JP2007278449A - V-belt type automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a V-belt type automatic transmission capable of generating proper side load suitable for engine torque by varying the width of a pulley so as to improve rotation transmission efficiency. <P>SOLUTION: A fixed cam 3 is attached to a driven shaft 4 in a fixed manner in the axial direction and in the direction of the periphery of the driven shaft. A first movable sheave 1 has first cam parts 13 formed in the vicinity of the surface center of a first face portion 12. A second movable sheave 2 has second cam parts 23 formed in the vicinity of the surface center of a second face portion 12. The first movable sheave 1 and the second movable sheave 2 are slidably mounted on the driven shaft 4 with the fixed cam 3 held therebetween. The first movable sheave 1 is pressed and urged against the second movable sheave 2 via a spring 8 so that the first cam parts 13 and the second cam parts 23 are engaged with the fixed cam 3. The first movable sheave 1 and the second movable sheave 2 rotate normally to thereby come close to the fixed cam 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a V-belt type automatic transmission capable of improving rotation transmission efficiency by varying a pulley width to obtain an appropriate side load suitable for engine torque.

  The generated torque of a power generation source such as an engine is transmitted from a drive-side variable pulley to a driven-side variable pulley by a V-belt wound between the variable pulleys, and when transmitting the torque, the drive-side variable pulley There is a V-belt type automatic transmission that changes the winding diameter of a V-belt pulley with a centrifugal force acting on a weight roller provided on the belt and a torque detection mechanism provided on a variable pulley on the driven side.

  In such a V-belt type automatic transmission, a fixed pulley that is integrally fixed to the rotating shaft and a cam mechanism that biases the movable pulley toward the fixed pulley according to the load torque are provided. It is disclosed in Patent Document 1. The one disclosed in Patent Document 1 is provided with a drive side cam mechanism in the configuration of the drive side pulley, and a driven side cam mechanism is also provided in the configuration of the driven side pulley. It consists of a fixed cam and a movable cam. The fixed cam constituting the drive-side cam mechanism is integrally fixed to the drive shaft, and the movable cam is integrally fixed to the movable pulley, and has a cam slope that is always in contact with the power transmission.

The fixed cam constituting the driven cam mechanism is integrally fixed to a side plate fixed to the driven shaft, and the movable cam has a slope that is fixed to the movable pulley and contacts the slope of the fixed cam. The cam mechanism is composed of a fixed cam fixed on the shaft member side and a movable cam fixed on the movable pulley side. Then, the movable pulley is moved toward the fixed pulley via the cam mechanism. In addition, the pulley groove is narrowed by the cam force of the inclined surfaces of the fixed cam and the movable cam that are in contact with each other according to the magnitude of the belt transmission force, that is, the belt is moved in the direction of increasing the belt winding diameter. The thickness is appropriately adjusted.
JP-A-4-151052 JP 61-270548 A

  In Patent Document 1, it is a cam mechanism that moves only a movable pulley relative to a fixed pulley. In the driven pulley, only the movable pulley is pressed in the axial direction by a flyweight, and the cam force of the previous cam mechanism and the flyweight A belt transmission force is received by the combined force with the pressing force and transmitted to the rotating shaft. In the drive pulley, only the movable pulley is pressed in the axial direction by the spring, and the rotational force of the drive shaft is transmitted to the belt by the combined force of the cam force and the spring force of the previous cam mechanism. Some driven pulleys receive a belt transmission force by a combined force of a cam force of a cam mechanism and a spring force and transmit it to a rotating shaft.

  For example, in Patent Document 2, a cam mechanism and a spring for moving only the movable pulley relative to the fixed pulley are provided on the one side of the movable pulley. In particular, in the driven pulley, the belt is sandwiched by the resultant force of the cam force and the spring force that moves only the movable pulley relative to the fixed pulley, and is transmitted to the driven shaft by receiving the belt transmission force. When receiving the belt transmission force, a belt transmission frictional force is generated between the pulley and the belt.

  This belt transmission frictional force acts as a frictional resistance element when the force pushing the pulley against the belt transmission force becomes large, and affects the transmission efficiency. The spring force for pushing the pulley is set to correspond to the maximum reduction ratio that requires a particularly large force to push the pulley. There exists a subject that it will act as a frictional resistance element and will reduce transmission efficiency.

  Furthermore, supplementally, at the maximum reduction ratio (when the belt winding diameter of the driven pulley is maximum), the force that resists the movable pulley from being separated from the fixed pulley is set by the resultant force of the cam force and the spring force. On the other hand, at the time of the minimum reduction ratio (when the belt-wound diameter of the driven pulley is minimum), the same cam has a force that contradicts the maximum reduction ratio, which makes the movable pulley easy to separate from the fixed pulley. It is extremely difficult to satisfy both the maximum reduction ratio and the minimum reduction ratio by setting with a spring. Therefore, the problem (technical problem or object) to be solved by the present invention is to provide a V-belt type automatic that can generate an appropriate side load more suitable for the engine torque with the aim of increasing the efficiency of V-belt transmission. The object is to provide a transmission.

  In view of this, the inventor has intensively studied to solve the above problems, and as a result, the invention of claim 1 is directed to the driven shaft in which the fixed cam is fixed in the axial direction and the axial direction. A first movable sheave having a first cam portion formed near the center of the surface and a second movable sheave having a second cam portion formed near the center of the surface of the second face portion sandwich the fixed cam. The first movable sheave is slidably mounted, and the first movable sheave is pressed and urged to the second movable sheave via a spring, and the first cam portion and the second cam portion are cam-engaged with the fixed cam. The V belt type automatic transmission in which the first movable sheave and the second movable sheave are moved close to the fixed cam side by the positive rotation of the first movable sheave and the second movable sheave. Is a solution.

  According to a second aspect of the present invention, there is provided a first movable sheave including a first boss portion, a first face portion, and a first cam portion formed near the surface center of the first face portion, a second boss portion, and a second boss portion. A second movable sheave composed of a face portion and a second cam portion formed near the center of the surface of the second face portion, and a fixed portion formed with a first engaged cam portion and a second engaged cam portion. The fixed cam comprises a cam, a driven shaft on which the first movable sheave and the second movable sheave are slidably mounted, and a spring that presses and urges the first movable sheave against the second movable sheave. Is fixed to the driven shaft in the axial direction and the axial circumferential direction, and is sandwiched between the first movable sheave and the second movable sheave, and the first cam portion, the first engaged cam portion, and the first 2 cam portions and the second engaged cam portion are engaged, and the first cam portion and the second cam The V-belt automatic transmission has an engagement inclined surface that is moved closer to the fixed cam side by forward rotation of the first movable sheave and the second movable sheave. It has been solved.

  According to a third aspect of the present invention, there is provided a V-belt automatic transmission according to the first or second aspect, wherein the engaged cam portion of the fixed cam is formed of a synthetic resin. Thus, the above-mentioned problems are solved. According to a fourth aspect of the present invention, in the above-described configuration, the angle of the engaging inclined surface of the first cam portion is formed larger than the angle of the engaging inclined surface of the second cam portion. By using a machine, the above-mentioned problems have been solved. According to a fifth aspect of the present invention, in the above-described configuration, the V-belt automatic transmission is configured such that the angle of the engagement inclined surface of the first cam portion is the same as the angle of the engagement inclined surface of the second cam portion. Thus, the above-described problems are solved.

  According to a sixth aspect of the present invention, in the above-described configuration, at least two first cam portions of the first movable sheave and two second cam portions of the second movable sheave are formed, and the first cam is provided on the fixed cam. The V belt type automatic transmission in which two or more engaging cam portions and second engaged cam portions are respectively formed is used to solve the above-described problem. According to a seventh aspect of the present invention, in the above-described configuration, the second cam portion is a V-belt type automatic transmission in which a restriction step portion for restricting a movement amount to the fixed cam member is formed. It solves the problem.

  According to the first aspect of the present invention, a first fixed cam, a first movable sheave having a first cam portion, and a second movable sheave having a second cam portion are provided, and the first cam portion is engaged with each other. The first movable sheave and the second movable sheave can move close to the fixed cam by the rotation of the second cam portion. As a result, the spring force for pushing the pulley does not require a particularly large force to push the pulley, and the frictional resistance applied by the first movable sheave and the second movable sheave can be reduced. The operation of the movable sheave can be stabilized.

  According to the invention of claim 2, the spring force provided on one movable sheave is appropriately reduced by operating with a rotating cam force and applying a cam force to each movable sheave so as to be sandwiched from both sides of the belt. Further, the force pushing the movable sheave against the belt transmission force corresponding to the engine torque can be improved. Therefore, by setting the resultant force of the movable sheave cam force and spring force at the maximum reduction ratio and the minimum reduction ratio and the cam force of the other movable sheave, the maximum reduction ratio and the minimum reduction ratio can be set. The operation at the time can be stabilized, and the operation at the minimum reduction ratio can be smoothly performed (load resistance due to the spring force is reduced). That is, it is possible to generate an appropriate side load that matches the engine torque, and to improve transmission efficiency.

  According to the third aspect of the present invention, the engaged cam portion of the fixed cam is formed of synthetic resin, thereby avoiding metal contact in the engagement with the first movable sheave and the second movable sheave. Metallic noise or noise can be prevented. Moreover, rotational vibration and vibration can be reduced by reducing the weight with a synthetic resin.

  According to a fourth aspect of the present invention, the angle of the engaging inclined surface of the first cam portion is formed larger than the angle of the engaging inclined surface of the second cam portion, so that the first movable sheave can be changed during shifting. When the first movable sheave moves closer to the fixed cam side, the first movable sheave starts to move faster than the second movable sheave, and stable shifting can be performed. Further, by appropriately setting the inclination angles of the cam of the cam member and the cam of the movable sheave, various shift patterns can be easily set according to the engine torque.

  According to the invention of claim 5, the angle of the engagement inclined surface of the first cam portion is the same as the angle of the engagement inclined surface of the second cam portion, so that the first movable sheave and the first When the two movable sheaves move closer to the fixed cam side, the first movable sheave starts to move at the same time as the second movable sheave, so that the belt can be held uniformly.

  According to a sixth aspect of the present invention, two or more first cam portions of the first movable sheave and two second cam portions of the second movable sheave are formed, and the fixed cam includes a first engaged cam portion and By forming two or more second engaged cam portions, each of the first movable sheave and the second movable sheave when the first movable sheave and the second movable sheave move closer to the fixed cam side during shifting. The movable sheave can start moving in a stable state.

  According to the seventh aspect of the present invention, the second cam portion is formed with a regulation step portion that regulates the amount of movement to the fixed cam member, so that the amount of movement of the second movable sheave toward the fixed cam is reduced. The number of movable sheaves can be smaller than that of one movable sheave, and the state where the belt is put on by the shifting operation can be stabilized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the configuration of the present invention mainly includes a first movable sheave 1, a second movable sheave 2, a fixed cam 3, a driven shaft 4, a spring 8, and the like. A driven sheave is configured by the configuration of these members, and a belt 9 is hung between the drive sheave (not shown), and rotation is transmitted to the driven sheave from the drive sheave.

  As shown in FIG. 2, the first movable sheave 1 includes a hollow cylindrical first boss portion 11, a first face 12, and a first cam portion 13, and an axis of the first boss portion 11. A central portion of the first face 12 is integrally formed at the end in the direction. A cylindrical recess 120 is formed from the center of the first face 12 to the periphery thereof (see FIGS. 2B and 2C). The concave portion 120 includes a bottom surface portion 121 and a circumferential inner surface portion 122, and the bottom surface portion 121 communicates with the shaft through hole 11 a of the first boss portion 11. The bottom part 121 is formed in a circular shape.

  Further, the first cam portion 13 is formed so as to protrude outward from the opening portion 120a of the concave portion 120 from the bottom surface portion 121 (see FIG. 2A). As shown in FIGS. 2 (B) and 2 (C), two first cam portions 13 are formed in the recess 120, and the formed state is the center of the diameter of the circular bottom portion 121. It is formed on both sides so as to be point-symmetric with the center position of the bottom surface 121 as the center point. The first cam portion 13 is formed as a plate-like body and has an engagement inclined surface 13a. The vicinity of the tip of the engagement inclined surface 13a protrudes from the opening 120a of the recess 120 to the outside. Further, in the first cam portion 13, the engagement inclined surface 13 a is inclined forward along the forward rotation direction of the first movable sheave 1. The inclination angle θa of the engagement inclined surface 13a is set so that the angle formed with the bottom surface portion 121 is an acute angle, as shown in FIGS.

  As shown in FIG. 3A, the second movable sheave 2 is composed of a second boss portion 21, a second face 22, and a second cam portion 23. The second boss portion 21 is This is a portion formed as a through hole 21 a in the center of the second face 22. A cylindrical recess 220 is formed from the center of the second face 22 to the periphery thereof. The concave portion 220 has the same shape as the concave portion 120 of the first movable sheave 1, and includes a bottom surface portion 221 and a circumferential inner surface portion 222, and the bottom surface portion 221 is a through hole of the second boss portion 21. It communicates with 21a. The bottom surface portion 221 is formed in a circular shape.

  Further, the second cam portion 23 is formed so as to protrude from the bottom surface portion 221 outward from the opening 220 a of the recess 220. Two second cam portions 23 are formed in the recess 220, and the formed state is that the center of the diameter of the circular bottom surface portion 221 is centered on the center position of the bottom surface portion 221 on both sides thereof. It is formed so as to be symmetrical.

  The second cam portion 23 is formed as a plate-like body and has an engagement inclined surface 23a. The vicinity of the tip of the engaging inclined surface 23a protrudes from the opening 220a of the recess 220 to the outside. Further, in the second cam portion 23, the engagement inclined surface 23 a is inclined forward along the forward rotation direction of the second movable sheave 2. The inclination angle θb of the engagement inclined surface 23a is set so that the angle formed with the bottom surface portion 221 is an acute angle (see FIGS. 3A and 3C).

  The first movable sheave 1 and the second movable sheave 2 are made of metal. Specifically, the first movable sheave 1 and the second movable sheave 2 are integrally formed of an aluminum alloy and die-casted with a mold. Since the movable sheave is integrally formed by die casting of an aluminum alloy with a mold, the surface formed by the mold is cooled to produce a chill layer and harden the surface.

  In addition, since the molding surface of the mold is made to have high surface accuracy in this way, a smooth surface can be obtained even in a cast surface state having a chill layer of the molded product. In the part of the face 22 such as the belt engaging surface or cam engaging surface that slides to prevent wear, the hardened surface (cast surface) of the chill layer is used as it is so Abrasion can be easily increased, and since no special surface treatment is performed, the cost can be reduced.

  Further, by integrally molding the first movable sheave 1 and the second movable sheave 2 with an aluminum alloy, a good hard surface can be easily provided, and the engagement sliding surface (belt surface, The wear resistance of the cam surface can be improved. In addition, the combination of the first engaged cam portion 31 and the second engaged cam portion 32 of the fixed cam 3 made of synthetic resin can prevent the movable sheave cams from being worn and facilitate maintenance.

  Next, as shown in FIGS. 4A and 5A, the fixed cam 3 is formed in a substantially disc shape, and a cam boss 33 is formed in the center portion. A first engaged cam portion 31 and a second engaged cam portion 32 are formed substantially radially from the periphery of the first engagement cam portion 31. Further, an outer ring portion 34 is formed so as to be connected to the tips of the first engaged cam portion 31 and the second engaged cam portion 32.

  The outer ring portion 34 has a circular ring shape and reinforces the first engaged cam portion 31 and the second engaged cam portion 32. The first engaged cam portion 31 and the second engaged cam portion 32 are formed at equal intervals (equal angles). In addition, it is most appropriate to form two first engaged cam portions 31 and two second engaged cam portions 32 to obtain the stability of the shifting operation. .

  4C is a cross-sectional view taken along the arrow Xe-Xe in FIG. 4A, and is a cross-sectional view in a state where the fixed cam 3 is developed along the circumferential direction. Further, FIG. 4D is an enlarged sectional view of the first engaged cam portion 31 and the second engaged cam portion 32. An engaged surface portion 31a is formed on one surface in the circumferential direction of the first engaged cam portion 31, and an engaged surface portion is formed on the one surface in the circumferential direction of the second engaged cam portion 32. A mating surface portion 32a is formed.

  Further, the engaged surface portion 31a and the engaged surface portion 32a are all formed in the same direction. The engaged surface portion 31 a and the engaged surface portion 32 a are formed as inclined surfaces, and the angle is an angle formed with the axial direction of the fixed cam 3. Specifically, the inclined angle θa ′ of the engaged surface portion 31a is the same as the angle θa of the engaging inclined surface 13a of the first cam portion 13, and the inclined angle θb ′ of the engaged surface portion 32a is The second cam portion 23 is formed at the same angle as the angle θb of the engaging inclined surface 23a (see FIGS. 4D and 9A).

  As shown in FIGS. 4C and 4D, the engaged surface portion 31a and the engaged surface portion 32a are inclined in opposite directions. The engaged surface portion 31a of the first engaged cam portion 31 and the engaged surface portion 32a of the second engaged cam portion 32 are rotated in a state where the fixed cam 3 rotates together with the driven shaft 4. It is formed on the surface opposite to the direction. A first gap portion 35 exists between the engaged face portion 31 a side of the first engaged cam portion 31 and the second engaged cam portion 32, and the first gap portion 35 includes the first gap portion 35. The one cam portion 13 is loosely inserted, and the engagement inclined surface 13a and the engaged surface portion 31a are engaged. Further, a second gap portion 36 exists between the engaged surface portion 32 a of the second engaged cam portion 32 and the first engaged cam portion 31, and the second gap portion 36 has the second gap portion 36. The two cam portions 23 are loosely inserted, and the engaging inclined surface 23a and the engaged surface portion 32a are engaged (see FIGS. 4 and 9).

  In the fixed cam 3, the cam boss 33 and the outer ring portion 34 are made of metal, and the first engaged cam portion 31 and the second engaged cam portion 32 are made of synthetic resin. As a specific structure thereof, as shown in FIGS. 6A and 6B, a connecting portion 37 is formed between the metal cam boss 33 and the outer ring portion 34 with a predetermined interval. The connecting portion 37 is made of metal and is formed in a shaft shape, and connects the outer peripheral side of the cam boss 33 and the inner peripheral side of the outer ring portion 34. The cross-sectional shape of the connecting portion 37 is a substantially square shape, an oval shape, or the like, specifically, a substantially rectangular shape, a substantially square shape, an oval shape, or the like (see FIG. 6C). Here, in FIG. 6, the structure in which the first engaged cam portion 31 and the second engaged cam portion 32 are cast into the connecting portion 37 is the same, and the second engaged cam portion 32 is illustrated as follows. The first engaged cam portion 31 is substituted, and the reference numerals for the second engaged cam portion 32 are shown in parentheses.

  The connecting portion 37 serves as a core material, and a first engaged cam portion 31 and a second engaged cam portion 32 made of synthetic resin are provided on the connecting portion 37. As its structure, a synthetic resin is cast around the connecting portion 37. Then, by forming a recess hole or the like on the surface of the connecting portion 37, the first engaged cam portion 31 and the second engaged cam portion 32 can be firmly coupled to the connecting portion 37. .

  Further, the first engaged cam portion 31 and the second engaged cam portion 32 made of synthetic resin are mounted between the cam boss 33 and the outer ring portion 34 without the connection portion 37 being present. There is also. In this case, as shown in FIGS. 7A and 7B, coupling tabs 31b and 32b are formed on the first engaged cam portion 31 and the second engaged cam portion 32, respectively. Yes. Further, the cam boss 33 and the outer ring portion 34 are formed with tab holes 33a and 34a corresponding to the connecting tabs 31b and 32b.

  The coupling tabs 31b and 32b are inserted and fixed in the tab holes 33a and 34a, and the first engaged cam portion 31 and the second engaged cam portion 32 are mounted on the cam boss 33 and the outer ring portion 34, respectively. The coupling tabs 31b and 32b and the tab holes 33a and 34a are preferably formed in a square shape in order to be firmly attached (see FIG. 7C). Here, FIG. 7 is the same as FIG. 6 in that the mounting structure of the first engaged cam portion 31 and the second engaged cam portion 32 is the same. The first engaged cam portion 31 is substituted, and the reference numerals for the second engaged cam portion 32 are shown in parentheses.

  Further, in the fixed cam 3, the cam boss 33, the outer ring portion 34, and the engaged cam portions (the first engaged cam portion 31 and the second engaged cam portion 32) are all made of metal and integrally formed. There is also. Further, as described above, the fixed cam 3 is made of a metal with the cam boss 33 and the outer ring portion 34 and the connecting portion 37 formed at a predetermined interval between the cam boss 33 and the outer ring portion 34. An embodiment in which the metal engaged cam portions (the first engaged cam portion 31 and the second engaged cam portion 32) are formed in the connecting portion 37 is cast. Is also present.

  In this embodiment, the cam boss 33, the outer ring portion 34, the connecting portion 37, and the engaged cam portion (first engaged cam portion 31, second engaged cam) formed in the connecting portion 37 by casting. The parts 32) are all made of the same metal. The metal material is an aluminum alloy or a steel material. The cam boss 33, the outer ring portion 34, the connecting portion 37, and the engaged cam portion formed in the connecting portion 37 (first engaged cam portion 31, second engaged cam portion 32). May be formed from different metal materials. In this case, for example, the cam boss 33, the outer ring portion 34, and the connecting portion 37 are made of steel, and the engaged cam portions (first engaged cam portion 31, second engaged cam portion 32). Is an aluminum alloy material.

  Further, in the fixed cam 3, the cam boss 33, the outer ring portion 34, and the engaged cam portions (first engaged cam portion 31 and second engaged cam portion 32) are integrally formed of synthetic resin. Sometimes. Further, as described above, the cam boss 33, the outer ring portion 34, the connecting portion 37, and the engaged cam portions (first engaged cam portion 31, second engaged cam) formed in the connecting portion 37 by casting. Part 32), all of which may be made of synthetic resin.

  The fixed cam 3 is fixed to the driven shaft 4 so as to be immovable in the axial direction and the axial direction, and the driven shaft 4 is inserted into the cam boss 33 so as not to idle. Retaining rings are attached to both sides of the cam boss 33 in the axial direction, and the fixed cam 3 is fixed to the driven shaft 4. The fixed cam 3 is immovable in the axial direction and the circumferential direction with respect to the driven shaft 4, and the fixed cam 3 and the driven shaft 4 rotate together.

  The driven shaft 4 is formed in a hollow cylindrical shape, and a retaining ring groove for fixing the fixed cam 3 is formed at a substantially intermediate position in the axial direction. A portion for mounting a bearing is formed at the axial end portion of the driven shaft 4 and on the inner peripheral side, and the axle 7 is rotatably mounted in the shaft through hole 4 a of the driven shaft 4.

  As shown in FIG. 1A, the clutch plate 5 is fixed to the axial end of the driven shaft 4 so as to rotate together with the driven shaft 4. Further, a clutch outer 6 is rotatably mounted via a bearing so as to cover the clutch plate 5 at the axial end of the driven shaft 4. The clutch outer 6 is connected to the axle 7.

  A spring 8 is mounted between the driven shaft 4 and the clutch plate 5. The spring 8 is abutted in the axial direction of the driven shaft 4 so as to sandwich the V-belt between the first face 12 of the first movable sheave 1 and the second face 22 of the second movable sheave 2. It plays a role of energizing the bullet. The spring 8 is a coil spring.

  Next, in the present invention, the operation of changing the pulley width by the first movable sheave 1, the second movable sheave 2, and the fixed cam 3 will be described. First, a belt 9 is hung between a driven sheave constructed according to the present invention and a drive sheave (not shown), and rotation is transmitted from the drive sheave to the driven sheave. The rotation transmission of the belt 9 generates a rotational force on the first movable sheave 1 together with the first face 12 in contact with the belt 9.

  As shown in FIGS. 8A and 9A, the first cam portion 13 of the first movable sheave 1 engages with the first engaged cam portion 31 of the fixed cam 3 in an inclined state. ing. The first movable sheave 1 moves toward the fixed cam 3 such that the positive rotation of the first movable sheave 1 causes the first cam portion 13 and the first engaged cam portion 31 to bite further. [See FIGS. 8B and 9B].

  Here, the normal rotation is a rotation direction in which rotation is transmitted from the drive sheave by the belt 9. At this time, the cam force Fa exerted on the first engaged cam portion 31 by the first cam portion 13, that is, the force applied in the axial direction of the fixed cam 3 is as follows. Fa = α × (T ÷ tan θa). Here, T is a component force applied in the circumferential direction of the fixed cam 3, and α is a coefficient (see FIG. 9A).

  Similarly, the second movable sheave 2 is also rotationally transmitted by the belt 9, the second cam portion 23 and the second engaged cam portion 32 are engaged, and the second movable sheave 2 moves to the fixed cam 3 side. . Further, the cam force Fb exerted on the second engaged cam portion 32 by the second cam portion 23, that is, the force applied in the axial direction of the fixed cam 3 is as follows. Fb = β × (T ÷ tan θb). Here, β is a coefficient (see FIG. 9A).

  As a result, the first face 12 of the first movable sheave 1 and the second face 22 of the second movable sheave 2 are close to each other, and the winding pattern of the belt 9 can be changed to set a shift pattern. Then, the rotation is transmitted from the fixed cam 3 to the driven shaft 4, and the rotation is transmitted from the driven shaft 4 to the axle 7 through the clutch plate 5 and the clutch outer 6.

  Here, the inclination angle θa of the engagement inclined surface 13a of the first cam portion 13 of the first movable sheave 1 is larger than the inclination angle θb of the engagement inclination surface 23a of the second cam portion 23 of the second movable sheave 1. By forming it larger, the cam force Fa can be made larger than the cam force Fb. As a result, the first movable sheave 1 can have a time difference at the start of movement so that the first movable sheave 1 moves closer to the fixed cam 3 first than the second movable sheave 2.

  The second cam portion 23 may be provided with a regulation step portion 23b on the engagement inclined surface 23a side and on the boss side. The regulation step portion 23b is a portion in which a root portion of the engagement inclined surface 23a protrudes forward in the circumferential direction. In the regulation step portion 23b, the second cam portion 23 engages with the second engaged cam portion 32, the second movable sheave 2 rotates, and the second cam portion 23 rotates into the second engaged portion. When it tries to bite into the cam part 32, it plays the role which regulates the biting depth so that it may become shallow. As a result, it is possible to provide a difference in the amount of movement of the first movable sheave 1 and the second movable sheave 2 to the fixed cam 3, and to stabilize the winding state of the belt 9 around the drive sheave.

  The spring 8 is provided on the back side of the first movable sheave 1, and the first face 12 and the second face 22 are obtained by a combined force (Fa + Fs) of the spring force Fs by the spring 8 and the cam force Fa. It is possible to appropriately cope with the belt tension that bites in between the belt and the belt so as not to be too tight. The second movable sheave 2 has a cam force Fb smaller than that of the first movable sheave 1 and has a small movement distance with respect to the axial movement of the first movable sheave 1.

  The inclination angle θa of the engagement inclined surface 13a is formed larger than the inclination angle θb of the engagement inclination surface 23a of the second cam portion 23 of the second movable sheave, whereby the first movable sheave 1 is Since it has a large cam force Fa and the axial direction of the driven shaft 4 moves to the fixed cam 3 side, the spring force Fs of the spring 8 can be made small, and the cam force Fa and the spring force Fs The resultant force and the cam force Fb on the other side can be appropriately matched at the maximum reduction ratio and the minimum reduction ratio.

(A) is a longitudinal side view of the present invention, (B) is an Xa-Xa arrow view of (A), and (C) is a longitudinal sectional side view of a main part in a state where a first face and a second face are closed. (A) is a longitudinal side view of the first movable sheave, (B) is a front perspective view taken along the line Xb-Xb of (A), and (C) is a perspective view of (B). (A) is a longitudinal side view of the second movable sheave, (B) is a front perspective view of (A) taken along the line Xc-Xc, and (C) is a perspective view of (B). (A) is a front view of the fixed cam, (B) is a cross-sectional view taken along arrow Xd-Xd in (A), (C) is a cross-sectional view taken along arrow Xe-Xe in (A), and (D) is a cross-sectional view taken from (C). It is a principal part enlarged view. (A) is a perspective view of a fixed cam, (B) is an enlarged perspective view of a first engaged cam portion, and (C) is an enlarged perspective view of a second engaged cam portion. (A) is an enlarged cross-sectional view of the main part of an embodiment in which the engaged cam portion made of a synthetic resin is provided on the fixed cam with a caster, (B) is a cross-sectional view taken along the arrow Xf-Xf in (A), C) is a cross-sectional view taken along line Xg-Xg of (A). (A) is an enlarged cross-sectional view of the main part of the embodiment in which the engaged cam portion made of synthetic resin is provided on the fixed cam, (B) is a cross-sectional view taken along the arrow Xh-Xh in (A), and (C) is ( It is Xi-Xi arrow sectional drawing of A). (A) is sectional drawing which shows the engagement state of a 1st movable sheave and a fixed cam, (B) is sectional drawing of the state which the 1st movable sheave adjoined to the fixed cam. (A) is an enlarged sectional view of a state in which the first cam portion and the second cam portion are engaged with the first engaged cam portion and the second engaged cam portion, and (B) is the first cam portion and It is sectional drawing of the state which the 2nd cam part adjoined to the 1st to-be-engaged cam part and the 2nd to-be-engaged cam part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st movable sheave, 11 ... 1st boss | hub part, 12 ... 1st face part, 13 ... 1st cam part, 13a ... Engagement inclined surface, 2 ... 2nd movable sheave, 21 ... 2nd boss | hub part, 22 ... 2nd face part, 23 ... 2nd cam part, 23a ... Engagement inclined surface, 3 ... Hand fixing cam, 31 ... 1st engaged cam part,
32 ... 2nd engaged cam part, 4 ... Driven shaft, 8 ... Spring.

Claims (7)

  A driven shaft having a fixed cam fixed in an axial direction and an axial circumferential direction, a first movable sheave having a first cam portion formed in the vicinity of the surface center of the first face portion, and a second shaft in the vicinity of the surface center of the second face portion. A second movable sheave formed with two cam portions is slidably mounted so as to sandwich the fixed cam, and the first movable sheave is pressed and urged against the second movable sheave via a spring. The first cam portion and the second cam portion are cam-engaged with the fixed cam, and the first movable sheave and the second movable sheave are moved by the positive rotation of the first movable sheave and the second movable sheave. A V-belt type automatic transmission characterized by moving close to a fixed cam side.   A first movable sheave including a first boss portion, a first face portion, and a first cam portion formed near the center of the surface of the first face portion; a second boss portion; a second face portion; and the second face. A second movable sheave comprising a second cam portion formed near the surface center of the portion, a fixed cam having a first engaged cam portion and a second engaged cam portion, and the first movable A driven shaft on which the sheave and the second movable sheave are slidably mounted; and a spring that presses and urges the first movable sheave against the second movable sheave. The fixed cam is pivoted on the driven shaft. And the first movable sheave and the second movable sheave, and the first cam portion, the first engaged cam portion, the second cam portion, and the second The engaged cam portion is engaged, and the first cam portion and the second cam portion are connected to the first allowable portion. The forward rotation of the sheave and the second movable sheave, V-belt type automatic transmission, characterized by comprising an engagement inclined surface that approach movement to the stationary cam side.   3. The V-belt automatic transmission according to claim 1, wherein the engaged cam portion of the fixed cam is formed of a synthetic resin.   4. The V-belt type automatic transmission according to claim 2, wherein the angle of the engagement inclined surface of the first cam portion is formed larger than the angle of the engagement inclined surface of the second cam portion. Machine.   4. The V-belt type automatic transmission according to claim 2, wherein an angle of the engagement inclined surface of the first cam portion is the same as an angle of the engagement inclined surface of the second cam portion.   In the description of any one of claims 1, 2, 3, 4 and 5, two or more first cam portions of the first movable sheave and second cam portions of the second movable sheave are respectively formed, The V-belt type automatic transmission is characterized in that two or more first engaged cam portions and second engaged cam portions are formed on the fixed cam.   7. The method according to any one of claims 1, 2, 3, 4, 5, and 6, wherein the second cam portion is formed with a regulation step portion that regulates a movement amount to the fixed cam member. V-belt type automatic transmission characterized.

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