JP4901382B2 - Variable speed transmission for tractor - Google Patents

Description

The present invention relates to a hydrostatic continuously variable transmission portion to which an output of an engine is input, a driving force output from the hydrostatic continuously variable transmission portion, and an engine that is not subjected to a shifting action by the hydrostatic continuously variable transmission portion. A planetary transmission unit that combines a driving force with a plurality of planetary transmission mechanisms, and a shift output unit that divides the combined driving force output from the planetary transmission unit into a plurality of speed ranges and outputs it from a single output rotating body. The present invention relates to a transmission device for a tractor including

In the above-described speed change transmission device, the hydrostatic continuously variable transmission unit is operated to change speed, and the gear change output unit is appropriately switched in accordance with this speed change operation, so that the driving force from the engine is in a multi-step speed range. The output is divided into steps and output in a stepless manner within the speed range of each step.
As this type of transmission, a patent application (Japanese Patent Application No. 2005-286072) has been developed first.

FIG. 7 is a diagram of the previously developed transmission 3. As shown in the figure, the previously developed transmission 3 is provided with a hydrostatic continuously variable transmission 20, a planetary transmission 3a, and a transmission output 3b. The planetary transmission unit 3a includes a pair of planetary transmission mechanisms PF and PR. Of the pair of planetary transmission mechanisms PF and PR, the planetary transmission mechanism PF on the upper side in the transmission direction includes a ring gear to which an engine driving force that is not subjected to a shifting action by the hydrostatic continuously variable transmission unit 20 is input, And a sun gear to which an output from the step transmission unit 20 is input. Of the pair of planetary transmission mechanisms PF and PR, the planetary gear 51 of the planetary transmission mechanism PF on the upper side in the transmission direction and the planetary gear 61 of the planetary transmission mechanism PR on the lower side in the transmission direction are interlocked. That is, the interlocking gear 51b that is interlocked with the planetary gear 51 via the rotating shaft 51a meshes with the interlocking gear 61b that is interlocked with the planetary gear 61 via the rotating shaft 61a. Yes. The carrier of the planetary transmission mechanism PF on the upper side in the transmission direction and the carrier of the planetary transmission mechanism PR on the lower side in the transmission direction are a common carrier K.
The shift output unit 3b includes a first clutch C1, a second clutch C2, a third clutch C3, a fourth clutch C4, and a planetary transmission mechanism PE, and further includes a brake BK that acts on the ring gear of the planetary transmission mechanism PF, And an output rotator 70 linked to the carrier of the transmission mechanism PE. The first clutch C1 is coupled to the ring gear of the planetary transmission mechanism PR of the planetary transmission unit 3a via the gear interlocking mechanism G1 and the sun gear of the planetary transmission mechanism PE via the rotary shaft 150 so as to be integrally rotatable. And an output gear C1b and a clutch gear C1k supported by the output gear C1b so as to be shiftable. The second clutch C2 includes an input gear C2a interlocked with a sun gear of the planetary transmission mechanism PR of the planetary transmission unit 3a via a rotation shaft, an output gear C2b shared with the output gear C1b and the clutch gear C1k of the first clutch C1, and And a clutch gear C2k. The third clutch C3 can be shifted to the input gear C3a linked to the carrier K of the planetary transmission unit 3a via the gear linkage mechanism G2, the output gear C3b linked to the carrier of the planetary transmission mechanism PE, and the output gear C3b. And a clutch gear C3k supported by the motor. The fourth clutch C4 includes an input gear C4a that is rotatably supported by the rotary shaft 150, and an output gear C4b and a clutch gear C4k that are shared with the output gear C3b and the clutch gear C3k of the third clutch C3. .

FIG. 8 shows the relationship between the shift state of the hydrostatic continuously variable transmission 20 in the previously developed transmission 3, the speed range, and the rotational speed of the output rotating body 70 (hereinafter referred to as output speed). It is explanatory drawing shown. “−MAX” shown in FIG. 8 indicates the maximum speed shift state in the reverse rotation transmission state of the hydrostatic continuously variable transmission portion 20, and “N” indicates the neutral state of the hydrostatic continuously variable transmission portion 20. “+ MAX” indicates the speed change state of the maximum speed in the forward rotation transmission state of the hydrostatic continuously variable transmission 20. FIG. 9 is an explanatory diagram showing the relationship between the speed range in the previously developed transmission 3 and the operating states of the first, second, third and fourth clutches C1, C2, C3 and C4 and the brake BK. “On” shown in FIG. 9 indicates the engaged state of the first, second, third, and fourth clutches C1, C2, C3, and C4 and the brake BK, and “−” indicates the first, second, third, and fourth clutches C1, The cut off state of C2, C3, C4 and brake BK is shown.
As shown in these drawings, the previously developed transmission 3 is as follows.
That is, when the first clutch C1 and the brake BK are operated to be engaged, and the hydrostatic continuously variable transmission unit 20 is shifted from “−MAX” to “+ MAX”, the transmission 3 is changed to the first speed. Shifting to the range, the speed is changed, and the output speed is increased steplessly from “0”. When the hydrostatic continuously variable transmission 20 is in the “+ MAX” shift state, the output speed is “B11”. Along with this, the second clutch C2 is operated to be engaged and the brake BK is maintained to be engaged, and the hydrostatic continuously variable transmission 20 is operated to shift from “+ MAX” to “−MAX”. Then, the transmission 3 is shifted to the second speed range, and the speed is changed, and the output speed is increased steplessly from “B11”. When the hydrostatic continuously variable transmission 20 is in the “−MAX” shift state, the output speed is “B12”. Accordingly, the second clutch C2 is maintained in the engaged state and the third clutch C3 is operated in the engaged state, and the hydrostatic continuously variable transmission portion 20 moves from “−MAX” to “+ MAX”. When a speed change operation is performed, the speed change transmission device 3 enters the third speed range and shifts, and the output speed increases steplessly from “B12”. When the hydrostatic continuously variable transmission 20 is in the “+ MAX” shift state, the output speed is “B13”. Accordingly, the second clutch C2 is maintained in the engaged state and the fourth clutch C4 is operated in the engaged state, and the hydrostatic continuously variable transmission unit 20 is operated to shift from “+ MAX” to “−MAX”. Then, the transmission 3 is shifted to the 4th speed range and the speed is changed, and the output speed is increased steplessly from “B13”. When the hydrostatic continuously variable transmission 20 is in the “−MAX” speed change state, the output speed becomes the maximum speed “B14”.

  In the case of the previously developed speed change transmission device, it is necessary to provide a planetary power transmission mechanism and a brake in addition to providing the speed change output unit with a clutch, which is disadvantageous in terms of structure.

It is an object of the present invention to divide the engine output into four speed ranges and shift the output continuously at each speed stage, and to output the tractor with a simple structure, but capable of obtaining a simple structure. To provide an apparatus.

According to the first aspect of the present invention, there is provided a hydrostatic continuously variable transmission unit that receives an engine output and is disposed on the rear side of the vehicle body relative to the engine, and the hydrostatic continuously variable transmission. The driving force output from the engine and the engine driving force that is not subjected to the shifting action by the hydrostatic continuously variable transmission unit are combined by a plurality of planetary transmission mechanisms , and rearward of the vehicle body than the hydrostatic continuously variable transmission unit. a planetary transmission section arranged to have a vehicle longitudinal direction axis of rotation inside of the transmission case in side, the staging and the vehicle body back and forth a combined drive force output from the planetary transmission section to the speed range of the plurality of stages a speed change output section disposed on the rear side of the vehicle body of the planetary transmission section and inside the transmission case in which the output from one of the output rotor having a rotational axis parallel deviate relative to the orientation axis of rotation A forward / reverse switching is provided for switching the driving force from the output rotator to a forward driving force and a backward driving force by a forward clutch and a reverse clutch, and disposed on the vehicle body rear side of the output rotator within the transmission case. for example Bei and equipment,
The planetary transmission unit includes a sun gear output body that is rotatable integrally with the sun gear of the lowermost planetary transmission mechanism located on the lowermost side in the transmission direction of the planetary transmission unit, and the carrier of the lowermost planetary transmission mechanism. A carrier output body rotatable integrally with the ring gear, and a ring gear output body rotatable integrally with the ring gear of the lowermost planetary transmission mechanism , wherein the sun gear output body has a diameter larger than that of the carrier output body and the ring gear output body. The sun gear output body, the carrier output body, and the ring gear output body are configured in a triple shaft structure having the vehicle body front-rear rotation axis so as to be positioned inward in the direction,
A transmission mechanism for a carrier that interlocks the carrier output body with the output rotating body with a pair of gears at the speed change output unit, and a mechanism that links the ring gear output body with the output rotating body with a pair of gears. A ring gear transmission mechanism arranged in parallel in the front-rear direction with respect to the transmission mechanism for driving, the sun gear output body interlocking with the output rotating body by two pairs of gears, and the transmission mechanism for the carrier, The sun gear front and rear transmission mechanisms arranged in parallel in the front and rear direction with respect to these transmission mechanisms on the rear side of the ring gear transmission mechanism, and these four transmission mechanisms are individually connected to the transmission state and transmission cut off. There are four clutches that can be switched to the state and the four speed ranges appear in the transmission state of each transmission mechanism .

According to the construction of the first invention, when switching operation the four states clutch enters corresponding to the speed range of the clutch, an appropriate transmission mechanism of the four transmission mechanism of the speed change output section The transmission is set in the transmission state, and the shift output unit has a predetermined speed range in which an appropriate output body among the sun gear output body, the carrier output body, and the ring gear output body of the planetary transmission section is linked to the output rotating body. As a result, even if the planetary transmission unit is a simple planetary transmission unit that does not have a planetary transmission mechanism and a brake that the planetary transmission unit was developed earlier, the speed change is performed in conjunction with the shifting operation of the hydrostatic continuously variable transmission unit. When the four clutches of the output unit are appropriately switched, the engine output is divided into four speed ranges by the output synthesis by the planetary transmission unit and the combined driving force by the shift output unit. In addition, the speed is output steplessly at each speed stage.

Accordingly, the engine output can be divided into four stages of speed ranges, and the tractor speed change transmission device that can be used in the speed change transmission device can be output in a stepless manner at each speed step. The structure can be simplified in terms of surface and can be obtained at low cost.

According to the configuration of the first aspect of the invention, the sun gear output body, the carrier output body, and the ring gear output body are arranged in a state of being collectively located on the same shaft core, and the four transmission mechanisms are arranged in the sun gear output body, the carrier output body, It can arrange | position in the state located collectively between a ring gear output body and an output rotary body.

Therefore, the speed change transmission device can be obtained in a compact manner in terms of the arrangement configuration of the sun gear output body, the carrier output body, and the ring gear output body, and also in terms of the arrangement configuration of the four transmission mechanisms.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, each of the four clutches is provided with an input-side rotating member to which driving forces from the four transmission mechanisms are input and a driving force to the output rotating body. An output-side rotating member that outputs, and these four sets of the input-side rotating member and the output-side rotating member are arranged in parallel in a direction along the rotation axis of the output rotating body. I support it.

Embodiments of the present invention will be described below with reference to the drawings.
[First Example]
FIG. 1 is a diagram of a transmission 3 according to a first embodiment of the present invention. As shown in this figure, the speed change transmission device 3 according to the first embodiment of the present invention is provided in a travel transmission device provided in a tractor. The traveling transmission device includes a main clutch 2 to which an output from the output shaft 1a of the engine 1 is input, the transmission transmission device 3 in which an input shaft 21 is linked to the output shaft 2a of the main clutch 2, and the transmission transmission. A forward / reverse switching device 30 in which an input shaft 31 is linked to an output shaft 70 as an output rotating body of the device 3, and a rear wheel differential in which an input gear 5 a is linked to an output shaft 32 of the forward / backward switching device 30. A mechanism 5, a front wheel output shaft 7 linked to the output shaft 32 of the forward / reverse switching device 30 via transmission gears 6 a and 6 b, and an input shaft connected to the front wheel output shaft 7 via a transmission shaft 8 The front wheel differential mechanism 9 with which 9a is interlocked is provided.
As shown in FIG. 1, a power take-out shaft 11 provided at the rear part of the transmission case 10 is used for various working devices such as a rotary tiller (not shown) connected to the rear part of the vehicle body of the tractor. Is to communicate. The power take-out shaft 11 is linked to the input shaft 21 of the transmission 3 via a transmission shaft 12, a work clutch 13, and transmission gears 14a and 14b.

As shown in FIG. 1, the transmission 3 has a hydrostatic continuously variable transmission 20 having a pump shaft that is the input shaft 21 (hereinafter, the input shaft 21 is referred to as a pump shaft 21). (Hereinafter abbreviated as a continuously variable transmission unit 20), a planetary transmission unit 3a having a pair of planetary transmission mechanisms PF and PR, and a transmission output unit 3b having the output shaft 70. is there. The continuously variable transmission unit 20 is provided outside the transmission case 10, and the planetary transmission unit 3a and the transmission output unit 3b, the forward / reverse switching device 30, and the rear wheel differential mechanism 5 are arranged in the transmission case. Oh Ru provided inside the 10.

  The continuously variable transmission 20 includes a hydraulic pump 23 having the pump shaft 21 and a hydraulic motor 24 driven by pressure oil from the hydraulic pump 23. The hydraulic pump 23 is composed of an axial plunger type and a variable displacement type hydraulic pump. The hydraulic motor 24 is constituted by an axial plunger type hydraulic motor.

  That is, the continuously variable transmission unit 20 inputs the output from the output shaft 1a of the engine 1 to the pump shaft 21 via the main clutch 2, and changes the swash plate angle of the hydraulic pump 23, thereby inputting the engine drive. The force is converted into a driving force in the forward rotation direction and a driving force in the reverse rotation direction, and is steplessly shifted in both the forward rotation direction and the reverse rotation direction and output from the motor shaft 22.

  As shown in FIG. 1, the planetary transmission unit 3 a includes the pair of planetary transmission mechanisms PF and PR arranged in the longitudinal direction of the vehicle body, and the rear of the pair of planetary transmission mechanisms PF and PR positioned on the vehicle body rear side. Three output bodies 41, 42, and 43 are provided on the vehicle body rear side of the planetary transmission mechanism PR.

  Of the pair of planetary transmission mechanisms PF and PR, the front planetary transmission mechanism PF located on the front side of the vehicle body includes a sun gear 50 that is rotatably supported by a cylindrical shaft 56 and an outer periphery of the sun gear 50. A plurality of planetary gears 51 that are dispersed in the circumferential direction of the sun gear 50 and meshed with the sun gear 50, a carrier 52 that rotatably supports each planetary gear 51, and meshed with each planetary gear 51 by internal teeth. Ring gear 53.

  Of the pair of planetary transmission mechanisms PF and PR, the rear planetary transmission mechanism PR is dispersed in the circumferential direction of the sun gear 60 around the sun gear 60 that is rotatably supported integrally with the rotation support shaft 67. And a plurality of planetary gears 61 meshed with the sun gear 60, a carrier 62 rotatably supporting each planetary gear 61, and a ring gear 63 meshed with each planetary gear 61 by internal teeth. .

  As shown in FIG. 2, the planetary gear 51 of the front planetary transmission mechanism PF and the planetary transmission mechanism PR of the rear planetary transmission mechanism PR that correspond to each other at a plurality of locations around the sun gears 50 and 60 of the front planetary transmission mechanism PF and the rear planetary transmission mechanism PR. The planetary gear 61 is engaged with the rear end portion of the planetary gear 51 and the front end portion of the planetary gear 61. As shown in FIG. 1, the support shaft 57 that rotatably supports each planetary gear 51 of the front planetary transmission mechanism PF is supported across the carrier 52 of the front planetary transmission mechanism PF and the carrier 62 of the rear planetary transmission mechanism PR. And rotates relative to the carriers 52 and 62. A support shaft 68 that rotatably supports each planetary gear 61 of the rear planetary transmission mechanism PR is supported across the carrier 52 of the front planetary transmission mechanism PF and the carrier 62 of the rear planetary transmission mechanism PR, and each of the carriers 52, 62. Rotates relative to. The rotation support shaft 56 of the sun gear 50 of the front planetary transmission mechanism PF is linked to the motor shaft 22 of the continuously variable transmission unit 20 so as to be integrally rotatable.

  The ring gear 53 of the front planetary transmission mechanism PF includes a rotation interlocking body 58 whose one end is connected to the ring gear 53 so as to be integrally rotatable, and a transmission gear 59a that is rotatably connected to the other end of the rotation interlocking body 58. The gear shaft 59 is linked to the pump shaft 21 via a transmission gear 59b that is rotatably supported integrally with the pump shaft 21 of the continuously variable transmission 20 in a state of meshing with the transmission gear 59a.

  The three output bodies 41, 42, and 43 are constituted by shaft bodies that overlap with a triple shaft structure having a rotation axis parallel to the rotation axis of the output shaft 70 so as to be relatively rotatable. Of the three output bodies 41, 42, 43, the ring gear output body 41 is composed of a cylindrical shaft located on the outermost side of the triple shaft structure, and rotates integrally with the ring gear 63 of the rear planetary transmission mechanism PR via the rotation interlocking body 69. It is connected freely. Of the three output bodies 41, 42, 43, the carrier output body 42 has a cylindrical shaft located in the middle of the triple shaft structure, and is connected to the carrier 62 of the rear planetary transmission mechanism PR so as to be integrally rotatable. Of the three output bodies 41, 42, 43, the sun gear output body 43 is a shaft body located on the innermost side of the triple shaft structure, and rotates integrally with the rotation support shaft 67 of the sun gear 60 of the rear planetary transmission mechanism PR. Rotates integrally with the sun gear 60.

  In other words, the planetary transmission unit 3a meshes with the planetary gear 51 of the front planetary transmission mechanism PF and the planetary gear 61 of the rear planetary transmission mechanism PR and rotates together with the planetary gears 51 and 60 maintaining the interlocked state. It is a compound planetary model in which a front planetary transmission mechanism PF and a rear planetary transmission mechanism PR are coupled so as to revolve around the planetary gear. Then, the planetary transmission unit 3 a inputs the driving force of the motor shaft 21 as the engine driving force that is not subjected to the shifting action by the continuously variable transmission unit 20 to the ring gear 53 of the previous planetary transmission mechanism PF, and the pump of the continuously variable transmission unit 20 The output from the shaft 22 is input to the sun gear 50 of the front planetary transmission mechanism PF, and the engine driving force not subjected to the shifting action by the continuously variable transmission unit 20 and the output of the continuously variable transmission unit 20 are transmitted to the rear planetary transmission mechanism PF and the rear. The combined drive force is output from the ring gear output body 41, the carrier output body 42 and the sun gear output body 43.

  As shown in FIG. 1, the shift output unit 3 b includes the output shaft 70, a first transmission mechanism 71 provided across the output shaft 70 and the ring gear output body 41, the output shaft 70, and the sun gear output. A second transmission mechanism 72 provided over the body 43, a third transmission mechanism 73 provided over the output shaft 70 and the carrier output body 42, and a fourth transmission mechanism provided over the output shaft 70 and the sun gear output body 43. A transmission mechanism 74 and clutches CL1, CL2, CL3, and CL4 provided on the four transmission mechanisms 71, 72, 73, and 74 are provided.

  The first transmission mechanism 71, the second transmission mechanism 72, the third transmission mechanism 73, and the fourth transmission mechanism 74 are juxtaposed in the direction along the rotational axis of the output shaft 70. The first transmission mechanism 71 includes an input gear 71a that is integrally rotatable with the ring gear output body 41, and an output gear 71b that is relatively rotatably attached to the output shaft 70 while meshing with the input gear 71a. It is. The second transmission mechanism 72 includes an input gear 72a provided so as to be rotatable integrally with the sun gear output body 43, and an output gear 72b attached to the output shaft 70 so as to be relatively rotatable while meshing with the input gear 72a. It is. The third transmission mechanism 73 includes an input gear 73a provided on the carrier output body 42 so as to be integrally rotatable, and an output gear 73b attached to the output shaft 70 so as to be relatively rotatable while meshing with the input gear 73a. It is. The fourth transmission mechanism 74 includes an input gear 74a provided on the sun gear output body 43 so as to be integrally rotatable, and an output gear 74b attached to the output shaft 70 so as to be rotatable relative to the input gear 74a. It is.

  The clutches CL1 to CL4 included in each of the transmission mechanisms 71 to 74 are supported by the input side rotation member 95 provided integrally with the output gears 71b, 72b, 73b, and 74b and the output shaft 70 so as to be integrally rotatable. An output-side rotating member 96, a multi-plate friction clutch body 97 provided between the output-side rotating member 96 and the input-side rotating member 95, and a hydraulic piston 98 provided inside the output-side rotating member 96; It is configured with. In each of the clutches CL1 to CL4, a plurality of clutch plates (not shown) of the friction clutch body 97 are pressed by a hydraulic piston 98, whereby the input side rotating member 95 and the output side rotating member 96 are integrated by friction. When the clutch plate of the friction clutch main body 97 is released by the hydraulic piston 98, the input rotary member 95 and the output rotary member 96 are disconnected from each other. .

  The transmission mechanisms 71 to 74 drive the ring gear output body 41, the carrier output body 42, or the sun gear output body 43 by switching the clutches CL1 to CL4 included in the transmission mechanisms 71 to 74 to the engaged state. The transmission enters a state in which the force is transmitted to the output shaft 70 by the input gears 71a, 72a, 73a, 74a, the output gears 71b, 72b, 73b, 74b, and the clutches CL1, CL2, CL3, CL4. The transmission mechanisms 71 to 74 are each configured to cut off transmission from the ring gear output body 41, the carrier output body 42, or the sun gear output body 43 to the output shaft 70 by switching the clutches CL1 to CL4 to the disengaged state. It becomes a state.

  The transmission ratios of the transmission mechanisms 71 to 74 are set so that the rotational speeds of the output shaft 70 when the output shaft 70 is driven by the transmission mechanisms 71 to 74 are different as follows. The rotational speed when driven by the second transmission mechanism 72 is faster than the rotational speed when driven by the first transmission mechanism 71. The rotational speed when driven by the third transmission mechanism 73 is faster than the rotational speed when driven by the second transmission mechanism 72. The rotational speed when driven by the fourth transmission mechanism 74 is set to be higher than that when driven by the third transmission mechanism 73.

  FIG. 3 is an explanatory diagram showing the relationship between the operation state of each of the clutches CL1 to CL4 and the speed range as the operation state of the shift output unit 3b. “On” shown in FIG. 3 indicates the engaged state of each of the clutches CL1 to CL4, and “−” indicates the disconnected state of each of the clutches CL1 to CL4. FIG. 4 is an explanatory diagram illustrating the relationship among the speed change state of the continuously variable transmission unit 20, the speed range of the speed change output unit 3b, and the output speed of the output shaft 70 of the speed change output unit 3b. The horizontal axis in FIG. 4 indicates the speed change state of the continuously variable transmission unit 20, and the vertical axis indicates the output speed by the output shaft 70. “-MAX” on the horizontal axis indicates a shift state in which the output speed of the motor shaft 22 of the continuously variable transmission unit 20 is the maximum speed in the reverse rotation direction, and “N” indicates a neutral state of the continuously variable transmission unit 20. “+ MAX” indicates a speed change state in which the output speed of the motor shaft 22 of the continuously variable transmission 20 is the maximum speed in the forward rotation direction.

  As shown in these drawings, in the transmission 3, the continuously variable transmission 20 is operated for shifting, and the clutches CL 1, CL 2, CL 3, and CL 4 of the transmission output unit 3 b are appropriately switched together with the shifting operation. As a result, the driving force from the engine 1 is divided into four speed ranges, and the speed is changed steplessly in each speed range and transmitted from the output shaft 70 to the forward / reverse switching device 30.

  That is, when the 1st speed clutch CL1 is operated to be engaged and the 2nd speed clutch CL2, the 3rd speed clutch CL3 and the 4th speed clutch CL4 are operated to be disengaged, the speed change output unit 3b outputs the ring gear output of the planetary transmission unit 3a. The combined drive force output from the body 41, the carrier output body 42, and the sun gear output body 43 is converted to a drive force in the speed range of the first speed range by the first transmission mechanism 71 and the first speed clutch CL1, and the output shaft 70 And is transmitted from the output shaft 70 to the forward / reverse switching device 30. When the continuously variable transmission unit 20 is shifted from “−MAX” to “+ MAX” in the state in which the planetary transmission unit 3 a is operated in this way, the rotational speed of the output shaft 70 is “0”. The speed increases steplessly. When the continuously variable transmission 20 is in the “+ MAX” shift state, the rotational speed of the output shaft 70 becomes “B1”.

  When the second speed clutch CL2 is operated to be engaged and the first speed clutch CL1, the third speed clutch CL3, and the fourth speed clutch CL4 are operated to be disengaged, the transmission output unit 3b is connected to the ring gear output body 41 of the planetary transmission unit 3a. The combined drive force output from the carrier output body 42 and the sun gear output body 43 is transmitted to the output shaft 70 by the second transmission mechanism 72 and the second speed clutch CL2 so as to become a drive force in the speed range of the second speed range. Then, it is transmitted from the output shaft 70 to the forward / reverse switching device 30. When the continuously variable transmission unit 20 is shifted from “+ MAX” to “−MAX” in the state where the transmission output unit 3b is operated in this way, the rotational speed of the output shaft 70 is changed to “B1”. The speed increases steplessly. When the continuously variable transmission 20 is in the “−MAX” shift state, the rotational speed of the output shaft 70 becomes “B2”.

  When the 3rd speed clutch CL3 is operated to be engaged and the 1st speed clutch CL1, the 2nd speed clutch CL2 and the 4th speed clutch CL4 are operated to be disengaged, the transmission output unit 3b is connected to the ring gear output body 41 of the planetary transmission unit 3a. And the combined driving force output from the carrier output body 42 and the sun gear output body 43 is transmitted to the output shaft 70 by the third transmission mechanism 73 and the third speed clutch CL3 so as to become a driving force in the speed range of the third speed range. Then, it is transmitted from the output shaft 70 to the forward / reverse switching device 30. When the continuously variable transmission unit 20 is shifted from “−MAX” to “+ MAX” in the state in which the transmission output unit 3b is operated in this way, the rotational speed of the output shaft 70 is changed to “B2”. The speed increases steplessly. When the continuously variable transmission 20 is in the “+ MAX” shift state, the rotational speed of the output shaft 70 becomes “B3”.

  When the fourth speed clutch CL4 is operated to be engaged and the first speed clutch CL1, the second speed clutch CL2 and the third speed clutch CL3 are operated to be disengaged, the transmission output unit 3b is connected to the ring gear output body 41 of the planetary transmission unit 3a. And the combined driving force output from the carrier output body 42 and the sun gear output body 43 is transmitted to the output shaft 70 by the fourth transmission mechanism 74 and the fourth speed clutch CL4 so as to become a driving force in the speed range of the fourth speed range. Then, it is transmitted from the output shaft 70 to the forward / reverse switching device 30. When the continuously variable transmission unit 20 is shifted from “+ MAX” to “−MAX” in the state in which the transmission output unit 3b is operated in this way, the rotational speed of the output shaft 70 is changed to “B3”. The speed increases steplessly. When the continuously variable transmission 20 is in the “−MAX” speed change state, the rotational speed of the output shaft 70 becomes the maximum speed “B4”.

  As shown in FIG. 1, the forward / reverse switching device 30 includes the input shaft 31 and the output shaft 32, and an input side rotating member is connected to the input shaft 31 via an interlocking member 34 so as to be integrally rotatable. The output side rotating member is coupled to the output shaft 32 via the interlocking member 35 so as to be integrally rotatable, and the input side rotating member is interlocked to the input shaft 31 via the reverse transmission gear mechanism 33. The rotating member includes a reverse clutch CR connected to the output shaft 32 through the interlocking member 35 so as to be integrally rotatable.

  That is, the forward / reverse switching device 30 transmits the driving force of the input shaft 31 to the output shaft 32 via the forward clutch CF by operating the forward clutch CF in the engaged state and the reverse clutch CR in the disconnected state. Go forward. The forward / reverse switching device 30 is operated so that the forward clutch CF is disengaged and the reverse clutch CR is engaged, so that the driving force of the input shaft 31 is output via the reverse transmission gear mechanism 33 and the reverse clutch CR. It will be in a reverse drive state to transmit to 32.

  FIG. 5 is a block diagram of the traveling operation device provided in the tractor. As shown in this figure, the travel operation device is connected to a main transmission lever 80 and a forward / reverse lever 81 provided in a driving portion of the tractor, a shift detection means 82 linked to the main transmission lever 80, and a forward / reverse lever 81. The forward / reverse detection means 83 and the control means 84 linked to the forward / backward detection means 83 and the shift detection means 82 are provided. The control means 84 includes a shift valve 85 for shifting the continuously variable transmission 20, a clutch valve 86 to 89 for switching the clutches CL1 to CL4, a forward valve 90 for switching the forward clutch CF, It is linked with each electromagnetic operation part with the reverse valve 91 which switches the reverse clutch CR. The control unit 84 is linked to a shift state detection unit 92 provided in the continuously variable transmission unit 20.

  The main transmission lever 80 is oscillated in an operation range from the neutral position S1 to the maximum speed position Max. Of the operating range of the main transmission lever 80, the neutral position S1 to the intermediate position C is a low speed range L mainly used during work, and the intermediate position C to the maximum speed position Max is mainly a high speed range H used for traveling. It has become. The forward / reverse lever 81 is switched to a neutral position S2, a forward position F, and a reverse position R.

  The shift detection means 82 is constituted by a rotary potentiometer whose operating portion is linked to the main shift lever 80, detects the operation position where the main shift lever 80 is operated, and outputs the detection result to the control means 84. The forward / reverse detection means 83 is constituted by a rotary potentiometer whose operating part is linked to the forward / reverse lever 81, detects the operation position where the forward / reverse lever 81 is operated, and outputs the detection result to the control means 84. . The shift state detection unit 92 detects the shift state of the continuously variable transmission unit 20 and feeds back the detection result to the control unit 84.

  The control means 84 is configured using a microcomputer, and the rotational speed corresponding to the operation position of the main speed change lever 80 is determined by the speed change transmission device 3 based on the detection information from the speed change detection means 82 and the speed change state detection means 92. So that the continuously variable transmission portion 20 is shifted by operating the speed change valve 85 and the clutch valves 86 to 89 are switched. Switch operation of CL4.

  The control means 84 switches the forward clutch 90 by switching the forward valve 90 so that the forward / reverse switching device 30 is in an operation state corresponding to the operation position of the forward / reverse lever 81 based on the information detected by the forward / reverse detection means 83. The reverse clutch CR is switched by switching the CF and switching the reverse valve 91.

  That is, when the tractor travels, the tractor travels by swinging the main transmission lever 80 from the neutral position S1, and as the operation stroke from the neutral position S1 of the main transmission lever 80 is increased, the traveling speed of the tractor is increased. When the main speed change lever 80 is operated to the maximum speed position Max, the traveling speed of the tractor becomes the maximum speed.

  That is, until the main transmission lever 80 is swung from the neutral position S1 to the setting position La in the low speed range L (hereinafter referred to as the low speed setting position La), the control means 84 moves the first speed clutch CL1. The operation is maintained in the on state, and the transmission 3 is shifted to the first speed range to perform the shifting operation. Further, as the main shift lever 80 is swung from the neutral position S1, the control means 84 shifts the continuously variable transmission 20 from the “−MAX” shift state to the “+ MAX” shift state. Go. Thus, as the main speed change lever 80 is operated from the neutral position S1, the output rotational speed of the output shaft 70 increases steplessly from “0”. When the main transmission lever 80 reaches the low speed setting position La, the output rotation speed of the output shaft 70 becomes “B1”. At this time, the controller 84 switches the first speed clutch CL1 to the disengaged state and the second speed clutch CL2 to the on state, respectively, and the transmission 3 is switched to the second speed range. Thereafter, until the main transmission lever 80 reaches the intermediate position C from the low speed setting position La, the control means 84 maintains the second speed clutch CL2 in the engaged state, and the transmission transmission 3 is maintained in the second speed range. Shift operation is performed. Further, as the main speed change lever 80 is swung from the low speed setting position La, the control means 84 shifts the continuously variable transmission 20 from the “+ MAX” speed change state to the “−MAX” speed change state. To go. As a result, as the main speed change lever 80 is operated from the set low speed position La, the output rotational speed by the output shaft 70 increases steplessly from “B1”. When the main transmission lever 80 reaches the intermediate position C, the output rotation speed of the output shaft 70 becomes “B2”. At this time, the control means 84 switches the second speed clutch CL2 to the disengaged state and the third speed clutch CL3 to the on state, respectively, so that the transmission 3 is switched to the third speed range. Thereafter, the control means 84 maintains the third speed clutch CL3 in the engaged state until the main transmission lever 80 reaches the setting position Ha of the high speed range H from the intermediate position C (hereinafter referred to as the high speed setting position Ha). When operated, the transmission 3 is shifted to the 3rd speed range to perform a shifting operation. Further, as the main speed change lever 80 is swung from the intermediate position C, the control means 84 shifts the continuously variable transmission 20 from the “−MAX” speed change state to the “+ MAX” speed change state. Go. As a result, as the main speed change lever 80 is swung from the intermediate position C, the output rotational speed of the output shaft 70 increases steplessly from “B2”. When the main transmission lever 80 reaches the high speed setting position Ha, the output rotation speed of the output shaft 70 becomes “B3”. At this time, the control means 80 switches the third-speed clutch CL3 to the disengaged state and the fourth-speed clutch CL4 to the engaged state, so that the transmission 3 is switched to the fourth-speed range. Thereafter, until the main transmission lever 80 reaches the maximum speed position Max from the high speed setting position Ha, the control means 84 operates to maintain the fourth speed clutch CL4 in the engaged state, and the transmission 3 is in the fourth speed range. Shift operation is performed. Further, as the main shift lever 80 is swung from the high speed setting position Ha, the control means 84 shifts the continuously variable transmission 20 from the “+ MAX” shift state to the “−MAX” shift state. To go. As a result, as the main speed change lever 80 is swung from the high speed setting position Ha, the output rotation speed by the output shaft 70 increases steplessly from “B3”. When the main transmission lever 80 reaches the maximum speed position Max, the control means 84 maintains the fourth speed clutch CL4 in the engaged state, the transmission transmission 3 is in the fourth speed range, and the control means 84 is not used. The step shift unit 20 is operated to the “−MAX” shift state. As a result, the output rotation speed of the output shaft 70 becomes the maximum speed “B4”.

When traveling in this way, the forward / reverse lever 81 is operated to the forward position F. Then, the control means 84 operates the forward clutch CF to be engaged and the reverse clutch CR to be disengaged. As a result, the forward / reverse switching device 30 enters the forward state, and the output from the output shaft 70 is transmitted to the rear wheel differential mechanism 5 and the front wheel differential mechanism 9 as the forward drive force, and the tractor travels forward. On the other hand, if the forward / reverse lever 81 is operated to the reverse position R, the control means 84 operates to disengage the forward clutch CF and engage the reverse clutch CR. As a result, the forward / reverse switching device 30 enters the reverse state, and the output from the output shaft 70 is transmitted to the rear wheel differential mechanism 5 and the front wheel differential mechanism 9 as a reverse drive force, and the tractor travels backward.
When the forward / reverse lever 81 is operated to the neutral position S2, the control means 84 switches the forward clutch CF and the reverse clutch CR to the disengaged state. As a result, the forward / reverse switching device 30 is in a neutral state, transmission to the rear wheel differential mechanism 5 and the front wheel differential mechanism 9 is stopped, and the tractor is stopped.

[Second Example]
FIG. 6 is a diagram of the transmission 3 according to the second embodiment of the present invention. As shown in this figure, the speed change transmission device 3 according to the second embodiment of the present invention is installed in a travel transmission device provided in a tractor. The travel transmission device includes a main clutch 2 to which an output from the output shaft 1a of the engine 1 is input, the shift transmission device 3 to which an output from the main clutch 2 is input, and an output rotation of the transmission transmission device 3. A forward / reverse switching device 30 linked to an output shaft 70 as a body, a rear wheel differential mechanism 5 linked to an output shaft 32 of the forward / backward switching device 30, and an output shaft 32 of the forward / backward switching device 30. An interlocked front wheel differential mechanism 9 is provided.

  Comparing the traveling transmission device equipped with the transmission transmission device 3 of the second embodiment with the traveling transmission device equipped with the transmission transmission device 3 of the first embodiment, the main clutch 2 and the forward / reverse switching device 30 are compared. And the rear wheel differential mechanism 5 and the front wheel differential mechanism 9 are equipped with the traveling transmission device equipped with the transmission transmission device 3 of the second embodiment and the transmission transmission device 3 of the first embodiment. The traveling transmission device has the same configuration.

  Next, the transmission 3 of the second embodiment will be described in detail. The transmission 3 of the second embodiment includes a hydrostatic continuously variable transmission 20 (hereinafter abbreviated as a continuously variable transmission 20) positioned on the vehicle body rear side of the main clutch 2, and the continuously variable transmission. The planetary transmission unit 3a located on the vehicle body rear side of the unit 20 and the speed change output unit 3b located on the vehicle body front side of the forward / reverse switching device 30 are provided.

  When the speed change transmission device 3 of the second embodiment is compared with the speed change transmission device 3 of the first embodiment, the speed change transmission of the second embodiment is different in terms of the continuously variable transmission portion 20 and the speed change output portion 3b. The device 3 and the transmission 3 of the first embodiment have the same configuration. In terms of the planetary transmission unit 3a, the transmission 3 of the second embodiment and the transmission 3 of the first embodiment have different configurations. Next, the planetary transmission unit 3a of the second embodiment will be described.

  As shown in FIG. 6, the planetary transmission unit 3a of the second embodiment includes three planetary transmission mechanisms P1, P2, and P3 arranged in the longitudinal direction of the vehicle body. Of the three planetary transmission mechanisms P1, P2, and P3, the first planetary transmission mechanism P1 located closest to the front of the vehicle body includes a sun gear 101 that is rotatably supported by a cylindrical shaft 100 and the sun gear. A plurality of planetary gears 102 that are dispersed in the circumferential direction of the sun gear 101 and are engaged with the sun gear 101, a carrier 103 that rotatably supports each planetary gear 102, and the planetary gears 102. And a ring gear 104 meshed with internal teeth. Of the three planetary transmission mechanisms P1, P2 and P3, the second planetary transmission mechanism P2 located at the center in the longitudinal direction of the vehicle body is a sun gear 111 that is supported by the cylindrical shaft 110 so as to be integrally rotatable. A plurality of planetary gears 112 that are dispersed in the circumferential direction of the sun gear 111 and are meshed with the sun gear 111, a carrier 113 that rotatably supports the planetary gears 112, and the planetary gears. 112 is provided with a ring gear 114 meshed with internal teeth. Of the three planetary transmission mechanisms P 1, P 2, P 3, the third planetary transmission mechanism P 3 located on the rearmost side of the vehicle body includes a sun gear 121 that is rotatably supported by the rotary support shaft 110, and an outside of the sun gear 121. A plurality of planetary gears 122 that are dispersed in the circumferential direction of the sun gear 121 and meshed with the sun gear 121, a carrier 123 that rotatably supports each planetary gear 122, and each planetary gear 122 with internal teeth. And an intermeshing ring gear 124. The carrier 103 of the first planetary transmission mechanism P1, the ring gear 114 of the second planetary transmission mechanism P2, and the carrier 123 of the third planetary transmission mechanism P3 are interlocked by the interlocking member 130 so as to be integrally rotatable. The ring gear 104 of the first planetary transmission mechanism P1 and the carrier 113 of the second planetary transmission mechanism P2 are interlocked by an interlocking member 131 so as to be integrally rotatable. The sun gear 111 of the second planetary transmission mechanism P2 and the sun gear 121 of the third planetary transmission mechanism P3 are linked together by the rotary support shaft 110 so as to be integrally rotatable. The interlocking member 131 is interlocked with the pump shaft 21 of the continuously variable transmission unit 20 via the rotation shaft 132, the transmission gear 133, the transmission gear 134, and the rotation support shaft 135. That is, the engine driving force that is transmitted from the output shaft 1a of the engine 1 to the front end side of the pump shaft 21 and that is output from the rear end side of the pump shaft 21 without being subjected to the shifting action by the continuously variable transmission 20 is the first. 1 is transmitted to the ring gear 104 of the planetary transmission mechanism P1. The rotation support shaft 100 is linked to the motor shaft 22 of the continuously variable transmission 20 through a transmission gear 136, a transmission gear 137, and a rotation support shaft 138. That is, the output from the motor shaft 22 of the continuously variable transmission unit 20 is transmitted to the sun gear 101 of the first planetary transmission mechanism P1.

  The planetary transmission unit 3a includes three output bodies 41, 42, and 43 located on the vehicle body rear side of the third planetary transmission mechanism P3. The three output bodies 41, 42, and 43 are constituted by shaft bodies that overlap with a coaxial core-like triple-axis structure so as to be relatively rotatable. Of the three output bodies 41, 42, 43, the ring gear output body 41 is composed of a cylindrical shaft positioned on the outermost side of the triple shaft structure, and includes three planetary transmission mechanisms P1, P2,. The ring gear 124 of the third planetary transmission mechanism P3 located on the lowest side in the transmission direction of the planetary transmission unit 3a of P3 is connected to the ring gear 124 via the rotation interlocking body 139 so as to be integrally rotatable. Of the three output bodies 41, 42, 43, the carrier output body 42 has a cylindrical shaft located in the middle of the triple shaft structure, and is coupled to the carrier 123 of the third planetary transmission mechanism P3 so as to be integrally rotatable. Of the three output bodies 41, 42, 43, the sun gear output body 43 is a shaft body located on the innermost side of the triple shaft structure, and rotates integrally with the rotation support shaft 110 of the sun gear 121 of the third planetary transmission mechanism P3. , Rotate integrally with the sun gear 121.

  The planetary transmission unit 3a inputs the driving force of the motor shaft 21 as the engine driving force that is not subjected to the shifting action by the continuously variable transmission unit 20 to the ring gear 104 of the first planetary transmission mechanism P1, and the motor shaft of the continuously variable transmission unit 20 22 is input to the sun gear 101 of the first planetary transmission mechanism P1, and the engine driving force that is not subjected to the shifting action by the continuously variable transmission unit 20 and the output of the continuously variable transmission unit 20 are combined with the first planetary transmission mechanism P1. The second planetary transmission mechanism P2 and the third planetary transmission mechanism P3 are combined to output a combined driving force from the ring gear output body 41, the carrier output body 42, and the sun gear output body 43.

[Another Example]
Instead of the speed change transmission apparatus of the above embodiments, a ring gear output member 41 and the carrier output member 42 and the sun gear output member 43 of the Yu star transmission section 3a, five transmission of which is provided over the output rotor 70 Doo shift output section 3b Mechanism and five clutches for switching the five power transmission mechanisms separately, the engine output is divided into five speed ranges, and the speed is steplessly changed in each speed range from 1st to 5th. such as to change transmission apparatus to be output, but the present invention when the speed change transmission apparatus to be staged in a plurality of stages of speed ranges large number than four stages can be applied.

  Instead of the clutches CL1 to CL4 shown in the above embodiments, a clutch configured to be switched between the on state and the off state by a shift operation of the clutch gear using the synchromesh may be employed. In addition, the object of the present invention can be achieved.

Diagram of tractor drive transmission Diagram of planetary transmission section in front view Explanatory drawing which shows the relationship between the operation state of a clutch, and the operation state of a transmission output part. Explanatory drawing which shows the relationship between the speed change state of a continuously variable transmission part, the speed range of a speed change output part, and an output speed. Block diagram of travel control device Diagram of a traveling transmission device provided with the speed change transmission device of the second embodiment Diagram of previously developed transmission Explanatory drawing which shows the relationship between the speed change state of the continuously variable transmission part of the speed change transmission device developed previously, the speed range of the speed change output part, and the output speed. Explanatory drawing which shows the relationship between the operation state of the clutch of the transmission gearbox developed previously, and the operation state of a transmission output part.

1 Engine 3a Planetary transmission part 3b Shifting output part
10 Mission case 20 Hydrostatic continuously variable transmission
30 Forward / reverse switching device 41 Ring gear output body 42 Carrier output body 43 Sun gear output bodies 60 and 121 Sun gears 62 and 123 of the lowermost planetary transmission mechanism Carriers 63 and 124 of the lowermost planetary transmission mechanism Planetary transmission of the lowermost hand side Ring gear 70 of the mechanism Output rotator 71, 72, 73, 74 Transmission mechanism
71a, 72a, 73a, 74a Input gear
71b, 72b, 73b, 74b Output gear
95 Input side rotating member
96 Output side rotating member PF, PR, P1, P2, P3, P4 Planetary transmission mechanism CL1, CL2, CL3, CL4 Clutch
CF forward clutch
CR reverse clutch

Claims (2)

An output of the engine is input , and a hydrostatic continuously variable transmission portion disposed on the rear side of the vehicle with respect to the engine, a driving force output from the hydrostatic continuously variable transmission portion, and the hydrostatic The engine driving force that is not subjected to the shifting action by the step transmission unit is combined by a plurality of planetary transmission mechanisms , and the rotational axis of the vehicle body in the longitudinal direction of the vehicle body in the transmission case at the rear side of the vehicle body from the hydrostatic continuously variable transmission unit A planetary transmission unit arranged so as to have a plurality of stages, and a combined driving force output from the planetary transmission unit is divided into a plurality of speed ranges to be biased and rotated in parallel with respect to the longitudinal axis of the vehicle body A shift output unit that outputs from one output rotating body having an axis and is disposed on the vehicle body rear side of the planetary transmission unit inside the transmission case, and a driving force from the output rotating body and a forward clutch rear E Bei a forward-reverse switching mechanism disposed on the vehicle rear side of the output rotor in the interior of and transmission case in which switching to the reverse drive force and forward drive force by the clutch,
The planetary transmission unit includes a sun gear output body that is rotatable integrally with the sun gear of the lowermost planetary transmission mechanism located on the lowermost side in the transmission direction of the planetary transmission unit, and the carrier of the lowermost planetary transmission mechanism. A carrier output body rotatable integrally with the ring gear, and a ring gear output body rotatable integrally with the ring gear of the lowermost planetary transmission mechanism , wherein the sun gear output body has a diameter larger than that of the carrier output body and the ring gear output body. The sun gear output body, the carrier output body, and the ring gear output body are configured in a triple shaft structure having the vehicle body front-rear rotation axis so as to be positioned inward in the direction,
A transmission mechanism for a carrier that interlocks the carrier output body with the output rotating body with a pair of gears at the speed change output unit, and a mechanism that links the ring gear output body with the output rotating body with a pair of gears. A ring gear transmission mechanism arranged in parallel in the front-rear direction with respect to the transmission mechanism for driving, the sun gear output body interlocking with the output rotating body by two pairs of gears, and the transmission mechanism for the carrier, The sun gear front and rear transmission mechanisms arranged in parallel in the front and rear direction with respect to these transmission mechanisms on the rear side of the ring gear transmission mechanism, and these four transmission mechanisms are individually connected to the transmission state and transmission cut off. A transmission device for a tractor provided with four clutches which are switched to a state and display a four-stage speed range when the transmission mechanism is in a transmission state . Each of the four clutches includes an input side rotating member to which driving force from the four transmission mechanisms is input, and an output side rotating member that outputs driving force to the output rotating body, The tractor speed change transmission device according to claim 1 , wherein the four sets of the input side rotating member and the output side rotating member are arranged in parallel in a direction along a rotation axis of the output rotating body and are supported by the output rotating body. .

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