JP3059677B2 - V-belt type automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-belt type automatic transmission comprising a fixed sheave and a movable sheave disposed on a drive shaft.

[0002]

2. Description of the Related Art A V-belt type automatic transmission, which is a type of continuously variable transmission, is mainly used as a driving force transmission mechanism for industrial vehicles such as automobiles and transport vehicles, and snowmobiles. Also called a belt converter. This V-belt type automatic transmission is a kind of a continuously variable transmission, in which a V-belt (endless belt) is stretched by turning a driving pulley and a driven pulley, and utilizing a centrifugal force due to the rotation speed of the driving pulley. The gear ratio is continuously changed by changing the effective diameter of the driving pulley.

[0003] As the V-belt type automatic transmission, a fixed sheave fixed on a drive shaft (for example, an engine output shaft) for taking in rotational force, and sliding along the drive shaft facing the fixed sheave. A movable sheave attached as possible,
A bracket fixed to a position of the drive shaft on the back surface side of the movable sheave, a centrifugal weight member pivotally supported on the bracket so as to be swingable and capable of pressing the movable sheave from the back surface by centrifugal force, Spring biasing means for biasing the movable sheave in a direction to separate the movable sheave from the fixed sheave, transmitting torque from a drive shaft to the movable sheave to the bracket and guiding the movable sheave in the axial direction. There is a configuration in which a spider section is provided. References disclosing such a configuration include, for example, Japanese Utility Model Publication No. 57-78.
No. 84 publication.

[0004]

However, in the V-belt type automatic transmission having the above-described structure, the movable sheave, the plurality of spider portions, and the plurality of guide portions (the movable sheave guide portion provided on the spider portion). ), A gap (backlash) is generated in the torque transmitting portion with respect to the movable sheave, and when the engine is combined with an engine having a large torque fluctuation (for example, a single cylinder engine having a relatively large displacement), the backlash is generated. A rattling sound (rattle sound) due to the above may be generated. This hammering sound is likely to occur in the transitional period of acceleration, and if it becomes harsh, it affects the commercial value.

Further, since the movable sheave and the guide portion are difficult to machine, it is difficult to reduce a gap (backlash) of the torque transmitting portion with respect to the movable sheave, so that the hitting sound is reduced. There is also a situation that it is difficult to sufficiently suppress the rattling sound.

SUMMARY OF THE INVENTION The present invention has been made in view of such prior art, and it is an object of the present invention to provide a simple and inexpensive structure which can reduce the increase in sliding resistance when the movable sheave moves while reducing the movable resistance. It is an object of the present invention to provide a V-belt type automatic transmission capable of eliminating backlash of a torque transmitting portion with respect to a sheave and preventing a hitting sound caused by the backlash.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a fixed sheave fixed on a drive shaft for taking in a rotational force, and a fixed sheave facing the fixed sheave along the drive shaft. A movable sheave slidably mounted, a bracket fixed to a position of the drive shaft on the back side of the movable sheave, and a movable sheave capable of swinging on the bracket and pressing the movable sheave from the back surface by centrifugal force. A centrifugal weight member pivotally supported by the spring, and a spring biasing means for biasing the movable sheave in a direction to separate the movable sheave from the fixed sheave.The bracket includes a guide member fixed to the movable sheave along a guide member. A spider portion for guiding the axial movement of the movable sheave and transmitting the rotational force from the drive shaft to the movable sheave via the guide member is formed, and the rotational speed of the drive shaft is formed. In a V-belt type automatic transmission configured to press the movable sheave toward the fixed sheave by centrifugal force acting on the centrifugal weight member in response thereto, the spider portion is formed at a plurality of circumferential positions, At least one spider portion is provided with elastic means that slidably abuts the guide portion of the guide member on a non-working surface side of the spider portion opposite to the rotational force transmitting portion with a predetermined elastic force, The elastic means includes a concave hole having a predetermined depth formed on the non-working surface side formed in the spider portion, a compression spring mounted in the concave hole, and a distal end portion of the compression spring. A cap that is pressed against the guide portion of the guide member with a predetermined elastic force by the compression spring.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of one embodiment of a V-belt type automatic transmission to which the present invention is applied, and FIG.
It is the front view which removed the cover from the arrow 2-2 of the inside, and was seen. 1 and 2, a drive shaft 11 for taking in rotational force is fixed to an output shaft 10 on a power source side such as an engine or a motor. In the illustrated example, the drive shaft 11
Has a structure in which a cylindrical retainer 13 is fitted to the outer end of a hollow main shaft 12, and these are screwed to the end of the output shaft 10 with bolts 14.

A fixed sheave 15 is fixed to an inner portion of the drive shaft 11 (a portion of the main shaft 12 near the output shaft 10). A movable sheave 16 slidable along the drive shaft 11 in a posture facing the fixed sheave 15 is mounted on the drive shaft 11. In the example shown,
The movable sheave 16 is slidably mounted on the main shaft 12 via a bush 17. Thus,
The inclined surface 15a of the fixed sheave 15 and the inclined surface 16a of the movable sheave 16 face each other on the drive shaft 11, and a V-shaped groove for holding the V-belt from both sides with a narrow pressure is formed therebetween.

In FIGS. 1 and 2, a bracket 18 is fixed on the drive shaft 11 at a position on the back side of the movable sheave 16 (opposite the inclined surface 16a). In the illustrated example, the bracket 18 is engaged with the main shaft 12 by a spline 19 so as to rotate integrally with the main shaft 12 and the retainer 13 and the split washer 20.
Between the main shaft 12 and
(Drive shaft 11). The split washer 20 also has a function as a stopper member at the position of the movable sheave 16 shown in FIG. 1 (the position farthest from the fixed sheave 15).

The movable sheave 16 has the inclined surface 16a.
An outer peripheral cylindrical portion 16b protruding from the outer peripheral portion to the rear surface side is formed, and the bracket 18 is housed inside the outer peripheral cylindrical portion 16b. The outer cylindrical portion 16b has an open end opposite to the inclined surface 16a, and a cover 21 is attached to the open end. The bracket 18
A compression coil spring 22 as a spring urging means is mounted between the cover 21 and the cover 21. The compression coil spring 22 connects the movable sheave 16 to the fixed sheave 1.
5 (to the left in FIG. 1).

The bracket 18 includes a centrifugal weight member 23.
And a spider portion 25 for transmitting a rotational force (torque) from the drive shaft 11 to the movable sheave 16. In the illustrated example, the support part 24 and the spider part 25 are each three,
It is formed so as to protrude radially at alternate positions in the circumferential direction. The spider portion 25 has a function as a guide means for guiding the sliding of the movable sheave 16 in the axial direction, in addition to the function of transmitting the rotational force.

1 and 2, the centrifugal weight member 2
Numeral 3 is pivotally supported by the support portion 24 via a pin 26, and is disposed so as to press the movable sheave 16 toward the fixed sheave 15 by centrifugal force accompanying rotation of the drive shaft 11. ing. A roller 28 is rotatably supported on the back surface of the movable sheave 16 via a pin 27,
As the rotation speed of the drive shaft 11 increases, the centrifugal weight member 2
3 presses the roller 28 more and more so that the movable sheave 16 overcomes the spring 22 and the fixed sheave 1
It is configured to move by a predetermined amount toward the fifth.
The rollers 28 are attached to support portions 29 protruding at positions (three places) corresponding to the centrifugal weight members 23 on the back surface of the movable sheave 16. Further, an additional weight 30 for adjusting the centrifugal force is exchangeably attached to each centrifugal weight member 23.

FIG. 3 is a partial sectional view taken along line 3-3 in FIG. 1, and FIG. 4 is a partial sectional view taken along line 4-4 in FIG. 1 to 4, a pair of axial ribs 31 are formed inside the outer peripheral cylindrical portion 16 b of the movable sheave 16 at positions corresponding to both sides of the distal end of each spider portion 25 of the bracket 18. Have been. A guide member 32 is inserted and fitted to the inner surfaces of each pair of ribs 31.

The guide member 32 forms an axial guide surface with respect to both side surfaces of the spider portion 25, and is preferably made of, for example, nylon or polycarbonate having excellent self-lubricating properties. The guide member 32 is, as shown in FIG.
It has a U-shape comprising a pair of left and right guide portions 32a and a stopper portion 32b connecting them. The stopper portion 32b is for forming a cushioning surface against which the bracket 18 abuts when the movable sheave 16 comes closest to the fixed sheave 15 (when it comes to the rightmost position in FIG. 1).

In the V-belt type automatic transmission according to the present embodiment, the drive shaft 11 is driven to rotate in the direction of arrow A in FIG. , A rotational force in the direction of arrow B (the same direction as arrow A) is transmitted through the bracket 18. Therefore, the guide member 32 is guided on a non-operating surface of each of the spider portions (three places) 25 of the bracket 18, that is, a surface (a counterclockwise side surface in FIG. 2) opposite to a surface to which rotation is transmitted. An elastic means 33 is attached to the portion 32a so as to abut with a predetermined pressing force.

The elastic means 33 includes a spring (compression coil spring) 35 mounted in a concave hole 34 having a predetermined depth formed in the spider portion 25, and a cap 36 attached to the tip of the spring 35. It consists of
The cap 36 comes into slidable elastic contact with the guide portion 32 a of the guide member 32. Thus, between the bracket 18 and the movable sheave 16, the movable sheave 1
A configuration is provided in which an elastic means 33 for urging the motor 6 in a direction opposite to the rotational force (the direction of the arrow A) transmitted from the drive shaft 11 is interposed.

In this embodiment, a spider portion 25 on the bracket 18 side and a pair of axial ribs 31 on the movable sheave 16 side are provided.
A guide mechanism having a configuration including a guide member 32 inserted through and fitted to the pair of ribs 31 is disposed at three locations in the circumferential direction. A spring (compression coil spring) as shown in FIGS. ) 35 and the elastic means 33 composed of the cap 36 attached to the tip of the spring 35 can be provided at all three guide mechanisms, but some of the guide mechanisms (one or two guide mechanisms) can be provided. Mechanism) only, and the elastic means 33 can be omitted in the remaining guide mechanisms. Also, the number of the spider portions 25 is not limited to three, but the number can be freely selected according to the design requirements of each V-belt type automatic transmission.

According to the embodiment described above, the drive shaft 11
A plurality of (three) spider portions 25 are formed in the circumferential direction in the bracket 18 fixed to the bracket 18, and the movable sheave 16 (the guide thereof) is formed on a non-working surface of the at least one spider portion 25 opposite to the rotational force transmitting portion. The elastic means 33, which comes into contact with the member 32) with a predetermined elastic pressure contact force, is attached.
Since the movable sheave 16 is biased in the direction opposite to the driving rotational force of the drive shaft 11 by forming the spring 3 and the cap 36, the following operation and effect can be obtained.

The elastic means 33 causes a backlash between the spider portion 25 of the bracket 18 and the rib 31 of the movable sheave 16 (specifically, the guide member 32 mounted on the rib 31). ) Can be eliminated, and the backlash can be eliminated with a relatively small pressing force because of the structure for urging the non-working surface side. Therefore, the elastic means 33 comprises only the small spring 35 and the cap 36,
It is only necessary to form a hole for inserting the spring 35 and the cap 36 into the hole. In addition, since the pressing force is small, the sliding friction resistance with the guide member 32 is small, and there is an advantage that the sliding of the movable sheave is not substantially hindered. Sound can be effectively prevented.

The reverse biasing force (repulsive rotational force) on the movable sheave 16 for eliminating the tapping sound can be adjusted by the spring force of the spring 35 and the number thereof. As a material of the spring 35, a normal spring material such as a SWPB material can be used, and the cap 36 can be manufactured at low cost by press molding. Also, the illustrated elastic means 3
In FIG. 3, the case where the elastic force is generated by the compression coil spring 35 is exemplified. However, this is not limited to any other types of springs such as a leaf spring and a rubber elastic body as long as the elastic force is exerted. May be used.

FIG. 5 is a longitudinal sectional view of a configuration example of a V-belt type automatic transmission according to the related art, and FIG. 6 is a view taken along a line 6 in FIG.
FIG. 7 is a front view in which a cover is removed from -6, and FIG. 7 is a perspective view showing a compression coil spring for urging the movable sheave in FIG. In this configuration example, the elastic means 33 including the spring 35 and the cap 36 is omitted from the embodiment described with reference to FIGS. 1 to 4, and the spring 22 is used instead of the spring 22 as a spring urging means for urging the movable sheave. In this modification, a compression coil spring 40 having locking projections for locking in both ends in a twisted state is used.

That is, in the configuration examples shown in FIGS. 5 to 7, the bracket 18 and the movable sheave 1 are used as spring biasing means for biasing the movable sheave 16 in a direction away from the fixed sheave 15.
6, and at the same time, the projections 41, 42 for hooking are formed at both ends of the coil spring 40, and these projections 41, 4 are formed.
2 is engaged with an engaging hole 43 formed on the bracket 18 and an engaging hole 44 formed on the movable sheave 16 side (cover 21), and the coil spring 40 is twisted and bent (torsion restoring torque is generated). By being mounted, the movable sheave 16 is assembled in a state where it is urged by an initial rotational force in a direction opposite to the drive rotational force from the drive shaft 11.

Therefore, the coil spring 40 of the present embodiment is
Has not only the function of urging the movable sheave 16 away from the fixed sheave 15 but also the function of the elastic means 33 for applying a reverse rotational force to the movable sheave 16 in the backlash removing direction. The configuration of other parts of the present configuration example is substantially the same as the embodiment of FIGS.
Corresponding parts are denoted by the same reference numerals, and detailed description thereof will be omitted.

The bracket 1 is also formed by the compression coil spring 40 according to the configuration example of the related art shown in FIGS.
8 between the spider portion 25 of the movable sheave 16 and the rib 31 of the movable sheave 16 (specifically, the guide member 32 attached to the rib 31) (a gap of the rotational force transmitting portion) can be eliminated. Accordingly, it is possible to prevent the occurrence of a tapping sound caused by the gap between the torque transmitting portions. Further, since it is only necessary to form the hook portions 41 and 42 at both ends of the existing coil spring 40, the striking sound caused by the backlash can be effectively reduced with an extremely simple and inexpensive configuration without increasing the number of parts. Can be prevented. The reverse biasing force (repulsive rotational force) on the movable sheave 16 for eliminating the hitting sound can be adjusted by changing the amount of torsional bending of the spring 40 (locking position).

[0026]

As is apparent from the above description, according to the present invention, a fixed sheave fixed on a drive shaft for taking in a rotational force, and a slide along the drive shaft opposed to the fixed sheave. A movable sheave movably mounted, a bracket fixed to a position of the drive shaft on the back side of the movable sheave, and a movable sheave capable of swinging on the bracket and pressing the movable sheave from the back surface by centrifugal force. A shaft-supported centrifugal weight member, and spring biasing means for biasing the movable sheave in a direction to separate the movable sheave from the fixed sheave, and the bracket includes a guide member fixed to the movable sheave along a guide member. A spider portion is formed for guiding the axial movement of the movable sheave and transmitting the rotational force from the drive shaft to the movable sheave via the guide member. Flip with the V-belt type automatic transmission configured to presses the movable sheave to the fixed sheave by the centrifugal force acting on the centrifugal weight member,
The spider portion is formed at a plurality of positions in the circumferential direction, and is slid on at least one spider portion with a predetermined elastic force on the guide portion of the guide member on the non-working surface side of the spider portion opposite to the rotational force transmitting portion. An elastic means movably abutting is provided, the elastic means includes a concave hole having a predetermined depth formed on the non-working surface side formed in the spider portion, and a compression spring mounted in the concave hole. And a cap attached to the distal end of the compression spring and pressed against the guide portion of the guide member with a predetermined elastic force by the compression spring, so that the movable sheave has a simple and inexpensive configuration. The backlash of the torque transmitting portion with respect to the movable sheave can be eliminated while reducing the sliding resistance when the gear moves, and the hammering caused by the backlash can be prevented. Reverse direction biasing force of the compression spring the spring force and the V-belt type automatic transmission in which the number can be easily and readily adjusted by simply changing the are provided for the movable sheave for abolish.

[0027]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a V-belt type automatic transmission to which the present invention is applied.

FIG. 2 is a front view showing a state where a cover is removed from a line 2-2 in FIG. 1;

FIG. 3 is a partial sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a partial sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a longitudinal sectional view showing a configuration example of a V-belt type automatic transmission according to a related technique.

FIG. 6 is a front view showing a state where a cover is removed from a line 6-6 in FIG. 5;

FIG. 7 is a perspective view of a compression coil spring in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Drive shaft 12 Main shaft 13 Retainer 15 Fixed sheave 16 Movable sheave 18 Bracket 21 Cover 22 Compression coil spring 23 Centrifugal weight member 25 Spider part 28 Roller 31 Rib 32 Guide member 32a Guide part 32b Stopper part 33 Elastic means 34 Concave hole 35 Spring 36 caps

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-238754 (JP, A) JP-A 54-124876 (JP, U) JP-A 50-90973 (JP, U) JP-A 51- 162175 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 9/00-9/26

Claims (1)

(57) [Claims] 1. A fixed sheave fixed on a drive shaft for taking in a rotational force, a movable sheave slidably mounted along the drive shaft opposite to the fixed sheave, A bracket fixed to a position on the back side of the movable sheave, a centrifugal weight member pivotally supported on the bracket so as to be able to swing and press the movable sheave from the back side by centrifugal force, and the movable sheave Spring biasing means for biasing the movable sheave in a direction away from the fixed sheave, and guides the bracket to guide the axial movement of the movable sheave along a guide member fixed to the movable sheave, and from the drive shaft. A spider portion for transmitting the rotational force of the movable sheave to the movable sheave via the guide member is formed,
In a V-belt type automatic transmission configured to press the movable sheave toward the fixed sheave by a centrifugal force acting on the centrifugal weight member in accordance with a rotation speed of the drive shaft, Formed at a plurality of positions in the direction, and at least one of the spider portions is slidably contacted with the guide portion of the guide member on the non-working surface side of the spider portion opposite to the rotational force transmitting portion with a predetermined elastic force. Means are provided, and said elastic means is provided on said spider portion.
A concave hole of a predetermined depth that opens to the working surface side, and is mounted in the concave hole
Compression spring and the tip of the compression spring
Attached to the guide member by the compression spring.
A V-belt type automatic transmission , comprising: a cap which is pressed against a guide portion with a predetermined elastic force .