JP2001082561A - Parking mechanism for vehicular belt-drive continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking mechanism for vehicular belt-drive continuously variable transmissions that can reduce moment exerted on a sprag support portion and thus ensure sufficient strength thereof, via a juxtaposition thereof to a parking gear. SOLUTION: A sprag 33 for locking a parking gear 31 is journalled on a support portion 32, which is positioned on the periphery of a housing member 8 for storing a forward/reverse changeover mechanism 6. The support portion 32 can be thus machined when the housing member 8 is in an individual position, so that restrictions on the machining are lifted off and the degree of freedom is widened in the installation position of the support portion 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parking mechanism for a belt-type continuously variable transmission for a vehicle, so-called CVT.

[0002]

2. Related Background Art For example, in a continuously variable transmission described in Japanese Patent Application Laid-Open No. 5-280607, a primary shaft and a secondary shaft are arranged in a casing in parallel, and a primary pulley provided on the primary shaft and a secondary shaft are provided on a secondary shaft. An endless belt is stretched between the secondary pulleys. The primary pulley and the secondary pulley each include a fixed sheave and a movable sheave, and the movable sheave is movable in an axial direction by an actuator. Then, the interval between the sheaves is adjusted by the hydraulic pressure supplied to the actuator or the like, so that the gear ratio can be changed steplessly. The driving force of the engine whose speed has been continuously changed is transmitted to the driving wheels via a differential gear or the like.

On the other hand, this type of continuously variable transmission needs to have a parking mechanism for preventing the vehicle from moving during parking.
A parking gear is provided on the secondary shaft, a lever-shaped sprag is provided in the vicinity of the parking gear, and the sprag is rotatably mounted on a support provided on the inner wall of the casing. The sprag is mechanically interlocked with the shift lever in the driver's seat, and when the shift lever is switched to the P (parking) position by the driver during parking, the sprag rotates and the tip is hooked on the outer periphery of the parking gear. It stops the rotation of the secondary shaft, that is, the movement of the vehicle.

[0004] The above-mentioned support portion is simultaneously cast into the inner wall of the casing when the casing is formed by die-casting with aluminum or the like, and thereafter, a pin hole for supporting the sprag, a guide surface for sliding contact with the sprag, and the like are machined. .

[0005]

By the way, at the time of parking, the reaction force when the vehicle is stopped and held acts on the tip of the sprag via the parking gear, and is further moved from the tip of the sprag to the center of rotation (support). Part) acts on the support part as a moment up to the part. Therefore, in order to reduce the moment, it is desirable to shorten the distance from the tip of the sprag to the support, in other words, to bring the position of the support closer to the parking gear. However, because of the necessity of machining the support part in the narrow casing as described above due to the cast-out of the support part, the installation position is limited, and as a result, the support part is moved from the tip of the sprag. It is difficult to shorten the distance to
There is a problem that it is difficult to secure a sufficient strength of the support portion.

An object of the present invention is to provide a vehicle belt type in which a sprag support is provided at a position close to a parking gear to reduce a moment acting on the support, thereby ensuring sufficient strength of the support. It is to provide a parking mechanism for a continuously variable transmission.

[0007]

In order to achieve the above object, according to the present invention, a primary shaft to which rotation of an engine is input and a secondary shaft arranged in parallel with the primary shaft are housed in a casing, A pulley driven by an actuator is provided on a primary shaft and a secondary shaft, and a forward / backward switching mechanism for switching forward / backward movement of a vehicle is housed in a belt type continuously variable transmission for a vehicle in which a belt is stretched between both pulleys. A housing member detachably fixed in the casing, a shift operating device for switching an operation range of the belt-type continuously variable transmission, a parking gear provided on a secondary shaft, and a switching operation of the shift operating device. A locking member that locks the parking gear with the rotation of the secondary shaft and regulates the rotation of the secondary shaft; And a support portion for supporting the member.

Accordingly, since the support portion is provided on the housing member, the support portion can be machined in a state of the housing member alone. For example, as in the case where the support portion is provided in the casing, the support portion is provided in a narrow casing. Since there is no need to process the support portion, there is no possibility that the support portion is limited to a position where the support portion can be processed, and the degree of freedom regarding the installation position of the support portion is increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied as a parking mechanism for a belt-type continuously variable transmission used in a front-engine / front-drive (FF) vehicle will be described below. FIG. 1 shows a cross section of a belt-type continuously variable transmission, and an engine (not shown) is connected to the right side of the continuously variable transmission in the figure. An input shaft 2 and a primary shaft 3 are coaxially arranged in a casing 1 of the continuously variable transmission, and a right end of the input shaft 2 is connected to a crankshaft 5 of the engine via a torque converter 4. The left end of the input shaft 2 is supported on the right end of the primary shaft 3 via a forward / reverse switching mechanism 6 including a planetary gear mechanism, a forward clutch, a reverse clutch and the like, not shown, and a primary pulley 7 is provided on the primary shaft 3. Have been. The forward / reverse switching mechanism 6 is housed in a brake support 8 as a cup-shaped housing member that opens rightward in the figure, and the opening of the brake support 8 is a reaction support 9.
It is closed at.

The outer periphery of the left side of the brake support 8 is fitted to the inner wall of the casing 1, and the flange 8 a formed on the outer periphery of the right side of the brake support 8 and the outer periphery of the reaction support 9 are overlapped with each other. The brake support 8 and the reaction support 9 are positioned and fixed in the casing 1 as a result. The inner circumference of the reaction support 9 supports the right end of the input shaft 2 via a shaft 25 and a bearing 26 that support a stator (not shown) of the torque converter 4, and the inner circumference on the left side of the brake support 8 includes a bearing 11 and a primary shaft. 3. Supports the right end of the primary shaft 3 and the left end of the input shaft 2 via the bearing 27.

The primary pulley 7 is composed of a fixed sheave 7a integrally formed with the primary shaft 3 and a movable sheave 7b movably provided on the primary shaft 3.
The movable sheave 7b can be moved toward and away from the fixed sheave 7a by a hydraulic actuator 13. A secondary shaft 14 is disposed in the casing 1 in parallel with the primary shaft 3, and a secondary pulley 15 is provided on the secondary shaft 14. Similarly to the primary pulley 7, the secondary pulley 15 includes a fixed sheave 15a integrally formed with the secondary shaft 14, and a movable sheave 15b movably provided on the secondary shaft 14, and the movable sheave 15b is The hydraulic actuator 16 can be moved toward and away from the fixed sheave 15a.

Primary pulley 7 and secondary pulley 1
An endless metal belt 17 is stretched between the movable sheaves 5 and 5, and the metal belt 17 is sandwiched in a V-shaped groove 18 formed between the fixed sheaves 7a and 15a and the movable sheaves 7b and 15b. Thus, the rotation of the primary pulley 7 is transmitted to the secondary pulley 15. Movable sheaves 7b, 15b of primary pulley 7 and secondary pulley 15
Are always driven in the opposite directions by the respective hydraulic actuators 13 and 16, whereby the effective diameter of one of the primary pulley 7 and the secondary pulley 15 increases and the effective diameter of the other decreases. When the effective diameter of the primary pulley 7 is larger than the effective diameter of the secondary pulley 15, the speed ratio shifts to the high speed (overdrive) side, and conversely, the effective diameter of the primary pulley 7 becomes the effective diameter of the secondary pulley 15. When the gear ratio is small, the gear ratio is low (low)
Move to the side.

A transfer drive gear 20 is spline-coupled to the secondary shaft 14, and the transfer drive gear 20 is meshed with a transfer dog gear 22 which is spline-coupled to a transfer shaft 21. A pinion gear 21a is integrally formed on the transfer shaft 21. This pinion gear 21a meshes with a final gear 23a of a differential mechanism 23, and the differential mechanism 23 is connected to left and right driving wheels (not shown) via a drive shaft 24. I have.

FIG. 2 is an explanatory view showing the positional relationship between the brake support and the parking gear.
A parking gear 31 is spline-coupled to 4. A pair of support portions 32 (only one is shown) are integrally formed on the outer periphery of the brake support 8. Although not shown, both support portions 32 are in the axial direction of the secondary shaft 14 (FIG. 2).
(In a direction perpendicular to the plane of the drawing) at predetermined intervals, and corresponds to the parking gear 31. Both support parts 32
A lever-shaped sprag 33 as a latching member is disposed between the sprags 33. The center of the sprag 33 is rotatably mounted on a pin 34 inserted into a pin hole 32a of each of the support portions 32. . The tip 33 a of the sprag 33 is formed so as to project toward the parking gear 31, and can be hooked on the outer periphery of the parking gear 31 as the sprag 33 rotates. Opposite surfaces of both support portions 32, that is, sprags 3
The surface that slides on and guides the side surface 3 is formed by casting. For this reason, by forming the support portion 32 on the brake support 8 separate from the casing 1, the casting depth becomes shallow, the casting gradient becomes gentle, and machining becomes unnecessary. The pin hole 32a of the support 32 is formed by machining.

Although not shown, the base end 33b of the sprag 33 is mechanically connected to a shift lever as a shift operating device provided at the driver's seat of the vehicle. When the sprag 33 is switched to the position, the sprag 33 rotates counterclockwise as shown by the solid line and locks its tip on the outer periphery of the parking gear 31, while the shift lever moves to the D (drive) or N When the position is switched to a position other than the P position such as (neutral), the sprag 33 rotates clockwise as shown by the phantom line to separate the tip from the parking gear 31.

Next, an operation state of the parking mechanism of the belt type continuously variable transmission for a vehicle configured as described above will be described. When the shift lever is at a position other than the P position as described above, the tip of the sprag 33 is separated from the outer periphery of the parking gear 31 as shown by a virtual line in FIG. The vehicle can be driven arbitrarily. From this state, the shift lever
When the position is switched to the position, the sprag 33 rotates to the position shown by the solid line, and locks the tip on the outer periphery of the parking gear 31. As a result, the rotation of the secondary shaft 14 is restricted together with the parking gear 31, and the transfer drive gear 20, the transfer doblin gear 22, the transfer shaft 21, the pinion gear 21 a, the differential device 23, which are members on the downstream side in the power transmission direction, The rotation of the drive wheels is prevented via the drive shaft 24, and the movement of the vehicle is restricted.

On the other hand, in the parking mechanism of the vehicle belt-type continuously variable transmission according to the present embodiment, the sprag 33
Since the support portion 32, which is the center of rotation of the support portion 32, is provided on the brake support 8, casting and machining of the support portion 32 during manufacturing are easy, and as a result, the support portion 3
The degree of freedom with respect to the installation position of (2) can be expanded.
The reason will be described in detail below. The brake support 8 is formed by aluminum die casting or the like, and at this time, the support portion 32 is cast at the same time. Thereafter, the pin hole 32a of the support portion 32 is formed by drilling. The final shape of the support portion 32 is adjusted. At this time, the guide surface is formed in a cast-out shape or by cutting with a milling machine or the like. Since these machining operations are performed in the state of the brake support 8 alone, the machining can be performed extremely easily regardless of where the support portion 32 is located on the outer periphery of the brake support 8.
Therefore, as in the conventional example (JP-A-5-280607) in which the support portion needs to be processed in a narrow casing,
There is no possibility that the support portion is limited to a position where the support portion can be processed, and the degree of freedom regarding the installation position of the support portion 32 can be greatly increased.

Further, in the conventional example in which the support portion is provided on the casing side, the support portion can be cast out unless the support portion is set outside the locus of the metal belt because the support portion is cast when the casing is formed. However, the position of the support is limited to the outside of the belt locus. On the other hand, in the present embodiment, since the support portion 32 is provided on the brake support 8 which is a separate component from the casing 1, the position of the support portion 32 can be set irrespective of the belt locus. Therefore, as shown in FIG. 2, the support portion 32 can be provided in the belt locus S, and the degree of freedom relating to the installation position of the support portion 32 can be further increased.

Due to the above factors, the support portion 32 can be arranged at a position close to the parking gear 8, and the sprag 3
The distance L from the distal end of the support 3 to the support portion 32 can be reduced, and the moment acting on the support portion 32 during parking can be reduced, and sufficient strength of the support portion 32 can be secured. In addition, not only the above-described processing of the support portion 32 but also the subsequent operation of attaching the sprag 33 to the support portion 32 can be performed in a state of the brake support 8 alone before being assembled to the casing 1. Therefore, there is an advantage that the operation can be simplified as compared with the conventional example in which these operations need to be performed in a narrow casing, and the production cost can be reduced.

The embodiment has been described above, but aspects of the present invention are not limited to this embodiment. For example, in the above embodiment, the parking mechanism of the belt-type continuously variable transmission for the FF vehicle is embodied, but the type of the vehicle to be applied is not limited.
(Rear drive) It may be embodied in a parking mechanism of a belt-type continuously variable transmission for a vehicle.

In the above-described embodiment, the parking mechanism is of a type in which the sprag 33 is rotated and the parking gear 31 is hooked by the tip thereof. (Sprag 3
If the configuration 3) is supported on the brake support 8 side,
The format is not limited. Therefore, for example, the sprag 33
Is slidably supported on the brake support 8, and the tip of the sprag 33 is attached to the parking gear 3 with the sliding.
You may comprise so that it may hang on 1. Even in this case, since the support portion of the sprag 33 can be installed at an arbitrary position, the distance L from the tip to the support portion can be reduced.

Further, in the above embodiment, the metal belt 17
The support portion 32 is arranged within the locus S of the
It is not necessary to set the support portion 32 outside the trajectory S, depending on the peripheral component layout or the like. As a result, the distance L of the sprag 33 may be reduced as a result. Therefore, in such a case, the support portion 32 may be disposed outside the locus S of the metal belt 17.

[0023]

As described above, according to the parking mechanism of the belt-type continuously variable transmission for a vehicle according to the present invention, since the support portion can be machined in a state of the housing member alone, there is a limitation in carrying out the machining. , And the degree of freedom regarding the installation position of the support portion can be greatly increased. As a result, it is possible to reduce the moment acting on the support portion by providing the support portion at a position close to the parking gear, thereby ensuring sufficient strength of the support portion.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a belt-type continuously variable transmission for a vehicle according to an embodiment.

FIG. 2 is an explanatory diagram showing a positional relationship between a brake support and a parking gear.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 3 Primary shaft 6 Forward / reverse switching mechanism 7 Primary pulley 8 Brake support (housing member) 13 Hydraulic actuator 14 Secondary shaft 15 Secondary pulley 16 Hydraulic actuator 17 Metal belt 31 Parking gear 32 Support part 33 Sprag (hook member)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Sawayama 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 3J050 AA02 AB03 BA03 CE06 CE10 DA01 3J067 AC23 AC53 BA27 FA57 FA63 FB85 GA01

Claims (1)

[Claims] 1. A pulley driven by an actuator, wherein a primary shaft to which rotation of an engine is input and a secondary shaft arranged parallel to the primary shaft are housed in a casing, and the primary shaft and the secondary shaft are driven by an actuator. A vehicle belt-type continuously variable transmission having a belt stretched between both pulleys, wherein a forward / backward switching mechanism for switching forward / backward movement of the vehicle is accommodated and detachably fixed in the casing. A housing member, a shift operation device for switching an operation range of the belt-type continuously variable transmission, a parking gear provided on the secondary shaft, and a parking gear in accordance with a switching operation of the shift operation device. A locking member that can be locked to restrict rotation of the secondary shaft; and a locking portion provided on the housing member. Vehicular belt-type continuously variable transmission of the parking mechanism, characterized in that a support portion for supporting the.