JP2013040633A - Traveling transmission device of farm working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute sub-speed change performed by a hydraulic motor in a state that a speed change trouble does not occur while having a speed range of HST transmission and a speed range of HMT transmission.SOLUTION: When a speed change gear is set at the HMT transmission and is in a transmission state that a synthetic drive force output by a speed change operation to a high-speed side in a reverse speed change range of a stepless speed change part 30 is increased in speed, speed change control to the high speed side of the hydraulic motor 33 is permitted. When the speed change gear is set at the HMT transmission and a synthetic drive force output by a speed change operation to a low-speed side in a forward speed range of the stepless speed change part 30 is increased in speed, speed change control to the high-speed side of the hydraulic motor 33 is restrained.

Description

  The present invention includes a hydrostatic continuously variable transmission that acts to input and shift the driving force from the engine and shift the output driving force along the HST shift line, and the driving force from the engine A transmission having a planetary transmission unit that acts to input and synthesize a variable speed driving force from a continuously variable transmission unit and output the combined driving force to be shifted along the HMT shift line by a shift of the continuously variable transmission unit. An HST setting state for setting the HST transmission for outputting the shift driving force output from the continuously variable transmission unit to the traveling device, and the HMT transmission for outputting the combined driving force output by the planetary transmission unit to the traveling device. A clutch mechanism that can be switched to an HMT setting state is provided in the transmission, and the hydraulic pump that constitutes the continuously variable transmission unit is controlled to shift based on a main transmission command from a main transmission operating tool and the clutch. About traveling transmission apparatus for agricultural machine comprising a shift control means for controlling switching mechanism.

  Agricultural work machines may be repeatedly switched between forward and backward, such as when changing the direction at the end of a work line. The traveling transmission device for an agricultural machine described above has output characteristics as shown in FIG. 6, and the output speed is set to the HST shift line by performing a shift operation to the forward side and the reverse side across the neutral state of the continuously variable transmission unit. Thus, the aircraft can be switched between forward and backward by simply performing a simple shift operation that does not require a special operation for forward / reverse switching.

  Conventionally, for example, Patent Document 1 discloses a traveling power transmission device of this type. In the one described in Patent Document 1, a hydraulic continuously variable transmission, a planetary gear mechanism, and two hydraulic clutches are provided in a transmission system that transmits engine output to front and rear wheels, and connection between the two hydraulic clutches is switched. Thus, a drive system in the HST mode is configured, and the driving force output from the motor output shaft of the hydraulic continuously variable transmission is transmitted to the front and rear wheels without being transmitted to the planetary gear mechanism. Further, by switching the connection of the two hydraulic clutches, an HMT mode drive system is configured, and the driving force output from the motor output shaft of the hydraulic continuously variable transmission is transmitted to the planetary gear mechanism to be transmitted to the planetary gear. The driving force from the hydraulic continuously variable transmission and the driving force from the engine are combined by the mechanism, and the combined driving force output from the planetary gear mechanism is transmitted to the front and rear wheels.

  Conventionally, for example, as disclosed in Patent Document 2, an actuator that controls a swash plate of a hydraulic motor that constitutes a continuously variable transmission is provided, and this actuator is operated by a command operation using a changeover switch, so that the hydraulic motor is operated at high speed and low speed. There was one configured to switch to two stages.

JP 2001-108061 A JP 2003-202067 A

  In the traveling transmission device for an agricultural machine described above, the hydraulic motor constituting the continuously variable transmission unit is configured to be a variable displacement type, and includes a sub-transmission actuator for changing the swash plate angle of the hydraulic motor, and operating the sub-transmission operation tool. When the sub-shift command is issued to control the sub-shift actuator to shift the hydraulic motor to the high speed side, it is convenient to travel at high speed during traveling. However, even if the hydraulic motor performs a sub-shift operation so as to shift to a high speed side, the traveling speed may be reduced without increasing.

  That is, FIG. 6 is a graph showing the output characteristics provided in the transmission. The vertical axis is a speed line indicating the rotational speed of the driving force output from the transmission. The horizontal axis passes through the position where the rotational speed of the vertical axis is zero “0”, and is an operation position line L indicating the swash plate position of the hydraulic pump constituting the continuously variable transmission. “N” in the operation position line L is a swash plate neutral operation position for setting the continuously variable transmission unit in a neutral state. “A” in the operation position line L is a set forward high speed position set as the maximum high speed position on the forward side of the swash plate operated by the shift control. “−max” of the operation position line L is a set reverse high-speed position set as the maximum high-speed position on the reverse side of the swash plate operated by the shift control.

  The shift line S through which the rotational speed passes through zero “0” is the HST shift line S indicating the change in the output speed of the transmission in the setting of the HST transmission. A shift line portion SF corresponding to a position between the swash plate positions “n” and “a” in the HST shift line S indicates a change in the output speed on the forward side, and the HST shift line on the forward side. SF. A shift line portion SR corresponding to a position between the swash plate positions “n” and “−max” in the HST shift line S indicates a change in the output speed on the reverse side, and the HST shift on the reverse side. Line SR. A shift line M that is continuous with the HST shift line S is an HMT shift line M that indicates a change in the output speed of the transmission in the setting of the HMT transmission.

  When the swash plate of the hydraulic pump is set to the set forward high speed position “a”, the switching control of the setting between the HST transmission and the HMT transmission is performed. The transmission in the transmission state in which the HMT transmission is set, The continuously variable transmission unit is shifted to the high speed side in the reverse shift range, and the output speed of the continuously variable transmission unit is increased to increase the output speed. On the other hand, the transmission in the transmission state in which the HMT transmission is set is output when the continuously variable transmission is shifted to the low speed side in the forward shift range and the output speed of the continuously variable transmission is reduced. Increase the speed.

  In other words, when the transmission is set to HMT transmission and is in a transmission state in which the combined driving force output by the shifting operation in the forward shifting range of the continuously variable transmission is increased or decreased, the hydraulic motor is shifted to the higher speed side. Then, the continuously variable transmission unit is shifted to increase the output speed, the output speed as the transmission gear is reduced, and the traveling speed is reduced without increasing.

  An object of the present invention is to provide a traveling transmission device for an agricultural machine capable of performing a sub-shift with a hydraulic motor while avoiding the occurrence of the shift problem described above.

According to the first aspect of the present invention, a hydrostatic continuously variable transmission that acts to input and shift a driving force from the engine and shift the output driving force along the HST shift line, and the driving force from the engine. And a shift drive force from the continuously variable transmission unit are input and combined, and a shift having a planetary transmission unit that acts so that the combined drive force to be output is shifted along the HMT shift line by the shift of the continuously variable transmission unit. Equipped with a transmission,
HST setting state for setting the HST transmission for outputting the shift driving force output from the continuously variable transmission unit to the traveling device, and the HMT setting state for setting the HMT transmission for outputting the combined driving force output by the planetary transmission unit to the traveling device. A clutch mechanism that can be switched between and is provided in the transmission.
In the traveling transmission device of an agricultural machine comprising shift control means for performing shift control of the hydraulic pump that constitutes the continuously variable transmission unit based on a main shift command from a main shift operation tool, and switching and controlling the clutch mechanism,
The hydraulic motor constituting the continuously variable transmission unit is configured in a variable displacement type,
A sub-shift operating tool that is manually maneuverable and issues a sub-shift command, and a sub-shift actuator that performs a swash plate angle change operation of the hydraulic motor;
The shift control means is configured to control the sub-shift actuator to shift the hydraulic motor to a high speed side based on the sub-shift command;
The transmission transmission is set to the HMT transmission, and the combined driving force output to the traveling device is increased by a shift operation to the high speed side in the reverse transmission range of the continuously variable transmission, and the continuously variable transmission When in the transmission state in which the combined driving force output to the traveling device is decelerated by the shifting operation to the low speed side in the reverse shifting range, the restraint is released so as to allow the control of the auxiliary shifting actuator by the shifting control means, The transmission gear is set to the HMT transmission, and the combined driving force output to the traveling device is increased by a shift operation to the low speed side in the forward shift range of the continuously variable transmission, and further, the continuously variable transmission of the continuously variable transmission If the combined drive force output to the traveling device is decelerated by a shift operation to the high speed side in the forward shift range, the control of the sub-shift actuator by the shift control means is stopped. It is provided with a check control means for restraining action cormorants.

  According to the configuration of the first aspect of the present invention, the transmission in which the transmission is set to HMT transmission and the combined drive force output to the traveling device is increased by the shift operation to the high speed side in the reverse transmission range of the continuously variable transmission. In this state, the restraint control means releases the restraint with respect to the shift control means, and when the sub-shift operating tool is operated to issue a sub-shift command, the shift control means controls the sub-shift actuator to move the hydraulic motor to the high speed side. Change the speed to. Since the hydraulic motor is shifted to the high speed side in the transmission state where the output speed of the transmission is increased by increasing the output speed of the continuously variable transmission, the output speed of the transmission is increased. In response, the speed increases.

  According to the configuration of the first aspect of the invention, the transmission in which the transmission is set to HMT transmission and the combined driving force output to the traveling device is increased by the shifting operation to the low speed side in the forward transmission range of the continuously variable transmission unit. In this state, even if the check control unit makes a check for the shift control unit and operates the sub-shift operating tool to issue a sub-shift command, the shift control unit performs a shift operation to the high speed side of the hydraulic motor. In spite of the transmission state where the output speed of the transmission is increased by the deceleration of the output speed of the continuously variable transmission, the hydraulic motor is shifted to the high speed side and the output speed of the transmission is reduced. Can be avoided.

  Therefore, the setting of HST transmission and HMT transmission can be switched, and the forward / backward switching of the machine can be easily performed by simply performing the shifting operation to the forward side and the reverse side across the neutral state of the continuously variable transmission. Although it is possible to perform the sub-shift by the shifting operation of the hydraulic motor, it is possible to easily shift the gear so that there is no trouble of decelerating despite the operation of the sub-shift operating tool.

According to the second aspect of the present invention, the reference swash plate angle is set such that the swash plate angle of the hydraulic pump positioned at a low speed side by a set angle with respect to the swash plate angle for performing switching control of the setting from HST transmission to HMT transmission. With plate angle setting means,
When the speed change transmission is set to the HST transmission and the swash plate angle of the hydraulic pump is lower than the reference swash plate angle, the check control means releases the check, and the speed change transmission moves to the HST transmission. Is set and the swash plate angle of the hydraulic pump is on the higher speed side than the reference swash plate angle, the check control means is used for checking.

  A sub-shift for shifting the hydraulic motor to the high speed side is performed with the HST transmission set, and the output speed increases along the HST shift line of the sub-shift setting that deviates from the HST shift line when there is no sub-shift setting. In this case, the intersection between the HST transmission line and the HMT transmission line that does not have a sub-shift setting for switching the setting from the HST transmission to the HMT transmission does not occur, and the setting is switched from the HST transmission to the HMT transmission. This makes it difficult to smoothly switch the clutch mechanism for performing the operation. On the other hand, according to the configuration of the second aspect of the invention, when the swash plate angle of the hydraulic pump exceeds the reference swash plate angle, the check control means is in a state for checking the shift control means to the high speed side of the hydraulic motor. The sub-shift setting cannot be performed by a shift operation, and a clutch mechanism for reliably generating an intersection between the HST shift line and the HMT shift line without the sub-shift setting and switching the setting from the HST transmission to the HMT transmission. Can be smoothly switched.

  Therefore, although the sub-shift can be performed by the shift operation of the hydraulic motor, the clutch mechanism is smoothly switched to perform the shift from the speed range of the HST transmission to the speed range of the HMT transmission. It can be done lightly so that shock does not easily occur.

  In the third aspect of the present invention, in the state where the shift control means is subjected to check production by the check control means, the output speed corresponding to the main shift command of the transmission is increased by the sub-shift command. The hydraulic pump is shift-controlled based on the main shift command and the sub-shift command.

  Even if the sub-shift operation tool is operated, if the check control means does not make a sub-shift by the hydraulic motor and the running speed does not increase because the check is produced, the sub-shift operation is performed. You will feel uncomfortable that the running speed will not increase. According to the configuration of the third aspect of the invention, even if the sub-shift operation tool is operated, if the check control means is used for checking and the sub-shift by the hydraulic motor is not performed, the shift control means performs the shift control of the hydraulic pump. Thus, the output speed of the transmission is increased from that according to the main transmission command, and the traveling speed can be increased.

  Therefore, if the sub-shift operating tool is operated, even if the sub-shift by the hydraulic motor is not performed, the sub-shift by the hydraulic pump is performed, and there is a sense of incongruity that the traveling speed does not increase even though the sub-shift operation has been performed. It is possible to make a good shift without any problems.

It is a side view which shows the whole combine. It is a schematic front view which shows a driving | running | working transmission apparatus. It is a vertical front view which shows the speed change transmission in HMT transmission. It is a vertical front view which shows the transmission in HST transmission. It is explanatory drawing which shows the relationship between the operation state of an HMT clutch and an HST clutch, the operation state of the clutch mechanism of transmission switching, and the transmission state of a transmission gearbox. It is a graph which shows the output characteristic with which a transmission is provided. It is explanatory drawing which shows the relationship between the value of N / X, and total efficiency. It is explanatory drawing which shows the relationship between the value of N / X and size reduction of a continuously variable transmission part. It is a block diagram which shows a speed change operation apparatus. It is a top view which shows the operation position of the main transmission operating tool.

Hereinafter, based on the drawings, a description will be given of the case where the combine is equipped with the transmission device of the agricultural machine according to the present invention.
As shown in FIG. 1, a combine is configured to be self-propelled by a pair of left and right crawler type traveling devices 1, 1, and is equipped with a riding type driving unit 2, and a body frame of the traveling body 3, a cutting part 4 connected to the front part of the machine frame 3, a threshing device 5 provided behind the cutting part 4 on the rear side of the machine body frame 3, and a lateral side of the threshing apparatus 5 on the rear side of the machine body frame 3. And a grain tank 6 arranged and provided on the side, and harvesting rice, wheat and the like.

  That is, the cutting unit 4 includes a cutting unit frame 4a that extends from the front portion of the body frame 3 so as to be able to swing up and down in the forward direction. The weeding tool 4b provided at the front end of the mowing unit 4 moves up and down to a lowering work position where the weeding tool 4b is lowered near the ground, and a rising non-working position where the weeding tool 4b is raised from the ground. When the mowing unit 4 is lowered to the lowering work position and the traveling machine body is run, the mowing unit 4 causes the planted culm to be harvested by the weeding tool 4b to be introduced into the path, and the planting that has been induced and introduced into the path. While raising the standing cereal and raising it by the device 4c, it is cut by the clipper type reaping device 4d, and the chopped cereal is supplied to the threshing device 5 by the supply device 4e. The threshing device 5 sandwiches the stock side of the harvested cereal meal from the supply device 4e by the threshing feed chain 5a and conveys it toward the rear of the machine body, and supplies the tip side of the harvested cereal meal to the handling room (not shown). The threshing process is performed, and the threshing grain is fed into the grain tank 6.

  An engine 8 is provided below a driver seat 2 a provided in the driving unit 2, and driving force output from the engine 8 is transmitted to a pair of left and right by a traveling transmission device 10 including a transmission case 11 provided at the front end of the body frame 3. It is comprised so that it may transmit to the traveling apparatuses 1 and 1.

  FIG. 2 is a front view showing a schematic structure of the traveling transmission device 10. As shown in this figure, the traveling transmission device 10 provides engine driving force from the output shaft 8a of the engine 8 on the side of the upper end of the transmission case 11 via the transmission mechanism 12 provided with the transmission belt 12a. To the left side of the pair of left and right steering clutch mechanisms 14, 14 included in the traveling mission 13 by inputting the output of the transmission transmission 20 to the traveling mission 13 built in the transmission case 11. Is transmitted from the steering clutch mechanism 14 to the drive shaft 1a of the left traveling device 1, and is transmitted from the right steering clutch mechanism 14 to the drive shaft 1a of the right traveling device 1.

  The traveling transmission device 10 includes a cutting mission 15 incorporated in the transmission case 11, and the output of the transmission 20 is input to the cutting mission 15 and transmitted from the cutting output shaft 16 to the drive shaft 4 f of the cutting unit 4.

The transmission 20 will be described.
As shown in FIGS. 3 and 4, the transmission 20 is connected to the planetary transmission unit 20 </ b> A having a transmission case 21 having a lateral side connected to the upper end side of the transmission case 11, and to the transmission case 11 of the transmission case 21. And a hydrostatic continuously variable transmission 30 having a casing 31 connected to a lateral side opposite to the side to be operated.

  The transmission case 21 houses a main case portion 21 a that houses the planetary transmission unit 40 and the transmission mechanism 50, a coupling portion of the input shaft 22, the transmission shaft 23, and the continuously variable transmission unit 30, and the transmission case 21 and the casing 31. A connection case portion 21b for connecting the port block 34 is provided. The transmission case 21 is connected to the transmission case 11 at a bulging portion 21c that is bulged outwardly on the lateral side of the lower side surface where the output rotating body 24 of the main case portion 21a is located. The size of the connecting case portion 21b in the vertical direction of the traveling machine body is smaller than the size of the main case portion 21a in the vertical direction of the traveling machine body. The main case portion 21a is formed so that the longitudinal cross-sectional shape when viewed in the longitudinal direction of the fuselage is a longitudinally long shape, and the casing 31 is formed such that the longitudinal sectional shape when viewed in the longitudinal direction of the aircraft is longitudinally elongated. While the section 20A and the continuously variable transmission section 30 are arranged in the lateral direction of the vehicle body, the lateral width of the entire transmission gearbox 20 is reduced, and the transmission gearbox 20 does not protrude laterally in the lateral direction of the traveling vehicle body. It is connected to the lateral side of the mission case 11 in a compact state. Further, a bulging portion 31B that supports the bearing of the motor shaft 33a is formed on the lower side surface of the casing 31, so that the transmission gearbox 20 can be made more compact. In addition, an oil filter 20F is disposed on the upper surface of the casing 31 so as to avoid protrusion of the oil filter 20F to the lateral outer side, thereby achieving further compactness.

  The planetary transmission unit 20A includes a laterally-facing input shaft 22 that is rotatably supported on the upper end side of the transmission case 21, and a transmission that is rotatably supported in parallel or substantially parallel to the input shaft 22 on the lower end side of the transmission case 21. A shaft 23 and a rotary shaft type output rotor 24; a planetary transmission unit 40 supported by the transmission shaft 23; and a transmission mechanism 50 provided across the input shaft 22 and the carrier 41 of the planetary transmission unit 40. Yes.

  The input shaft 22 is arranged so as to be arranged coaxially with the pump shaft 32 a of the continuously variable transmission 30. The input shaft 22 is configured to be coupled to the output shaft 8a of the engine 8 via the transmission mechanism 12 on the side projecting laterally outward from the transmission case 21, and the joint on the opposite side to the side coupled to the engine 8 It is connected to the pump shaft 32a of the continuously variable transmission unit 30 via 22a so as to be rotatable together. The engine driving force is input via the transmission mechanism 12, and the hydraulic pressure of the continuously variable transmission unit 30 is driven by the engine driving force. The pump 32 is driven.

  The output rotator 24 is arranged on the same side as the side where the engine coupling side of the input shaft 22 is located with respect to the continuously variable transmission 30 so as to be aligned coaxially with the motor shaft 33a of the continuously variable transmission 30. The output rotator 24 is configured to be interlocked with the input portion of the traveling mission 13 on the side projecting laterally outward from the transmission case 21, and the driving force from the planetary transmission unit 40 and the continuously variable transmission unit 30 is used as the traveling mission. 13 to the pair of left and right traveling devices 1, 1.

  The continuously variable transmission unit 30 includes a hydraulic pump 32 in which a pump shaft 32a is rotatably supported on the upper end side of the casing 31, and a hydraulic motor 33 in which a motor shaft 33a is rotatably supported on the lower end side of the casing 31. It is configured with. The hydraulic pump 32 is a variable displacement axial plunger pump, and the hydraulic motor 33 is a variable displacement axial plunger motor. The hydraulic motor 33 is driven by pressure oil that is discharged by the hydraulic pump 32 and supplied through an oil passage formed inside the port block 34. The continuously variable transmission 30 is supplied with supplementary hydraulic fluid by a charge pump 90 provided at the end of the pump shaft 32a. The charge pump 90 includes a rotor 90a that is attached to the pump shaft 32a so as to be integrally rotatable, and a pump casing 90b that is detachably connected to the casing 31.

  Therefore, the continuously variable transmission unit 30 is switched to the forward transmission state, the reverse transmission state, and the neutral state by performing an angle changing operation of the swash plate 32b included in the hydraulic pump 32. When the continuously variable transmission unit 30 is switched to the forward drive state, the engine drive force transmitted from the input shaft 22 to the pump shaft 32a is converted into the forward drive force and output from the motor shaft 33a to enter the reverse drive state. When the switching operation is performed, the engine driving force transmitted from the input shaft 22 to the pump shaft 32a is converted into a reverse driving force and output from the motor shaft 33a, and the engine driving force in both the forward transmission state and the reverse transmission state. Is output in a stepless manner. The continuously variable transmission unit 30 stops the output from the motor shaft 33a when switched to the neutral state.

  The planetary transmission unit 40 is disposed on the same side as the side where the engine coupling side of the input shaft 22 is positioned with respect to the continuously variable transmission unit 30 and is positioned between the motor shaft 33 a and the output rotating body 24. The planetary transmission unit 40 is configured to freely rotate a sun gear 42 supported by the transmission shaft 23, a plurality of planetary gears 43 that mesh with the sun gear 42, a ring gear 44 that meshes with each planetary gear 43, and a plurality of planetary gears 43. And a carrier 41 to be supported. The carrier 41 includes an arm portion 41a that rotatably supports the planetary gear 43 at the extended end portion, and a cylindrical shaft portion 41b to which the base end sides of the plurality of arm portions 41a are connected. The transmission shaft 23 is rotatably supported via a bearing.

  The transmission shaft 23 and the motor shaft 33a are connected so as to be integrally rotatable via a joint 23a, and the transmission shaft 23 and the sun gear 42 are connected so as to be integrally rotatable via a spline structure. The shaft 33a is interlocked with the shaft 33a so as to be integrally rotatable.

  The ring gear 44 and the output rotating body 24 are integrally rotatable by an annular planetary interlocking body 26 and an annular output side interlocking body 27 that are externally fitted to the transmission shaft 23 so as to be relatively rotatable side by side in the axial direction. It is linked to. That is, the planetary interlocking body 26 includes a plurality of engagement arm portions 26 a that extend radially and integrally from the outer peripheral portion of the planetary interlocking body 26. The plurality of engagement arm portions 26 a are engaged with a plurality of locations of the ring gear 44, and the planetary interlocking body 26 is interlocked with the ring gear 44 so as to be integrally rotatable. The output-side interlocking body 27 is engaged with the planetary-side interlocking body 26 so as to be integrally rotatable with an engaging claw 27a, and is integrally engaged with the output rotating body 24 with a spline structure. The interlocking body 26 and the output rotating body 24 are connected so as to be rotatable together. The planetary interlocking body 26 is supported on the transmission shaft 23 through a bearing so as to be relatively rotatable. The output side interlocking body 27 is rotatably supported by the transmission case 21 via a bearing.

  The transmission mechanism 50 is a transmission gear 52 that is supported on the input shaft 22 through a needle bearing so as to be relatively rotatable while meshing with an input gear 41c of the carrier 41 that is provided rotatably on the cylindrical shaft portion 41b of the carrier 41. And an HMT clutch 55 provided across the transmission gear 52 and the input shaft 22.

  The HMT clutch 55 includes a clutch body 56 that is supported by the input shaft 22 so as to be integrally rotatable and slidable, and a clutch main body 57 that is provided across one end side of the clutch body 56 and the lateral side portion of the transmission gear 52. It is prepared. The clutch body 56 is slid and operated by a hydraulic piston 58 fitted in the end of the clutch body 56. The clutch body 57 is configured as a meshing clutch so that the meshing claw provided on the clutch body 56 and the meshing claw provided on the transmission gear 52 are engaged and disengaged to switch between the on state and the off state.

  When the clutch body 57 is switched to the engaged state, the HMT clutch 55 is switched to the input state so as to interlock the input shaft 22 and the transmission gear 52 so as to be integrally rotatable, and the HMT clutch 55 is switched to the carrier 41 of the planetary transmission unit 40. The HMT transmission is set so as to interlock with the input shaft 22.

  When the clutch main body 57 is switched to the disengaged state, the HMT clutch 55 is switched to the disengaged state so as to disconnect the input shaft 22 and the transmission gear 52 from each other, and the carrier 41 of the planetary transmission unit 40 and the input shaft 22 are switched. The state where the setting of HMT transmission is canceled so as to cut off the interlocking of the motor is brought about.

  Accordingly, the planetary transmission unit 40 is switched from the portion located between the engine connecting side of the input shaft 22 and the continuously variable transmission unit connecting side to the input shaft when the HMT clutch 55 is switched to the state in which the HMT transmission is set. The driving force 22 is input to the carrier 41 through the transmission mechanism 50. The planetary transmission unit 40 is switched to the state in which the HMT clutch 55 has released the setting of the HMT transmission, so that the interlocking of the carrier 41 with the input shaft 22 is cut off.

  An HST clutch 60 including a clutch body 61 fitted on the transmission shaft 23 is provided across the sun gear 42 of the planetary transmission unit 40 and the planetary side interlocking body 26.

  The clutch body 61 is slidably operated toward the sun gear 42 against the energizing spring 62 when pressure oil is supplied to an oil chamber formed on the inner peripheral side of the clutch body 61, so that the clutch body 61 is in the cut position. When the pressure oil is discharged from the oil chamber, the urging spring 62 is slid toward the planetary interlocking body 26 to switch to the entry position. When the clutch body 61 is switched to the entering position, the clutch pawl 61 a provided on the clutch body 61 and the clutch pawl provided on the planetary interlocking body 26 are engaged with each other, so that the clutch body 61 is integrated with the planetary interlocking body 26. Connect freely. The clutch body 61 is slid while maintaining a state in which the clutch body 61 is engaged with the sun gear 42 by the engaging claws 61b so as to be integrally rotatable. When the clutch body 61 is switched to the disengagement position, the clutch pawl 61a is disengaged from the planetary interlocking body 26.

  Therefore, the HST clutch 60 rotates the motor shaft 33a integrally with the output rotating body 24 by interlocking the sun gear 42 and the planetary interlocking body 26 so that the clutch body 61 is switched to the engaged position. The HST transmission is set so as to enable the output from the output rotating body 24 by the continuously variable transmission unit 30 to be interlocked freely. In the HST clutch 60, when the HST transmission is set, the sun gear 42 and the transmission shaft 23 are interlocked so as to be integrally rotatable, and the ring gear 44 and the planetary side interlocking body 26 are interlocked so as to be integrally rotatable. The sun gear 42, the carrier 41, and the ring gear 44 can rotate integrally with the motor shaft 33a so that the rotation does not occur.

  The HST clutch 60 switches the sun gear 42 and the output rotating body 24 of the planetary transmission unit 40 between the interlocking on state and the interlocking off state while maintaining the ring gear 44 and the output rotating body 24 of the planetary transmission unit 40 in an interlocking state.

  When the clutch body 61 is switched to the disengagement position, the HST clutch 60 stops the interlocking of the sun gear 42 and the planetary side interlocking body 26, disconnects the interlocking of the motor shaft 33a with the output rotating body 24, and planetary transmission. The ring gear 44 of the unit 40 and the output rotator 24 are linked together so that they can rotate together, and the HST transmission is set so that the combined driving force of the planetary transmission unit 40 can be output from the output rotator 24. It will be in a released state.

  Therefore, the planetary transmission unit 40 is switched to the state in which the HMT clutch 55 is set to HST transmission, and the HST clutch 60 is switched to the state in which the setting of the HST transmission is released to be transmitted to the input shaft 22 from the engine. The driving force thus generated is input to the carrier 41 via the transmission mechanism 50, and the shift driving force output from the motor shaft 33a of the continuously variable transmission unit 30 is input to the sun gear 42 via the transmission shaft 23 to drive from the engine. The combined driving force is generated by combining the force and the speed change driving force from the continuously variable transmission unit 30, and the generated combined driving force is output from the ring gear 44 via the planetary side interlocking body 26 and the output side interlocking body 27. Output to the body 24.

  That is, a transmission setting clutch mechanism 70 is provided that includes the HMT clutch 55 and the HST clutch 60 and switches the transmission 20 to be set between HMT transmission and HST transmission.

  FIG. 5 is an explanatory diagram showing the relationship between the operating state of the HMT clutch 55 and the HST clutch 60, the operating state of the transmission-set clutch mechanism 70, and the transmission state of the transmission 20. “Disconnected” shown in FIG. 5 indicates the disengaged state of the HMT clutch 55 and the HST clutch 60, and “On” indicates the engaged state of the HMT clutch 55 and the HST clutch 60. As shown in this figure, when the HMT clutch 55 is switched to the disengaged state and the HST clutch 60 is switched to the engaged state, the transmission setting clutch mechanism 70 enters the HST transmission setting state, and the transmission 20 Set HST transmission to. When the HMT clutch 55 is switched to the engaged state and the HST clutch 60 is switched to the disengaged state, the transmission setting clutch mechanism 70 enters the HMT transmission setting state and sets the HMT transmission in the transmission 20.

  FIG. 3 is a longitudinal front view showing the transmission 20 with HMT transmission. As shown in this figure, in the transmission 20, when the HMT clutch 55 is switched to the engaged state and the HST clutch 60 is switched to the disconnected state, the driving force of the input shaft 22 (the driving force from the engine 8). ) Is input to the carrier 41 of the planetary transmission unit 40 via the transmission mechanism 50, and the continuously variable transmission unit 30 shifts the driving force input from the input shaft 22 and outputs the transmission driving force output from the motor shaft 33a to the planetary transmission unit. 40 is input to the sun gear 42, and the planetary transmission unit 40 combines the driving force from the engine 8 input from the input shaft 22 by the planetary transmission unit 40 and the transmission driving force input from the continuously variable transmission unit 30 by the planetary transmission unit 40. , And the combined driving force output from the ring gear 44 by the planetary transmission unit 40 is transmitted to the end of the output rotating body 24 via the planetary side interlocking body 26 and the output side interlocking body 27 to be output to the output rotating body 24. To output La running mission 13.

  FIG. 4 is a longitudinal front view showing the transmission 20 with HST transmission. As shown in this figure, in the transmission 20, when the HMT clutch 55 is switched to the disengaged state and the HST clutch 60 is switched to the engaged state, the continuously variable transmission 30 receives the drive input from the input shaft 22. The speed change driving force output from the motor shaft 33a by shifting the force is transmitted to the end of the output rotating body 24 via the transmission shaft 23, the HST clutch 60, the planetary side interlocking body 26 and the output side interlocking body 27 for output. Output from the rotating body 24 to the traveling mission 13.

  When the HST transmission is set, the transmission setting clutch mechanism 70 is in a state where transmission from the input shaft 22 to the carrier 41 of the planetary transmission unit 40 is cut off, and the sun gear 42 is connected to the motor shaft 33 a via the transmission shaft 23. Since the ring gear 44 is in a state of being linked to the motor shaft 33a via the planetary side linkage body 26, the clutch body 61, the sun gear 42, and the transmission shaft 23, the ring gear 44 is linked to the motor shaft 33a. The sun gear 42, the carrier 41, and the ring gear 44 of the planetary transmission unit 40 are rotated integrally with the motor shaft 33a, and the transmission 20 does not cause the planetary gear 43 to rotate in HST transmission, that is, the sun gear 42 and the planetary gear. Without causing relative rotation of the gear 43 and relative rotation of the planetary gear 43 and the ring gear 44, the motor shaft 33a of the continuously variable transmission unit 30 can be The transmitted to the output rotor 24.

  FIG. 6 is a graph (speed diagram) showing output characteristics of the transmission 20. The vertical axis of this graph is a speed line indicating the rotational speed of the output rotating body 24. The horizontal axis of this graph passes through the position where the rotational speed of the vertical axis is zero “0”, and is an operation position line L indicating the swash plate position of the hydraulic pump 32 in the continuously variable transmission 30. “N” in the operation position line L is a neutral position of the swash plate 32b that brings the continuously variable transmission 30 to a neutral state. “A” on the operation position line L is a set forward high speed position set as the fastest speed position on the forward side of the swash plate 32b for switching between setting of HST transmission and HMT transmission in no-load drive. “+ Max” of the operation position line L is the actual forward maximum high-speed position of the continuously variable transmission 30, and when the continuously variable transmission 30 is shifted to the operation limit on the forward high speed side, the swash plate 32 b of the hydraulic pump 32. Is the swash plate angle position actually generated. The set forward high speed position “a” is an actual forward movement in order to maintain speed continuity at the point where the HST transmission and the HMT transmission are switched in a simple configuration in which the rotation of the motor shaft 33a is input to the planetary terminal without increasing or decreasing. It is set to a position before the maximum speed position “+ max”. “−max” of the operation position line L is a set reverse high speed position set as the maximum reverse speed position on the reverse side of the swash plate 32b operated by the shift control. The set reverse high speed position “−max” is set to the same position as the swash plate angular position actually generated in the swash plate 32b of the hydraulic pump 32 when the continuously variable transmission 30 is changed to the reverse high speed operation limit. It is.

  The shift line S shown in FIG. 6 indicates the rotational speed of the output rotating body 24 when the transmission transmission 20 is shifted by HST transmission in a state where the engine 8 is accelerator-set so as to output a set constant speed driving force. HST shift line (hereinafter abbreviated as HST shift line S) showing the change of the shift line M, and the shift line M is a shift transmission in a state where the engine 8 is accelerator-set so as to output a set driving force at a constant speed. This is an HMT shift line (hereinafter abbreviated as HMT shift line M) indicating a change in the rotational speed of the output rotating body 24 when the motive 20 is shifted by HMT transmission.

  As shown in FIG. 6, in the state where the HMT clutch 55 is controlled to be switched off, the HST clutch 60 is controlled to be switched on and the HST transmission is set, and the setting of the HST transmission is maintained, the continuously variable transmission unit 30 is shifted from the neutral position “n” toward the set forward high speed position “a”, so that the rotational speed of the output rotating body 24 moves from zero “0” to the forward side along the forward travel area SF of the HST shift line S. When the continuously variable transmission 30 reaches the set forward high speed position “a”, the rotational speed of the output rotating body 24 becomes the first forward intermediate speed “V1”.

  When the continuously variable transmission 30 reaches the set forward high speed position “a”, the HMT clutch 55 is controlled to be switched from the disengaged state to the engaged state, and the HST clutch 60 is controlled to be switched from the engaged state to the disengaged state to change to HST transmission. In a state where the HMT transmission is set and the setting of the HMT transmission is maintained, the continuously variable transmission unit 30 is shifted from the set forward high speed position “a” to the neutral position “n”, thereby When the rotational speed increases steplessly from the first forward intermediate speed “V1” along the low speed region ML of the HMT shift line M and the continuously variable transmission 30 reaches the neutral position “n”, the output rotation The rotation speed of the body 24 becomes the second forward intermediate speed “V2”. In the state where the setting of the HMT transmission is maintained, the rotation speed of the output rotating body 24 is set to the second speed by changing the speed of the continuously variable transmission 30 from the neutral position “n” toward the set reverse high speed position “−max”. When the continuously variable transmission section 30 reaches the set reverse high speed position “−max”, the output rotating body 24 increases steplessly along the high speed range MH of the HMT shift line M from the forward intermediate speed “V2”. Is the maximum forward speed “V3”.

  In the state where the setting of the HST transmission is maintained, the rotation speed of the output rotating body 24 is reduced to zero by operating the continuously variable transmission 30 from the neutral position “n” toward the set reverse high speed position “−max”. When the continuously variable transmission unit 30 reaches the set reverse high speed position “−max”, the speed of the output rotating body 24 rotates. The speed becomes the reverse maximum speed “VR”.

  In a shift state corresponding to the low speed range ML of the HMT shift line M so that the driving force output in the shift state corresponding to the high speed range MH of the HMT shift line M becomes a driving force having a rotational speed suitable for traveling. Further, the driving force input from the engine 8 is adopted while adopting the continuously variable transmission unit 30 in which the discharge capacity of the hydraulic pump 32 is as small as possible so that the output driving force becomes a driving force having a rotation speed suitable for work travel. The inclination angle B of the HMT shift line M with respect to the operation position line L is set as follows so that the loss associated with the shift can be reduced as much as possible to obtain the driving force after the shift.

  The shift line extension line ME shown in FIG. 6 is obtained by extending the HMT shift line M toward the operation position line L, and the position “P” on the operation position line L indicates the shift line extension line ME and the operation position line. This is the intersection position where L intersects. It is assumed that the swash plate 32b of the hydraulic pump 32 of the continuously variable transmission unit 30 can be tilted to the crossing position “P” beyond the actual forward maximum high-speed position “+ max” as the maximum forward tilt position where the tilting can be actually performed. The value of the virtual inclination angle that the swash plate 32b has when the tilt operation is performed to the intersection position “P” is “N”, and the continuously variable transmission unit 30 that has been shifted to the actual forward maximum high speed position “+ max”. When the value of the actual maximum swash plate angle actually generated in the hydraulic pump 32 is “X”, the HMT shift line M is set to an inclination angle corresponding to N being twice X (N / X = 2.0). An inclination angle B with respect to the operation position line L is set. The setting of N / X = 2.0 depends on the setting of the discharge capacity of the hydraulic pump 32 and the setting of the gear transmission ratio in the planetary transmission unit 40 and the mechanical transmission unit other than the planetary transmission unit 40.

  The inclination angle B of the HMT shift line M with respect to the operation position line L is the rotational speed of the output rotating body 24 at the first forward intermediate speed “V1” when the rotational speed of the output rotating body 24 at the maximum forward speed “V3”. The inclination angle is set to be twice or more.

The setting of N / X = 2.0 is based on the ground explained below.
When the output rotation of the continuously variable transmission unit 30 is zero and the output rotational speed is V2, all power is output without passing through the continuously variable transmission unit 30. At the position (P) of the virtual swash plate angle at which the output rotation is zero, the power at the output rotation speed V2 is returned to the drive side through the continuously variable transmission 30 and the output becomes zero. That is, the mechanical transmission force that does not pass through continuously variable transmission 30 is balanced with the power of continuously variable transmission 30 (hereinafter referred to as HST power). Actually, since the position (P) of the virtual swash plate angle is a virtual position, considering the actual maximum inclination angle X = 1 at the actual forward maximum speed position “+ max” of the continuously variable transmission unit 30, the HST power is Since the rotational speed is 1 / N, it is 1 / N times the mechanical transmission power that does not pass through the continuously variable transmission 30.

If the mechanical efficiency is KM with mechanical transmission power and KH with power passing through the continuously variable transmission 30, the output power is constant mechanical power ± HST power, and the total efficiency exhibited by the transmission 20 is:
When the continuously variable transmission 30 is in the neutral position “n”, (1 + 0 × 1 / N) / (1 / KM + 0 × 1 / N / KH) = KM is calculated,
If the continuously variable transmission 30 is at the set reverse high speed position “−max”, it is calculated as (1 + 1 / N) / (1 / KM + 1 / N / KH) = KM · KH (N + 1) / (KM + KH · N)
When the continuously variable transmission 30 is at the actual forward maximum high speed position “+ max”, (1-1 / N) / (1 / KM−1 / N · KH) = KM (N−1) / (N−KM · KH) and the higher the efficiency, the higher the N is.

  FIG. 7 is an explanatory diagram showing the relationship between the total efficiency and the shift position when the value of N / X is changed. Here, KM = 0.95, KH = 0.7, N / X = 1.0, N / X = 2.0, and N / X = 3.0. Is shown.

  The horizontal axis shown in FIG. 7 indicates the speed change position, and the forward reverse speed position is set for the output rotational speed when the continuously variable transmission 30 is changed to an arbitrary speed change position in the forward side in HST transmission and in the HMT transmission. The ratio of the output rotation speed when the gear is shifted to “−max” is the shift position on the horizontal axis. That is, assuming that the rotational speed of the driving force output when the continuously variable transmission 30 is shifted to an arbitrary shift position in the forward side in the HST transmission and the HMT transmission is Vn / V3, the horizontal shift position is Vn / V3. It is said. A vertical line D shown in FIG. 7 is a line indicating the highest speed of HST transmission when N / X = 2.0, and indicates Vn / V3 = 0.33 (between 0.2 and 0.4). is there. A vertical line E shown in FIG. 7 is a line indicating HMT transmission when N / X = 2.0 and the speed of the swash plate neutral of the hydraulic pump 32. Vn / V3 = 0.67 (0.6 and 0) .8). Therefore, the set forward high speed position “a” of the continuously variable transmission unit 30 is a position between 0.2 and 0.4 on the horizontal axis, and the neutral position “n” of the continuously variable transmission unit 30 is on the horizontal axis. Between 0.6 and 0.8.

  The efficiency line K shown in FIG. 7 indicates the total efficiency of the continuously variable transmission unit 30. The efficiency line K1 shown in FIG. 7 shows the total efficiency estimated as N / X = 1.0, and the efficiency line K2 shows the total efficiency estimated as N / X = 2.0. The efficiency line K3 shows the total efficiency estimated as N / X = 3.0.

  Between the vertical line D and the vertical line E, the total efficiency is good when N / X = 1.0, but since the output on the high speed side is large, the loss power is large and there is a small efficiency difference. It cannot be ignored. When the loss power multiplied by the loss rate and the output power is examined, N / X = 1.8 is a minimum value. The optimum value as the loss power is wide on the side where N / X is small across N / X = 1.8, but N / X = 2.0 is the optimum value for downsizing of the continuously variable transmission unit 30. If this balance is taken and N / X = about 1.5 to 2.5, high efficiency in the high speed range is realized and the size of the continuously variable transmission 30 can be reduced to about 38%. Is done. At this time, the output rotation of the planetary transmission unit 40 in the HMT transmission can also be designed in a realistic region not exceeding 10,000 rpm. When the transmission transmission 20 unit is independent, the influence of the torque cross due to the seal of the output unit or the like can be reduced if the speed is reduced to about the number of revolutions from the drive source. This is also easy to configure realistically. In order to employ the simple transmission setting clutch mechanism 70 as described above to achieve high efficiency and downsizing of the continuously variable transmission unit 30, a setting of N / X = 1.5 to 2.5 is advantageous.

  FIG. 8 is an explanatory diagram showing the relationship between the value of N / X and the size reduction of the continuously variable transmission unit 30. The horizontal axis in FIG. 8 indicates the value of N / X. A line F shown in FIG. 8 indicates the ratio “W” of the HST power (1 / N) to the total power (1 + 1 / N). The larger the ratio “W”, the larger the continuously variable transmission unit 30 is required in which the discharge capacity of the hydraulic pump 32 is increased.

  When the driving force over a predetermined shift range is obtained by the output from the planetary transmission unit 40, the continuously variable transmission unit 30 can be made smaller than the case where it is obtained by the output from the continuously variable transmission unit 30, as shown in FIG. Line G shows the relationship between the value of N / X and the degree to which the continuously variable transmission unit 30 can be miniaturized.

  That is, if the point at which the HST transmission and the HMT transmission are switched is the actual maximum tilt position “+ max”, the maximum speed in the HMT transmission (forward maximum speed “V3”) is similar to the maximum speed in the HST transmission. (N + 1) / (N-1) = Z. Z becomes 5.0 when N / X = 1.5, becomes 3.0 when N / X = 2.0, becomes 2.3 when N / X = 2.5, and N / X = 3 If it is .0, it becomes 2.0. The value indicated by the vertical axis in FIG. 8 is a value of 1 / Z.

  As the value of Z increases, the speed change range that can be obtained by HMT transmission becomes wider, the speed change range by HST transmission can be made smaller, and the continuously variable transmission 30 can be made more compact. However, if the discharge capacity of the hydraulic pump 32 is made too small, a driving trouble such as the relief circuit opening and operating will occur. Therefore, by adopting N / X = 2.0 that expresses the intersection between the line F and the line G, the forward maximum speed “V3” and the second forward intermediate speed “V2” by HMT transmission are moved or worked. Thus, it is possible to obtain the speed change transmission 20 capable of speed change transmission while avoiding the occurrence of drive troubles in the stepless speed change portion 30 while reducing the size of the stepless speed change portion 30 while maintaining the required speed.

  FIG. 9 is a block diagram showing a speed change operating device 71 for speed changing the speed change transmission 20. As shown in this figure, the shift operation device 71 is a control device linked to the operation portions 55a and 60a of the main transmission operation portion 30a and the auxiliary transmission operation portion 30b of the continuously variable transmission portion 30, the HMT clutch 55 and the HST clutch 60. 72, a main transmission operation tool 77, a sub transmission operation tool 85, an engine speed sensor 74, a swash plate angle sensor 75, an output speed sensor 76a, and an output speed sensor 76b linked to the control device 72. .

  The main transmission operating unit 30a operates the hydraulic pump 32 by operating a main transmission actuator 32c for changing the angle of the swash plate 32b of the hydraulic pump 32 in the continuously variable transmission unit 30. The sub-transmission operation unit 30b operates the sub-transmission actuator 33c to change the angle of the swash plate 33b of the hydraulic motor 33 in the continuously variable transmission unit 30, thereby shifting the hydraulic motor 33. The main transmission actuator 32c and the auxiliary transmission actuator 33c are configured by hydraulic cylinders, and the main transmission operation unit 30a and the auxiliary transmission operation unit 30b are configured by operation valves of the hydraulic cylinder. The operation portion 55a of the HMT clutch 55 is configured by an operation valve connected to the hydraulic piston 58 via an operation oil passage formed inside the input shaft 22, and the clutch body 56 is operated by operating the hydraulic piston 58. The HMT clutch 55 is switched by performing a sliding operation. The operation portion 60a of the HST clutch 60 is configured by an operation valve connected to the oil chamber of the clutch body 61 via an operation oil passage formed inside the transmission shaft 23, and the operation of the clutch body 61 with respect to the oil chamber is performed. By supplying and discharging oil, the clutch body 61 is slid and the HST clutch 60 is switched.

  FIG. 10 is a plan view showing the operation position of the main transmission operating tool 77. As shown in FIGS. 9 and 10, the main speed change operation tool 77 is constituted by a speed change lever provided in the driving portion 2 so as to be swingable in the longitudinal direction of the traveling machine body. Is swung in a forward operation area “77F” extending forward from the vehicle body and in a backward operation area “77R” extending rearward from the neutral position “77N”. The shift operation tool 77 is linked to the control device 72 via a shift detection sensor 73 that detects an operation position of the shift operation tool 77. The shift detection sensor 73 is constituted by a rotary potentiometer in which a rotation operation shaft is interlocked with the shift operation tool 77. The shift operation tool 77 is operated to swing, thereby operating the shift detection sensor 73 to change the speed. A main shift command is output from the detection sensor 73 to the control device 72 as an electric signal.

  The auxiliary transmission operating tool 85 is constituted by a shift lever provided in the driving unit 2 so as to be swingable in the longitudinal direction of the traveling machine body, and swings between the low speed position “L” and the high speed position “H”. ing. The auxiliary transmission operation tool 85 is linked to the control device 72 via an operation position detection switch 86 that detects an operation position of the auxiliary transmission operation tool 85. When the sub-shift operating tool 85 is operated to the low speed position “L”, the operation position detecting switch 86 is actuated to the OFF side, and a low-speed sub shift command is output from the operating position detecting switch 86 by an electric signal. Output to. When the sub-shift operating tool 85 is operated to the high speed position “H”, the operation position detection switch 86 is operated to the ON side, and a high-speed sub shift command is output from the operation position detection switch 86 by an electric signal. Output to.

  The engine speed sensor 74 detects the speed of the engine 8 and outputs the detection result to the control device 72. The swash plate angle sensor 75 detects the swash plate angle of the hydraulic pump 32 of the continuously variable transmission 30 and outputs the detection result to the control device 72. The output rotation speed sensor 76 a detects the rotation speed of the output rotating body 24 as the output rotation speed of the transmission 20 and outputs the detection result to the control device 72. The output rotation speed sensor 76 b detects the rotation speed of the motor shaft 33 a as the output rotation speed of the continuously variable transmission unit 30 and outputs the detection result to the control device 72.

  The control device 72 is configured using a microcomputer, and includes a speed change control means 78, a check control means 81, a speed change swash plate angle setting means 80, and a reference swash plate angle setting means 82.

  The transmission swash plate angle setting means 80 is configured by a storage unit provided in the control device 72. As shown in FIG. 6, the transmission swash plate angle setting means 80 inputs a swash plate angle for performing switching control of setting from HST transmission to HMT transmission as a preset transmission swash plate angle “c”. Has been. The set forward high speed position “a” is set as the set speed change swash plate angle “c”.

  The reference swash plate angle setting means 82 is configured by a storage unit of the control device 72. As shown in FIG. 6, the reference swash plate angle setting means 82 sets the reference swash plate angle to the swash plate angle of the hydraulic pump 32 that is positioned on the low speed side by the set angle “d” with respect to the set speed change swash plate angle “c”. It is preset and input as “e”.

  The shift control means 78 detects the rotation speed of the accelerator-set engine 8 based on information detected by the engine rotation speed sensor 74, the detection result, the main shift command from the main shift operation tool 77, and the sub-shift. The hydraulic pump 32 and the hydraulic motor 33 are shift-controlled based on the sub-shift command from the operation tool 85, the detection information by the swash plate angle sensor 75, and the detection information by the output rotation speed sensor 76a and the output rotation speed sensor 76b. The HST clutch 60 and the HMT clutch 55 of the clutch mechanism 70 are switched and controlled.

  The shift control means 78 compares the detected swash plate angle by the swash plate angle sensor 75 with the set shift swash plate angle “c” by the shift swash plate angle setting means 80, and detects the detected swash plate angle and the set shift swash plate angle “c”. ”Is determined to be equal to each other, it is determined whether the swash plate angle sensor 75 has detected a swash plate angle equal to the set speed change swash plate angle“ c ”. When it is determined that the swash plate angle sensor 75 has detected a swash plate angle equal to the set transmission swash plate angle “c”, the speed change control means 78 controls the HST clutch 60 of the clutch mechanism 70 to be switched off, and controls the HMT clutch. 55 is switched to the on state, and the setting is switched from HST transmission to HMT transmission.

  When the low-speed sub-shift command is input from the sub-transmission operation tool 85, the shift control means 78 outputs an output speed corresponding to the main shift command from the main transmission operation tool 77. That is, that is, the main transmission operating tool so that the output speed of the output rotating body 24 of the transmission 20 changes along the HST transmission line S and the HMT transmission line M in accordance with the operation of the main transmission operation tool 77. The hydraulic pump 32 is shifted based on a main shift command from 77 and a low-speed sub-shift command from the sub-shift operating tool 85.

  When a high-speed sub-transmission command is input from the sub-transmission operation tool 85, the shift control means 78 outputs an output speed corresponding to the main transmission command from the main transmission operation tool 77. The hydraulic pump 32 is shifted based on a main shift command from the main shift operation tool 77 and a high-speed sub-shift command from the sub-shift operation tool 85 so that the output speed is further increased.

  The check control means 81 is detected information by the swash plate angle sensor 75, setting information of HST transmission and HMT transmission by the shift control means 78, setting information by the reference swash plate angle setting means 82, and setting by the transmission swash plate angle setting means 80. Based on the information, the transmission state of the transmission 20 is detected, and based on the detection result, the shift control unit 78 is switched between a check production state and a check release state.

  The check control means 81 increases the combined driving force output by the shift operation to the high speed side in the reverse speed range of the continuously variable transmission 30 when the transmission 20 is set to HST transmission, and further continuously variable. When it is detected that the composite drive force output by the speed change operation to the low speed side in the reverse speed range of the unit 30 is in the reverse transmission state to decelerate, the shift control means 78 is switched to the state in which the check is released. 78 is allowed to control the auxiliary transmission actuator 33c to the high speed side.

  The check control means 81 is a high-speed side between the neutral position “n” and the reference swash plate angle “e” in the forward transmission range of the continuously variable transmission 30 when the transmission 20 is set to HST transmission. The combined driving force output by the shifting operation to is increased, and further, toward the low speed side between the neutral position “n” and the reference swash plate angle “e” in the forward shift range of the continuously variable transmission 30. When it is detected that the first forward transmission state that decelerates the combined drive force output by the shift operation is detected, the shift control unit 78 switches to a state in which the check is released, and the shift control unit 78 moves to the high speed side of the sub-shift actuator 33c. Allow control.

  The check control means 81 is configured so that the transmission 20 is set to HST transmission and the reference swash plate angle “e” in the forward shift range of the continuously variable transmission 30 and the set transmission swash plate angle “c”. The combined driving force output by the shifting operation to the high speed side is increased, and further, between the reference swash plate angle “e” and the set transmission swash plate angle “c” in the forward shift range of the continuously variable transmission 30. When it is detected that the combined driving force output by the shifting operation to the low speed side is decelerated in the second forward transmission state, the shift control unit 78 is switched to a state for checking, and the sub-shift by the shift control unit 78 is performed. The control to the high speed side of the actuator 33c is restrained.

  The check control means 81 decelerates the combined driving force that is output by the shifting operation to the high speed side in the forward transmission range of the continuously variable transmission 30 when the transmission 20 is set to HMT transmission, and further the continuously variable transmission When it is detected that the composite drive force output by the speed change operation to the low speed side in the 30 forward shift range is in the third forward transmission state, the shift control means 78 is switched to the check preparation state, Control of the auxiliary transmission actuator 33c to the high speed side by the control means 78 is restrained.

  The restraint control means 81 increases the combined driving force output by the shift operation to the high speed side in the reverse shift range of the continuously variable transmission 30 when the transmission 20 is set to HMT transmission, and further continuously variable. When it is detected that the composite drive force output by the speed change operation to the low speed side in the reverse speed range of the unit 30 is in the fourth forward transmission state, the shift control means 78 is switched to the state in which the check is released. Control by the control means 78 to the high speed side of the auxiliary transmission actuator 33c is permitted.

  That is, the check control unit 81 causes the sub-shift by the hydraulic motor 33 to function when the output of the continuously variable transmission unit 30 is in the same rotational direction as the output of the planetary transmission unit 40. When there are a plurality of speed ranges for HMT transmission, the restraint control means 81 and the shift control means 78 are configured to function as follows. That is, the speed range of the HMT transmission on the low speed side (n-th stage) in the process of increasing the speed by the main transmission operation tool 77 after switching the auxiliary transmission operation tool 85 from the low speed position “L” to the high speed position “H”. Is switched to the speed range (n + 1 stage) of the HMT transmission on the high speed side, the swash plate position to be switched is set near the point where the speed line of the nth stage and the n + 1 stage of the auxiliary transmission high speed stage intersect. When the sub-shift is switched at the position of the pump swash plate that is tilted deeper than the point at which the speed lines intersect, the motor swash plate is not tilted, and the pump swash plate is tilted by the speed increase by the motor. When the output of the continuously variable transmission unit 30 is in the direction of rotation opposite to the output of the planetary transmission unit 40, the check control unit 81 causes the sub-shift by the hydraulic pump 32 to function without performing the sub-shift by the hydraulic motor 33. As a result of tilting the pump swash plate, when the swash plate neutral of the continuously variable transmission 30 is exceeded, the motor sub-shift is switched near the pump swash plate neutral.

  When the shift control means 78 receives a high-speed sub-shift command from the sub-shift operating tool 85 in a state where the check control means 81 receives the check-making, the shift control means 78 sets the output speed corresponding to the main shift command of the transmission 20 to the sub-shift command. The hydraulic pump 32 is shift-controlled to the high-speed side based on the main shift command and the high-speed sub-shift command so as to increase the speed. That is, as indicated by an arrow “I” in FIG. 6, the shift control means 78 has displaced the swash plate 32 b of the hydraulic pump 32 by a set angle to the high speed side from the swash plate angular position “f” corresponding to the main shift command. The hydraulic pump 32 is sub-shift controlled to the high speed side so as to tilt to the swash plate angular position “a”. Alternatively, as indicated by an arrow “B” in FIG. 6, the speed change control means 78 causes the swash plate 32 b of the hydraulic pump 32 to be displaced by a set angle to the low speed side from the swash plate angular position “g” corresponding to the main speed change command. The hydraulic pump 32 is sub-shift controlled to the low speed side so as to tilt to the swash plate angular position “h”. The set angle in these cases is the same or substantially the same speed increase as the output of the transmission 20 is increased by sub-shifting the hydraulic motor 33 to the high speed side based on the sub-shift command on the high speed side. A swash plate angle corresponding to generating a speed increase of one minute at the output of the transmission 20 is set.

  Accordingly, the engine 8 is accelerator-set so as to output a driving force at a constant rotational speed, and the main transmission operating tool 77 is moved over the reverse operation range [77R], the neutral position “77N”, and the forward operation range “77F”. By operating the auxiliary transmission operating tool 85 to switch between the low speed position “L” and the high speed position “H”, the transmission control means 78 switches the transmission 20 to HST transmission and HMT transmission for setting. Control and shift control of the hydraulic pump 32 and the hydraulic motor 33 can be performed to switch the traveling machine body between the forward side and the backward side and to run while stopping at the forward side and the backward side.

  That is, when the main transmission operating tool 77 is operated to the neutral position [77N], the reverse operation area “77R” and the low speed area “77FL” of the forward operation area “77F”, the main transmission command from the main transmission operation tool 77 and The transmission 20 is set to HST transmission by switching control of the HMT clutch 55 and the HST clutch 60 of the transmission control unit 78 based on the setting information by the transmission swash plate angle setting unit 80. When the main transmission operation tool 77 is operated to the middle speed region “77FM” and the high speed region “77FH” of the forward operation region “77F”, the main transmission command and the transmission swash plate angle setting means 80 from the main transmission operation device 77 are displayed. The transmission transmission 20 is set to HMT transmission by switching control of the HMT clutch 55 and the HST clutch 60 of the transmission control means 78 based on the setting information.

  When the main transmission operation tool 77 is operated to the neutral position “77N”, the transmission control means 78 operates the swash plate 32b of the hydraulic pump 32 to the neutral position “n” based on the main transmission command from the main transmission operation tool 77, The continuously variable transmission unit 30 becomes neutral and the transmission 20 stops output.

  When the main transmission operation tool 77 is operated in the low speed region [77FL] of the forward operation region “77F” in a state where the auxiliary transmission operation device 85 is operated to the low speed position “L”, the transmission control unit 78 causes the main transmission operation device 77 to operate. The swash plate 32b of the hydraulic pump 32 is tilted on the forward side from the neutral position “n” based on the main shift command from, the low-speed sub-shift command from the sub-shift operating tool 85, and the information detected by the output rotation speed sensor 76a. The driving force output from the transmission 20 shifts along the forward travel area SF of the HST shift line S.

  When the main transmission operation tool 77 is operated in the middle speed region [77FM] and the high speed region “77FH” of the forward operation region “77F” with the auxiliary transmission operation device 85 being operated to the low speed position “L”, the shift control is performed. The means 78 moves the swash plate 32b of the hydraulic pump 32 forward and backward based on the main transmission command from the main transmission operating tool 77, the low-speed auxiliary transmission command from the auxiliary transmission operating tool 85, and the detection information by the output rotational speed sensor 76a. The driving force output from the transmission 20 is shifted along the low speed range ML and the high speed range MH of the HMT shift line M.

  When the main transmission operating tool 77 is operated in the low speed region “77FL” of the forward operation area [77F], if the auxiliary transmission operating tool 85 is operated to the high speed position “H”, the transmission control means 78 causes the hydraulic pump 32 to operate. When the gear shift operation is performed between the neutral position “n” and the reference swash plate angle “e”, the check control means 81 is in the release state, and the shift control means 78 performs the sub-shift operation of the hydraulic motor 33 to the high speed side. The driving force output by the transmission 20 is shifted along the forward travel area SAF of the HST shift line SA of the sub shift.

  When the main transmission operating tool 77 is operated in the low speed region “77FL” of the forward operation area [77F], even if the auxiliary transmission operating tool 85 is operated to the high speed position “H”, the speed change control means 78 is the hydraulic pump. When the speed change operation is performed between the neutral position “n” and the reference swash plate angle “e”, the check control means 81 is switched to a check production state, and the speed change control means 78 is used for the high speed operation of the hydraulic motor 33. Sub-shift control to the side is not performed. In this case, the shift control means 78 performs shift control to the high speed side of the hydraulic pump 32 as indicated by an arrow “I” in FIG. 6, and the driving force output from the shift transmission 20 is the forward range of the HST shift line S. The speed is changed along the SF, and the driving force is higher than the speed corresponding to the operation position of the main transmission operation tool 77 when the auxiliary transmission operation tool 85 is operated to the low speed position “L”.

  With the main transmission operation tool 77 positioned at the operation position in the low speed region “77FL” of the forward operation area “77F”, the sub transmission operation tool 85 is switched from the low speed position “L” to the high speed position “H”. In this case, if the swash plate 32b of the hydraulic pump 32 is located at the swash plate angle position between the neutral position “n” and the reference swash plate angle “e”, the check control means 81 is in the check release state. Then, the shift control means 78 controls the hydraulic motor 33 to the high speed side, and the driving force output from the transmission 20 is changed to the driving force at the speed on the advance area SAF of the HST shift line SA of the sub shift. Become.

  When the main speed changer 77 is operated in the middle speed range “77FM” of the forward operation range [77F], even if the auxiliary speed changer 85 is operated to the high speed position “H”, the check control means 81 is suppressed. The shift control means 78 does not perform sub shift control to the high speed side of the hydraulic motor 33. In this case, the shift control means 78 performs sub-shift control to the high speed side of the hydraulic pump 32 as indicated by an arrow “B” in FIG. 6, for example, and the driving force output from the shift transmission 20 is applied to the HMT shift line M. The speed is changed along the low speed region ML, and the driving force is higher than the speed corresponding to the operation position of the main transmission operation tool 77 when the auxiliary transmission operation tool 85 is operated to the low speed position “L”.

  When the main transmission operation tool 77 is positioned at the operation position in the middle speed region “77FM” of the forward operation area “77F”, the sub transmission operation tool 85 is switched from the low speed position “L” to the high speed position “H”. Even so, the check control means 81 is in a check production state, and the shift control means 78 does not perform sub-shift control to the high speed side of the hydraulic motor 33. In this case, the shift control means 78 performs sub-shift control to the high speed side of the hydraulic pump 32 as indicated by an arrow “B” in FIG. 6, for example, and the driving force output from the shift transmission 20 is applied to the HMT shift line M. The speed is changed along the low speed region ML, and the driving force is higher than the speed corresponding to the operation position of the main transmission operation tool 77 when the auxiliary transmission operation tool 85 is operated to the low speed position “L”.

  When the main transmission operating tool 77 is operated in the high speed region “77FH” of the forward operation area [77F], if the auxiliary transmission operating tool 85 is operated to the high speed position “H”, the checking control means 81 releases the checking. In this state, the shift control means 78 sub-shifts the hydraulic motor 33 to the high speed side, and the driving force output from the shift transmission 20 shifts along the HMT shift line MA of the sub-shift.

  With the main transmission operation tool 77 positioned at the operation position in the high speed area “77FH” of the forward operation area “77F”, the sub transmission operation tool 85 is switched from the low speed position “L” to the high speed position “H”. In this case, the restraint control means 81 is in a restraint release state, the shift control means 78 performs sub-shift control of the hydraulic motor 33 to the high speed side, and the driving force output from the shift transmission 20 is the HMT shift line for the sub-shift. The driving force is at the speed on the line of MA.

  When the main transmission operation tool 77 is operated in the reverse operation region “77R” in a state where the auxiliary transmission operation tool 85 is operated to the low speed position “L”, the transmission control means 78 causes the main transmission command from the main transmission operation tool 77 to Based on the low-speed sub-shift command from the shift operation tool 85 and information detected by the output rotational speed sensor 76a, the swash plate 32b of the hydraulic pump 32 is tilted backward from the neutral position “n”, and the transmission 20 is output. The driving force is changed along the reverse range SR of the HST shift line S.

  When operating the main transmission operation tool 77 in the reverse operation range [77R], if the auxiliary transmission operation tool 85 is operated to the high speed position “H”, the check control means 81 is in the check release state, and the shift control means. 78 sub-shifts the hydraulic motor 33 to the high speed side, and the driving force output from the transmission 20 shifts along the reverse travel area SAR of the HST shift line SA of the sub-shift.

  When the auxiliary transmission operation tool 85 is switched from the low speed position “L” to the high speed position “H” in a state where the main transmission operation tool 77 is positioned at the operation position in the reverse operation area “77R”, the check control means 81 Is in a state in which the control is released, the shift control means 78 controls the hydraulic motor 33 to the high speed side, and the driving force output from the transmission 20 is on the reverse shift range SAR line of the HST shift line SA of the sub shift. It becomes the driving force of the speed which got on.

  In the shift range A shown in FIG. 6, the shift control means 78 can only generate the control target speed by only the shift control of the hydraulic pump 32, and only the shift control of the hydraulic pump 32 even if there is a high-speed sub-shift command. The speed increase control by the sub shift control of the hydraulic motor 33 is not performed.

[Another Example]
(1) In the above-described embodiment, an example in which only one stage of the HMT transmission speed range is provided has been described. However, the embodiment may be configured to have two or more speed ranges of HMT transmission.

(2) In the above-described embodiment, an example in which the clutch mechanism 70 is configured by the bite type HMT clutch 55 and the HST clutch 60 is shown, but the clutch mechanism 70 is configured by the friction type HMT clutch 55 and the HST clutch 60. May be implemented.

  INDUSTRIAL APPLICABILITY The present invention can be used for various agricultural machines such as a rice transplanter and a transporter in addition to a combine.

DESCRIPTION OF SYMBOLS 1 Traveling device 8 Engine 20 Transmission transmission 30 Continuously variable transmission part 32 Hydraulic pump 33 Hydraulic motor 40 Planetary transmission part 70 Clutch mechanism 75 Swash plate angle sensor 77 Main transmission operation tool 78 Shift control means 81 Check control means 82 Reference swash plate angle Setting means c Setting shift swash plate angle e Reference swash plate angle S HST shift line

Claims (3)

A hydrostatic continuously variable transmission that operates to input and shift the driving force from the engine and shift the output driving force along the HST shift line, and the driving force from the engine and the continuously variable transmission. A shift transmission having a planetary transmission that acts so as to shift the combined drive force from the variable speed drive along the HMT shift line by the shift of the continuously variable transmission;
HST setting state for setting the HST transmission for outputting the shift driving force output from the continuously variable transmission unit to the traveling device, and the HMT setting state for setting the HMT transmission for outputting the combined driving force output by the planetary transmission unit to the traveling device. A clutch mechanism that can be switched between and is provided in the transmission.
A traveling transmission device for an agricultural machine comprising shift control means for performing shift control of the hydraulic pump that constitutes the continuously variable transmission unit based on a main shift command from a main shift operation tool and switching and controlling the clutch mechanism,
The hydraulic motor constituting the continuously variable transmission unit is configured in a variable displacement type,
A sub-shift operating tool that is manually maneuverable and issues a sub-shift command, and a sub-shift actuator that performs a swash plate angle change operation of the hydraulic motor;
The shift control means is configured to control the sub-shift actuator to shift the hydraulic motor to a high speed side based on the sub-shift command;
The transmission transmission is set to the HMT transmission, and the combined driving force output to the traveling device is increased by a shift operation to the high speed side in the reverse transmission range of the continuously variable transmission, and the continuously variable transmission When in the transmission state in which the combined driving force output to the traveling device is decelerated by the shifting operation to the low speed side in the reverse shifting range, the restraint is released so as to allow the control of the auxiliary shifting actuator by the shifting control means, The transmission gear is set to the HMT transmission, and the combined driving force output to the traveling device is increased by a shift operation to the low speed side in the forward shift range of the continuously variable transmission, and further, the continuously variable transmission of the continuously variable transmission If the combined drive force output to the traveling device is decelerated by a shift operation to the high speed side in the forward shift range, the control of the sub-shift actuator by the shift control means is stopped. Cormorants supervision of agricultural machines are provided with a check control means acting traveling transmission apparatus. Reference swash plate angle setting means is provided for setting a swash plate angle of the hydraulic pump positioned at a low speed side by a set angle as a reference swash plate angle with respect to a swash plate angle for performing switching control of setting from HST transmission to HMT transmission. ,
When the speed change transmission is set to the HST transmission and the swash plate angle of the hydraulic pump is lower than the reference swash plate angle, the check control means releases the check, and the speed change transmission moves to the HST transmission. The traveling transmission device for an agricultural working machine according to claim 1, wherein when the swash plate angle of the hydraulic pump is set at a higher speed side than the reference swash plate angle, the check control means is used for checking production.   In a state where the shift control means is subjected to checking by the check control means, the main shift command and the main shift command and the sub-shift command so as to increase the output speed according to the main shift command of the transmission. The traveling transmission device for an agricultural machine according to claim 1 or 2, wherein the hydraulic pump is shift-controlled based on a sub-shift command.

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