the winding diameter of the drive belt.

As a pulley structure of such a continuously variable transmission, a movable sheave is assembled to a primary shaft and a secondary shaft integrally formed with a fixed sheave so as to face the fixed sheave, and on the back side of the movable sheave. The shell member is assembled so as to be arranged. And in order to fix a shell member with respect to a primary axis | shaft or a secondary axis | shaft, the nut member is fastened by the edge part of a primary axis | shaft or a secondary axis | shaft, and a shell member comes to be fastened and fixed using a nut member. (For example, refer to Patent Document 1).
JP-A-8-14348

  However, when hydraulic fluid is supplied to the hydraulic fluid chamber, hydraulic pressure is applied not only to the movable sheave but also to the shell member. Therefore, the nut member that fixes the shell member and its tightening portion act on the shell member. The strength to catch the thrust (about 10t) is required. In order to secure such strength, it is necessary to increase the length and diameter of the threaded portion formed on the primary shaft and the secondary shaft. While increasing the total length of the shaft and the secondary shaft, it would lead to an increase in the size of the primary pulley and the secondary pulley, which was not a desirable measure. In addition, since the fixed sheave is integrally formed with the primary shaft and the secondary shaft, it is necessary to assemble the movable sheave from the screw portion side, so increasing the diameter dimension of the screw portion regulated by the movable sheave It was difficult.

  An object of the present invention is to provide a pulley structure that can reliably receive a thrust applied to a shell member.

  The pulley structure of the continuously variable transmission according to the present invention includes a pulley support shaft that is rotatably accommodated in a transmission case, a fixed sheave fixed to the pulley support shaft, and the pulley support shaft facing the fixed sheave. A pulley structure of a continuously variable transmission that includes a movable sheave provided in a freely movable axial direction, and includes a fitting hole that fits into the pulley support shaft, and a hydraulic oil chamber that moves the movable sheave forward and backward. A shell member defined on the back side of the movable sheave; a first shaft portion that supports the fixed sheave on the pulley support shaft; and a second shaft that supports the movable sheave adjacent to the first shaft portion. And a third shaft portion that supports the shell member adjacent to the second shaft portion, and the first and second shaft portions are formed narrower than the fitting hole of the shell member, and A shell that positions the shell member in the axial direction. And forming integrally Tsu path to the third shaft portion.

  The pulley structure of the continuously variable transmission according to the present invention is characterized in that the stopper is formed in a bowl shape.

  The pulley structure of the continuously variable transmission according to the present invention is characterized in that the shell member is assembled to the third shaft portion from the first and second shaft portions.

  The pulley structure of the continuously variable transmission according to the present invention is characterized in that the movable sheave is assembled to the pulley support shaft after the shell member is assembled, and the fixed sheave is assembled after the movable sheave is assembled.

  According to the present invention, the first shaft portion that supports the fixed sheave and the second shaft portion that supports the movable sheave are formed on the pulley support shaft, and the first and second shaft portions are formed from the fitting holes of the shell member. Since the shell member is formed thin, the shell member can be guided from the first shaft portion side toward the third shaft portion, and a stopper for positioning the shell member in the axial direction is formed integrally with the third shaft portion. Is possible. As a result, the rigidity of the stopper can be increased, so that it is possible to reliably receive the thrust applied to the shell member by supplying hydraulic oil. In addition, since the movable sheave can be assembled after the shell member is assembled, the diameter of the third shaft portion that supports the shell member is not limited by the movable sheave, and the strength of the pulley support shaft can be ensured. It becomes easy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram showing a continuously variable transmission 10 having a pulley structure according to an embodiment of the present invention. As shown in FIG. 1, the continuously variable transmission 10 is a belt-type continuously variable transmission. In a transmission case 11, a primary shaft 13 as a pulley support shaft driven by an engine 12 and a parallel shaft are provided. A secondary shaft 14 serving as a pulley support shaft is rotatably accommodated. A transmission mechanism 15 is provided between the primary shaft 13 and the secondary shaft 14, and the rotation of the primary shaft 13 is transmitted to the secondary shaft 14 after being continuously variable through the transmission mechanism 15. Yes. The rotation of the secondary shaft 14 is transmitted to the left and right drive wheels 18 via the speed reduction mechanism 16 and the differential mechanism 17.

  A primary pulley 20 is provided on the primary shaft 13, and the primary pulley 20 is slidable in the axial direction on the primary shaft 13 so as to be opposed to the fixed sheave 20 a fixed to the primary shaft 13. And a movable sheave 20b to be mounted. Further, the secondary shaft 14 is provided with a secondary pulley 21. The secondary pulley 21 is fixed to the secondary shaft 14 and is fixed to the secondary shaft 14 so as to be slidable in the axial direction on the secondary shaft 14. And a movable sheave 21b to be mounted.

  A drive belt 22 is wound around the primary pulley 20 and the secondary pulley 21, and by changing the pulley groove width between the primary pulley 20 and the secondary pulley 21 and changing the winding diameter of the drive belt 22, The rotation can be changed steplessly and transmitted to the secondary shaft 14. If the winding diameter of the drive belt 22 around the primary pulley 20 is Rp and the winding diameter around the secondary pulley 21 is Rs, the transmission ratio of the continuously variable transmission 10 is Rs / Rp.

  In order to change the pulley groove width of the primary pulley 20, the plunger 23 as a shell member is fixed to the primary shaft 13, and the movable sheave 20 b is provided with a cylinder 24 that slidably contacts the outer peripheral surface of the plunger 23. A hydraulic oil chamber 25 is defined on the back side of the movable sheave 20b by the plunger 23 and the cylinder 24. Similarly, in order to change the pulley groove width of the secondary pulley 21, a plunger 26 as a shell member is fixed to the secondary shaft 14, and a cylinder 27 that slidably contacts the outer peripheral surface of the plunger 26 is provided to the movable sheave 21b. A hydraulic oil chamber 28 is defined on the back side of the movable sheave 21 b by the plunger 26 and the cylinder 27. The pulley groove width of each of the pulleys 20 and 21 is controlled by adjusting the primary pressure introduced into the primary hydraulic fluid chamber 25 and the secondary pressure introduced into the secondary hydraulic fluid chamber 28.

  Cover members 24a and 27a are attached to the cylinders 24 and 27 provided in the movable sheaves 20b and 21b, and the balance oil chambers 29a and 29b are provided on the back side of the plungers 23 and 26 by the cover members 24a and 27a. Is to be partitioned. By supplying hydraulic oil to the balance oil chambers 29a and 29b, the centrifugal hydraulic pressure generated in the hydraulic oil chambers 25 and 28 with the rotation of the primary pulley 20 and the secondary pulley 21 can be canceled. And the secondary pulley 21 can be appropriately controlled.

  A torque converter 30 and a forward / reverse switching mechanism 31 are provided between the crankshaft 12 a and the primary shaft 13 in order to transmit engine power to the primary pulley 20. The torque converter 30 includes a pump shell 30a connected to the crankshaft 12a and a turbine runner 30b facing the pump shell 30a. A turbine shaft 32 is connected to the turbine runner 30b. Further, a lock-up clutch 33 for fastening the crankshaft 12a and the turbine shaft 32 is incorporated in the torque converter 30 in accordance with the traveling state.

  The forward / reverse switching mechanism 31 includes a double pinion planetary gear train 34, a forward clutch 35, and a reverse brake 36. By operating the forward clutch 35 and the reverse brake 36, an engine power transmission path is provided. Are to be switched. When both the forward clutch 35 and the reverse brake 36 are released, the turbine shaft 32 and the primary shaft 13 are disconnected, and the forward / reverse switching mechanism 31 is switched to a neutral state in which power is not transmitted to the primary shaft 13. When the forward clutch 35 is engaged with the reverse brake 36 released, the rotation of the turbine shaft 32 is transmitted to the primary pulley 20 as it is. Further, when the reverse brake 36 is engaged with the forward clutch 35 opened, the rotation of the turbine shaft 32 is reversed and transmitted to the primary pulley 20.

  FIG. 2 is a schematic diagram showing a hydraulic control system and an electronic control system of the continuously variable transmission 10. As shown in FIG. 2, the continuously variable transmission 10 is provided with an oil pump 40 driven by the engine 12 in order to supply hydraulic oil to the primary pulley 20 and the secondary pulley 21. The secondary pressure path 42 connected to the discharge port of the oil pump 40 is connected to the hydraulic oil chamber 28 of the secondary pulley 21 and to the pressure regulating port 43 a of the secondary pressure regulating valve 43. The line pressure adjusted by the secondary pressure adjusting valve 43, that is, the secondary pressure is adjusted to a pressure that does not cause the drive belt 22 to slip. The secondary pressure path 42 is connected to the input port 44 a of the primary pressure adjustment valve 44, and the primary pressure path 45 extending from the output port 44 b of the primary pressure adjustment valve 44 is connected to the hydraulic oil chamber 25 of the primary pulley 20. Yes. By the primary pressure adjusting valve 44, the secondary pressure is regulated to a primary pressure corresponding to the target gear ratio, and the groove width of the primary pulley 20 is set.

  Here, the primary pressure is a pressure obtained by reducing the secondary pressure, but since the pressure receiving area of the hydraulic oil chamber 25 is set larger than that of the hydraulic oil chamber 28, the groove of the primary pulley 20 is controlled by controlling the primary pressure. While changing the width, the groove width of the secondary pulley 21 can be changed via the drive belt 22. The secondary pressure adjustment valve 43 and the primary pressure adjustment valve 44 are electromagnetic pressure control valves, respectively, and control the current value supplied from the CVT control unit 41 to the solenoid coils 43b and 44c, thereby adjusting the secondary pressure and the primary pressure. It becomes possible to press.

  The CVT control unit 41 that controls the gear ratio of the continuously variable transmission 10 by controlling the groove widths of the primary pulley 20 and the secondary pulley 21 includes a microprocessor (CPU) (not shown). The ROM, RAM, and I / O port are connected via the interface. The ROM stores a control program, an engine torque map, and the like, and the RAM temporarily stores data calculated by the CPU. Also, detection signals indicating the running state of the vehicle are input from various sensors to the CPU via the I / O port.

  As various sensors for inputting a detection signal to the CVT control unit 41, a primary rotational speed sensor 50 for detecting the rotational speed of the primary pulley 20, a secondary rotational speed sensor 51 for detecting the rotational speed of the secondary pulley 21, and an accelerator opening degree are detected. An accelerator pedal sensor 52 for detecting the vehicle speed, a vehicle speed sensor 53 for detecting the vehicle speed, a throttle opening sensor 54 for detecting the throttle opening, and the like. An engine control unit 55 is connected to the CVT control unit 41 so that the continuously variable transmission 10 and the engine 12 are controlled in cooperation with each other.

  Next, the pulley structure of the secondary pulley 21 will be described. FIG. 3 is an exploded view showing the structure of each component constituting the secondary pulley 21, and FIGS. 4A and 4B are cross-sectional views showing the secondary pulley 21 assembled. 4A shows a state where the movable sheave 21b is moved forward in a direction approaching the fixed sheave 21a, and FIG. 4B shows a state where the movable sheave 21b is moved backward in a direction away from the fixed sheave 21a. Yes. Note that the primary pulley 20 also has the same pulley structure as the secondary pulley 21.

  As shown in FIGS. 3 and 4, the secondary shaft 14 is adjacent to the first shaft portion 61 that supports the fixed sheave 21 a, the second shaft portion 62 that supports the movable sheave 21 b adjacent thereto, and the second shaft portion 62. And a third shaft portion 63 that supports the plunger 26. The shaft portion 62 that supports the movable sheave 21b is formed thicker than the diameter of the shaft portion 61 that supports the fixed sheave 21a, and the shaft portion 63 that supports the plunger 26 is the shaft portion 62 that supports the movable sheave 21b. It is formed thicker than the diameter dimension. Further, the shaft portion 63 is integrally formed with a stopper 64 for positioning the plunger 26 in the axial direction, and this stopper 64 is formed in a bowl shape extending radially outward from the outer peripheral surface of the shaft portion 63. Yes. That is, the diameter dimension of the secondary shaft 14 is formed so as to increase gradually in the order of the shaft portion 61, the shaft portion 62, the shaft portion 63, and the stopper 64.

  The fixed sheave 21 a fixed to the secondary shaft 14 includes a sleeve portion 71 having a through hole 70 and a disk portion 73 having a cone surface 72. The fixed sheave 21 a is shrink-fitted to the shaft portion 61. It is fixed by. The movable sheave 21b assembled to the secondary shaft 14 so as to face the fixed sheave 21a has a sleeve portion 81 having a through hole 80 in which spline teeth are formed and a disc portion 83 having a cone surface 82. The movable sheave 21b is splined to the shaft portion 62 so as to be movable in the axial direction. The drive belt 22 is sandwiched between a pair of conical surfaces 72 and 82 facing each other. As shown in FIG. 4A, when the movable sheave 21b is moved forward in a direction approaching the fixed sheave 21a, the drive belt On the other hand, when the movable sheave 21b is moved backward in the direction away from the fixed sheave 21a as shown in FIG. 4B, the winding diameter of the drive belt 22 is reduced. Is possible.

  In order to move the movable sheave 21b forward and backward in this way, the plunger 26 is fixed to the secondary shaft 14, and the hydraulic oil chamber 28 is defined by the plunger 26 on the back side of the movable sheave 21b. The plunger 26 is formed in a substantially tapered shape by pressing a plate material. A fitting hole 91 that fits the shaft portion 63 is formed in the inner peripheral portion 90, and an oil seal is incorporated in the outer peripheral portion 92. An annular groove 93 is formed. The plunger 26 is fixed to the secondary shaft 14 by press-fitting the inner peripheral portion 90 of the plunger 26 with respect to the shaft portion 63, and the outer peripheral portion 92 is slid against the inner peripheral surface of the cylinder 27. It comes to contact freely.

  Further, since a hook-shaped stopper 64 is integrally formed on the shaft portion 63, when the plunger 26 is press-fitted into the shaft portion 63, the plunger 26 is axially moved by the stopper 64 with which the inner peripheral portion 90 abuts. Will be positioned. Moreover, since the stopper 64 is formed integrally with the secondary shaft 14 and it is easy to increase the rigidity of the stopper 64, the hydraulic oil is supplied to the hydraulic oil chamber 28 as shown in FIG. Even when the movable sheave 21 b moves forward, the hydraulic reaction force received by the plunger 26 can be reliably received by the stopper 64.

  When assembling such a secondary pulley 21, the plunger 26 is first press-fitted into the shaft part 63 of the secondary shaft 14, and after the plunger 26 is press-fitted, the movable sheave 21b is splined to the shaft part 62, After the movable sheave 21b is assembled, the fixed sheave 21a is shrink-fitted to the shaft portion 61. When the secondary pulley 21 is housed in the transmission case 11, one end of the secondary shaft 14 is supported via the bearing 95, while the other end of the secondary shaft 14 is mounted on the fixed sheave 21 a. It comes to be supported through.

  As described above, the secondary shaft 14 and the fixed sheave 21a are configured as separate parts, and the shaft portions 61 and 62 of the secondary shaft 14 are formed to be narrower than the fitting hole 91 of the plunger 26. It can be assembled to the shaft portion 63 from the portion 61 side, and a stopper 64 for positioning the plunger 26 in the axial direction can be formed integrally with the shaft portion 63. As a result, the rigidity of the stopper 64 can be increased, so that it is possible to reliably receive the thrust applied to the plunger 26 by supplying hydraulic oil. Further, since the movable sheave 21b can be assembled after the plunger 26 is assembled, the diameter of the shaft portion 63 that supports the plunger 26 is not limited by the movable sheave 21b, and the strength of the secondary shaft 14 is ensured. Is also possible.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the plunger 26 is provided as a shell member that is fixed to the primary shaft 13 and the secondary shaft 14 and partitions the hydraulic oil chamber. However, the plunger 26 is not limited to this, and a plunger is provided on the movable sheave 21b. A cylinder as a shell member may be provided on the shaft 13 or the secondary shaft 14.

  The secondary shaft 14 and the movable sheave 21b are splined by meshing spline teeth with each other. However, the present invention is not limited to this, and the secondary shaft 14 and the movable sheave 21b are splined by a ball spline structure. You may make it let it.

  Furthermore, the fixed sheave 21a is fixed to the secondary shaft 14 by shrink fitting, and the plunger 26 is fixed to the secondary shaft 14 by press-fitting. However, the fixed sheave 21a may be fixed by press-fitting or the like. May be fixed by shrink fitting.

It is a skeleton figure which shows the continuously variable transmission provided with the pulley structure which is one embodiment of this invention. It is the schematic which shows the hydraulic control system and electronic control system of a continuously variable transmission. It is an exploded view which shows the structure of each component which comprises a secondary pulley. (A) And (B) is sectional drawing shown in the state which assembled the secondary pulley.

Explanation of symbols

10 continuously variable transmission 11 transmission case 13 primary shaft (pulley support shaft)
14 Secondary shaft (pulley support shaft)
20 Primary pulley 20a Fixed sheave 20b Movable sheave 21 Secondary pulley 21a Fixed sheave 21b Movable sheave 23 Plunger (shell member)
25 Hydraulic oil chamber 26 Plunger (shell member)
28 Hydraulic Oil Chamber 61 Shaft (First Shaft)
62 Shaft (Second Shaft)
63 Shaft (Third Shaft)
64 Stopper 91 Fitting hole

Claims (4)

A pulley support shaft rotatably accommodated in a transmission case, a fixed sheave fixed to the pulley support shaft, and a movable sheave provided on the pulley support shaft so as to be axially movable facing the fixed sheave. A continuously variable transmission pulley structure comprising:
A shell member that includes a fitting hole that fits into the pulley support shaft, and that partitions a hydraulic oil chamber that moves the movable sheave forward and backward on the back side of the movable sheave;
A first shaft portion supporting the fixed sheave on the pulley support shaft; a second shaft portion supporting the movable sheave adjacent to the first shaft portion; and the shell adjacent to the second shaft portion. Forming a third shaft portion that supports the member;
The first and second shaft portions are formed thinner than the fitting holes of the shell member, and a stopper for positioning the shell member in the axial direction is formed integrally with the third shaft portion. Transmission pulley structure.   2. The pulley structure of a continuously variable transmission according to claim 1, wherein the stopper is formed in a hook shape.   3. The continuously variable transmission pulley structure according to claim 1, wherein the shell member is assembled to the third shaft portion from the first and second shaft portions. .   The pulley structure of the continuously variable transmission according to any one of claims 1 to 3, wherein the movable sheave is assembled to the pulley support shaft after the shell member is assembled, and the fixed after the movable sheave is assembled. A pulley structure for a continuously variable transmission, wherein a sheave is assembled.

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