JP2805446B2 - V-belt type automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle,
The present invention relates to a V-belt type automatic transmission used for snowmobiles and the like. 2. Description of the Related Art A V-belt type automatic transmission has a V-belt stretched between a driving pulley and a driven pulley, and the driving pulley and the driven pulley each have a rotating shaft. And a movable pulley plate which forms a belt groove facing the fixed pulley plate and is movable in the axial direction. The movable pulley plate of the drive side pulley is formed of an aluminum material from the viewpoint of workability, weight, and the like, and a cam member disposed on the opposite side (back side) of the movable pulley plate from the fixed pulley plate. There was a weight between them. The drive-side pulley pushes the movable pulley plate by the centrifugal force of the weight rotating on the drive-side pulley in contact with the back surface and the peripheral wall of the movable pulley plate, thereby continuously changing the engagement radius between the V-belt and the pulley. Was configured to change. In many cases, the cam member is formed by pressing a steel plate from the viewpoint of rigidity and workability. In recent years, this type of V-belt type automatic transmission has been able to smoothly adjust the gear ratio in a stepless manner and has a simple structure. Widely used for etc. In this type of V-belt type automatic transmission, the weight is continually slid according to the fluctuation of the rotation speed of the rotating shaft, and the speed is changed. For this reason, as disclosed in Japanese Utility Model Laid-Open No. 55-152900, a grease reservoir is formed on the back side of the movable pulley plate, and the weight slides on the back surface of the movable pulley plate by a lubricant such as grease. Wear during movement is suppressed. [0005] However, this type of conventional V-belt type automatic transmission is provided with a cover for preventing the scattering of the lubricant (see, for example, Japanese Unexamined Patent Publication No. Sho 57-57). 124152), the space in which the weights are stored becomes hot without touching the outside air, and the structure is complicated, and the life of the weights and the V-belt is shortened. The problem to be solved by the invention of this application is to provide a V-belt type automatic transmission capable of solving the above-mentioned problems, in other words, an outer peripheral surface of a weight that comes into contact with a movable pulley plate and a cam member. An object of the present invention is to provide a V-belt type automatic transmission in which the life of a weight, a V-belt, and the like having the resin portion can be extended even when the V-shaped automatic transmission is formed by a resin portion. [0007] The invention of this application can solve the above-mentioned problems, and the V-belt type automatic transmission of the invention of this application is provided in a transmission case arranged in contact with the engine body. And a fixed pulley plate fixed to a crankshaft extending into the transmission case, a belt groove is formed opposite the fixed pulley plate, and the belt groove is formed on the crankshaft so as to be able to advance and retreat in its axial direction. A pulley having a movable pulley plate, a weight engaged with the back surface and the peripheral wall of the movable pulley plate and pushing the movable pulley plate by centrifugal force caused by the rotation of the pulley, and clamping the weight between the movable pulley plate and the weight; V-belt type automatic transmission having a plate-like cam member fixed to the crankshaft as described above, the inner peripheral surface of the peripheral wall of the movable pulley plate and A gap is provided between the outer edge of the cam member in the radial direction and a weight storage space formed between the cam member and the movable pulley plate to communicate with the outside, and the movable pulley plate is formed of an aluminum material. The cam member is formed of a steel material, and the weight is formed into a cylindrical shape by providing a resin portion on an outer peripheral surface of the weight adjusting member made of a metal material so as not to cover an inner peripheral surface of an inner hole of the cylindrical body. The resin part is formed of a resin composition obtained by mixing a polyamide resin as a base material with polytetrafluoroethylene as a solid lubricant. According to the V-belt type automatic transmission of the present invention, the cam member and the movable pulley plate are disposed between the inner peripheral surface of the peripheral wall of the movable pulley plate and the radially outer edge of the cam member. The gap is formed between the cam member and the movable pulley plate to allow air to flow from the outside into the weight storage space through the gap between the cam member and the movable pulley plate. By doing so, the weight can be cooled and the movable pulley plate can be cooled. The V-belt type automatic transmission according to the invention of this application is:
The movable pulley plate is formed of aluminum material,
The cam member is formed of a steel material, and the weight is formed in a cylindrical shape by providing a resin portion on an outer peripheral surface thereof so as not to cover an inner peripheral surface of an inner hole of the cylindrical body of the weight adjusting member made of a metal material. Since the resin portion is composed of a polyamide resin as a base material and a resin composition in which polytetrafluoroethylene is mixed as a solid lubricant with the polyamide resin, the high heat resistance of the polyamide resin as a base material of the resin portion of the weight is used. Thus, the weight can withstand high temperatures. In addition, since the polyamide resin, which is the base material of the resin part of the weight, is mixed with polytetrafluoroethylene as a solid lubricant, it has appropriate hardness and self-lubricating properties, and is a movable pulley plate made of aluminum material. Is hard to be worn, and
The resin portion of the weight itself is less likely to be worn by engaging with the steel cam member. An embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 shows a front portion of a unit swing type engine 1 such as a scooter provided with a V-belt type automatic transmission according to the present invention. Engine 1
Functions as one component of a suspension device for suspending the rear wheel 2, and is pivotally supported by a rear portion of a vehicle body (not shown) so as to be vertically swingable. The unit swing type engine 1 includes an engine body 3, a power transmission mechanism 6 for transmitting the power of the engine body 3 to a rear wheel side pulley shaft 5 via a crankshaft 4, and a rear wheel side pulley shaft 5 A transmission case 9 integrally holds a rear wheel axle 8 connected to a speed reducer 7 for reducing the rotation of the vehicle. A V-belt type automatic transmission 10 constituting the power electric mechanism 6 together with the centrifugal clutch 11 includes a crank-side pulley 12 supported on a crankshaft 4 serving as a rotation shaft.
And a rear wheel side pulley shaft 14 via a rotatable collar 13.
Rear-wheel-side pulley 114 supported by the
The V-belt 15 and the like are stretched between the belts 2 and 14 and transmit the rotation of the crankshaft 4 to the rear wheel-side pulley shaft 5 via the centrifugal clutch 11. The rotation of the rear wheel side pulley shaft 5 is transmitted to the rear wheel shaft 8 after being further reduced by the speed reducer 7. The crank side pulley 12 and the rear wheel side pulley 14 form fixed pulley plates 12a, 14a fixed to the crankshaft and the collar 14, respectively, and form belt grooves facing the fixed pulley plates 12a, 14a. A movable pulley plate 12b, 1 which can move forward and backward in the axial direction.
4b. The fixed pulley plate 12a of the crank side pulley 12 is formed in an umbrella shape from, for example, aluminum, iron, stainless steel, or the like. The movable pulley plate 12b is formed in an umbrella shape from aluminum material. In the embodiment, the fixed pulley plate 12a and the movable pulley plate 12b are made of aluminum die-cast. A peripheral wall protruding rearward in the axial direction is integrally formed on the outer peripheral portion of the movable pulley plate 12b. The weight 16 has a circular cross section as shown in FIGS. 3 and 4, and is in contact with a cam surface formed on the back surface of the movable pulley plate 12b and on the inner surface of the peripheral wall. The cam member 17 is located behind the movable pulley plate 12b and is fixed to the crankshaft 4. The cam member 17 is formed by pressing a steel plate into an umbrella shape. The weight 16 is slidably and rotatably held in the radial direction therebetween. In other words, the weight 16 is stored in a weight storage space S formed between the movable pulley plate 12b and the cam member 17, and the back surface of the movable pulley plate 12b and the cam surface of the cam member 17 Has been tied to. The cam surface extends in the radial direction, and the distance between the cam surface and the rear surface is such that the movable pulley plate 12b is pushed by the centrifugal force of the weight 16 caused by the rotation of the crank side pulley 12, and
It is set so that it gradually narrows radially outward so as to change the engagement radius with the belt 15. That is, the rear surface of the movable pulley plate 12b is formed so as to gradually swell backward, and the cam surface of the cam member 17 is formed so as to gradually swell forward. The weight 16 is, as shown in FIG.
A cylindrical weight adjusting member 18 made of a metal material such as iron or brass is provided inside. In other words, weight 16
Is formed in a cylindrical shape with a resin portion 16a described later provided on the outside thereof so as not to cover the inner peripheral surface of the inner hole of the weight adjusting member 18. Further, the weight is set to a weight at which a centrifugal force for pushing the movable pulley plate 12b is obtained when the crankshaft 4 reaches a predetermined number of rotations. Since the weight adjusting member 18 of this embodiment is formed in a cylindrical shape having an inner hole, air can flow through the inner hole to increase the contact area with air.
Moreover, the weight can be adjusted to a desired value by changing the inner diameter. The weight adjustment member 18 is fixed by inserting the weight adjustment member 18 when the weight 16 is formed, or by press-fitting the weight 16 after the formation. Here, the shape of the weight adjusting member 18 can be variously changed. As a material for forming the resin portion 16a of the weight 16, a resin mixed with a solid lubricant or a fiber-reinforced resin as a resin composite material in which the resin is filled with fibers is used. As the base resin, polyamide (nylon resin) is used, and as the fiber, glass fiber, carbon fiber or aramid fiber (for example,
Kepler fiber manufactured by DuPont) or the like is used. Also,
Polytetrafluoroethylene (PTFE) is used as a solid lubricant mixed in the resin. Specifically, for example, it is as shown in Table 1 below. [Table 1] The outer diameter of the cam member 17 is smaller than the inner diameter of the peripheral wall of the movable pulley plate 12b.
A gap g that connects the weight storage space S to the outside of the crank-side pulley 12 is provided between the inner periphery of the crankcase pulley 12 and the inner periphery. The gap g is determined by the fact that the movable pulley plate 12b is made of aluminum die-cast at the time of top shown by the two-dot chain line in FIG.
b is set so as to be maximum by being separated in the axial direction. The guide member 19 includes the movable pulley plate 1.
It is interposed between 2b and the cam member 17 to guide the cam member 17. The movable pulley plate 12b and the cam surface of the cam member 17 may have a surface finishing accuracy of a little rough because the weight 16 has self-lubricating properties, and may be plated by hard plating or the like, although not necessarily required. May be. In the V-belt type automatic transmission constructed as described above, the resin portion of the weight 16 which pushes the movable pulley plate 12b by centrifugal force is provided with a PT as a solid lubricant.
Because FE (polytetrafluoroethylene) was mixed,
It has self-lubricating properties and can suppress its wear without supplying a lubricant. Therefore, there is no need to attach a cover as in the conventional case, the structure is simplified, and the cam member 17 can be exposed outside the crank side pulley. Further, since a gap g is provided between the outer peripheral edge of the cam member 17 and the inner peripheral surface of the peripheral wall of the movable pulley plate 12b to allow the weight storage space S to communicate with the outside, the outside air is weighted from the gap g. It can be distributed to the storage space S. The centrifugal force acting on the weight 16 changes in response to the change in the number of revolutions of the crankshaft 4, and the weight 16 moves radially outward or inward in accordance with the change in the centrifugal force, and the cam 16 Member 17 and movable pulley plate 12b
The volume of the space between the movable pulley plate 12 and the end of the cam member 17 and the movable pulley plate 12
The flow of the outside air through the gap g between the inner peripheral surface of the peripheral wall b is activated, and the air in the weight storage space S is ventilated. As a result, the outside air can be brought into direct contact with the back surface of the weight 16 and the movable pulley plate 12b, so that the heat of these members can be transferred to the outside air and cooled. At this time, since the heat of the V belt 15 is transmitted to the cooled movable pulley plate 12b, the V belt 15 is also cooled at the same time. In other words,
The heat of the V-belt 15 is transmitted to the outside air via the movable pulley plate 12b. Further, since the cylindrical weight adjusting member 18 made of a metal material having excellent heat conductivity and heat conductivity is inserted into the weight 16, outside air flows through the inner hole thereof. This weight adjusting member 18 can function as a kind of heat radiating member. Thereby, the heat of the weight 16 is transmitted from the weight adjusting member 18 to the outside air, and the heat is smoothly dissipated, so that the cooling can be performed effectively. Moreover, the resin portion of the weight 16 is made of a polyamide resin, and the polyamide resin (6.6 nylon) has high heat resistance. And the like can withstand severe conditions such as In addition, since the weight 16 has a resin portion 16a made of the polyamide resin as a base material and has an appropriate hardness, the movable pulley plate 12b made of aluminum material is hardly worn, and the weight of the steel cam member 17 is reduced. Due to the engagement, the resin portion 16a of the weight 16 is less likely to be worn. Further, since the polyamide resin has high adhesion to fibers and the like, the filling thereof facilitates adjustment of the hardness of the resin portion 16a. Therefore, weight 16,
It is possible to prevent the movable pulley plate 12b and the V bolt 15 from becoming high temperature, and to reduce their deterioration and deterioration. According to the experiment, it was found that the wear of the weight 16 was reduced in the embodiment of Table 1 and that the wear was increased when the weight adjusting member 18 was removed in the comparative example. In the V-belt type automatic transmission of the embodiment, the crankshaft 4, the cam member 17, the movable pulley plate 12
b, etc., is heated, and a repeated impact load due to the vibration of the engine acts on the cam member 17, the movable pulley plate 12b, the weight 16, and the like. Plate 12b, cam member 17, weight 16
Etc. are heated. When the resin portion 16a of the weight 16 is made of a nylon resin, such as a composition example shown in Table 1, in which carbon fiber is mixed as a reinforcing material and polytetrafluoroethylene is mixed as a solid lubricant, A weight 16 having excellent heat resistance, abrasion resistance and fatigue resistance can be obtained. Since the weight 16 can sufficiently withstand the heat and impact loads and has self-lubricating properties, it has stable shifting characteristics over a long period of time. Can be maintained. As described above, the polyamide resin which is the base material of the resin part of the weight of the present invention has high heat resistance, is resistant to repeated impact loads, and has high impact resistance. However, it is a resin that can maintain stable properties for a long time, and polytetrafluoroethylene as a solid lubricant mixed into the resin part of the present invention has high heat resistance, a small friction coefficient, and is stable for a long time. Since the resin can maintain the properties, the resin part of the weight provided on the outer peripheral surface of the weight adjusting member made of the metal material of the present invention so as not to cover the inner peripheral surface of the inner hole of the cylindrical body is the base material. The weight is excellent in heat resistance, abrasion resistance, and fatigue resistance because it is composed of a resin composition in which polytetrafluoroethylene as a solid lubricant is mixed in a polyamide resin. And can sufficiently withstand impact loads, etc.
The self-lubricating property of the weight reduces the coefficient of friction on the surface of the weight, eliminating the need for lubricant supply.The weight rolls smoothly without lubricant and prevents its local wear can do. The V-belt type automatic transmission according to the present invention is formed between the cam member and the movable pulley plate between the inner peripheral surface of the peripheral wall of the movable pulley plate and the radially outer edge of the cam member. The weight storage space is provided with a gap that communicates with the outside, so that the weight storage space communicates with the outside through the gap, and outside air can be circulated in the weight storage space. Outside air flows through the inner hole of the cylindrical body of the weight adjusting member, and the weight adjusting member can function as a kind of heat radiating member. Therefore, the weight, the movable pulley plate, and the cam member are efficiently cooled. The V-belt that is in contact with the movable pulley plate can also be indirectly cooled,
Deterioration and wear of the V-belt and the like can be reduced, and their life can be extended. In the V-belt type automatic transmission according to the present invention, the movable pulley plate is formed of an aluminum material, the cam member is formed of a steel material, and the weight is formed in a cylindrical body of a weight adjusting member made of a metal material. The hole was formed in a cylindrical shape by providing a resin portion on the outer peripheral surface so as not to cover the inner peripheral surface, and the resin portion was mixed with polytetrafluoroethylene as a solid lubricant with a polyamide resin as a base material. Since it is composed of the resin composition, the polyamide resin of the resin portion of the weight has an appropriate hardness, and does not damage the movable pulley plate formed of the aluminum material. The resin part itself is not damaged. Also,
Since the movable pulley plate is made of an aluminum material and the cam member is made of a steel material, a difference occurs in the circumferential frictional force of a portion of the resin portion of the weight that comes into contact with the resin portion, so that the weight easily rolls, and a local portion of the resin portion of the weight is formed. Wear can be prevented. In the V-belt type automatic transmission according to the present invention, the polyamide resin, which is the base material of the resin portion of the weight, has a high water absorption. Even if the temperature drops and the water in the air condenses into water, the water is absorbed by the resin portion of the weight, so that the rust of the cam member or the like formed of steel can be prevented. . Also, even if the resin portion of the weight made of a polyamide resin as a base material and mixed with polytetrafluoroethylene as a solid lubricant is worn to generate abrasion powder, the abrasion powder has the above-mentioned properties of the polyamide resin. As a result, water is easily absorbed and becomes heavy, so that it does not scatter unnecessarily and adhere to the V-belt or the like. In the V-belt type automatic transmission according to the present invention, the weight is provided with a resin portion on its outer peripheral surface so as not to cover the inner peripheral surface of the inner hole of the cylindrical body of the weight adjusting member made of a metal material. Formed in a cylindrical shape, the resin portion is made of a resin composition obtained by mixing polytetrafluoroethylene as a solid lubricant with a polyamide resin as a base material, so that the weight has heat resistance, abrasion resistance and It has excellent fatigue resistance and can sufficiently withstand heat, impact load, etc. even when placed in the transmission case placed in contact with the engine body.
It is possible to maintain stable shift characteristics over a long period of time. Therefore, the V-belt type automatic transmission according to the present invention can stabilize its shift characteristics over a long period of time, and can simplify maintenance and inspection.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional plan view showing a main part of a front part of a unit swing type engine such as a scooter provided with a V-belt type automatic transmission according to an embodiment. FIG. 3 is a plan view showing a cross-section of a main part of a rear part of a unit swing type engine such as a scooter equipped with a V-belt type automatic transmission. [Description of Signs] 1 Unit swing type engine 2 Rear wheel 4 Crank shaft 5 Rear wheel side pulley shaft 10 V-belt type automatic transmission 12 Crank side pulley 12a Fixed pulley plate 12b Movable pulley Plate 15 V-belt 16 Weight 16a Resin portion 17 Cam plate 18 Weight adjusting member g Clearance

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 9/00-9/26

Claims (1)

(57) [Claims] Placed in the transmission case placed in contact with the engine body
A fixed pulley plate fixed to a crankshaft extending into the transmission case, a movable pulley forming a belt groove facing the fixed pulley plate, and being mounted on the crankshaft so as to be able to advance and retreat in the axial direction thereof. a pulley having a plate, and the weights to push the movable pulley plate by centrifugal force accompanying the rotation of the pulley in contact engagement with the rear surface and a peripheral wall of the movable pulley plate, so as to sandwiching the weights between the movable pulley plate Fixed to the crankshaft
In a V-belt type automatic transmission including a plate-like cam member, an inner peripheral surface of a peripheral wall of a movable pulley plate and a cam member
Between the cam member and the movable pulley
Weight storage space formed between the
The movable pulley plate is made of aluminum
The cam member is formed of a steel material.
A weight adjusting member formed of a metal material;
Forming a cylindrical by in its outer peripheral surface so as not to cover the inner peripheral surface of the inner bore of the tubular body providing the <br/> resin portion, to which the solid lubricating the resin portion of the polyamide resin as a base material and wood
With a resin composition mixed with polytetrafluoroethylene
A V-belt type automatic transmission characterized by being constituted .