JPH0929564A - Belt transmission assembly device - Google Patents

Abstract

(57) [Summary] In a pulley type continuously variable transmission, when a rear case is assembled to a front case 2 in which a tension mechanism 38 and the like are already assembled, a tension spring 48 is preliminarily interposed and a tension pulley 41 is installed. This allows the assembling work to be carried out without being disturbed by the tension pulley 41 even when the belt protrudes from the normally pressed position with respect to the belt 30. SOLUTION: A tension engaging portion 111b for engaging a tension pulley 41 so as to be able to press the tension pulley 41 in a direction opposite to the rotational urging direction of a tension spring 48 is provided at a tip end portion of a plate-shaped main body 111a extending in a substantially linear shape. Pin engaging part 1 in the middle part
11 c, each of which is provided with an assembling jig 111, and the tension jig 4 is attached to the screw hole 4 located near the tension pulley 41 of the front case 2 by the assembling jig 111.
When 1 is pushed into a predetermined assembling position, the tension engaging portion 111b is centered and is releasably locked to the intermediate engaging portion 111c in a plane orthogonal to the assembling direction of the rear case. The locking pin 7 that holds the tension pulley 41 in the assembled position in the stopped state is provided upright.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt transmission device such as a pulley type continuously variable transmission, in which one of the divided cases is assembled with a tension mechanism for pressing the loose side span of a transmission belt wound around a pulley. The present invention relates to an assembling apparatus used when assembling the other split case.

[0002]

2. Description of the Related Art Conventionally, in agricultural machines and the like, a pulley-type transmission using a belt transmission has been frequently used in order to change the power of an engine and transmit the power to driving wheels or various working devices. As an example of a pulley type transmission using this belt transmission, a conventional pulley type transmission, for example,
As shown in Japanese Patent No. 4352, a fixed sheave fixed to each of a pair of rotating shafts arranged in parallel with each other is integrally and non-slidingly fixed to the rotating shaft, and between the fixed sheave. A movable sheave that is disposed so as to form a belt groove having a substantially V-shaped cross section and is slidably and slidably provided on a rotating shaft, and one of the movable sheaves faces the fixed sheave. A pair of variable pulleys are installed in which the direction of the other movable sheave to the fixed sheave is set to be opposite to each other, and the transmission belt is wound between the belt grooves of these variable pulleys, while the rear side of the movable sheave of each variable pulley is provided. On the side,
Each of them is composed of a rotating cam rotatable about a rotation axis and a fixed cam connected to the inner surface of the case of the transmission and unable to rotate. The movable sheave is rotated by rotating the rotating cam with respect to the fixed cam. The movable sheave approaches the fixed sheave in one of the variable pulleys by arranging the cam mechanisms that move the fixed sheave so as to move toward and away from the fixed sheave, and connecting the rotating cams of these both cam mechanisms with the rod and the speed change shaft. Then,
In the other variable pulley, the rotating cams of both cam mechanisms are rotated in cooperation with each other so that the movable sheave moves away from the fixed sheave, and the effective radius (pulley diameter) of each variable pulley with respect to the transmission belt is changed to make both rotations. A variable pulley type is known in which the gear ratio between the shafts is changed.

It is also known that the transmission is provided with a tension mechanism for pressing the loose side span of the transmission belt to generate thrust between the belt and the pulley. As such a tension mechanism, generally, a tension arm rotatably provided in a plane orthogonal to the axial direction of the rotary shaft and a tension arm rotatably around an axis extending in the axial direction of the rotary shaft. The tension pulley is provided and a tension spring that biases the tension arm to rotate the tension arm in the direction of pressing the belt, and the loose side span of the belt is cut into the belt groove of each pulley. As described above, for example, the inner surface is pressed.

[0004]

By the way, when the variable pulley, the belt, the tension mechanism, and the like are housed in a case in a substantially hermetically sealed manner, the case is divided in the axial direction of the rotary shaft to form two divided cases. It is conceivable that the variable pulley, the belt, the tension mechanism, etc. are formed in one of the divided cases in advance, and the other divided case is attached to the divided case at the opening end.

However, when the tension spring of the tension mechanism is already interposed at the time of the above-mentioned assembling, the tension urging force causes the tension pulley to largely protrude from the normal pressing position for shifting the belt. It is in a state of being. For example, when the tension pulley pushes the belt from the inner surface, the tension pulley may be pushed out of the split case while pushing the belt. There is a problem that it becomes difficult.

The present invention has been made in view of the above problems, and its main purpose is to assemble a case having a simple structure when the other split case is assembled to one case to which a tension mechanism or the like is assembled. By developing a new jig, even if the tension spring is pre-installed in the above tension mechanism and the tension pulley protrudes from the normal pressing position against the belt, it will be assembled without being disturbed by the tension pulley. To be able to work.

[0007]

In order to achieve the above object, in the inventions of claims 1 and 2, the tension pulley can be pushed into the normal pressing position by the assembling jig, and after the pushing, the above-mentioned tension pulley is pushed. The assembling jig can be kept in that state until just before the assembling work is completed.

Specifically, according to the first aspect of the invention, a case in which the two divided cases formed in a divided manner are assembled in a substantially hermetically-sealed manner by a plurality of assembly bolts at the opening end, and each of the cases has an axial center. At least one pair of rotating shafts arranged so as to extend in the assembling direction of the split cases and supported by the split cases, pulleys respectively provided on the rotary shafts in the case, and windings between these pulleys. The belt has a hung belt, a tension pulley that presses the slack side span of the belt, and a tension spring that urges the tension pulley to move the belt so that the belt is pressed. A belt transmission device comprising: a tension mechanism that applies a belt tension by pressing the tension pulley with the rotation shaft, the pulley, and the transmission belt. Assembling device on one of the split case and Pensions mechanism are assembled assembling the other split case is premised.

An intermediate portion of the main body and a tension engaging portion which is provided at the tip of the main body extending in a substantially straight line and engages the tension pulley in a direction opposite to the direction in which the tension spring is rotated and biased. And an assembling jig having an intermediate engaging portion provided on a portion thereof and the tension pulley are provided on a substantially extended line in a direction of pressing the belt. When pushed into the assembling position, the tension pulley is releasably engaged with the intermediate engaging portion in a plane centered on the tension engaging portion and orthogonal to the assembling direction of the split case, and the tension pulley is retained in the engaged state. And a locking portion for holding the assembly position.

In the above structure, when one split case in which the rotary shaft, the pulley, the transmission belt, and the tension mechanism are assembled and the other split case is assembled at the open end, the tension pulley of the tension mechanism is a tension spring. It is pressed by the assembly jig in the direction opposite to the rotational biasing direction against the rotational biasing force, and is pushed into a predetermined mounting position. At this time, the intermediate engaging portion of the assembling jig is locked by the locking portion, so that the state in which the tension pulley is pushed into the assembling position is maintained. Then, the divided cases are assembled at the opening ends, and immediately before the assembling work is completed, the intermediate engaging portion is disengaged from the locking portion, and the assembling jig is pulled out from between the two divided cases to complete the assembling. Therefore, even if the tension spring is already interposed in the tension mechanism, the split case can be assembled without being disturbed by the tension pulley.

According to a second aspect of the present invention, a case in which the two divided cases formed in a divided manner are assembled in a substantially sealed manner at the opening end by a plurality of assembling bolts, and a set of the divided cases each having an axial center. A pair of rotating shafts that are arranged so as to extend in the attachment direction and that are supported by the respective split cases, and are provided on the respective rotating shafts in the above-mentioned cases, respectively, so that they are rotationally integrated with the rotating shafts and cannot move in the axial direction. A fixed sheave fixedly supported by the fixed sheave, and a boss portion which is arranged to face the fixed sheave so as to form a belt groove having a substantially V-shaped cross section between the fixed sheave and which extends in the axial direction on the back side. The boss portion is composed of a movable sheave that is externally fitted and supported on the rotary shaft so as to rotate integrally with the rotary shaft and is movable in the axial direction. One of the movable sheave faces the fixed sheave and the other movable sheave fixes. The direction to the sheave is the same Drive and driven pulleys set in the opposite direction to each other, a belt wound between belt grooves of the drive and driven pulleys, and a movable sheave rear surface of each of the drive and driven pulleys. A rotating cam that is supported on the boss portion of the shaft through a bearing so as to move together with the movable sheave in the axial direction so as to be relatively rotatable, and a cam that is provided immovably in the axial direction of the rotating shaft and comes into cam contact with the rotating cam. The movable sheave is moved in the axial direction so as to move toward and away from the fixed sheave by the rotation of the rotary cam around the rotary cam with respect to the fixed cam, and the effective radii of the respective pulleys are respectively changed. When the movable sheave approaches the fixed sheave on one of the drive pulley side and the driven pulley side cam mechanism, and the drive sheave on the other side, the movable sheave moves on the other side. A gear shift switching mechanism that changes the gear ratio between the rotary shafts by rotating the rotary cams of the cam mechanisms so as to move away from the constant sheave so as to be orthogonal to the axial direction of the rotary shafts. A tension arm rotatably provided in the plane, a tension pulley rotatably provided on the tension arm about an axis parallel to the axis of the rotary shaft via a shaft portion, and the tension pulley is the belt. It consists of a tension spring that urges the tension arm to rotate in the direction of pressing, and presses the loose side span of the belt wound between the drive and driven pulleys so that the belt bites into the belt groove of each pulley. In a belt transmission device including a tension mechanism for generating thrust to the belt,
It is premised on an assembling apparatus that assembles the other split case to the one split case in which the rotary shaft, the drive / driven pulley, the transmission belt, the drive pulley side / driven pulley side cam mechanism, the speed change mechanism and the tension mechanism are assembled. is there.

As in the case of the first aspect of the present invention, the tension pulley is provided at the tip of the main body extending in a substantially straight line and is capable of pressing the tension pulley in the direction opposite to the direction in which the tension spring rotates. An assembling jig having an engaging tension engaging portion and an intermediate engaging portion provided at an intermediate portion of the main body, and the tension pulley is provided on a substantially extended line in a direction of pressing the belt, When the tension pulley is pushed into a predetermined assembly position by the assembly jig, it can be engaged with and disengaged from the intermediate engagement part in a plane centered on the tension engagement part and orthogonal to the assembly direction of the split case. And a locking portion for holding the tension pulley in the assembled position in the locked state. Therefore, the same operation as in the case of the invention of claim 1 is performed.

According to the invention of claim 3, the above claims 1 and 2 are provided.
In the invention described above, the engaging portion is constituted by a pin projecting at the opening end of one of the split cases of the pulley type transmission so as to extend in the axial direction of the rotating shaft.

In the above structure, the pins that are provided in advance in the split case can be used to assemble the split case with an assembly jig. Therefore, maintenance such as overhaul of the pulley type transmission can be performed. Facilitated.

According to the invention of claim 4, in the invention of claim 3, a positioning hole is provided at the opening end of the other split case. The pin is a knock pin that is fitted into the positioning hole to position the split case.

In the above structure, the knock pin for positioning the split case is also used as the jig locking pin used when assembling the split case. Therefore, when the assembly jig can be used, the number of parts is reduced. And the assembly work can be facilitated.

According to a fifth aspect of the present invention, in the above-mentioned fourth aspect, the knock pin is formed of a collar which is fitted into the bolt hole of one of the divided cases and into which the assembly bolt can be inserted. On the other hand, the positioning hole is formed by a bolt hole that is tightened together with the bolt hole by an assembly bolt inserted in the collar with the collar inserted.

In the above structure, when the divided case is assembled using the assembling bolt, the collar fitted in the bolt hole of the divided case is used as a knock pin which can be used also as a locking portion for assembling. Therefore, a dedicated knock pin is unnecessary. In other words, of the bolt holes that have already been laid out, it is of course possible to use it as a bolt hole by simply inserting the collar into the bolt hole that is near the extension line in the direction in which the tension pulley presses the belt. Also, it can be used as a positioning pin at the time of assembling and as a locking portion for assembling.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 2 and 3 show the overall structure of a pulley type continuously variable transmission T according to the present invention.
Although not shown, it is arranged in a power transmission path between an engine and driving wheels in a traveling agricultural machine.

2 and 3, reference numeral 1 denotes a case of the transmission T, which is divided into a front case 2 on the left side of FIG. 2 and a rear case 3 on the right side. The front case 2 is a dish-shaped member opened to the right side in FIG. 2, and a bottomless cylindrical input bearing hole 2a is formed at the upper part of FIG.
Further, a cylindrical output bearing hole 2b having a bottom is formed in the lower portion in a concave shape. Further, the rear case 3 is a dish-shaped one opened to the left side in FIG. 2, and the boss-shaped input bearing hole 3a is shown in the upper part of the figure.
Is formed so as to correspond to the input bearing hole 2a of the front case 2 and a similar output bearing hole 3b is formed in the lower portion so as to correspond to the output bearing hole 2b of the front case 2. And
A flange 2c is formed at the opening edge of the front case 2, and a plurality of screw holes 4, 4, ... Are opened in the flange 2c. On the other hand, a flange 3c joined to the flange 2c of the front case 2 is formed at the opening edge of the rear case 3, and the screw holes 4, 4, 4 of the front case 2 are formed in the flange 3c.
A plurality of bolt insertion holes 5, 5, ... are provided corresponding to ... and both flanges 2c,
3c are brought into contact with each other, and the assembly bolts 6 are inserted into the respective bolt insertion holes 5 of the rear case 3, and the tips of the respective assembly bolts 6 are screwed into the corresponding screw holes 4 of the front case 2. Then, both cases 2 and 3 are assembled together.

As shown in FIG. 3, the left and right middle portions of the lower portion of the transmission case 1 are partially recessed so that the lower side of the transmission T does not interfere with the propeller shaft 113 extending in the longitudinal direction of the agricultural machine. There is.

In the transmission case 1, an input shaft 9 (rotary shaft) and an output shaft 13 arranged in parallel with each other
3 is rotatably supported. The input shaft 9 and the output shaft 13 rotate counterclockwise in FIG. The front end portion (the left end portion in FIG. 2) of the input shaft 9 rotates through the bearing 10 in the input bearing hole 2a of the front case 2, and the rear end portion rotates through the bearing 11 in the input bearing hole 3a of the rear case 3. Supported as possible. The front end of the input shaft 9 (the left end in FIG. 2) projects from the case 1 to the outside, and the output shaft of the engine (not shown) is drive-connected to this end. The input bearing hole 2a of the input shaft 9 is sealed with a dust seal 107.

On the other hand, a small diameter portion 13a is formed at the front end portion (the left end portion in FIG. 2) of the output shaft 13, and the output shaft 13 is inserted into the output bearing hole 2b of the front case 2 through the bearing 14 at the small diameter portion 13a. It is rotatably supported. On the other hand, the rear end of the output shaft 13 is rotatably supported by an output bearing hole 3b of the rear case 3 via a bearing 15.
The rear end protrudes out of the case 1 and is drivingly connected to a driving wheel (not shown). A sleeve 16 (in this embodiment, the sleeve 16 and the output shaft 13 constitute a rotating shaft in the present invention) is fitted to the intermediate portion of the output shaft 13 so as to be relatively rotatable. The inner diameter of the front end of the sleeve 16 is made larger than that of the other portions to form a large diameter portion 16a, and the large diameter portion 16a and the small diameter portion 13 at the front end of the output shaft 13 are formed.
The bearing 17 is interposed between the bearing 14 and the rear side of the bearing 14 by engaging the inner ring 17a with the small diameter portion 13a of the output shaft 13 and the outer ring 17b with the sleeve 16, respectively.

A transmission pulley mechanism 20 for drivingly connecting the input shaft 9 and the output shaft 13 by a V-belt 30 is accommodated in the transmission case 1. The speed change pulley mechanism 20 has a drive pulley 21 that is a speed change pulley arranged on the input shaft 9. This drive pulley 21
A flange-shaped fixed sheave 22 which is keyed integrally and non-slidably on the input shaft 9 in a non-slidable manner, and is slidable on the input shaft 9 by a boss 23a so as to face the fixed sheave 22 and It comprises a flange-shaped movable sheave 23 supported so as to be relatively rotatable, and a belt groove 24 having a substantially V-shaped cross section is formed between the sheaves 22 and 23. On the back surface of the fixed sheave 22, a plurality of fins 22a, 22 for air cooling are radially arranged at equal intervals in the circumferential direction.
are integrally formed. Also, the input shaft 9
Has a relatively large inner diameter of the drive pulley 21, which is about 1/3 of the outer diameter, to a certain extent.

On the other hand, a driven pulley 26 composed of a variable speed pulley having the same diameter as the driving pulley 21 is provided on the sleeve 16 externally fitted to the output shaft 13. The driven pulley 26 has the same configuration as that of the drive pulley 21, and includes a flange-shaped fixed sheave 27 which is keyed integrally and non-slidably on the sleeve 16 of the output shaft 13, and a sleeve 16 (output shaft). 13), the boss 28a is slidably and relatively rotatably coupled to the fixed sheave 27 so as to oppose the movable sheave 23 to the fixed sheave 22 in the driving pulley 21 in the opposite direction to the fixed sheave 22. A flange-shaped movable sheave 28 is formed, and a belt groove 29 having a substantially V-shaped cross section is formed between the sheaves 27 and 28. Fixed sheave 27 of the driven pulley 26
A plurality of fins 27a, 27a,... For cooling air that are radially arranged at equal intervals in the circumferential direction are integrally formed on the rear surface of the fixed sheaves 22, 27. An air flow is generated in the case 1 by the 27a to cool the heat generating portion. Also, with respect to the output shaft 13, the inner diameter of the driven pulley 26 is about 1/3 of the outer diameter, and is relatively large with respect to the outer diameter of the driven pulley 26.

The sliding structure of the driving pulley 21 with respect to the input shaft 9 of the movable sheave 23 and the sliding structure of the driven pulley 26 with respect to the sleeve 16 (output shaft 13) of the driven pulley 26 are the same. The driven pulley 26 will be described, and the same reference numerals will be given to the drive pulley 21 side, and detailed description will be omitted. That is, as also shown in FIG. 4, on the inner peripheral surface of the boss portion 28a of the movable sheave 28 in the driven pulley 26, the fixed sheave 27 from the end on the fixed sheave 27 side of the boss portion 28a is located at a position opposed to the diametrical direction. A pair of engagement grooves 31, 31 having a substantially rectangular cross-section extending in the axial direction over the entire end to the opposite side is formed by broaching.

On the other hand, the outer peripheral surface of the sleeve 16 (the input shaft 9 on the side of the drive pulley 21) is located at a position diametrically opposed.
Notches 32, 32 in which a part of the outer circumferential surface of the sleeve 16 in the axial direction is partially cut out by a predetermined depth in parallel with the tangential direction.
Are formed. Further, the sleeve 16 and the output shaft 13
On the (rotary shaft), pins 33 penetrating both in the diameter direction are fixedly supported by press-fitting into the sleeve 16 (press-fitted and fixed to the input shaft 9 on the drive pulley 21 side). It projects from the notch 32 by a predetermined dimension. As shown in FIG. 4, the pin 33 has a long hole 36 having a longer diameter larger than the outer diameter of the pin 33 in the output shaft 13.
And is rotatable relative to the output shaft 13 by a predetermined angle. A pair of bearings 34, 34 are respectively supported on the projections at both ends of the pin 33 by respective inner races 34b. Each of the bearings 34 is engaged with the inner periphery of the boss 28a of the movable sheave 28. The outer ring 34 a is engaged with the groove 31 and rolls by contacting the side surface of the engagement groove 31. Further, the outer diameter of each bearing 34 (outer diameter of the outer ring 34a) is equal to that of the sleeve 16
The outer diameter of the (input shaft 9) is 1 / 2.5 or more.

The belt groove 2 of the drive pulley 21
The V-belt 30, which is, for example, a block belt, is wound between the belt pulley 4 and the belt groove 29 of the driven pulley 26, and the movable sheaves 23, 2 of the pulleys 21, 26 are wound around the V-belt 30.
8 is moved toward and away from the fixed sheaves 22 and 27, respectively, to change the belt winding diameter of each pulley 21 and 26. For example, when the movable sheave 23 of the drive pulley 21 is brought close to the fixed sheave 22 and the movable sheave 28 of the driven pulley 26 is separated from the fixed sheave 27, the belt winding diameter of the drive pulley 21 becomes larger than that of the driven pulley 26. As a result, a high speed state is achieved in which the rotation of the input shaft 9 is accelerated and transmitted to the output shaft 13. On the other hand, conversely, when the movable sheave 23 of the drive pulley 21 is separated from the fixed sheave 22 and the movable sheave 28 of the driven pulley 26 is brought close to the fixed sheave 27, the belt winding diameter of the drive pulley 21 becomes small. By increasing the belt winding diameter of the driven pulley 26, the rotation speed of the input shaft 9 is reduced and the rotation speed is transmitted to the output shaft 13.

In the transmission case 1, the loose side span 30a of the pair of spans of the V belt 30 stretched between the drive and driven pulleys 21 and 26 is pressed outward from the inner surface thereof. A tension mechanism 38 that generates a belt thrust by applying tension to the belt 30 is provided. As shown in FIG. 5, the tension mechanism 38 has a tension arm 39 rotatably fitted to and supported by a boss portion 39a on the base end side of a boss-shaped portion around the output bearing hole 2b in the front case 2. The boss portion 39a of the tension arm 39 is integrally welded to the main body of the tension arm 39. A tension shaft 40 extending rearward in parallel with the output shaft 13 (input shaft 9) is integrally welded to the tip end of the tension arm 39, and the tip end of the tension shaft 40 is a belt groove 24, 29 in each pulley 21, 26. A tension pulley 41, which is located at a portion and is capable of pressing the loose side span 30 a of the V belt 30 from the inner surface, is rotatably supported via a bearing 42. The position of the tension pulley 41 is always constant regardless of the axial movement of the V-belt 30 due to the gear shift.
1 is set at a position where it can contact a part of the inner surface of the belt 30 and press it. Both side surfaces of the tension pulley 41 in cross section have belt grooves 24 of the pulleys 21 and 26,
The angle is parallel to the side surface of the tension pulley 41, so that the inclination angle of the side surface of the tension pulley 41 matches the sectional angle of the belt grooves 24 and 29, and the axial length of the outer peripheral surface of the tension pulley 41 is smaller than the width on the outer surface side of the belt 30. Has also been made smaller.

The tension arm 39 is integrally formed with a spring mounting arm 43 extending in a direction from the distal end toward the base end (substantially opposite to the tension shaft 40). Is bent forward, and a spring engaging portion 44 formed of a concave portion is formed in the bent portion. On the other hand, as shown in FIG. 6, a ring-shaped tension collar 46 is attached and fixed to one inner surface of the front case 2 by a mounting bolt 47 extending parallel to the output shaft 13 (input shaft 9). One end of a tension spring 48, which is a tension spring, is locked to the collar 46 in an externally fitted state, and the other end of the spring 48 is engaged with the spring locking portion 44 of the spring mounting arm portion 43 of the tension arm 39. The tension arm 39 is urged to rotate counterclockwise in FIG. 3 by the spring force of the tension spring 48, and the tension pulley 41 causes the tension pulley 41 to rotate on the loose side span 30 of the V belt 30.
The inner surface of a is pressed. The tension spring 41 causes the tension spring 39 to rotate and bias the tension pulley 41 so that the tension pulley 41 extends toward the loose side span 30a of the belt 30.
Is set to be pressed with a tension larger than the maximum tension generated in the slack side span 30a, and the belt thrust is generated by this tension.

A drive pulley side cam mechanism 50 as a drive mechanism for bringing the movable sheave 23 into and out of contact with the fixed sheave 22 is provided on the input shaft 9 on the rear side of the movable sheave 23 in the drive pulley 21. ing. The cam mechanism 50 includes a rotating cam 51 having a cylindrical cam body 52 made of, for example, an aluminum alloy, and the rotating cam 51 is
On the boss portion 23a of the movable sheave 23, an outer fitting support is provided via a bearing 57 so as to be relatively rotatable around the input shaft 9 and axially movable integrally. The end surface (front end surface) of the cam body 52 opposite to the fixed sheave 22 is located at the upper and lower positions radially outward of the bearing 57 and equiangularly spaced (180 ° apart) in the circumferential direction. As shown in FIG. 9, a pair of arcuate plate-shaped cam tips 53, 53 made of a sintered metal attach the tapping screw 54 to each cam tip 53.
The cam body 52 is inserted through a bolt insertion hole 53a formed in
The cam tips 53 are attached and fixed by screwing, and each of the cam tips 53 has an inclined cam surface 55 inclined at a predetermined angle. Further, on the outer periphery of the cam main body 52, a rotating lever 56 extending downward along a line passing through the cam tips 53, 53 (see FIG. 3. In FIG. 2, the rotating lever 56 extends on the side opposite to the output shaft 13 for the sake of explanation. (Shown) are provided so as to integrally rotate.

On the back side of the rotating cam 51, the cam chips 53 are provided at positions corresponding to the cam chips 53.
A pair of cam receiving bearings 59, 59 as fixed cams which come into contact with the cam surface 55 of the input shaft 9 are disposed and fixed on the inner surface of the front case 2 along the radial direction of the input shaft 9. The support shaft 60 is supported. That is, as shown in the enlarged view of FIG.
1 on the inner surface of the shaft 1 arranged in the radial direction of the input shaft 9
A pair of bearings 61 and 63 are provided so as to project, and one of the bearings 6
1 is formed with a bottomed screw hole 62 extending in a direction parallel to the input shaft 9, that is, in a direction from the inner surface of the front case 2 toward the opening. A recess 64 having a substantially semicircular cross section is formed at the tip of the other bearing 63. And the support shaft 6
One end of 0 has a flat plate shape and a through-hole bolt hole 60a is formed therein, and the other end of the support shaft 60 is tightly fitted in the recess 64 of the other bearing 63, and the mounting bolt 65 is
Is inserted into the bolt hole 60a at one end of the support shaft 60 and screwed into the screw hole 62 of the one bearing portion 61, so that the cam bearing 59 is fixedly supported on the inner surface of the front case 2 by the support shaft 60. Has become.

On the other hand, on the output shaft 13, a driven pulley 26
At the back side of the movable sheave 28,
A driven-pulley-side cam mechanism 67 for bringing the stationary sheave 27 into and out of contact with the stationary sheave 27 is provided. The driven pulley-side cam mechanism 67 has the same configuration as that of the drive pulley-side cam mechanism 50, and is arranged around the output shaft 13 via a bearing 74 on a bearing collar 68 externally fitted to the boss portion 28a of the movable sheave 28. The rotary cam 69 has an externally fitted and supported rotatably rotatable and axially movable integral fit. This rotating cam 6
Reference numeral 9 denotes a cam main body 70 and an end surface (rear end surface) opposite to the fixed sheave 28, which is fixedly mounted at a vertical position in the radial direction of the output shaft 13 and at an equal angular interval in the circumferential direction with respect to the bearing 74. , And a pair of cam tips 71, 71 made of sintered metal, each having an inclined cam surface 72. Each cam tip 71 is similar to the rotary cam 51 of the drive pulley side cam mechanism 50 (this time The same FIG. 7 as the dynamic cam 51
(Described with reference to FIG. 9), the tapping screw 54 is inserted into the bolt insertion hole 71a of the cam tip 71 and is screwed and fixed to the cam body 70 to be fixed. Further, on the outer periphery of the cam body 70, the cam chips 71, 71
A rotation lever 73 extending in the same direction as the rotation lever 56 of the drive-pulley-side cam mechanism 50 (in FIG. 2, it is described as extending to the side opposite to the input shaft 9 for the sake of explanation). Are provided so as to integrally rotate.

On the back side of the rotating cam 69, a pair of cam receiving bearings 76, 76 as fixed cams which come into cam contact with the respective cam tips 71 are provided.
And each cam receiving bearing 76
Are supported on a support shaft 77 arranged and fixed on the inner surface of the rear case 3 along the radial direction of the output shaft 13. Since the support structure of the cam receiving bearing 76 is the same as that of the drive pulley side cam mechanism 50 (see FIG. 10), FIG.
The same parts as 0 are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 11 and 12,
In the drive pulley side cam mechanism 50, the tip end of the turning lever 56 on the outer circumference of the cam 51 and the tip end of the turning lever 73 on the outer circumference of the cam 69 of the driven pulley side cam mechanism 67 are linked to each other so that they rotate. They are connected by 79. The link bar 79 is made of an elongated, substantially triangular plate material, and an intermediate portion of the link bar 79 is a recessed portion (see FIG.
The upper end is bent upward so as not to interfere with the front end, and a rib-shaped flange 79a is integrally formed on the front edge thereof.
A pin hole 80 is provided at one end of the link bar 79 (a portion forming one of the three apexes of the triangle), and the drive pulley side cam mechanism 5 is provided.
A pin hole 81 having a diameter smaller than that of the pin hole 80 is penetratingly formed in parallel with the input shaft 9 at the front end portion of the turning lever 56 of 0.
When the bush 82 made of sintered metal is fitted in the pin hole 80 of the above, the link pin 83 is inserted into both the pin holes 80 and 81 to prevent the link pin 83 from being pulled out.
The tip portion is swingably connected by a link pin 83.

On the other hand, at the other end of the link bar 79, a pin hole 85 is formed at the rear end (a portion forming one of the remaining two apexes of the triangle), and the tip end of the rotary lever 73 of the driven pulley side cam mechanism 67. The pin hole 8 having a smaller diameter than the pin hole 85
6 are formed in parallel with the output shaft 13 so that the pin holes 85 and 86 are aligned with each other and the pin holes 8 of the link bar 79 are formed.
By inserting the link pin 88 into both pin holes 85 and 86 in a state where the sintered metal bush 87 is fitted in 5, the link bar 79 and the tip end portion of the rotary lever 73 are linked pin 88. Are connected so that they can swing. And
The rotation levers 56, 73, the link pins 83, 88, and the link bar 79 constitute a shift change mechanism 89. The shift change mechanism 89 allows the cam mechanisms 50, 6 to move.
7, the rotating cams 51 and 69 are linked to each other and rotated around the boss portions 23a and 28a of the movable sheaves 23 and 28, and the cam receiving bearings 59 and 76 are provided on the cam surfaces 55 and 72 of the respective cam tips 53 and 71. By rolling the movable sheaves 23 and 28 of the respective pulleys 21 and 26 in the axial direction so that the movable sheaves 23 and 28 come into contact with and separate from the fixed sheaves 22 and 27, and the effective radii of the belt grooves 24 and 29, that is, The belt winding diameter on each pulley 21, 26 is variable,
The pulley ratio between the two pulleys 21 and 26, that is, the gear ratio of the transmission T is changed.

A torque cam mechanism 91 for moving the movable sheave 28 in the axial direction to generate a belt thrust when a transmission torque acts on the driven pulley 26 side and the movable sheave 28 and the output shaft 13 relatively rotate. Is provided. The torque cam mechanism 91, as shown in FIG.
The boss portion 28a of the movable sheave 28 is inclined at a diametrically opposed position (a position offset by 90 ° from the engaging grooves 31, 31) toward the circumferential direction toward the axial direction of the output shaft 13. Moreover, a pair of cam holes 92, 92 penetrating the inner and outer surfaces of the boss portion 28a are provided. Further, the output shaft 1 is provided at a position diametrically opposed to the outer peripheral surface of the portion of the output shaft 13 not covered by the sleeve 16.
3. Notches 93, 93 are formed by cutting out a part of the outer peripheral surface in the axial direction partially in parallel to the tangential direction by a predetermined depth. A pin 94 penetrating in the diametrical direction is fixedly supported on the output shaft 13 by press fitting, and both ends of the pin 94 project from the notches 93, 93 by a predetermined dimension, and the projecting parts at both ends of the pin 94 respectively. , The movable sheave 2
8 is engaged with the cam hole 92 in the boss portion 28a of the outer ring 9
A bearing 95 for rolling the 5a in contact with the side surface of the cam hole 92 is supported. When a transmission torque acts on the driven pulley 26, the cam effect of the cam hole 92 and the bearing 95 causes the movable sheave 28 to move in the axial direction. It is moved to generate belt thrust.

Further, in the front wall portion of the front case 2, there is a boss-shaped shaft insertion hole 97 at a position substantially between the input shaft 9 and the output shaft 13 and on a plane passing through each shaft center of both shafts 9, 13. An operation shaft 98 which is formed so as to penetrate therethrough and extends in a direction parallel to the input shaft 9 (output shaft 13) is rotatably supported by a bearing 99, and one end of the operation shaft 98 is outside the transmission case 1. It extends and has a quadrangular cross section, and an operation lever (not shown) is attached to the end of the unit so as to rotate integrally. The shaft insertion hole 97 of the operation shaft 98 is sealed with a dust seal 107.

As shown in FIGS. 3, 11 and 12, the other end of the operating shaft 98 is located inside the transmission case 1, and the base end of the crank arm 100 is rotationally and integrally welded and fixed to the other end. ing. The crank arm 100 is made of a plate material bent in a substantially rectangular shape, and has a connecting rod 1
02 is connected to one end. This connecting rod 102
A pair of link balls 101, 101 each having a shaft portion 101a in the orthogonal direction rotatably supported at the distal end thereof.
01a and 101a are connected so as to be arranged in opposite directions, and one link ball 101 of the connecting rod 102 is attached to the tip of the crank arm 100 by its shaft 101a.
It is connected by. The other end of the connecting rod 102, that is, the shaft portion 101a of the other link ball 101 is connected to the vicinity of the rotating lever 56 of the driving pulley cam mechanism 50 by the link bar 79. And the operation axis 9
8 is switched between a Lo position and a Hi position by an operation lever to operate the transmission changeover mechanism 89,
Each rotating arm 5 projecting from each rotating cam 51, 69
By rotating the gears 6, 73 between the Lo and Hi positions and changing the pulley ratio of the speed change pulley mechanism 20, the output shaft 13 is switched to the deceleration state or the speed increase state with respect to the input shaft 9 to change the speed. ing.

Next, the operation of the pulley type continuously variable transmission T will be described. The engine mounted on the agricultural machine is drivingly connected to the input shaft 9 of the transmission T, and the output shaft 13 is drivingly connected to the driving wheels. Is transmitted to Since the rotating levers 56 and 73 of the driving and driven pulley side cam mechanisms 50 and 67 are linked to each other by the link bar 79, the pulley ratio of the transmission pulley mechanism 20 is changed by the switching operation of the operation shaft 98 to change the speed. The gear ratio of the machine T is switched.

(Low-speed state) Specifically, when the transmission gear ratio of the transmission T is lowered to the low-speed state (Lo state), the operating shaft 9
8 is rotated and operated by the operation lever to be positioned at the Lo position. That is, the base end of the crank arm 100 is integrally fixed to the inner end of the operation shaft 98, and the tip end of the crank arm 100 is connected to the link bar 79 via the connecting rod 102. Since the rotating lever 56 on the outer periphery of the rotating cam 51 in the driving pulley side cam mechanism 50 and the rotating lever 73 on the outer periphery of the rotating cam 69 in the driven pulley side cam mechanism 67 are connected,
With the rotation of the operation shaft 98, the crank arm 100 rotates, and the two rotation levers 56, 73 rotate. When the operating shaft 98 is switched to the Lo position, the rotating cam 69 of the driven pulley side cam mechanism 67 moves its cam tip 7
The driven pulley 26 rotates in one direction around the boss 28a of the movable sheave 28 while rolling the cam receiving bearings 76 on the cam surfaces 72, 72 of the base 71. By this rotation, the cam surfaces 72 are pushed by the cam receiving bearings 76, and the rotating cam 69 moves on the sleeve 16 around the output shaft 13, and the cam 69
The movable sheave 28 which moves integrally with the movable sheave 28 moves in the same direction and approaches the fixed sheave 27 via the movable sheave 4. As a result, the driven pulley 26 closes and the belt winding diameter increases, and the V-belt 30 is driven by the driven pulley 26
Attracted to the side.

At the same time, the L of the operating shaft 98 is
o, the driving pulley cam mechanism 50 is synchronized with the movement of the movable sheave 28 of the driven pulley 26.
The rotating cam 51 rotates on the input shaft 9 in the same direction as the cam 69 of the driven pulley side cam mechanism 67. This cam 5
Due to the rotation of 1, the pressing of the cam surface 55 of each cam tip 53 against the cam receiving bearing 59 is eliminated. Therefore, the cam 51 and the movable sheave 23 connected thereto via the bearing 57 move on the input shaft 9 in a direction away from the fixed sheave 22 by the tension of the belt 30 moving to the driven pulley 26 side. Both sheaves 22, 23
, The drive pulley 21 is opened and the belt winding diameter is reduced. As a result, the belt winding diameter of the driven pulley 26 becomes larger than that of the drive pulley 21, and the rotation of the input shaft 9 is reduced and transmitted to the output shaft 13. As a result, the transmission T enters the Lo state, and the rotation of the engine is reduced and transmitted to the drive wheels.

The tension arm 39 is moved by the urging force of the tension spring 48 of the tension mechanism 38 as shown in FIG.
Is urged to rotate in a clockwise direction by the tension pulley 41 at its tip end to press the inner surface of the loose side span 30a of the belt 30, and the pressing force imparts tension to the belt 30.
At this time, this tension is larger than the maximum tension generated in the slack side span 30a, so that the belt tension causes a wedge effect on the pulleys 21 and 26 of the belt 30 to generate thrust, and this thrust causes both pulleys 21 and 26 to be generated. Power is transmitted via the belt 30 between them.

(High speed state) On the other hand, the operating shaft 98 is set to Hi.
When the position is switched to the Hi position,
The movable sheave 23 of the drive pulley 21 while the cam 51 of the drive pulley side cam mechanism 50 rolls the cam receiving bearing 59 on the cam surface 55 of each cam tip 53.
About the boss 23a in the other direction. As a result, the cam surface 55 is pushed by the cam receiving bearing 59 so that the cam 51 moves on the input shaft 9, and the movable sheave 23 integral with the cam 51 moves in the same direction to move the fixed sheave 22.
Approach. As a result, the drive pulley 21 is closed to increase the belt winding diameter, and the V belt 30 is pulled toward the drive pulley 21 side due to the increase in the belt winding diameter.

At the same time, the cam 69 of the driven pulley side cam mechanism 67 rotates on the sleeve 16 in the same other direction as the cam 51 of the drive pulley side cam mechanism 50.
Due to the rotation of the cam 69, there is no pressing against the cam receiving bearing 76. For this reason, due to the tension of the belt 30 moving to the drive pulley 21 side, the movable sheave 2 connected to the cam 69 and the cam 69 via the bearing 74.
8 moves on the sleeve 16 in a direction away from the fixed sheave 27, and the separation between the sheaves 27 and 28 opens the driven pulley 26 to reduce the belt winding diameter. As a result, the belt winding diameter of the driving pulley 21 is
And the rotation of the input shaft 9 is accelerated and transmitted to the output shaft 13. As a result, the transmission T enters the Hi state, and the rotation of the engine is accelerated and transmitted to the drive wheels.

In the case of this embodiment, the speed change pulley mechanism 20
The rotating cams 51 and 69 of the cam mechanisms 50 and 67 are supported on bearings 57 and 74 on the bosses 23a and 28a of the movable sheaves 23 and 28 of the pulleys 21 and 26, respectively. , 69 pivot lever 5 on the outer periphery
6 and 73 are connected by one link bar 79, so that when the speed change of the speed change pulley mechanism 20 is switched, the rotating cam 51 is moved from the cam receiving bearings 59 and 76 supported by the front case 2 and the rear case 3, respectively. , 69 apply force to the cam surfaces 55, 72 of the cam tips 53, 71.
5 and 72, and a force perpendicular to the input shaft 9 and the output shaft 13 is applied to the input shaft 9 and the output shaft 1.
When acting at right angles to the line connecting the axis of No. 3 and the connection point to the link bar 79, the pulley ratio of the pulley ratio to the line connecting the axis of the input shaft 9 and the output shaft 13 and the connection point to the link bar 79. Regardless of the change, a cam rotation reaction force is generated at a right angle and opposite to the right angle component, and this cam rotation reaction force is applied to the boss portions 23a, 28a of the movable sheaves 23, 28 on which the rotating cams are supported. The pulleys 21 and 26 act to press the bosses 23a and 28a at the center of the area around which the belt 30 is wound. That is, the bosses 23a, 28
The cam rotation reaction force with respect to a is a clearance in the sliding portion between the boss portions 23a and 28a and the input shaft 9 and the output shaft 13, and when the movable sheaves 23 and 28 receive thrust from the belt 30, the movable sheaves 23 and 28 are moved. Acts on the input shaft 9 and the output shaft 13 so as to generate a moment in the direction opposite to the moment acting in the tilting direction, and this moment cancels the original moment to make it smaller, and the boss portions of the movable sheaves 23, 28 become smaller. 23a, 28a inner surface of the input shaft 9 and the output shaft 13 outer surface pressure distribution is dispersed in the axial direction,
The sliding resistance of the boss portions 23a and 28a is reduced. As the sliding resistance decreases, the load of the belt-generated thrust applied to the fixed point by the rotating cams 51 and 69 (that is, the take-out thrust) increases. 51 and 69 are transmitted as the extraction thrust. When changing the pulley ratio, the difference between the belt generated thrust and the take-out thrust is the load (operating force) required for the speed change operation. Therefore, the larger the take-out thrust, the smaller the operation force is. become. As a result, the two speed change pulleys 2 in the speed change pulley mechanism 20 are used.
The shift operation force can be reduced by the thrust balance of the belt 30 between 1 and 26.

Further, in this embodiment, the movable sheave 23 of the drive pulley 21 moves on the input shaft 9 at the time of shifting as described above.
Further, when the movable sheave 28 of the driven pulley 26 receives the transmission load torque on the sleeve 16 and moves in the axial direction, the bearings 34 on the pins 33 projecting from the outer periphery of the input shaft 9 or the sleeve 16 are changed. Movable sheaves 23, 2
The bosses 23a and 28a of FIG. The sliding resistance at this time is the rolling resistance between the outer peripheral surface of the outer ring 34a of the bearing 34 and the side surface of the engagement groove 31 and the rolling resistance of the inner and outer rings of the bearing 34, and no sliding resistance occurs. Therefore, the shift operation force can be further reduced by the sliding resistance composed of the rolling resistance.

Further, since the outer diameter of the bearing 34 is 1/2 or more of the outer diameter of the input shaft 9 or the sleeve 16 and is relatively large, the Hertz stress generated in the engagement groove 31 and the bearing 34 is small. The outer ring 34 of the bearing 34 becomes smaller
a It is not necessary to quench the outer peripheral surface and the side surface of the engaging groove 31,
Cost can be reduced.

Further, one pin 33 is diametrically penetrated through the input shaft 9 or the sleeve 16 so that both ends thereof are projected on the surface of the input shaft 9 or the sleeve 16, and the projected pin 33 is formed.
Since the bearings 34, 34 are respectively supported at both ends of the bearing, the pins 33 supporting both bearings 34, 34 can be shared to reduce the number of parts and facilitate assembly.

Further, the engaging groove 31 on the inner periphery of the boss portions 23a, 28a of each of the movable sheaves 23, 28 has the boss portion 23
Since the a and 28a are broached in the lengthwise direction, the sheave portions of the movable sheaves 23 and 28 are obstructed as compared with the case where the engaging groove 31 is punched from the outer peripheral side of the boss portions 23a and 28a. Without engaging the engaging groove 31 with the bosses 23a, 2
8a can be machined over the entire length, and the bearing 3
4 is effectively moved, and the boss 2
The total length of 3a and 28a can be shortened, and movable sheaves 23 and 28
As a result, the pulleys 21 and 26 can be made compact.

Further, the rotary cams 51, 69 in the cam mechanisms 50, 67 are composed of the cam bodies 52, 70 and the cam tips 53, 71 made of sintered metal attached to the cam bodies 52, 70. That is, only the portions of the rotating cams 51, 69 that come into contact with the cam receiving bearings 59, 76 are separated from the other portions, and the hard sintered metal cam tips 53, 71 are different from them. The cam surfaces 55 and 72 of the rotating cams 51 and 69 are hardly worn by repeated rolling of the cam receiving bearings 59 and 76, and the transmission operability of the transmission T is kept stable for a long period of time. be able to.

By forming the cam surfaces 55 and 72 of the cams 51 and 69 on the cam tips 53 and 71 which are separate from the cam bodies 52 and 70, the cam tips 53 and 71 are formed.
Can be easily replaced with another, and the cam surface 55,
It becomes easy to change the specification of the inclination of 72.

Moreover, the cam tips 53, 71 of the rotary cams 51, 69 have a radius larger than the positions of the bearings 57, 74 for supporting the cam bodies 52, 70 on the boss portions 23a, 28a of the movable sheaves 23, 28. Since it is arranged on the outside in the direction, the cam surfaces 55 of the cam tips 53 and 71,
72 can be arranged closer to the center side of the pulleys 21 and 26 (to the fixed sheaves 22 and 27 side) than the bearings 57 and 74. Accordingly, the lengths of the cam mechanisms 50 and 67 in the axial direction can be shortened to make the pulleys 21 and 26 compact.

The cam receiving bearings 59, 76 of the cam mechanisms 50, 67 are supported on support shafts 60, 77 mounted on the inner surface of the transmission case 1, and one end of each of the support shafts 60, 77 is used for speed change. Bearing part 6 on the inner surface of machine case 1
3 is fitted in the concave portion 64, and the other end is screwed and fastened to the other bearing portion 61 by the mounting bolt 65. Therefore, the mounting bolt 65 is fixedly attached to the case 1 only by bolting the other end portion. The cam bearings 59 and 76 can be supported on the inner surface of the transmission case 1 in a cantilevered manner.
It can be easily attached and supported by.

The screw holes 62 into which the mounting bolts 65 for fastening the ends of the support shafts 60 and 77 are screwed are formed in the transmission case 1 in a direction parallel to the input / output shafts 9 and 13. Since it extends in the direction from the inner surface toward the opening, if the hole portion for the screw hole 62 is formed when casting the transmission case 1, it can be easily formed only by processing the screw portion thereafter. The screw hole 62, the input / output shaft 9,
A hole for inserting a tool and a lid portion after the machining are not required when forming in a direction orthogonal to 13.

Further, since the torque cam mechanism 91 is provided on the driven pulley 26 side, when transmission torque acts on the driven pulley 26 and the movable sheave 28 and the output shaft 13 rotate relative to each other, the boss of the movable sheave 28 is rotated. The side surface of each inclined cam hole 92 of the portion 28 a is the bearing 9 on the outer circumference of the sleeve 16.
5, the movable sheave 28 is axially moved by the cam effect, and a belt thrust is generated.

At this time, the pair of bearings 95, 95 of the torque cam mechanism 91 are supported by both ends of the pin 94 press-fitted and fixed to the output shaft 13 at a portion not covered by the sleeve 16, while the movable sheave is being moved. The pin 33 for supporting the bearing 34, which slidably engages the sleeve 28 with the sleeve 16, is inserted into an elongated hole 36 having a longer diameter larger than the outer diameter of the pin 33 in the output shaft 13 so as to form a predetermined angle with the output shaft 13. Since it is capable of relative rotation, the output shaft 13
The engagement of the torque cam mechanism 91 with the movable sheave 28 and the engagement of the sleeve 16 with the movable sheave 28 are separated. Therefore, the pulley 26 including the torque cam mechanism 91
Even in this case, the sliding structure of the movable sheave 28 can utilize the bearing 34.

The small diameter portion 13a at the front end of the output shaft 13 is also provided.
The sleeve 16 on the outer ring 17b of the bearing 17 arranged in
Of the small diameter portion 13 of the output shaft 13 to the inner ring 17a.
Since the step portion between a and the other portion is locked, the inner ring 17a of the bearing 17 shares the thrust load by the torque cam mechanism 91, and the outer ring 17b shares the thrust load acting on the fixed sheave 27 from the belt 30. Thus, the resistance of the relative rotation of the sleeve 16 and the output shaft 13 can be made a small rolling resistance between the inner and outer races 17a and 17b of the bearing 17. The sleeve 16
A needle bearing (not shown) may be interposed between the inner peripheral surface and the outer peripheral surface of the output shaft 13, or the needle bearing and the bearing 17 may be provided in combination.

In the tension mechanism 38,
Since the tension arm 39, its boss portion 39a, the tension shaft 40, and the spring attachment arm portion 43 are all joined and integrated by welding, the structure of the tension mechanism 38 is simplified, the number of parts is reduced, and the assemblability is improved. Can be improved.

Further, since the fixed side end of the tension spring 48 is locked to the tension collar 46 mounted and fixed in the transmission case 1, the spring 48 can be locked and fixed to the case 1 side. It ’s easy and
Since the spring 48 does not go out of the transmission case 1, the degree of sealing of the transmission case 1 can be enhanced.

Further, the link bar 79 is made of a substantially triangular plate material, and one end which is one of the three vertices of the link bar 79 is provided at one end of the rotary lever 5 of the rotary cam 51 of the drive pulley side cam mechanism 50.
6 is connected, the rotation lever 73 on the outer periphery of the rotation cam 69 of the driven pulley-side cam mechanism 67 is connected, and the connecting rod 1 on the operation shaft 98 side is connected to the rear peak of the remaining two vertices.
Since the end of 02 is connected to the drive pulley side cam mechanism 50 near the turning lever 56, compared to the case where the end of the connecting rod 102 is connected to the front apex of the remaining two apexes. Since there is no concentration of bending stress on the link bar 79, it is possible to reliably prevent breakage and the like.

Further, the bushes 8 made of sintered metal are respectively provided in the pin holes 80 and 85 at both ends of the link bar 79.
2, 87 are fitted and inserted, and with the bushes 82, 87 fitted, the link pins 83, 88 are inserted into the pin holes 80, 85 and the pin holes 81, 86 at the tips of the rotating levers 56, 73. Since the rotating levers 56, 73 and the link bar 79 are swingably connected, wear of these connecting portions is reduced by the bushes 82, 87, and stable shift operability is ensured over a long period of time. Obtainable.

As a feature of the present invention, as shown in FIG. 1, the tension pulley 41 of the tension mechanism 38 is tensioned by being provided at the tip of the plate-shaped main body 111a which extends substantially linearly and has a thickness of about 3 mm. A shaft engaging portion 111b serving as a tension engaging portion that engages in a direction opposite to the direction in which the spring 48 is rotated and biased, and the main body 111a.
And an assembling jig 111 having a pin engaging portion 111c as an intermediate engaging portion that can be engaged with the tension shaft 40. Further, the tension pulley 41 is provided on a substantially extended line in the direction of pressing the V belt 30, and the tension pulley 41 is attached by the assembling jig 111.
When it is pushed into a normal pressing position which is a predetermined position, it is releasably locked to the pin engaging portion 111c in a plane centered on the shaft engaging portion 111b and orthogonal to the assembling direction of the front and rear cases 2 and 3. The collar 7 is provided as a locking portion that holds the tension pulley 41 at a predetermined position in the locked state.

Specifically, the shaft engaging portion 111b of the assembling jig 111 is notched in a substantially U shape on one side of the tip portion (right side in the example shown in FIG. 1), and the tension shaft 40 is formed. The distal end portion of the is releasably housed in a direction orthogonal to its axial direction. In addition, the pin engaging portion 11
1c has a substantially U-shaped notch formed on the other side of the intermediate portion,
When the assembling jig 111 is rotated about the tension shaft 40 toward the other side (left side in the example shown in FIG. 1) in a state where the tension pulley 41 is pushed into the regular pressing position from just above. The collar 7 is housed in the pin engaging portion 111c.

On the other hand, the collar 7 includes the tension pulley 4 among the plurality of screw holes 4, 4, ... In the front case 2.
1 is inserted into a screw hole 4 (the one on the upper left side of FIGS. 1 and 3) located in the vicinity of 1. Further, the same collar 7 as in the above case is inserted into the screw hole 4 (on the right side at the lower end of each drawing) substantially on the opposite side of the tension pulley 41 with respect to the screw hole 4 into which the collar 7 is inserted. Has been done. The collars 7 and 7 correspond to the corresponding bolt insertion holes 5 of the rear case 3.
It can be inserted into. That is, these collars have the function of a knock pin, so that they can be centered when the front and rear cases 2 and 3 are assembled. Further, the shaft portions of the assembly bolts 6 can be inserted into these collars 7 and 7, so that the assembly bolts 6 can also be inserted into the screw holes 4 and 4 into which the collars 7 and 7 are inserted and the bolt insertion holes 5 and 5.
It is designed to be fastened and fixed.

Here, the operation of assembling the tension spring 48 in the transmission case 1 while tensioning the tension spring 48 will be described with reference to FIG. 1. The speed change pulley mechanism 20, the tension mechanism 38, and the cam mechanisms 50 are previously attached to the front case 2. , 67, the speed change mechanism 89, the operating shaft 98, etc. are assembled to leave only the rear case 3 unassembled, and the tension spring 48 is used for tensioning the spring mounting arm portion 43 of the tension arm 39 and the inner surface of the front case 2. It is stretched over the collar 46 in a contracted state. At this time, since the tension spring 48 is contracting, the tension pulley 41 causes the tension-side span 3 of the belt 30 to relax.
0a is largely pressed and transmission case 1 (front case 2)
It will be in a state of being spilled out.

The assembly jig 111 is prepared, and the rear case 3 is temporarily attached to the front case 2 with both flanges 2c and 3c in close proximity to each other. , 3 inserted between the open ends of the shaft engaging portion 1
11b is engaged with the tension shaft 40, and in that state, the assembling jig 111 is pushed down in its length direction to extend the tension spring 48, and the tension pulley 41
The inside of the transmission case 1 and then the assembly jig 1
11 as a fulcrum at an engagement position with the tension shaft 40.
Is turned counterclockwise, and the pin engagement portion 111c is engaged with the collar 7 fitted into the screw hole 4 of the flange 2c of the front case 2 near the tension pulley 41 and stopped. In this state, the tension spring 48 is extended and the tension pulley 41 moves into the transmission case 1, and the tension pulley 41 presses the inner surface of the belt 30. It is located at the pressing position. Thereafter, the case 3 after the temporary attachment is assembled to the front case 2 by inserting and fastening the assembly bolts 6, 6, ... Immediately before the assembly is completed, that is, the gap between the opening ends of the front and rear cases 2 and 3 is reduced. For example, when it is narrowed to about 4 mm, the fastening work of the assembling bolts 6, 6, ... Is temporarily interrupted, and the assembling jig 111 is rotated clockwise to disengage the pin engaging portion 111c from the collar 7. After the upper case is pulled out from the gap between the front and rear cases 2 and 3, the fastening operation is restarted to complete the assembling of the front and rear cases 2 and 3.

At this time, since the collars 7, 7 as knock pins are fitted in the pair of screw holes 4, 4 of the front case 2 in advance, when the rear case 3 is positioned and assembled to the front case 2, Both the above collars 7 and 7 are attached to the rear case 3
It is possible to perform accurate positioning simply by fitting and inserting into the corresponding bolt insertion holes 5 and 5, and the positioning can be performed easily.

Moreover, since one of the collars 7 and 7 also serves as a locking portion for fixing the tensioning spring 48 to the assembly jig 111, the locking portion and the knock pin are combined. The combined use can reduce the number of parts and facilitate the work of assembling the case 1 (the work of assembling the transmission T).

In the above embodiment, the locking portion is constituted by the collar 7 fitted in the screw hole 4 of the front case 2, but is constituted by a knock pin for positioning the rear case 3 with respect to the front case 2. It may be configured with a simple locking pin. Also, in the case of a simple locking pin,
The front case 2 may be provided separately from the front case 2 on a table or the like for supporting and fixing the front case 2 during the assembling work.

In the above embodiment, the tension pulley 41 presses the belt 30 from the inner surface, but the present invention can be applied to the case where the tension pulley 41 presses the belt from the back surface.

Further, in the above embodiment, the tension coil spring is used as the tension spring 48. However, the tension spring may be of a type other than the coil spring, and may be a compression coil spring or the like in the compression direction. It may have a biasing force of.

Further, although the above embodiment is applied to the pulley type continuously variable transmission T having the speed change pulley mechanism 20 composed of a pair of speed change pulleys, the present invention is wound around at least two pulleys. Any belt transmission device having a tension mechanism that presses the loose side span of the belt can be applied.

[0074]

As described above, according to the first aspect of the invention, the two divided cases which are formed separately are assembled in a substantially hermetically-sealed manner by a plurality of assembly bolts at the opening end, and the above-mentioned divided case. At least one pair of rotating shafts arranged to extend in the assembling direction of the case and supported by the respective divided cases, pulleys respectively arranged on the rotating shafts in the case, and wound between these pulleys. In a belt transmission device including a transmission belt and a tension mechanism that applies a belt tension by pressing a loose side span of the belt, one division case in which the tension mechanism or the like is attached and the other division case is attached. As an assembling device, an assembly jig having a tension engaging portion at the tip end and an intermediate engaging portion at the middle portion, and a tension puller by the assembling jig. When the re-push is pushed into the predetermined assembly position, the intermediate engagement portion is releasably locked to hold the tension pulley in the assembled position. Even if the tension spring is already interposed in the tension mechanism, the split case can be assembled without being disturbed by the tension pulley.

According to a second aspect of the present invention, the stationary sheave and the movable sheave are respectively arranged on at least one pair of rotating shafts in the case, and the directions of the movable sheave with respect to the fixed sheave are set to be opposite to each other. Drive and driven pulleys, a belt wound between these pulleys, a rotary cam arranged on the boss side of the movable sheave and a fixed cam arranged on the inner surface of the case on the back side of each movable sheave. It consists of a drive pulley side cam and a driven pulley side cam mechanism that move the movable sheave in the axial direction to change each pulley diameter by the rotation of the rotating cam, and both cam mechanisms are linked together to make both rotations. A belt transmission including a gear change mechanism for changing the gear ratio between the shafts and a tension mechanism for pressing the loose side span of the belt to generate thrust on the belt. In pulley type transmission as,
Similarly, as an assembling device for assembling the other split case to the one split case to which the above tension mechanism and the like are assembled, an assembling jig having a tension engaging portion at the tip portion and an intermediate engaging portion at the intermediate portion is provided. When the tension pulley is pushed into a predetermined assembling position by this assembling jig, the tension pulley is detachably engaged with the intermediate engaging portion and the tension pulley is held at the assembling position in the engaged state. And a locking portion. Therefore, according to this invention, the same effect as that of the invention of claim 1 can be obtained.

According to the invention of claim 3, the locking portion is
Since it is configured with pins protruding from the opening end of one of the split cases so as to extend in the axial direction of the rotating shaft, the assembly work of the split case can be performed using the above pins if there is an assembly jig. Therefore, maintenance such as overhaul of the belt transmission can be facilitated.

According to the invention of claim 4, a positioning hole is provided at the opening end of the other split case, and the pin is formed by a knock pin which is fitted into the positioning hole to position the split case. As a result, the knock pin for positioning the split case can also be used as the jig locking pin used when assembling the split case, and the number of parts does not increase when using the assembly jig. Moreover, the assembling work can be facilitated.

According to the fifth aspect of the present invention, the knock pin is formed by a collar which is fitted into the bolt hole of one of the divided cases and through which the assembly bolt can be inserted, and the positioning hole is fitted by the collar. Since it is configured by a bolt hole that is tightened together with the bolt hole by the assembly bolt inserted in the collar in the inserted state, simply by inserting the collar into the already laid out bolt hole, Not only can it be used as a bolt hole, but it can also be used as a positioning pin at the time of assembling and as a locking portion for assembling.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which front and rear cases are assembled while tension springs are tensioned by an assembly jig that is an embodiment of the present invention.

FIG. 2 is a horizontal sectional view of a pulley type continuously variable transmission according to the present invention.

FIG. 3 is a front view showing a pulley type transmission with a case opened.

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is an enlarged front view of a tension arm.

FIG. 6 is an enlarged cross-sectional view showing a structure of a spring mounting portion in the case.

FIG. 7 is an enlarged front view showing the mounting structure of the cam tip on the cam body of the rotating cam.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is an enlarged development view showing the mounting structure of the cam tip on the cam body.

FIG. 10 is an enlarged cross-sectional view showing the structure of the cam receiving bearing mounting portion of the fixed cam in the case.

FIG. 11 is an enlarged front view showing the connecting structure of the link bar, the connecting rod, the crank arm, and the operating shaft of the speed change mechanism.

FIG. 12 is an enlarged plan view showing a partial cross-section of the link bar, connecting rod, crank arm, and operating shaft connecting structure of the speed change mechanism.

[Explanation of symbols]

 T pulley type continuously variable transmission (belt transmission) 1 case 2 front case (split case) 3 rear case (split case) 4 screw hole (bolt hole) 5 bolt insertion hole (bolt hole) 7 collar (locking part) 9 input shaft (rotary shaft) 13 output shaft (rotary shaft) 21 drive pulley (pulley) 26 driven pulley (pulley) 22,27 fixed sheave 23,28 movable sheave 23a, 28a boss portion 24,29 belt groove 30 V belt ( Belt) 38 Tension mechanism 39 Tension arm 41 Tension pulley 48 Tension spring 50 Drive pulley side cam mechanism 67 Driven pulley side cam mechanism 51,69 Rotating cam 57,74 Bearing 58,75 Fixed cam 89 Speed change mechanism 111 Assembling jig 111a Main body 111b Shaft engaging part (tension engaging part) 111c Pin engaging part Intermediate engaging portion)

Claims (5)

[Claims] 1. A case in which two separately formed split cases are assembled in a substantially hermetically-sealed manner by a plurality of assembly bolts at an opening end, and each has an axis extending in the assembly direction of the split case. At least one that is placed in and supported by each split case
A pair of rotating shafts, a pulley provided on each rotating shaft in the case, a transmission belt wound between the pulleys, a tension pulley that presses the loose side span of the belt, and a belt that presses the belt. And a tension spring that urges the tension pulley to move, and a tension mechanism that applies belt tension by pressing the loose side span of the belt with the tension pulley. An assembly device for assembling one split case, in which a shaft, a pulley, a transmission belt, and a tension mechanism are assembled, with the other split case. An intermediate portion between the tension engaging portion that engages in a direction opposite to the rotational urging direction so that it can be pressed, and the main body. And an assembling jig having an intermediate engaging portion provided on the belt, and the tension pulley is provided on a substantially extended line in the direction of pressing the belt. When pushed into the attaching position, the tension pulley is releasably engaged with the intermediate engaging portion in a plane centered on the tension engaging portion and orthogonal to the assembling direction of the split case, and the tension pulley is retained in the engaged state. An assembling apparatus for a belt transmission, comprising: a locking portion that holds the assembly position. 2. A case in which two separately formed split cases are assembled in a substantially hermetically-sealed manner by a plurality of assembly bolts at the opening end, and each has an axis extending in the assembly direction of the split case. And a pair of rotating shafts supported by the respective divided cases, and provided on the respective rotating shafts in the case.
A fixed sheave, which is fixed to the rotary shaft so as to rotate integrally and immovably in the axial direction, and is disposed so as to face the fixed sheave so as to form a belt groove having a substantially V-shaped cross section between the fixed sheave; And a movable sheave that has an axially extending boss portion on the back side and is externally fitted and supported by the boss portion so as to be rotatable integrally with the rotary shaft and movable in the axial direction. One of the movable sheaves is fixed. A drive and driven pulley in which the direction of the sheave and the direction of the other movable sheave to the fixed sheave are set to be opposite to each other; a belt wound between belt grooves of the drive and driven pulley; A rotary cam that is disposed on the back side of each movable sheave of the driven pulley, and that is supported on the boss portion of the movable sheave through a bearing so as to move together with the movable sheave in an integral and relatively rotatable manner, and a rotary shaft. Axis of And a fixed cam which is provided so as not to be movable in the opposite direction and comes into cam contact with the rotary cam, and the movable sheave is brought into contact with and separated from the fixed sheave by the rotation of the rotary cam around the rotation axis with respect to the fixed cam. A drive pulley-side and driven pulley-side cam mechanism that moves in the axial direction to change the effective radii of each of the above-mentioned pulleys; A shift switching mechanism that changes the gear ratio between the rotary shafts by rotating the rotary cams of the both cam mechanisms so as to separate from each other, and a plane in a plane orthogonal to the axial direction of the rotary shafts. And a tension arm rotatably mounted on the tension arm and a tension arm rotatably mounted on the tension arm about an axis parallel to the axis of the rotary shaft via a shaft portion. And a tension spring that biases the tension arm to rotate the tension arm in the direction in which the belt pushes the belt. The belt spans the slack side of the belt wound between the drive and driven pulleys. A belt transmission device comprising a tension mechanism that presses the belt groove so as to generate a thrust force to the belt, wherein both rotary shafts, a drive and driven pulley, a transmission belt, a drive pulley side, and a driven pulley side cam mechanism. An assembling device for assembling one split case, in which a gear changeover mechanism and a tension mechanism are assembled, and the other split case. The tension pulley is provided at the tip of the main body that extends in a substantially straight line, and the tension pulley rotates the tension spring. A tension engaging portion that engages in a direction opposite to the biasing direction so that it can be pressed, and a middle portion of the main body. The assembly jig having the intermediate engaging portion and the tension pulley are provided on a substantially extended line in the direction of pressing the belt, and the tension pulley is moved to a predetermined assembly position by the assembly jig. When it is pushed in, the tension pulley is releasably engaged with the intermediate engagement portion in a plane centered on the tension engagement portion and orthogonal to the assembling direction of the split case, and the tension pulley is attached at the assembling position in the engagement state. An assembling apparatus of a belt transmission, comprising: 3. The belt transmission assembling apparatus according to claim 1 or 2, wherein the locking portion is formed by a pin projecting at an opening end of one of the split cases so as to extend in the axial direction of the rotation shaft. An assembling device for a belt transmission, which is characterized in that 4. The belt transmission assembling apparatus according to claim 3, wherein a positioning hole is provided at an opening end of the other split case, and the pin is fitted into the positioning hole to position the split case. An assembling device for a belt transmission, comprising a knock pin. 5. The apparatus for assembling a belt transmission according to claim 4, wherein the knock pin is formed of a collar that is fitted into a bolt hole of one of the split cases and is capable of inserting an assembly bolt, and the positioning hole is An apparatus for assembling a belt transmission, comprising: a bolt hole that is fastened together with the bolt hole by an assembly bolt inserted into the collar with the collar inserted.