JPH0914367A - V belt type transmission - Google Patents

Abstract

PURPOSE: To provide heat radiation more than before, to restrain manufacturing cost and not to give a bad thermal effect to a V belt by constituting a fixed sheave and a movable sheave on a driven pulley of aluminum die-cast in the same shape. CONSTITUTION: A fixed sheave 41 and a movable sheave 42 of a driven pulley 40 are in the same shape molded by aluminum casting. When the number of rotation of an engine 2 gradually increases, centrifugal force applied on weight becomes stronger accordingly, and the weight starts to move outward in the diametrical direction. In accordance with this movement of the weight, a movable sheave 22 is pushed to the side of a fixed sheave 21 and moves, and it increases a wrapping radius of a V belt on a driving pulley 20. Consequently, the movable sheave 42 of the driven pulley 40 is moved in a direction separated from the fixed sheave 41 against force of a spring, reduces the wrapping radius of the V belt on the driven pulley 40 and motive power transmission is transferred from LOW to HI.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a V-belt type transmission, and more particularly to an improvement in a driven pulley in a V-belt type transmission.

[0002]

2. Description of the Related Art As a V-belt transmission that automatically shifts by using a V-belt, a drive pulley is provided on a crankshaft of an engine, and a driven pulley is driven by a driven shaft that is connected to wheels via a shift gear. In general, the V-belt is laid between the driven pulley and the output of the engine to the wheels. The drive pulley and the driven pulley each include a fixed sheave fixed to a shaft (that is, a crank shaft and a driven shaft) and a movable sheave slidably attached to the shaft, and driven according to the engine speed. The movable sheave of the pulley slides back and forth in the axial direction on the crankshaft to change the distance between the corresponding sheave and the corresponding sheave, thereby changing the winding radius ratio of the V belt between the drive pulley and the driven pulley to change the speed. To do. Conventionally, the fixed sheave and the movable sheave in the driven pulley are formed of different materials in different shapes. Specifically, the fixed sheave was made of sheet metal, and the movable sheave was made of die-cast aluminum.

[0003]

As described above, since sheet metal products are less expensive than aluminum die-cast products, if one sheave (that is, a fixed sheave) is made of sheet metal, the other sheave is made. Although it is made of aluminum die-casting with good heat dissipation, there is an advantage that the overall cost does not rise and the heat dissipation performance of the movable pulley as a whole goes up, but between the movable sheave and the fixed sheave while the engine is driving. There is a problem in that a temperature difference occurs and the temperature conditions on the left and right of the V-belt change, which is not preferable. As a method of solving the above-mentioned problem, if both sheaves may be molded from either sheet metal or aluminum, for example, if both sheaves are manufactured from sheet metal, the heat dissipation performance of the driven pulley as a whole is reduced, which is preferable. Without
Further, if both sheaves are to be molded by aluminum die casting, two different sheave molds have to be manufactured, which is not realistic because it requires considerable time and cost. The present invention solves the above-mentioned problems, and provides a V-belt transmission having a driven pulley which has heat dissipation higher than conventional ones, does not increase the manufacturing cost, and does not have a bad thermal influence on the V-belt. It is in.

[0004]

In order to achieve the above object, a V-belt type transmission according to the present invention is provided with a drive pulley on a drive shaft and a driven pulley on a driven shaft. In a V-belt type transmission including a fixed sheave fixed to a shaft and a movable sheave provided slidably with respect to the shaft, a fixed sheave and a movable sheave of a driven pulley are formed in the same shape. It is characterized by being composed by die casting.

[0005]

According to the V-belt type transmission of the present invention configured as described above, since the fixed sheave and the movable sheave are made of aluminum die-cast in the same shape, the mold can be shared.
Further, there is an effect that the heat radiation performance of the entire movable sheave is improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the V-belt type transmission according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of a power unit of a scooter type motorcycle which employs a V-belt type transmission according to the present invention. The power unit 1 is configured to transmit the output of the engine 2 to wheels (not shown) via the V-belt type transmission 10.

The structure of the V-belt type transmission 10 will be described in detail below. The V-belt type transmission 10 includes a drive pulley 20 and a driven pulley 40, and a V-belt (not shown) is spanned between the two pulleys 20 and 40 to transmit power.

FIG. 2 shows a drive pulley 20 of the V-belt transmission.
FIG. The drive pulley 20 has a fixed sheave 21 and a movable sheave 22. The fixed sheave 21 is spline-fitted to a crank shaft (hereinafter, referred to as a drive shaft) 23, and a drive shaft 23 is provided by a nut 24 and a cylindrical spacer 25. It is fixed to. The fixed sheave 21 is made by casting an appropriate material such as iron into a substantially disk shape, and the surface on the movable sheave side is inclined toward the movable sheave to form a V-belt support surface 21a. And the V
The fin support surface 2 located on the opposite side of the belt support surface 21a
A plurality of cooling fins 21c extending in the axial direction of the drive shaft 23 are formed on the 1b. The spacer 25 is spline-fitted to the drive shaft 23, and an oil hole for supplying lubricating oil supplied from an oil passage (not shown) formed inside the drive shaft 23 to the sliding surface of the movable sheave 22. 25
a is formed. The oil hole 25a is the spacer 2
An appropriate number is formed so as to penetrate 5 in the radial direction. The movable sheave 22 is provided on the outer periphery of the spacer 25 so as to be slidable and rotatable in the axial direction of the drive shaft 23. Also,
A cam plate 28 made of sheet metal is spline-fitted to the rear side of the movable sheave 22 (that is, the right side in FIG. 2) of the drive shaft 23. The cam plate 28 is axially fixed by the spacer 25 and the second spacer 29, engages with the movable sheave 22, and transmits the rotational force of the drive shaft 23 to the movable sheave 22.

Hereinafter, the movable sheave 22 and the cam plate 2 will be described.
The configuration of No. 8 will be described in more detail. FIG. 3 shows a schematic side view of the assembled state of the movable sheave 22 and the cam plate 28 as seen from the right side in FIG. FIG.
And the movable sheave 22 and the cam plate 28 in FIG.
Shows a cross section taken along the line AA in FIG. The movable sheave 22 is formed by integrally casting a cylindrical sliding portion 22a slidably mounted on the spacer 25 and a disc-shaped portion 22b extending radially outward from the outer periphery of the sliding portion 22a. A cylindrical plain bearing 26 is interposed between the sliding portion 22a and the spacer 25. A shallow groove (no reference numeral) that is long in the axial direction and is supplied with lubricating oil from the oil hole 25a is formed on the inner peripheral surface of the plain bearing 26.
Lubricating oil supplied by seal rings 27 provided at both ends of the movable sheave 22 is sealed so as not to leak outside. The surface of the disk-shaped portion 22b on the fixed sheave 21 side is inclined toward the fixed sheave 21 so as to taper in the axial direction, and a V-belt support surface 22c corresponding to the V-belt support surface 21a of the fixed sheave 21 is formed. Is formed. A side wall 22d extends in the axial direction of the drive shaft 23 from the vicinity of the outer periphery of the disk-shaped portion 22b, and four engagement flanges 22e extending inward in the radial direction are formed on the inner periphery of the side wall 22d. It is formed integrally. Further, a portion of the disc-shaped portion 22b opposite to the V-belt supporting surface 22c, which is sandwiched between the engaging flanges 22e, is a tapered weight supporting surface 22f. The cam plate 28 is formed of a substantially circular plate body, and is provided at a portion of the movable pulley 22 corresponding to the engaging flange 22e.
A notch portion 28a that engages with is formed. The portion of the cam plate 28 where the cutout portion 28a is formed is bent so as to project toward the movable sheave 22 side, and the rigidity is enhanced. In addition, each notch 2 of the cam plate 28
The portion sandwiched by 8a is inclined so as to come closer to the movable sheave 22 as it goes radially outward, and this portion forms a weight support surface 28b corresponding to the movable sheave 22.

A resin slider 30 and a leaf spring elastic member 31 are attached to the notch 28a of the cam plate 28. FIG. 4 (a) is a schematic perspective view of the leaf spring elastic member 31,
FIG. 4B is a schematic perspective view of the resin slider 30. The leaf spring elastic member 31 is formed by forming a plate body into a substantially U-shape, forming the arm portions 31a and 31b at both ends thereof into a wide width, and bending the arm portions 31a and 31b at a substantially central portion to generate elastic force. I have it. Further, the resin slider 30 is formed in a substantially U shape, and the groove 30a is formed on the outer peripheral portion thereof. The groove 30a has a wide portion 30b to which the elastic member 31 can be attached and a narrow portion 30c to be attached to the cutout portion 28a of the cam plate 28.
FIG. 5 shows the state where the resin slider 30 and the elastic member 31 are assembled to the cam plate 28.
8 is an assembly drawing, and FIG. 6 is a detailed drawing of a mounting state of the resin slider 30 and the elastic member 31 on the cam plate 28. As shown in FIG. 5, first, the elastic member 31
Is the wide portion 3 of the groove 30a of the resin slider 30.
0b, and then the resin slider 30 is attached to the cutout portion 28a of the cam plate 28. Therefore, when the elastic member 31 is mounted on the cam plate 28, the elastic member 31 is located between the notch 28a of the cam plate 28 and the resin slider 30, and as shown in FIGS. 6 (a) and 6 (b), The arm portions 31a and 31b include the cam plate 28 and the resin slider 3
Partial contact with both 0's. Also, this elastic member 31
Since each of the arm portions 31a and 31b is formed wide, it acts so as to diffuse the contact pressure of the cam plate 28 on the resin slider 30 as shown in FIG. 6 (b). The elastic force of the elastic member 31 is preferably such that the resin slider can slide outward in the radial direction by the centrifugal force when the cam plate rotates, which is a design reason (since it is a cast product, Even if the flange portion is slightly tapered for the reason that it can be removed, it is possible to follow the engagement flange and slide to ensure a sufficient contact surface with the engagement flange. . In this way, by interposing the elastic member 31 between the resin slider 30 and the cam plate 28, for example, backlash occurs when the engine brake or the like is applied, and the movable pulley 22 strongly adheres to the cam plate 28. Even if it hits, the elastic member 31 can absorb the impact and prevent the generation of impact noise, so-called rattling noise.

The weight support surface 2 of the movable sheave 22
A plurality of cylindrical weights 32 are provided between the 2f and the weight supporting surface 28b of the cam plate 28. When the engine 2 is driven, the weights 32 are moved radially outward by the centrifugal force of the drive shaft 23. Then, the movable sheave 22
Push it to the fixed sheave 21 side to move the V of the movable sheave 22.
The gap between the belt supporting surface 22c and the V belt supporting surface 21a of the fixed sheave 21 is narrowed, the winding radius of the V belt is varied, and the gear ratio is set to Hi.

Next, the structure of the driven pulley 40 will be described in detail. 7 is an enlarged view around the driven pulley in FIG. 1, and FIG. 8 is a view showing only the fixed sheave 41 and the movable sheave 42 from the left side in FIG. The fixed sheave 41 and the movable sheave 42 in FIG.
It is cut at positions e and 42e. Driven pulley 40
Has a fixed sheave 41 and a movable sheave 42. The fixed sheave 41 and the movable sheave 42 have tapered portions 41a and 42a that are bent toward the outer periphery in a tapered shape, and flat plane portions 41b and 42b.
a and 42a on one side of the V belt supporting surfaces 41c and 4a
It is a disk-shaped plate that can be used as 2c, and has the same shape formed by aluminum casting. Further, the V-belt supporting surface 41c in the tapered portions 41a and 42b
A plurality of cooling flanges 41d and 42d extending in the axial direction are formed on the surface located on the opposite side of the and 42c. Further, the fixed sheave 41 and the movable sheave 42 are provided with appropriate numbers of mounting holes 41e and 42e (four in the embodiment at 45 degree intervals) on their plane portions 41b and 42b. Fixed sheave 4 configured as described above
The 1 and the movable sheave 42 are arranged so that the respective V-belt supporting surfaces 41c and 42c face each other as shown in FIG. 7, and support the V-belt between the V-belt supporting surfaces 41c and 42c.

The fixed sheave 41 has a cylindrical support cylinder 46.
The mounting pin 41f is provided at the position of the mounting hole 41e on the annular flange 46a formed to extend radially outward at one end of the mounting pin 41f.
Installed with. The mounting pin 41f is configured such that at least the head portion 41g on the movable sheave 42 side projects from the surface of the flat surface portion 41b when the fixed sheave 41 is fixed to the flange 46a, and the movable sheave 42 in the assembled state. Cannot directly contact the fixed sheave 41. The support cylinder 46 is rotatably mounted on the driven shaft 43 via a bearing, and the outer peripheral surface of the end opposite to the end where the flange 46a is provided has a weight of the centrifugal clutch 47. A step portion is formed that is radially inwardly reduced so that the support plate 47a can be fixed.

The movable sheave 42 is located at the position of the mounting hole 42e in an annular flange 48a extending outward in the radial direction formed at one end of a movable cylinder 48 which is slidably provided in the support cylinder 46 in the axial direction. It is attached with a mounting pin 42f. The mounting pin 42f has the same configuration as the mounting pin 41f for mounting the fixed sheave 41, and at least the head 42g on the side of the fixed sheave 41 projects from the surface of the flat portion 42b in a state where the movable sheave 42 is mounted on the flange 48a. Is configured. In addition, this movable sheave 42
Mounting pin 42f for mounting the fixed sheave 41
As shown in FIG. 8, the movable sheave 42 is attached to the fixed sheave 41 by shifting the positions of the attachment holes 42e in the circumferential direction so that the attachment pins 41f for attaching the same do not overlap in the axial direction in the assembled state. A torque groove 48b is formed in the movable cylinder 48. The torque groove 48b is formed so as to penetrate the movable cylinder 48 in the radial direction,
After the movable cylinder 48 is attached to the support cylinder 46, the torque pin 46b is attached to the support cylinder 46 so as to engage with the torque groove 48b.
The support cylinder 46 and the movable cylinder 48 are integrally rotated. Lubricating oil that lubricates the sliding movement of the movable barrel 48 is supplied between the inner surface of the movable barrel 48 and the outer surface of the support barrel 46, and the lubricating oil does not leak to both ends of the movable barrel 48. Thus, the seal rings 48b and 48c are attached.

A spring 49 is interposed between the movable cylinder 48 described above and the weight support plate 47a of the centrifugal clutch 47, and the movable cylinder 48 is always provided with the flange 46a of the support cylinder 46 by the spring 49. Biased to the side. Therefore, the movable cylinder 48 is held by the spring 49 until the V-belt is stretched between the movable sheave 42 and the fixed sheave 41.
The flange 48a of the support cylinder 46
Although the heads 41g and 42g of the mounting pins 41f and 42f for fixing the sheaves 41 and 42 are projected as described above, as shown in FIG. , 46a never come into contact with each other. As a result, the seal ring 48b attached to the end of the movable cylinder 48 is not damaged by the relief recess formed at the corner of the fixed sheave support cylinder 46 during manufacturing (FIG. 9).
9 (b) and 9 (c), FIG. 9 (b) shows the positional relationship between the movable cylinder and the support cylinder in this embodiment before the V-belt is attached, and FIG. 9 (c) shows the head of the mounting pin protruding. The positional relationship just before the contact between the movable cylinder and the support cylinder when there is not is shown. ).

The centrifugal clutch 47 comprises the weight support plate 47a and an outer cylinder 47b. The weight support plate 47a is composed of a disk-shaped plate, and a plurality of weights 47c are rotatably provided on the outer peripheral end of the weight support plate 47a. The weight support plate 47a is fixed to the support cylinder 46 with nuts 47d so that it can rotate together with the support cylinder 46. Has been done. The weight 4
7c has a friction surface 47e, and when the centrifugal force is not applied, the friction surface 47e has another member (specifically, the outer cylinder 47e).
Stop at a position that does not contact b). In addition, when the weight support plate 47a rotates with the rotation of the support cylinder 46, the weight 47c is centrifugally moved by the centrifugal force of the weight support plate 47a.
7e rotates to a position where it comes into frictional contact with the friction surface 47f of the outer cylinder 47b. In FIG. 7, a state where no centrifugal force is applied to the weight 47c is shown on the upper side with the driven shaft 43 as the center, and a state where centrifugal force is applied to the weight 47c is shown on the lower side. On the other hand, the outer cylinder 47b is formed of a bottomed cylindrical body, and the side wall 47g has an inner surface formed with the friction surface 47f that makes frictional contact with the weight 47c. This outer cylinder 47b has a nut 47h on the driven shaft 43.
And is rotated integrally with the driven shaft 43. Therefore, the rotational force of the support cylinder 46 is applied to the outer cylinder 47 via the weight 47c.
b is transmitted to the driven shaft 43 from the outer cylinder 47b. Then, the rotational force transmitted to the driven shaft 43 is transmitted to the axle shaft 50 via a transmission gear (not shown) housed in the transmission gear chamber, and rotates a wheel (not shown).

The relationship and operation between the drive pulley 20 and the driven pulley 40 will be described below. First, after the assembly is completed, the V-belt is wound around the drive pulley 20 and the driven pulley 40 between the movable sheaves 22 and 42 and the fixed sheaves 21 and 41, respectively. In this state, the movable sheave 42 of the driven pulley 40 is urged toward the fixed sheave 41 by the spring 49, and the winding radius of the V belt is large (that is, the LOW side). Therefore, the V belt is on the driven pulley 40 side. The movable sheave 22 on the drive pulley 20 side is pushed by the V belt in the direction away from the fixed sheave 21, and the winding radius of the V belt is small (that is, LOW side).
It has become. In this state, the nut 47d is tightened to appropriately adjust the biasing force of the spring 49, and the winding radius of the V belt of the driven pulley 40 is adjusted to complete the setting of the V belt. When the engine 2 is driven, the drive pulley 20 rotates as the drive shaft 23 rotates, and the driven pulley 40 also rotates via the V belt. When the number of revolutions exceeds a predetermined value, the weight 4 of the centrifugal clutch 47 is
7c frictionally engages the friction surface 47f of the outer cylinder 47b to rotate the driven shaft 43, and further rotates the axle 50, that is, the wheel via the transmission gear. When the rotation speed of the engine 2 is gradually increased, the centrifugal force applied to the weight 32 interposed between the movable sheave 22 of the drive pulley 20 and the cam plate 28 is increased accordingly, and the weight 32 is radially outward. Start moving towards. Along with the movement of the weight 32, the movable sheave 22 is pushed toward the fixed sheave 21 and moves to increase the winding radius of the V belt in the drive pulley 20,
As a result, the V-belt is pulled toward the drive pulley 20, so that the movable sheave 42 of the driven pulley 40 has the spring 49.
Is moved in the direction away from the fixed sheave 41 against the force of, and the winding radius of the V belt in the driven pulley 40 is reduced, and the power transmission shifts from LOW to HI. Further, when the rotational speed of the engine 2 decreases and the force of the spring 49 pushing the movable sheave 42 on the driven pulley 40 side becomes stronger than the centrifugal force applied to the weight 32 on the drive pulley 20 side, the power transmission is HI due to the opposite action. To LOW.

In the V-belt transmission of this embodiment constructed as described above, both the movable sheave and the fixed sheave of the driven pulley are made of aluminum.
Heat is efficiently dissipated during operation, and the durability of the V-belt can be improved. In addition, since the movable sheave and the fixed sheave are formed of the same material in the driven pulley, the temperature conditions of the two become extremely close,
The temperature is substantially the same on the left and right sides of the V belt in the driven pulley. Further, since the movable sheave and the fixed sheave of the driven pulley are made to have the same shape member, even if both are formed by aluminum casting as in the embodiment, they can be manufactured by the same mold, so that the manufacturing cost is extremely low. Has the effect.

[0019]

According to the V-belt type transmission according to the present invention described above, since the fixed sheave and the movable sheave are formed by aluminum die casting into the same shape, the die can be used in common, so a relatively expensive aluminum material is used. However, the total cost is reduced. Further, since both the fixed sheave and the movable sheave are formed of the same material, the temperature conditions of both are almost the same, and aluminum is particularly excellent in heat dissipation, so that it is effective for the V belt. Play.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a power unit of a scooter type motorcycle which employs a V-belt type transmission according to the present invention.

FIG. 2 is an enlarged view of the periphery of a drive pulley 20 in FIG.

FIG. 3 is a schematic side view of the assembled state of the movable sheave 22 and the cam plate 28 as seen from the right side in FIG.

FIG. 4A is a schematic perspective view of a leaf spring elastic member 31,
(b) is a schematic perspective view of the resin slider 30.

FIG. 5 is a schematic assembly diagram of a cam plate.

6A is a partially enlarged view of FIG. 5, FIG. 6B is a sectional view taken along line BB in FIG. 5A, and FIG. 6C is a sectional view taken along line CC of FIG.

7 is an enlarged view around the driven pulley in FIG. 1. FIG.

FIG. 8 is a schematic side view showing only a fixed sheave and a movable sheave from the left side in FIG.

9A is an enlarged view of the movable sheave and the fixed sheave showing a state where the movable sheave is in contact with the fixed sheave in FIG. 7, and FIG. 9B is a movable barrel and a support barrel in this embodiment before the V belt is attached. FIG. 3C is a diagram showing the positional relationship between the movable cylinder and the supporting cylinder when the head of the mounting pin is not protruding, and FIG.

FIG. 10 is a schematic plan view of a cam plate.

11 (a) is a partially enlarged view around the cutout portion of the cam plate in FIG. 10, (b) is a sectional view taken along line EE in (a), and (c) is a sectional view taken along line FF in (b). Is.

[Explanation of symbols]

 1 Power Unit 2 Engine 10 V Belt Type Transmission 11 V Belt 20 Drive Pulley 21 Fixed Sheave 21a V Belt Supporting Surface 21b Fin Supporting Surface 21c Cooling Fin 22 Movable Sheave 22a Cylindrical Sliding Part 22b Disk Part 22c V Belt Support surface 22d Side wall 22e Engagement flange 22f Weight support surface 23 Drive shaft (crank shaft) 24 Nut 25 Spacer 25a Oil hole 26 Sliding bearing 27 Oil seal 28 Cam plate 28a Notch portion 28b Weight support surface 29 Second spacer 30 Resin Slider 30a Groove 30b Wide part 30c Narrow part 31 Leaf spring elastic member 31a Arm part 31b Arm part 32 Weight 40 Driven pulley 41 Fixed sheave 41a Tapered part 41b Flat part 41c V belt support surface 41d Cooling flange 41e mounting hole 41f mounting pin 41g head 42 movable sheave 42a taper portion 42b flat surface portion 42c V-belt support surface 42d cooling flange 42e mounting hole 42f mounting pin 42g head 43 driven shaft 46 support cylinder 46a flange 46b torque pin 47 centrifugal clutch 47a Support plate 47b Outer cylinder 47c Weight 47d Nut 47e Friction surface 47f Friction surface 47g Side wall 47h Nut 48 Movable cylinder 48a Flange 48b Seal ring 48c Seal ring 49 Spring 50 Axle

Claims (1)

[Claims] 1. A drive shaft is provided with a drive pulley, a driven shaft is provided with a driven pulley, and each pulley is a fixed sheave fixed to a corresponding shaft, and a movable sheave slidable with respect to the shaft. In the V-belt type transmission configured as described above, the fixed sheave and the movable sheave in the driven pulley are made of aluminum die cast with the same shape.