JP2006077811A - Transmission structure for traveling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively use hydraulic continuously variable transmission and high-speed transmission not through a hydraulic transmission in a simple structure. <P>SOLUTION: A transmission switching mechanism 10 is interposed in a transmission system between a main transmission 8 including the hydraulic continuously variable transmission and a traveling device 1, thereby switching and shifting a shift member S2 provided in the transmission switching mechanism 10 between a first transmission position to engage and interlock with a shifting rotation transmitter G9 driven by the power output from the main transmission 8 and a second transmission position to engage and interlock with a constant speed rotation transmitter G10 driven by predetermined high-speed power not through the main transmission 8. With the shift member S2 switched to the first transmission position, the traveling device 1 is driven at continuously variable speed by the output of the main transmission 8, and with the shift member S2 switched to the second transmission position, the traveling device 1 is driven at constant high speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a traveling transmission structure used in a farm work machine such as a combine or a rice transplanter.

  A hydraulic continuously variable transmission (HST) is often used for a traveling transmission structure of an agricultural machine, and a gear-type sub-transmission mechanism is used to output a shift output from the hydraulic continuously variable transmission to ensure a traveling transmission width. In many cases, a transmission structure that shifts gears to two or three speeds and transmits them to the traveling device is employed.

The hydraulic continuously variable transmission is excellent in speed change operability and exhibits excellent maneuverability capable of starting at zero speed and traveling at a low speed, such as a gear transmission or a belt type continuously variable transmission. The transmission efficiency is lower than that of a mechanical transmission. Therefore, a transmission structure has been proposed in which the traveling device is driven with a predetermined high-speed power without using a hydraulic continuously variable transmission during high-speed traveling (see, for example, Patent Document 1).
Japanese Patent No. 3375371

  The proposed transmission structure is capable of high-speed traveling with high transmission efficiency while taking advantage of the hydraulic continuously variable transmission, but there is room for improvement in terms of structure. That is, in the above transmission structure, there are a multi-plate transmission clutch that is hydraulically operated in each of an input system and an output system of the hydraulic continuously variable transmission and a high-speed transmission system independent of the hydraulic continuously variable transmission. Intervene. In the transmission range of the hydraulic continuously variable transmission, the input and output transmission clutches are engaged and the transmission clutch of the high-speed transmission system is disengaged. At high speeds exceeding the transmission range of the hydraulic continuously variable transmission, the input and output systems The high-speed transmission system and the high-speed transmission clutch are included, and many transmission clutches and a hydraulic control circuit that synchronizes the transmission clutch are required. The structure is complicated and the number of parts is high. It was.

  The present invention has been made paying attention to such points, and it is possible to select and use a hydraulic continuously variable transmission and a high-speed transmission not via a hydraulic transmission with a simple structure. The main purpose.

According to a first aspect of the present invention, a transmission switching mechanism is interposed in a transmission system between a main transmission including a hydraulic continuously variable transmission and a traveling device, and a shift member provided in the transmission switching mechanism is provided from the main transmission. The first transmission position interlocked with the variable speed rotation transmission driven by the output power and the constant speed rotation transmission driven by the predetermined high speed power not via the main transmission are interlocked with each other. It can be switched to the second transmission position and shiftable,
In the state where the shift member is switched to the first transmission position, the traveling device is continuously driven by the output of the main transmission, and in the state where the shift member is switched to the second transmission position, the traveling device is driven at a predetermined high speed. It is configured to be driven at a constant speed.

  According to the above configuration, by shifting the shift member to the first transmission position, the traveling device is continuously driven with the output of the main transmission, and the transmission from the constant-speed rotating transmission is cut off in synchronization with this. Can do. On the contrary, by switching the shift member to the second transmission position, transmission is performed from the constant speed rotating transmission body to drive the traveling device at a predetermined high speed, and in synchronization with this, the main transmission and the traveling The transmission with the device is cut off and the main transmission is in a no-load state.

  Therefore, according to the first aspect of the present invention, a complicated structure and clutch control means for controlling on / off of a transmission structure that selects and uses high-speed transmission without using a hydraulic transmission in synchronization with a plurality of transmission clutches are required. It can be provided easily and inexpensively.

According to a second invention, in the first invention,
The constant speed rotary transmission is linked and connected to an input shaft that drives a variable displacement pump provided in the main transmission at a constant speed.

  According to the above configuration, the number of parts can be reduced by using the single transmission shaft as the input shaft of the hydraulic continuously variable transmission and the input shaft of the constant speed transmission system. To encourage.

According to a third invention, in the first or second invention,
The variable speed rotation transmission body and the constant speed rotation transmission body are arranged so as to be freely rotatable on a transmission shaft linked to the traveling device, and are positioned between the transmission speed rotation transmission body and the constant speed rotation transmission body. The shift member arranged in such a manner is mounted on the transmission shaft so as to be able to shift and transmit rotation, and the shift member is switched between forward and reverse so as to be engaged with the variable speed rotation transmission body or the constant speed rotation transmission body from the axial direction. It is configured.

  According to the above configuration, it is possible to adopt a claw clutch structure in which the shift member is engaged with the opposite side surfaces of the variable speed rotation transmission body and the constant speed rotation transmission body using the engagement protrusion or the engagement recess, and the transmission system is switched. The structure is excellent in durability and can be easily constructed at a much lower cost than a multi-plate clutch.

  FIG. 1 shows a self-removing combine as an example of a working machine having a traveling transmission structure according to the present invention. This self-detaching combine is connected to a front portion of a traveling machine body 2 having a pair of left and right traveling devices 1 configured in a crawler type so that a cutting portion 3 having a plurality of trimming specifications swings up and down around a rear fulcrum X. In addition, the driving unit 2 has a structure in which the driving unit 4, the threshing device 5, the grain collection tank 6, and the like are mounted.

  FIG. 2 shows an outline of the transmission structure in this combine. As shown in the figure, a part of the power of the engine 7 installed horizontally below the seat of the driving unit 4 is belt-transmitted to a main transmission 8 comprising a hydraulic continuously variable transmission (HST) capable of switching between forward and reverse. In addition, another part of the power of the engine 7 is transmitted to the threshing device 5 by a belt. The transmission output of the main transmission 8 is transmitted to the left and right crawler travel devices 1 via the side clutch 12 after passing through the transmission switching mechanism 10 and the sub-gear transmission 11 in the transmission case 9. . Further, a part of the engine power input to the main transmission 8 is branched as work system power in the transmission case 9 and is shifted in two stages by the cutting transmission mechanism 13 and output from the PTO shaft 14. Is transmitted to the belt.

  The main transmission 8 uses an axial plunger type hydraulic continuously variable transmission equipped with a variable displacement pump P and a constant displacement motor M, and is driven at a constant speed by an input shaft 15. The output shaft 16 of the motor M is driven forward or backward steplessly by changing the discharge oil amount and the discharge direction by adjusting the swash plate angle.

  A traveling transmission gear G11 and a working transmission gear G12 are secured to an in-case extension 15a of the input shaft 15 in the main transmission 8. The mowing transmission mechanism 13 includes an input transmission shaft 17 having an input gear G2 meshed with the transmission gear G12, and a transmission transmission shaft 18 linked to the PTO shaft 14 via gears G3 and G4. The large and small gears G5 and G6 are fixed to the input transmission shaft 17, and the high-speed transmission gear G7 and the low-speed transmission gear G8, which are always meshed with the gears G5 and G6, are connected to the transmission transmission shaft 18. A shift member S1 that is loosely fitted to the transmission gear and that can be engaged and disengaged from the side face of the transmission gear G7 is spline-fitted to the transmission transmission shaft 18.

  Here, the transmission gear G8 for low-speed transmission is loosely fitted to the transmission transmission shaft 18 via the one-way clutch 20, so that the transmission transmission shaft 18 is allowed to rotate at a higher speed than the transmission gear G8. Yes. Therefore, as shown in FIG. 4 (a), in the "low speed" state in which the shift member S1 is disengaged from the transmission gear G7 for high speed transmission, the power transmitted to the input transmission shaft 17 is the gear G6, which is for low transmission. "High-speed" state in which the transmission member 18 is transmitted to the transmission shaft 18 through the transmission gear G8 and the one-way clutch 20, and the shift member S1 is engaged with the high-speed transmission gear G7 as shown in FIG. In this case, the transmission transmission shaft 18 rotates at a high speed in advance of the low-speed transmission transmission gear G8 that is driven to rotate, and the transmission from “low speed” to “high speed” or vice versa is performed without any interruption of transmission. Is called.

  The transmission switching mechanism 10 includes a transmission shaft 21, a pair of gears G9 and G10 loosely supported by the transmission shaft 21, and a shift member S2 that is splined to the transmission shaft 21 between both gears G9 and G10. Yes. Also, one gear (transmission rotation transmission body) G9 is meshed with an output gear G1 provided on the output shaft 16 of the main transmission 8 and is continuously driven to change speed, and the other gear (constant speed rotation transmission body). G10 is meshed with the transmission gear G11 provided at the input shaft extension 15a in the main transmission 8 and driven at a constant speed.

  According to the above configuration, as shown in FIG. 3 (a), when the shift member S2 is shifted to the first transmission position engaged with the gear G9, the output shaft 16 of the main transmission 8 is transmitted through the gears G1 and G9. In this way, the traveling device 1 is brought into a continuously variable state by the power from the main transmission 8. Further, as shown in FIG. 3B, when the shift member S2 is shifted to the second transmission position where the gear G10 is engaged, the output shaft 16 and the transmission shaft 21 are disconnected from each other and driven at a constant speed. The input shaft 15 (15a) and the transmission shaft 21 are connected to each other through transmission gears G11 and G10, whereby the traveling device 1 is driven at a constant speed without going through the main transmission 8. It is. Here, the transmission ratio of the gears G10 and G11 is set so that the traveling speed when the shift member S2 is engaged with the gear G10 is higher than the traveling speed when the main transmission 8 is shifted to the highest speed. Has been.

  As shown in FIG. 5, the shift member S2 in the transmission switching mechanism 10 is mechanically linked to the main transmission lever 22 for operating the main transmission 8, and the main transmission lever 22 is moved forward and continuously variable. By further laterally operating from the continuously variable maximum speed position a set at the high speed side limit of F to the forward maximum speed position b, the swing arm 23 is swing-operated by the main speed change lever 22, and this swing arm The shift member S2, which is linked to the wire 23, is shifted, so that a constant speed drive is performed at a high speed without the main transmission 8 as described above.

  [Other Examples]

  (1) As a means for shifting the shift member S2, the shift member S2 is shifted by a hydraulic or electric actuator in addition to mechanically interlocking and connecting to the main transmission lever 22 as described above. It is also possible to configure such that these actuators are actuated by appropriately detecting that the main transmission lever 22 has been operated to the maximum forward speed position b beyond the continuously variable maximum speed position a.

  (2) As shown in FIG. 6, the shift member of the transmission switching mechanism 10 is constituted by a shift gear SG in which the gear G9 and the gear G10 are integrated, and this shift gear (shift member) SG is used as a variable speed rotation transmission body. It is also possible to carry out in a form of directly engaging with the output gear G1 or the transmission gear G11 as a constant speed rotating transmission body.

Combine side view Schematic diagram of transmission system Cross section of transmission switching mechanism Cross section of mowing transmission mechanism Schematic plan view of the shifting operation Schematic showing the transmission system of another embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling device 8 Main transmission 10 Transmission switching mechanism 15 Input shaft 21 Transmission shaft G1 Variable speed rotation transmission body (output gear)
G9 Variable speed rotation transmission (gear)
G10 Constant speed rotating transmission (gear)
G11 Constant speed rotating transmission (transmission gear)
S2 Shift member SG Shift member (shift gear)

Claims (3)

A transmission switching mechanism is interposed in a transmission system between a main transmission including a hydraulic continuously variable transmission and a traveling apparatus, and a shift member provided in the transmission switching mechanism is driven by power output from the main transmission. A first transmission position that is engaged with the transmission transmission that is driven, and a second transmission position that is engaged with the constant speed rotation transmission driven by a predetermined high speed power without passing through the main transmission. It is configured to be switchable,
In the state where the shift member is switched to the first transmission position, the traveling device is continuously driven by the output of the main transmission, and in the state where the shift member is switched to the second transmission position, the traveling device is driven at a predetermined high speed. A traveling power transmission structure configured to be driven at a constant speed.   2. The traveling transmission structure according to claim 1, wherein the constant speed rotating transmission body is interlocked and connected to an input shaft for driving a variable displacement pump provided in the main transmission at a constant speed.   The variable speed rotation transmission body and the constant speed rotation transmission body are arranged so as to be freely rotatable on a transmission shaft linked to the traveling device, and are positioned between the transmission speed rotation transmission body and the constant speed rotation transmission body. The shift member arranged in such a manner is mounted on the transmission shaft so as to be able to shift and transmit rotation, and the shift member is switched between forward and reverse so as to be engaged with the variable speed rotation transmission body or the constant speed rotation transmission body from the axial direction. The power transmission structure according to claim 1 or 2, wherein the power transmission structure is configured.

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