JP4685612B2 - Gearbox for work vehicle - Google Patents

Description

  The present invention relates to a technology for a transmission for a work vehicle in which a planetary gear mechanism is provided on the output side of a metal belt type continuously variable transmission.

Conventionally, in a belt-type continuously variable transmission suitable for being mounted on an automobile, the belt-type continuously variable transmission is used to change the forward / reverse rotation of the output shaft, or to obtain a gear ratio that cannot be realized only by the belt-type continuously variable transmission. An example of a V-belt continuously variable transmission provided with a planetary gear mechanism on the output side of the step transmission (Patent Document 1), and a belt-type continuously variable transmission for agricultural machinery that requires a relatively small traction force In order to prevent wear and improve the life of the V-belt wound around the variable pulley mechanism, a planetary gear mechanism is provided on the output side of the belt-type continuously variable transmission, and the sun gear and the internal gear of the planetary gear mechanism are , V belts that are in the opposite directions and have the same rotation speed and maintain a planetary carrier in a non-rotating state to create a neutral state and eliminate the belt pitch deviation of the V belt. Examples of the transmission (Patent Document 2) are disclosed, which techniques are known. Further, as a means for obtaining a wide range of gear ratio in a work vehicle transmission or the like, it is common to combine with a sub-transmission having a plurality of shift stages, and is widely practiced.
JP-A-1-58848 Japanese Patent Laid-Open No. 3-92656

  An agricultural work vehicle such as a tractor may require a very large traction force in an extremely low speed traveling state, and the output from the engine is transmitted to the wheels even when the traveling speed is near “0”. There is a need. For this reason, it is desirable that the mechanism be capable of setting the traveling speed to “0” while maintaining output transmission from the engine to the wheels. In general, in a belt-type continuously variable transmission, the minimum speed ratio can be obtained only up to about 40% with respect to the input rotation. That is, with only the belt type continuously variable transmission, the output rotational speed cannot be set to “0” unless the input rotational speed is “0”. Therefore, as a technology for achieving a traveling speed of “0” while maintaining output transmission from the engine to the wheels by a belt-type continuously variable transmission and a planetary gear mechanism provided on the output side of the belt-type continuously variable transmission. (Patent Document 1) and (Patent Document 2) have been proposed. However, in the embodiment shown in the above (Patent Document 1), the traveling speed “0” is achieved by suppressing the output transmission by the sliding action of the fluid coupling in the low rotation range. Therefore, this method cannot achieve a large traction force in an extremely low speed range, and is not suitable for an agricultural work vehicle or the like. Further, in the embodiment shown in the above (Patent Document 2), since the clutch operation is required to shift to the neutral state, the clutch operation is expected to be complicated when traveling at a very low speed. Therefore, it is not suitable for applications such as agricultural work vehicles that require a large traction force during low-speed traveling. In any of the above embodiments, the V-belt is used as the driving belt wound around the variable pulley of the belt-type continuously variable transmission, so that it can be used for agricultural work vehicles that require a large traction force. However, improvement is necessary.

  On the other hand, an agricultural work vehicle such as a tractor is preferably capable of traveling at a certain high speed, although not as much as an automobile, in consideration of movement to a farm field. For this reason, in a transmission in which a planetary gear mechanism is provided on the output side of the belt-type continuously variable transmission, it is effective to combine with a sub-transmission having a plurality of shift stages in order to obtain a wider range of gear ratio. However, in such a case, although the continuously variable transmission is adopted, it is unavoidable that the power is cut off at the time of changing the speed of the sub-transmission, and the entire transmission is not continuously variable. There is a problem.

  Accordingly, in the present invention, in view of such a situation, it is possible to maintain output transmission even in the state of the traveling speed “0” while ensuring the necessary traction force even in the extremely low-speed traveling state, and to perform the auxiliary transmission. Provided is a work vehicle transmission device provided with a metal belt type continuously variable transmission device that does not lose power when the gear speed of the device is switched.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

In Claim 1, it is a work vehicle transmission (1) which provides a planetary gear mechanism in the output side of a metal belt type continuously variable transmission (2), and the planetary gear mechanism is a first planetary gear mechanism (21). ) And the second planetary gear mechanism (22) are arranged on the planetary gear shaft (16), which is the same transmission shaft, from the input shaft (10) of the metal belt type continuously variable transmission (2). Power is transmitted to the first planetary carrier (51) of the first planetary gear mechanism (21) and the second sun gear (54) of the second planetary gear mechanism (22), and the metal belt type continuously variable transmission ( The power from the output shaft (14) of 2) is transmitted to the first sun gear (50) of the first planetary gear mechanism (21) and the second planetary carrier (56) of the second planetary gear mechanism (22), An output shaft (14) of the metal belt type continuously variable transmission (2), A sub-speed that shifts by connecting / disconnecting a plurality of clutches to the output side of the first internal gear (53) of the first planetary gear mechanism (21) and the second internal gear (57) of the second planetary gear mechanism (22). A transmission unit (30) is provided, and the clutches of the sub-transmission unit (30) are the switching clutches (35, 36, 37) of the sub-speed stage and the switching clutches of the two sets of planetary gear mechanisms. It comprises a first main clutch (32a) and a second main clutch (32b), and each switching clutch (35, 37) of the sub-shift stage and the first main clutch (32a) are sub-shafts that have the same transmission shaft. The clutch mechanism is arranged on the transmission shaft (31), and the other switching clutch (36) of the auxiliary gear stage and the second main clutch (32b) are arranged on the auxiliary transmission shaft (33). And the two constituting the clutch mechanism The transmission shafts (31, 33) are arranged in parallel, and from the two output shafts of the first output shaft (40) and the second output shaft (41) on the same axis as the two auxiliary transmission shafts. The power is taken out .

According to a second aspect of the present invention, in the transmission for a work vehicle according to the first aspect, each switching clutch (35, 36,...) Of the auxiliary gear stage is provided from the output shaft (14) of the metal belt type continuously variable transmission (2). 37) and the first main clutch (32a) and the second main clutch (32b) for switching the planetary gear mechanism, the forward and reverse high speed stages are obtained .

According to a third aspect of the present invention, there is provided the transmission for a work vehicle according to the first or second aspect, wherein each of the switching gears (35, 36, 37) of the auxiliary gear and the first main gear for switching the planetary gear mechanism. Switching between the clutch (32a) and the second main clutch (32b) is switched in synchronization with the maximum position or the minimum position of the pulley width of the metal belt type continuously variable transmission (2) .

  As effects of the present invention, the following effects can be obtained.

In Claim 1, it is a work vehicle transmission (1) which provides a planetary gear mechanism in the output side of a metal belt type continuously variable transmission (2), and the planetary gear mechanism is a first planetary gear mechanism (21). ) And the second planetary gear mechanism (22) are arranged on the planetary gear shaft (16), which is the same transmission shaft, from the input shaft (10) of the metal belt type continuously variable transmission (2). Power is transmitted to the first planetary carrier (51) of the first planetary gear mechanism (21) and the second sun gear (54) of the second planetary gear mechanism (22), and the metal belt type continuously variable transmission ( The power from the output shaft (14) of 2) is transmitted to the first sun gear (50) of the first planetary gear mechanism (21) and the second planetary carrier (56) of the second planetary gear mechanism (22), An output shaft (14) of the metal belt type continuously variable transmission (2), A sub-speed that shifts by connecting / disconnecting a plurality of clutches to the output side of the first internal gear (53) of the first planetary gear mechanism (21) and the second internal gear (57) of the second planetary gear mechanism (22). A transmission unit (30) is provided, and the clutches of the sub-transmission unit (30) are the switching clutches (35, 36, 37) of the sub-speed stage and the switching clutches of the two sets of planetary gear mechanisms. It comprises a first main clutch (32a) and a second main clutch (32b), and each switching clutch (35, 37) of the sub-shift stage and the first main clutch (32a) are sub-shafts that have the same transmission shaft. The clutch mechanism is arranged on the transmission shaft (31), and the other switching clutch (36) of the auxiliary gear stage and the second main clutch (32b) are arranged on the auxiliary transmission shaft (33). And the two constituting the clutch mechanism The transmission shafts (31, 33) are arranged in parallel, and from the two output shafts of the first output shaft (40) and the second output shaft (41) on the same axis as the two auxiliary transmission shafts. Since the motive power is taken out , when a sub-shift stage is provided after the main shift stage by the metal belt type continuously variable transmission, a shift without torque interruption between the sub-shift stages is possible.

Further , by selecting a sub-shift clutch and a planetary gear mechanism switching clutch, it is possible to perform a multi-stage shift.

Further , the clutch mechanism can be configured compactly.

According to a second aspect of the present invention, in the transmission for a work vehicle according to the first aspect, each switching clutch (35, 36,...) Of the auxiliary gear stage is provided from the output shaft (14) of the metal belt type continuously variable transmission (2). 37) and the first main clutch (32a) and the second main clutch (32b) for switching the planetary gear mechanism, the forward and reverse high speed stages are obtained, so that the power loss is small and the high speed stage is obtained. .

According to a third aspect of the present invention, there is provided the transmission for a work vehicle according to the first or second aspect, wherein each of the switching gears (35, 36, 37) of the auxiliary gear and the first main gear for switching the planetary gear mechanism. Since the switching of the clutch (32a) and the second main clutch (32b) is switched in synchronization with the maximum position or the minimum position of the pulley width of the metal belt type continuously variable transmission (2) , the shift stage can be switched. Can be smooth. In addition, there is no idling, slipping or shock when switching.

  Next, embodiments of the invention will be described.

  First, the overall configuration of the transmission according to one embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the work vehicle transmission 1 includes a metal belt type continuously variable transmission 2, a planetary gear mechanism 20, and an auxiliary transmission unit 30, and a rear stage (downstream side) of the metal belt type continuously variable transmission 2. The planetary gear mechanism 20 is disposed at the rear of the planetary gear mechanism 20, and the auxiliary transmission unit 30 is disposed downstream of the planetary gear mechanism 20.

  The metal belt type continuously variable transmission 2 includes an input shaft 10, a first variable pulley 11, a second variable pulley 12, a metal belt 13, a CVT output shaft 14, and the like, and the planetary gear mechanism 20 includes a planetary gear. The auxiliary transmission unit 30 includes an auxiliary input shaft 15, a first auxiliary transmission shaft 31, a switching clutch mechanism, an auxiliary transmission gear, And second main clutches 32a and 32b, a second auxiliary transmission shaft 33, a first output shaft 40, a second output shaft 41, and the like.

  The input shaft 10, the CVT output shaft 14, the auxiliary input shaft 15, the planetary gear shaft 16, the first auxiliary transmission shaft 31, the second auxiliary transmission shaft 33, the first output shaft 40, the second output shaft 41, etc. These are rotatably supported on a transmission case or the like (not shown) via bearings or the like, and are arranged in parallel to each other and horizontally installed in the transmission case.

  Below, the structure of the metal belt type continuously variable transmission 2 will be described. As shown in FIG. 1, the first variable pulley 11 is disposed at the input start end of the input shaft 10. The first variable pulley 11 includes a first variable sheave 11a that is supported by an actuator such as a hydraulic cylinder or a motor (not shown) so as to be capable of reciprocating in the axial direction, and a first fixed sheave fixed to the input shaft 10. 11b. The actuator is connected to the main transmission operating means. The second variable pulley 12 is disposed on the CVT output shaft 14. The second variable pulley 12 includes a second variable sheave 12a that is supported by an urging means such as a spring (not shown) so as to be reciprocally displaceable in the axial direction, and a second fixed sheave supported on the CVT output shaft. 12b. The distance between the input shaft 10 and the CVT output shaft 14 is kept constant.

  On the first variable pulley 11 and the second variable pulley 12, the metal belt 13 having a constant cross section and processed into a circular shape having a constant circumference is wound. For example, when the groove width of each of the pulleys 11 and 12 is wide, the metal belt 13 is positioned in a deep part (axial direction) of the pulley groove, so that the diameter of the contact pulley with the belt becomes small. On the contrary, when the groove width of each pulley 11 and 12 is narrow, the metal belt 13 is positioned in a shallow portion (circumferential direction) of the pulley groove, so that the diameter of the contact pulley with the belt increases. By utilizing this action and changing the groove widths of the pulleys 11 and 12, the pulley diameters on the input side and the output side of the metal belt type continuously variable transmission 2 can be changed relatively. Since there are an infinite number of combinations of input and output pulley diameters, the gear ratio can be varied steplessly.

  Below, the structure of the planetary gear mechanism 20 is demonstrated. As shown in FIG. 1, the planetary gear mechanism 20 includes two sets of planetary gears, a first planetary gear mechanism 21 and a second planetary gear mechanism 22. The first planetary gear mechanism 21 is disposed on the input upstream side (hereinafter referred to as the front side) of the planetary gear shaft 16 and is arranged on the downstream (hereinafter referred to as the rear side) planetary gear shaft 16. The first planetary gear mechanism 21 includes a first sun gear 50, a first planetary carrier 51, a plurality of first planetary gears 52, 52... And a first internal gear 53. .

  The first sun gear 50 is a circular external gear and is fixed on the planetary gear shaft 16 so as not to be relatively rotatable. The first internal gear 53 has an internal gear on the inner peripheral portion of the open end surface of the cylindrical member whose one end surface (front end) is open, and the outer periphery on the other closed end surface side (rear portion). The external gear 66 is formed on the outer peripheral portion of a cylindrical connecting member 58 that connects a first planetary carrier 51 and a second sun gear 54 to be described later via a bearing or the like. It is supported rotatably.

  The first planetary gear 52 is a circular external gear, and a plurality of first planetary gears 52, 52,... Are rotatably supported by the first planetary carrier 51, and the first sun gear 50 and the It meshes with both internal gears formed on the first internal gear 53. The first planetary gear 52 revolves around the first sun gear 50 and transmits this revolution as a rotation around the planetary gear shaft 16 to a connecting member 58 connected to the downstream side of the first planetary carrier 51. .

  The connecting member 58 is a substantially cylindrical member, and is externally fitted to the planetary gear shaft 16 via a bearing or the like so as to be rotatable relative to the first planetary carrier 51 and the second sun gear 54. It is installed. That is, the first planetary carrier 51 and the second sun gear 54 are connected to both the front and rear sides of the connecting member 58 and are integrally configured.

  A first input gear 60 is fixed to the front end portion of the first planetary carrier 51 through a cylindrical member 59 so as not to be relatively rotatable. The first input gear 60 is a circular external gear and meshes with the first reverse gear 61. The first reverse gear 61 meshes with a power output gear 62 fixed on the input shaft 10, and the rotation transmitted from the power output gear 62 rotates in the same direction as the first input gear 60. As transmitted.

  A CVT output gear 70 is fixed on the rear portion of the CVT output shaft 14, a first reduction gear 71 is fixed on the front portion of the auxiliary input shaft 15, and a CVT transmission gear 72 is positioned on the front and rear intermediate portions. The second reduction gear 73 is fixed on the rear portion.

  The CVT output gear 70 meshes with the first reduction gear 71, transmits the output of the metal belt type continuously variable transmission 2 to the first reduction gear 71, and rotationally drives the auxiliary input shaft 15. To do. The CVT transmission gear 72 is meshed with a fifth transmission gear 46 described later, and transmits rotation to the fifth transmission gear 46.

  The second reduction gear 73 meshes with a second input gear 63 fixed on the front end of the planetary gear shaft 16, and transmits power to the planetary gear shaft 16. Since the diameter of the second reduction gear 73 is smaller than that of the first reduction gear 71, the rotation transmitted from the first reduction gear 71 is reduced and transmitted to the planetary gear shaft 16.

  As shown in FIG. 1, the second planetary gear mechanism 22 includes a second sun gear 54, a second planetary carrier 55, a plurality of second planetary gears 56, 56,. . The second sun gear 54 is a circular external gear and is fixed to the connecting member 58.

  The second internal gear 57 forms an internal gear on the inner peripheral portion of the open end surface of the cylindrical member whose one end surface (front end) is open, and is external to the outer peripheral portion of the other closed end surface (rear portion). The external gear 67 is a member formed with a toothed gear 67, and is rotatably supported on the planetary gear shaft 16 via a bearing or the like.

  The second planetary gear 56 is a circular external gear, and is rotatably supported by the second planetary carrier 55. The second planetary gear 56 is an internal gear formed on the second sun gear 54 and the second internal gear 57. It meshes with both sides. The second planetary carrier 55 is a substantially cylindrical member, and rotatably supports a plurality of second planetary gears 56, 56... At one end face (front side), and the rear part is the planetary gear. The shaft 16 is fixed so as not to be relatively rotatable. The second planetary gears 56, 56... Revolve around the second sun gear 54 and rotate integrally with the planetary gear shaft 16 via the planetary carrier 55.

  With the configuration described above, the rotation of the input shaft 10 is input from the first input gear 60 and is transmitted to the first planetary carrier 51 of the first planetary gear mechanism 21 and the second sun gear 54 of the second planetary gear mechanism 22. Rotation is transmitted. Further, the rotation of the CVT output shaft 14 is input from the second input gear 63, and the rotation is transmitted to the first sun gear 50 of the first planetary gear mechanism 21 and the second planetary carrier 55 of the second planetary gear mechanism 22.

  Hereinafter, the configuration of the auxiliary transmission unit 30 will be described. As shown in FIG. 1, the sub-transmission unit 30 includes a first sub-transmission shaft 31, a first main clutch 32a, a second main clutch 32b, a second sub-transmission shaft 33, switching clutches 35, 36, and 37, and a first output. The shaft 40 and the second output shaft 41 are configured. In the present embodiment, the first main clutch 32a and the second main clutch 32b are friction clutch type, and the switching clutches 35, 36, and 37 are dog type clutches (meshing type clutches). A sliding type, a synchronous mesh type clutch, an electromagnetic clutch type, a hydraulic clutch type, or the like may be used. The first switching clutch 35 and the second switching clutch 37 are spline-fitted on the first auxiliary transmission shaft 31 and supported by the third switching clutch 37 so as not to be relatively rotatable and slidable in the axial direction. Is spline-fitted onto the second auxiliary transmission shaft 33 and is supported so that it cannot rotate relative to the second auxiliary transmission shaft 33 and can slide in the axial direction. The first output shaft 40 is arranged concentrically with the first auxiliary transmission shaft 31 and rearwardly extended, and the first main clutch 32 a is arranged between the first output shaft 40 and the first auxiliary transmission shaft 31. As described above, the shafts 31, 33, 40, and 41 are horizontally disposed in parallel to each other through a bearing or the like in a transmission case (not shown), and the input shaft 10, the planetary gear shaft 16, and the CVT are arranged. All the axes of the output shaft 14 are also parallel to each other.

  A first transmission gear 31, a first switching clutch 35, a first transmission gear 42, a third switching clutch 37, a third transmission gear 44, are arranged on the first auxiliary transmission shaft 31 and the first output shaft 40 in order from the front side. A first main clutch 32a and a first output gear 38 are disposed.

  The paths through which the outputs from the planetary gear mechanism 20 and the metal belt type continuously variable transmission 2 are transmitted to the shafts 31 and 33 of the auxiliary transmission unit 30 are divided into the following three systems. First, the first path is formed by meshing the external gear 66 provided at the rear portion of the first internal gear 53 of the first planetary gear mechanism 21 and the first transmission gear 42. In the second path, the third transmission gear 44 meshes with the third reverse gear 65 meshing with the external gear 67 provided at the rear portion of the second internal gear 57 of the second planetary gear mechanism 22. Is formed. The third path is formed by meshing the CVT transmission gear 72 fixed on the sub input shaft 15 and the fifth transmission gear 46. That is, an input path from an appropriate power source is selected from three systems in accordance with a change in the operating state (that is, in accordance with a change in STAGE).

  Hereinafter, the auxiliary transmission unit 30 will be further described in detail. The fifth transmission gear 46 is pivotally supported by the first auxiliary transmission shaft 31 via a bearing or the like. The first switching clutch 35 has a sliding body that is spline-fitted onto the first auxiliary transmission shaft 31 and is slidable in the axial direction and is pivotally supported so as not to rotate relative to the front and rear ends of the sliding body. Each constitutes a tooth part. The fifth transmission gear 46 is also formed with a tooth portion that meshes with the tooth portion. In this way, power is transmitted from the fifth transmission gear 46 to the first auxiliary transmission shaft 31 by displacing the first switching clutch 35 in the axial direction on the input upstream side and meshing with the fifth transmission gear 46. Further, the first switching clutch 35 is displaced in the axial direction on the input downstream side to be separated from the fifth transmission gear 46, thereby interrupting power transmission. Further, a tooth portion is formed at the front portion of the boss portion of the first transmission gear 42 in accordance with the position of the tooth portion, and the first transmission clutch 35 is displaced in the axial direction on the input downstream side, thereby the first transmission. By engaging with the gear 42, power is transmitted from the first transmission gear 42 to the first auxiliary transmission shaft 31.

  The third transmission gear 44 is pivotally supported on the first auxiliary transmission shaft 31 via a bearing or the like, and forms a tooth portion at the front portion of the boss portion. The third switching clutch 37 has a sliding body that is spline-fitted onto the first auxiliary transmission shaft 31 and is slidable in the axial direction and is pivotally supported so as not to be relatively rotatable. A tooth portion is formed at the rear of the sliding body. Has been. Power is transmitted from the third transmission gear 44 to the first auxiliary transmission shaft 31 by displacing the third switching clutch 37 in the axial direction on the input downstream side and meshing with the third transmission gear 44.

  A fourth transmission gear 45, a second switching clutch 36, a second transmission gear 43, a second main clutch 32b, and a second output gear 39 are arranged on the second auxiliary transmission shaft 33 and the second output shaft 41 in order from the front side. It is arranged.

  The fourth transmission gear 45 is rotatably supported on the second auxiliary transmission shaft 33 via a bearing or the like, and a tooth portion is formed at the rear portion of the boss portion of the fourth transmission gear 45. A tooth portion is also formed at the front portion of the boss portion of the second transmission gear 43. The second switching clutch 36 has a sliding body that is spline-fitted onto the second sub-transmission shaft 33, is slidable in the axial direction, and is pivotally supported so that it cannot rotate relative to the front and rear ends of the sliding body. The tooth part is comprised according to the said tooth part, respectively. Power is transmitted from the fourth transmission gear 45 to the second auxiliary transmission shaft 33 by displacing the second switching clutch 36 in the axial direction on the input upstream side and meshing with the teeth of the fourth transmission gear 45. be able to. Further, the second switching clutch 36 is displaced in the axial direction on the input downstream side and meshed with the second transmission gear 43 so that power can be transmitted from the second transmission gear 43 to the second auxiliary transmission shaft 33. Yes. The power transmission can be cut off by separating the second switching clutch 36 from the second transmission gear 43 and the fourth transmission gear 45. Further, the first transmission gear 42 and the fourth transmission gear 45 are meshed, and the third transmission gear 44 and the second transmission gear 43 are meshed.

  The second output shaft 41 is disposed concentrically with the second auxiliary transmission shaft 33 and rearwardly extending, and the second main clutch 32 b is disposed between the second output shaft 41 and the second auxiliary transmission shaft 33. The first output gear 38 fixed on the first output shaft 40 is engaged with the second output gear 39 fixed on the second output shaft 41 via the second reverse gear 64. The above is the description of the configuration of the auxiliary transmission unit 30.

  As described above, the work vehicle transmission 1 is provided with the planetary gear mechanism 20 on the output side of the metal belt type continuously variable transmission 2, and the planetary gear mechanism 20 includes the first planetary gear mechanism 21 and the second planetary gear mechanism 21. A gear mechanism 22 is disposed on the same planetary gear shaft 16, and the power from the input shaft 10 of the metal belt type continuously variable transmission 2 receives the first planetary carrier 51 and the second planetary gear 51 of the first planetary gear mechanism 21. The power transmitted from the CVT output shaft 14 of the metal belt type continuously variable transmission 2 is transmitted to the second sun gear 54 of the gear mechanism 22 and the first sun gear 50 and the second planetary gear mechanism 22 of the first planetary gear mechanism 21. The first main clutch 32a or the second main clutch 32b is provided on the output side of the first internal gear 53 or the second internal gear 57. It is.

  As a result, when the sub-transmission unit 30 is provided at the rear stage of the main gear stage by the metal belt type continuously variable transmission 2, it is possible to perform a shift without torque interruption between the sub-gear stages.

  As described above, the clutch mechanism includes the main clutches 32a and 32b of the auxiliary transmission unit 30 and the switching clutches 35, 36, and 37 of the planetary gear mechanism 20, and the same first auxiliary The first main clutch 32 a of the auxiliary transmission unit 30 disposed on the transmission shaft 31, the first and third switching clutches 35 and 37, and the auxiliary transmission unit 30 disposed on the same second auxiliary transmission shaft 33. The second main clutch 32b and the second switching clutch 36 are connected in parallel.

  Accordingly, by selecting the main clutches 32a and 32b of the sub-transmission unit 30 and the switching clutches 35, 36, and 37 of the planetary gear mechanism 20, a multiple speed change is possible. Further, the clutch mechanism can be configured compactly.

  Next, the power transmission flow of the work vehicle transmission device 1 will be described by way of example with reference to FIGS. 2 to 7. First, the power transmission in (STAGE 1) will be described with reference to FIGS. (STAGE 1), the sub-transmission unit 30 has two reverse speeds, the first switching clutch 35 (one side of DC1) meshes with the first transmission gear 42, the first main clutch 32a (MC1) is operated, The first output shaft 40 is configured to transmit to the second output shaft 41 via the first output gear 38, the second reverse gear 64, and the second output gear 39 for output. In such a switched state, the output of the second internal gear 57 of the second planetary gear mechanism 22 is idle.

  Under the above conditions, when power from a prime mover such as an engine is transmitted to the input shaft 10, one of the rotations is transmitted from the power output gear 62 to the first planetary carrier 51 of the first planetary gear mechanism 21, The other is transmitted from the metal belt type continuously variable transmission 2 to the first sun gear 50 via the second input gear 63 and the like, and the combined power of the two input elements is output from the first internal gear 53. That is, the rotation of the power output gear 62 is transmitted to the first input gear 60 via the first reverse gear 61. The first input gear 60 rotates the first planetary carrier 51.

  On the other hand, power is transmitted from the input shaft 10 to the metal belt type continuously variable transmission 2, and the CVT output shaft 14, the CVT output gear 70, the first reduction gear 71, the auxiliary input shaft 15, the second reduction gear 73, and the second input gear. 63, the first sun gear 50 is rotated via the planetary gear shaft 16. The combined power of the rotation of the first sun gear 50 and the rotation of the first planetary carrier 51 is transmitted from the first internal gear 53 through the external gear 66 to the first transmission gear 42, the first switching clutch 35, and the first auxiliary gear 35. Output from the second output shaft 41 via the transmission shaft 31, the first main clutch 32 a, the first output shaft 40, the first output gear 38, the second reverse gear 64, and the second output gear 39.

  Next, the power transmission in (STAGE 2) will be described with reference to FIGS. In (STAGE 2), the subtransmission unit 30 is in the first reverse speed, the second switching clutch 36 (two sides of DC2) meshes with the second transmission gear 43, and the second main clutch 32b (MC2) operates. Thus, the second output shaft 41 is configured to output. In such a switched state, the output of the first internal gear 53 of the first planetary gear mechanism 21 is idle.

  Under the above conditions, when power from a prime mover such as an engine is transmitted to the input shaft 10, the rotation is transmitted from the power output gear 62 to the second planetary gear mechanism 22. That is, the rotation of the power output gear 62 is transmitted to the first input gear 60 via the first reverse gear 61. In the first input gear 60, the first planetary carrier 51, the connecting member 58, and the second sun gear 54 are integrally formed, so that power is transmitted to the second sun gear 54 of the second planetary gear mechanism 22.

  In the second planetary gear mechanism 22, the power input to the second sun gear 54 is transferred from the second planetary gears 56, 56... Serving as one output element to the planetary gear shaft 16 via the second planetary carrier 55. Furthermore, the second input gear 63, the second reduction gear 73, the auxiliary input shaft 15, the first reduction gear 71, the CVT output gear 70, the CVT output shaft 14, and the metal belt type continuously variable transmission 2 are transmitted. Circulated.

  From the second internal gear 57 serving as the other output element, the external gear 67, the third reverse gear 65, the third transmission gear 44, the second transmission gear 43, the second switching clutch 36 (DC2), the second auxiliary transmission shaft. 33, the second main clutch 32b (MC2) and the second output shaft 41 are transmitted. At this time, when the pulley width of the first variable pulley 11 of the metal belt type continuously variable transmission 2 is maximized and the pulley width of the second variable pulley 12 is minimized (point A in FIG. 2), the second output The pulley diameter and the number of teeth of the gear to which the power is transmitted are set so that the output rotation of the shaft 41 is “0” (that is, the rotation speed of the second internal gear 57 is “0”). Yes. In this state, when the pulley width of the first variable pulley 11 is gradually reduced, the pulley width of the second variable pulley 12 is gradually increased. As shown in the (STAGE 2) diagram of FIG. 2, the second output shaft The rotation of 41 is increased by reverse rotation.

  In the state where the pulley width of the first variable pulley 11 of the metal belt type continuously variable transmission 2 is the smallest and the pulley width of the second variable pulley 12 is the largest (point B in FIG. 2), The number of gear teeth is set so that the rotation speed of the first transmission gear 42 meshed with the external gear 66 provided at the rear portion of the first internal gear 53 of the planetary gear mechanism 21 matches the rotation speed of the first output shaft 40. Has been.

  Therefore, in this synchronized state, the first main clutch 32a (MC1) is turned on (contacted), the first switching clutch 35 (one side of DC1) is engaged with the first transmission gear 42, and then the second switching clutch 36 ( (2 side of DC2) is disengaged from the second transmission gear 43 and the second main clutch 32b (MC2) is turned off so that there is no shift shock (STAGE1) while transmitting power. be able to.

  In the state immediately after switching from (STAGE 2) to (STAGE 1), the pulley width of the first variable pulley 11 of the metal belt type continuously variable transmission 2 is the smallest, and the second variable pulley The pulley width of 12 is the widest state. In this state, when the pulley width of the first variable pulley 11 is increased and the pulley width of the second variable pulley 12 is decreased, the rotation of the second output shaft 41 is rotated as shown in the diagram (STAGE 1) in FIG. Is increased by reverse rotation. That is, the reverse speed increases.

  Next, the power transmission in (STAGE 3) will be described with reference to FIGS. (STAGE 3), the subtransmission unit 30 is in the first forward speed, the third switching clutch 37 (3 side of DC3) meshes with the third transmission gear 44, the first main clutch 32a (MC1) is operated, The first output shaft 40 is transmitted to the second output shaft 41 via the first output gear 38 and the second reverse gear 64 and output. In such a switched state, the output of the first internal gear 53 of the first planetary gear mechanism 21 is idle.

  Under the above conditions, when power from a prime mover such as an engine is transmitted to the input shaft 10, one of the rotations is from the power output gear 62 to the first planetary carrier 51 of the first planetary gear mechanism 21 to the second planetary gear 51. Power is transmitted to the second sun gear 54 of the gear mechanism 22. The other is transmitted from the metal belt type continuously variable transmission 2 to the second planetary carrier 55 through a gear, and the combined power of the two input elements is output from the second internal gear 57. The external gear 67, the third reverse gear 65, the third transmission gear 44, the third switching clutch 37 (DC3), the first auxiliary transmission shaft 31, the first main clutch 32a (MC1), the first output shaft 40, Output from the second output shaft 41 via the first output gear 38, the second reverse gear 64, and the second output gear 39.

  At this time, in the state where the pulley width of the first variable pulley 11 of the metal belt type continuously variable transmission 2 is the largest and the pulley width of the second variable pulley 12 is the smallest (point A in FIG. 2), The pulley diameter and the number of teeth of the gear to which the power is transmitted are set so that the output rotation of the output shaft 41 is “0” (that is, the rotation speed of the second internal gear 57 is “0”). ing. When the pulley width of the first variable pulley 11 is gradually reduced in this state, the pulley width of the second variable pulley 12 is gradually increased, and as shown in the diagram (STAGE 3) in FIG. 2, the second output shaft The rotation of 41 is increased with a positive rotation.

  In the state where the pulley width of the first variable pulley 11 of the metal belt type continuously variable transmission 2 is the smallest and the pulley width of the second variable pulley 12 is the largest (point C in FIG. 2), The external gear 66 provided at the rear portion of the first internal gear 53 of the planetary gear mechanism 21 and the rotational speed transmitted to the fourth transmission gear 45 via the first transmission gear 42 and the second main clutch 32b (MC2) The number of gear teeth is set so that the number of rotations of the second auxiliary transmission shaft 33 when the switch is turned on coincides.

  Accordingly, in this synchronized state, the second main clutch 32b (MC2) is turned ON, the second switching clutch 36 (four sides of DC2) is meshed with the fourth transmission gear 45, and then the third switching clutch 37 (DC3-3). ) Is released from the third transmission gear 44 and the first main clutch 32a (MC1) is turned OFF, so that it is possible to switch to (STAGE 4) without transmission shock while transmitting power.

  Next, power transmission in (STAGE 4) will be described with reference to FIGS. (STAGE 4), the subtransmission unit 30 has two forward speeds, the second switching clutch 36 (four sides of DC2) meshes with the fourth transmission gear 45, and the second main clutch 32b (MC2) is operated. The second output shaft 41 is configured to output. In such a switched state, the outputs of the second planetary carrier 55 and the second internal gear 57 of the second planetary gear mechanism 22 are idle.

  Under the above conditions, when power is transmitted to the input shaft 10, the rotation is transmitted from the power output gear 62 to the first planetary carrier 51 of the first planetary gear mechanism 21, and one is transmitted from the first sun gear 50 to the planetary gear. Is transmitted to the shaft 16 and further transmitted to the second input gear 63, the second reduction gear 73, the auxiliary input shaft 15, the first reduction gear 71, the CVT output gear 70, the CVT output shaft 14, and the metal belt type continuously variable transmission 2. The power is circulated. On the other hand, the first transmission gear 42, the fourth transmission gear 45, the second switching clutch 36 (DC2), the second auxiliary transmission shaft 33, the second main clutch 32b, from the first internal gear 53 through the external gear 66, The output is transmitted to the second output shaft 41.

  When the pulley width of the first variable pulley 11 of the metal belt type continuously variable transmission 2 is increased in order to increase the speed, the number of rotations of the fifth transmission gear 46 meshing with the CVT transmission gear 72, The gears are set so that there is a shift position where the rotational speed of the first auxiliary transmission shaft 31 coincides when the one main clutch 32a (MC1) is turned on. When the first main clutch 32a (MC1) is turned on and the rotational speeds coincide with each other (point D in FIG. 2), the first switching clutch 35 (5 side of DC1) is slid to the fifth transmission gear 46. By engaging, releasing the engagement of the second switching clutch 36 (4 side of DC2) and the fourth transmission gear 45 and turning off the second main clutch 32b (MC2), there is no shift shock while transmitting power. It is possible to switch to (STAGE5).

  Next, the power transmission in (STAGE 5) will be described with reference to FIGS. (STAGE 5), the subtransmission unit 30 has three forward speeds, the first switching clutch 35 is engaged with the fifth transmission gear 46, the first main clutch 32a is operated, the first output shaft 40, the first output The gear 38, the second reverse gear 64, the second output gear 39, and the second output shaft 41 are transmitted and output. In such a switched state, the outputs of the first internal gear 53 of the first planetary gear mechanism 21 and the second internal gear 57 of the second planetary gear mechanism 22 are idle.

  Under the above conditions, when power is transmitted to the input shaft 10, one of the rotations is transmitted from the power output gear 62 to the first planetary carrier 51 of the first planetary gear mechanism 21 and from the first sun gear 50 to the planet. .., And simultaneously transmitted from the connecting member 58 to the second planetary gear mechanism 22, the second planetary gears 56, 56... And the second planetary carrier 55 to the planetary gear shaft 16. Power is circulated through the input gear 63, the second reduction gear 73, and the auxiliary input shaft 15. The other is transmitted from the metal belt type continuously variable transmission 2 to the CVT output shaft 14, the CVT output gear 70, and the first reduction gear 71 to the auxiliary input shaft 15, and the CVT transmission gear 72 is rotated. Then, the CVT transmission gear 72, the fifth transmission gear 46, the first switching clutch 35 (DC1), the first auxiliary transmission shaft 31, and the first main clutch 32a (MC1) are operated, and the first output shaft 40, the first The output is output from the second output shaft 41 via the output gear 38, the second reverse gear 64, and the second output gear 39. This completes the description of the power transmission flow of the work vehicle transmission 1.

  As described above, as shown in the power transmission in (STAGE 5), the first main clutch 32a of the auxiliary transmission unit 30 and the first switching clutch 35 are transmitted from the CVT output gear 70 of the metal belt type continuously variable transmission 2. It is set as the structure which obtains a high-speed stage via.

  Thereby, the power loss is small and a high speed stage can be obtained.

  As described above, as shown in FIG. 2, at each point A, B, C, and D, the main clutches 32a and 32b of the auxiliary transmission unit 30 and the switching clutches 35, 36, and 37 are switched. In the metal belt type continuously variable transmission 2, the pulleys 11 and 12 are switched in synchronization with the maximum position or the minimum position of the pulley width.

  Thereby, the shift stage can be switched smoothly. Also, there is no idling, slipping or shock at the time of switching.

The skeleton figure which showed the whole structure of the transmission which concerns on one Example of this invention. The correlation diagram which showed the relationship of the gear ratio of a metal belt type continuously variable transmission and the whole transmission. The skeleton figure which showed the structure of the transmission in (STAGE1). The skeleton figure which showed the structure of the transmission in (STAGE2). The skeleton figure which showed the structure of the transmission in (STAGE3). The skeleton figure which showed the structure of the transmission in (STAGE4). The skeleton figure which showed the structure of the transmission in (STAGE5).

DESCRIPTION OF SYMBOLS 1 Work vehicle transmission 2 Metal belt type continuously variable transmission 10 Input shaft 11 First variable pulley 14 CVT output shaft 20 Planetary gear mechanism 21 First planetary gear mechanism 22 Second planetary gear mechanism 56 Second planetary gear 57 Second Internal gear 73 Second reduction gear

Claims (3)

A transmission (1) for a work vehicle in which a planetary gear mechanism is provided on the output side of a metal belt type continuously variable transmission (2), wherein the planetary gear mechanism includes a first planetary gear mechanism (21) and a second planetary gear. The mechanism (22) is arranged on the planetary gear shaft (16), which is the same transmission shaft, and the power from the input shaft (10) of the metal belt type continuously variable transmission (2) is the first planetary gear. It is transmitted to the first planetary carrier (51) of the gear mechanism (21) and the second sun gear (54) of the second planetary gear mechanism (22), and the output shaft (2) of the metal belt type continuously variable transmission (2) ( 14) is transmitted to the first sun gear (50) of the first planetary gear mechanism (21) and the second planetary carrier (56) of the second planetary gear mechanism (22), and the metal belt type continuously variable Output shaft (14) of transmission (2), said first planetary gear mechanism 21) A sub-transmission section (30) that shifts by connecting and disconnecting a plurality of clutches is disposed on the output side of the first internal gear (53) and the second internal gear (57) of the second planetary gear mechanism (22). The sub-transmission unit (30) includes a clutch for each sub-shift gear (35, 36, 37) and a first main clutch (32a) that is a switching clutch for the two planetary gear mechanisms. The second main clutch (32b), and the switching clutches (35, 37) and the first main clutch (32a) of the sub shift stage are placed on the sub transmission shaft (31) which is the same transmission shaft. The clutch mechanism is arranged, and the other switching clutch (36) of the auxiliary gear stage and the second main clutch (32b) are arranged on the auxiliary transmission shaft (33) to form a clutch mechanism, which constitutes the clutch mechanism. Two auxiliary transmission shafts (31, 33 Parallel and arranged, and characterized in that takes power from the two output shafts of the said two identical axis and sub transmission shaft, the first output shaft (40) and a second output shaft (41) A transmission for a working vehicle. The transmission for a work vehicle according to claim 1, wherein each of the sub-shift gears (35, 36, 37) and the planetary gear are output from an output shaft (14) of the metal belt type continuously variable transmission (2). A transmission for a work vehicle, characterized in that high speed stages of forward and reverse are obtained via a first main clutch (32a) and a second main clutch (32b) for switching a gear mechanism . The work vehicle transmission according to claim 1 or 2, wherein each of the sub-shift gears (35, 36, 37), the first main clutch (32a) for switching the planetary gear mechanism, 2. A transmission for a work vehicle characterized in that the switching of the two main clutches (32b) is switched in synchronization with the maximum position or the minimum position of the pulley width of the metal belt type continuously variable transmission (2) .

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