JP3380684B2 - Adjustment device for continuously variable transmission mechanism in work vehicle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjusting device for a continuously variable transmission mechanism in a work vehicle equipped with a hydraulic continuously variable transmission such as a combine.

[0002]

2. Description of the Related Art Conventional work vehicles, for example combine harvesters, are constructed so as to travel by transmitting a driving force from an engine to a traveling device via a transmission. The speed is changed by controlling the transmission by the swinging movement of the. The transmission equipped with a hydraulic continuously variable transmission (HST) is an operating shaft (trunnion shaft) that shifts the main gearshift lever and the HST.
The HST is switched to a speed change ratio corresponding to the swing setting position of the main speed change lever by connecting the spaces with a connecting tool, and the traveling speed of the machine body is continuously changed.

[0003]

However, the above-mentioned connecting member undergoes expansion and contraction changes due to the swinging motion of the main speed change lever, the load on the main speed change lever, temperature changes, etc., and the continuously variable gear corresponding to the set position of the main speed change lever. There is a problem that an error may occur in the gear ratio of the transmission or the neutral position of the main transmission lever.

[0004]

An adjusting device for a continuously variable transmission mechanism in a work vehicle includes a hydraulic continuously variable transmission device 17 for continuously changing the rotational driving force of an engine, and a shift operation of the hydraulic continuously variable transmission device 17. And a connecting tool 33 for connecting the speed change lever 14 and the operating shaft 34 of the hydraulic continuously variable transmission 17 to each other, and the speed change lever 14 and the hydraulic continuously variable transmission by the connecting tool 33. An adjusting portion 46 for adjusting the connection relation of 17 is provided on the connecting tool 33 side, and the speed change ratio of the hydraulic continuously variable transmission 17 is set steplessly according to the swing angle of the speed change lever 14 to set the machine traveling speed steplessly. In a work vehicle that shifts gears to, the position detecting means for detecting the neutral position of the speed change lever 14, the output detecting means 15 for detecting the output rotation of the hydraulic continuously variable transmission 17, and the drive gear for operating the adjusting portion 46. And Chueta 49, a control device for controlling the drive actuator 49 by the detection information of the position detecting means and the output detecting unit 15 and (56) is provided, in the neutral position of the shift lever (14), a hydraulic stepless
Connect the transmission (17) so that it is in neutral.
The controller (56) automatically adjusts the length of the tie (33)
The first feature is to control .

Further, the position detecting means is a gear shift lever 14
A plurality of detecting means 18, 3 that operate in accordance with the swing position of the
0, the control device 56 detects the neutral position of the speed change lever 14 by the position detecting means and the output detecting means 15, and detects a plurality of detecting means 1 of the position detecting means.
A second feature is that the control device is provided with a determination system for confirming the neutral position of the speed change lever 14 by the operation of at least two detecting means of the output detecting means 15 and the output detecting means 15.

Further, the control device 56 is provided with a protection system which detects deceleration traveling or stoppage of the vehicle body 3 when the gearshift lever 14 is in the neutral position and deactivates the drive actuator 49 during deceleration traveling. It has the third feature.

[0007]

FIG. 1 is a perspective view of a combine to which the present invention is applied. The machine body frame 1 is supported by the traveling device 2, and the machine body 3 is formed on the machine body frame 1. In addition, a pretreatment unit 4 is attached to the front of the machine body 3 so as to be vertically movable and swingable with respect to the machine body 3.
A threshing unit (not shown) is provided on the left rear of the
By a carrier (not shown) provided between the threshing unit and the pretreatment unit 4, the grain culms cut by the pretreatment unit 4 are conveyed to the threshing unit.

On the other hand, a driver's seat 7 having a seat 6 and the like is installed on the upper right side of the machine body 3, and as shown in FIG. 2, a front operation panel 8 is provided in front of and on the left side of the seat 6.
And a side operation panel 9 are provided. An auxiliary shift lever guide 11 and a main shift lever guide 12 are provided on the side operation panel 9, and the auxiliary shift lever guide 1
A sub-transmission lever 13 is provided so as to project from No. 1, and a main transmission lever 14 is provided so as to project from the main transmission lever guide 12.

On the other hand, in the body 3 below the driver's seat 7, FIG.
(A), (b) and FIGS. 4 (a), (b) are internally provided with a transmission case 16 in which a transmission is constituted by gears and an engine (not shown). The case 16 has a hydraulic continuously variable transmission (HS) for traveling speed shifting, which continuously changes the rotational driving force of the engine and outputs it to the transmission side.
T) 17 is attached. The output side of the HST 17 is provided with a rotary encoder 15 (see FIG. 6) that detects and outputs the output rotation direction and rotation speed of the HST 17.

The HST 17 is the main transmission lever 14
Of the main transmission lever guide 12 and the auxiliary transmission gear (not shown) in the transmission are operated by the front and rear oscillation of the auxiliary transmission lever 13 along the auxiliary transmission lever guide 11. The rotational driving force of the engine is changed in speed by the operation of each of the levers 13 and 14 and transmitted to the traveling device 2, and the traveling device 2 causes the machine body 3 to travel. At this time, the traveling speed of the machine body 3 corresponds to the gear ratio of the HST 17, and the gear ratio of the HST 17 corresponds to the swing angle of the main gear shift lever 14.

That is, when the main transmission lever 14 is located at the forward transmission portion 12a of the main transmission lever guide 12 shown in FIGS. 2 and 5, the main body 3 is moved forward as the main transmission lever 14 is swung forward. The traveling speed increases steplessly, decreases steplessly as it swings backward, and the reverse transmission unit 12
When it is located at c, the vehicle body 3 travels in reverse at a speed corresponding to the swing angle of the main transmission lever 14 as described above.

When the main transmission lever 14 is located at the neutral portion 12b, the HST 17 becomes neutral and the fuselage 3 does not run. That is, the neutral portion 12b is the main shift lever 1
It is in neutral position 4 (neutral position). At this time, as shown in FIG. 5, a neutral switch which is turned on when the main transmission lever 14 is located at the neutral portion 12b on the main transmission lever guide 12 side, in other words, when the main transmission lever 14 is switched to the neutral position. 18 is provided.

Next, the connecting mechanism between the main shift lever 14 and the HST 17 will be described with reference to FIGS. The HST1 attached to the mission case 16 as described above
7, a stay 26 is erected from the upper end portion on the left side (right side in front view (FIG. 3)), and protrudes to the right side (left side in front view) in the vicinity of the substantially vertical center of the stay 26. Bracket 27 is provided. The bracket 27 is provided with a fulcrum shaft 28 protruding rightward (same as above), and an arm 29 is supported on the fulcrum shaft 28 so as to be swingable back and forth.

At this time, a boss 29a is provided at the upper end of the arm 29 in the front-rear direction, and a fitting portion 14a projecting forward is provided at the base end of the main transmission lever 14. The fitting portion 14a is fitted in the boss 29a so as to be rotatable left and right. In addition, the main shift lever 14
A spring fixing portion 31 projecting to the right is also provided at the base end portion of, and is connected to the right side surface of the arm 29 by a spring 32.

That is, the main shift lever 14 is swingable back and forth around the fulcrum shaft 28 and is swingable left and right around the fitting portion 14a. In addition, the spring 3
It is urged rightward by 2 around the fitting portion 14a. As a result, the main shift lever 14 swings back and forth and left and right along the main shift lever guide 12, that is, the forward and backward swings in the forward shift portion 12a and the reverse shift portion 12c and the left and right swings in the neutral portion 12b (the swing to the left side does not occur). It is possible to resist the biasing force of the spring 32).

On the other hand, one end of a sensing rod 21 is attached rearward from the arm 29, and the other end of the sensing rod 21 is connected to a potentiometer 30 fixedly attached to a bracket 27 via a link arm 22. Are linked together. When the main transmission lever 14 is swung in the front-back direction by this, the potentiometer 30 is operated by the sensing rod 21 and the link arm 22 in accordance with the swing angle of the main transmission lever 14, and the potentiometer 30 operates. A data value corresponding to the swing angle of 14 is output to continuously detect the swing angle of the main shift lever 14 (arm 29) in the front-rear direction, that is, the shift position of the main shift lever 14.

Below the arm 29, one end of a main speed change rod 33, which is a connecting member, which will be described later, is connected, and the other end of the main speed change rod 33 is HST1.
7 is connected to an HST trunnion 36 mounted on a swingable trunnion shaft 34 which is an operating shaft for shifting gears. With the above structure, the arm 29 is vertically swung by swinging the main shift lever 14 back and forth, and the main shift rod 33 is vertically moved by the vertical swing of the arm 29. The vertical movement of the main shift rod 33 causes the HST trunnion 36 to move. Is swung, and the trunnion shaft 34 is swung by the swing of the HST trunnion 36 to shift the HST 17.

As a result, the trunnion shaft 34 swings at an angle corresponding to the swing angle of the main transmission lever 14, so that HS
T17 is switched to a gear ratio corresponding to the swing angle of the main gearshift lever 14, the traveling device 2 operates at a speed (rotation speed) corresponding to the gear ratio of the HST 17, and the machine body 3 is moved by the traveling device 2 to the gear ratio of the HST 17. The vehicle runs at a speed corresponding to the stepless speed change. At this time, the swing angle of the main transmission lever 14, that is, the shift position of the main transmission lever 14 is continuously detected by the potentiometer 30. 3 and 4, the main gearshift lever 14 has a neutral portion 12b.
The HST 17 is in the neutral position and is in the neutral position.

A brake mechanism 35 for preventing the swinging of the arm 29 is provided between the arm 29 and the bracket 27 side, and an operation load is applied to the main shift lever 14 by the brake mechanism 35. . The braking force by the brake mechanism 35 (the operation load of the main speed change lever 14) is adjusted so that the reaction force from the HST 17 does not cause the arm 29 to swing and the set position of the main speed change lever 14 to change. ing.

The brake mechanism 35 in the present embodiment has the brake lining 3 pivotally supported by the fulcrum shaft 28.
The inner side surfaces of 8, 8 have a structure in which the arm 29 is sandwiched from the left and right. At this time, gears 37 are concentrically provided on the left and right outer surfaces of the brake linings 38 and 42, and the brake lining 3 on the fulcrum shaft 28 is provided.
A nut 39 is screwed to the right side (left side in FIG. 3) of the gear 37 of FIG. 8 via a disc spring 40 fitted on the fulcrum shaft 28. The nut 39 adjusts the force with which the disc spring 40 presses the arm 29 of the brake lining 38 to adjust the braking force of the brake mechanism 35.

Next, the structure of the main transmission rod 33 will be described. As shown in FIGS. 3A and 3B and FIGS. 4A and 4B, the main transmission rod 33 is the lever-side rod 3
3a and the rod 33b on the HST side are configured to be connected in the axial direction by a turnbuckle 46 which is a length adjusting portion. By rotating the turnbuckle 46, the rod 33a and the rod 33b move closer to or away from each other. As a result, the entire length of the main transmission rod 33 is adjusted.

In the present embodiment, the turnbuckle 46 has a structure in which a right-handed internal thread is provided on the inner peripheral surface of the upper end and a left-handed internal thread is provided on the inner peripheral surface of the lower end, and the rod 33a is provided at the end of the turnbuckle 46 side. The structure is such that a right-handed male screw is provided, and the rod 33b has a structure in which a left-handed male screw is provided at the end of the turnbuckle 46 side.
The rod 33a and the rod 33b are turnbuckles 46
It has a structure in which the upper and lower ends are concentrically screwed together. At this time, a gear 47 is integrally fixed to the outer circumference of the turnbuckle 46, and the gear 47 has an adjusting motor 49 via a reduction gear unit 48 formed by meshing a plurality of gears.
And the output gear of the adjusting motor 49.

The adjusting motor 49 and the reduction gear unit 48 are integrally attached to the drive case 51, and the drive case 51 cannot be moved up and down at a predetermined position of the turnbuckle 46 by the ring restrictor 44. It is rotatably attached in a regulated state. That is, the turnbuckle 46 is rotatable with respect to the drive case 51 integrally with the gear 47 located inside the drive case 51 depending on the mounting state of the drive case 51.

The drive case 51 is rotatably supported by a stopper shaft 53 provided upright from a mounting plate 52 integrally fixed to the rod 33b so that the drive case 51 can slide up and down. The rotation around the rod 33), that is, the rotation of the drive case 51 around the turnbuckle 46 is restricted. That is, the stopper shaft 53 serves as a regulation guide that guides the drive case 51 in the axial direction of the main transmission rod 33 and regulates the rotation around the rod 33b.

With the structure shown above, the turnbuckle 4
6 is decelerated and rotated with respect to the rods 33a and 33b via the reduction gear unit 48 by the rotation of the adjustment motor 49, and the length of the main transmission rod 33 is adjusted as described above. At this time, since the turnbuckle 46 moves up and down relatively to the rods 33a and 33b, the turnbuckle 46 moves up and down integrally with the drive case 51 using the stopper shaft 53 as a guide. That is, the length of the main transmission rod 33 is adjusted by the rotation of the turnbuckle 46 by the adjustment motor 49, which is a drive actuator.

At this time, the adjusting motor 49 is controlled by the control device 56 (see FIG. 6), which will be described later, so that the rotary encoder 15, the potentiometer 30,
The rotation is electrically controlled based on the information from the neutral switch 18, that is, the length (total length) of the main transmission rod 33 is based on the sensor (the rotary encoder 15, the potentiometer 30, the neutral switch 18) and the control device. It is regulated and controlled by 56.

Next, the structure and operation of the control device 56 will be described. As shown in FIG. 6, the control device 56 includes a microcomputer unit 57, which is an arithmetic unit, and
The neutral position (neutral portion 12b), which is the neutral position of the rotary encoder 15 and the main transmission lever 14 which are the output detecting means for detecting the output rotation of T17, is set to O.
The neutral switch 18 that detects N and OFF and the output of the potentiometer 30 that detects the predetermined output data are connected to the input side of the microcomputer unit 57, and the adjustment motor 49 is connected to the output side of the microcomputer unit 57. There is. That is, the position detecting means for detecting the neutral position of the main transmission lever 14 has two detecting means, that is, the neutral switch 18 and the potentiometer 30.

In the control device 56, the microcomputer unit 57 includes the rotary encoder 15 and the potentiometer 3.
0, data (detection information) from the neutral switch 18 and the like is processed as described later, so that the main transmission lever 1
No. 4 neutral position is detected, and H when the main transmission lever 14 is in the neutral position
The output rotation of ST17 is detected, and a predetermined rotation instruction is adjusted so that the output rotation of HST17 becomes a predetermined value when the main transmission lever 14 is in the neutral position.
Output to the side and actively adjust the length of the main transmission rod 33. In this embodiment, the main shift lever 14
Is controlled to a neutral state (output rotation is 0) when is in the neutral position.

Next, the main transmission rod 33 by the control device 56.
The length adjustment control operation will be described. The control operation of the control device 56 in the present embodiment is performed by the data from the rotary encoder 15, the potentiometer 30, and the neutral switch 18, as will be described later.
When it is confirmed that the main gear shift lever 14 is in the neutral position, the determination system for setting the neutral flag by software or hardware that gives the microcomputer unit 57 the information that the main transmission lever 14 is in the neutral position, and the microcomputer unit 57 will be described later. Adjustment control for issuing a rotation instruction to the adjustment motor 49 as described later when the neutral flag is confirmed under a predetermined condition is provided.

First, the operation of the determination system will be described with reference to the flowchart of FIG. Microcomputer unit 57
First, the data of the potentiometer 30 is checked. If the output data value of the potentiometer 30 is the value when the main transmission lever 14 is in the neutral position (neutral value), then the neutral switch 18 is checked, and then the neutral switch If the switch 18 is ON, it is determined (confirmed) that the main transmission lever 14 is in the neutral position, and the neutral flag is set as described above.

On the other hand, if the neutral switch 18 is turned off by checking the neutral switch 18 when the potentiometer 30 outputs the neutral value as described above, the data (output pulse) of the rotary encoder 15 is checked next. At this time, the rotary encoder 1
A pulse signal is output as output data 5 and the HST is checked by checking the pulse width of this output pulse.
The output rotation of 17 and the rotation direction can be detected.

When the pulse width of the output pulse is equal to or greater than a predetermined value, in other words, the output rotation of the HST 17 is less than or equal to a predetermined value, the main transmission lever 14 and the HST 17 are slightly deviated from each other in the neutral position and the main transmission lever 14 is in the neutral position. Therefore, the neutral flag is set in the same manner as above. When the output data of the rotary encoder 15 is checked and the pulse width of the output pulse is less than or equal to a predetermined value (the output rotation of the HST 17 is greater than or equal to a predetermined value), the main shift lever 14 takes out the predetermined output rotation from the HST 17 in neutral. It is determined that the position has been switched to a position other than the position, and the neutral flag is reset.

Next, the case where the data value of the potentiometer 30 has a value other than the neutral value in the data check of the potentiometer 30 will be described. Also in this case, the neutral switch 18 is checked next, and if the neutral switch 18 is ON, the data of the rotary encoder 15 is further checked, and when the pulse width of the output pulse is a predetermined value or more, the neutral flag is set as in the above. . If the neutral switch 18 is turned off by checking the neutral switch 18 or if the pulse width of the output pulse is less than a predetermined value by checking the data of the rotary encoder 15, the neutral flag is reset,
It is determined that the main shift lever 14 is switched to a position other than the neutral position.

As described above, the determination system detects that the main transmission lever 14 is in the neutral position as described above, that is, the rotary encoder 15 as the output detecting means.
And data of a plurality (three) systems from the neutral switch 18 and the potentiometer 30 which are a plurality (two) of the position detection means are checked, and at least two data indicate the neutral of the main transmission lever 14. The neutral flag is set according to the judgment.

As a result, when one of the data for performing the neutral check of the main transmission lever 14 becomes abnormal data due to a malfunction of the detecting means (potentiometer 30, the neutral switch 18, the rotary encoder 15), a failure, a wiring abnormality, or the like. However, it is possible to accurately determine that the main shift lever 14 is in the neutral position, and it is possible to appropriately operate the adjustment control in which the setting of the neutral flag is one of the control conditions, as described later. You can also check for abnormal parts.

Next, the above-mentioned adjustment control will be described with reference to the flowchart of FIG. The adjustment control operates in parallel or in series with the neutral check control described above, and the setting of the neutral flag is one of the control conditions. First, it is checked whether or not the engine has just been started. If the engine has not just been started, then it is checked whether or not the neutral flag is present.

At this time, it is judged whether or not the engine is just started, for example, when the power switch for engine start is set to O.
It can be confirmed by operating a timer for a predetermined time after N. When the engine is just started, it is electrically unstable, and the adjustment motor 4
An instruction not to rotate 9 is issued to the adjustment motor 49 side, and the adjustment control is not performed.

On the other hand, the presence or absence of the neutral flag is checked, and when the neutral flag is set, that is, the main speed change lever 1
4 is in the neutral position, it is checked whether or not the decelerating traveling of the machine body 3 is performed from the time when the main gearshift lever 14 is switched to the neutral position until the machine body 3 stops, and then the machine body 3 is decelerated. If it is determined that the vehicle has stopped after the deceleration run of No. 3, then HS
When the rotary encoder 15 or the like checks whether T17 outputs the rotational drive force (whether the output rotation is greater than 0) and outputs the rotational drive force (the output rotation is greater than 0). Checks the rotation direction of the HST 17 with the rotary encoder 15 or the like.

When the HST 17 is outputting the rotational driving force in the forward direction of the machine body 3, the adjustment motor 49 is instructed to rotate in the direction of shortening the length of the main transmission rod 33, and the HST trunnion 36 is turned on. H by swinging upward
The output rotation (rotational driving force) of ST17 is adjusted to the backward direction side of the machine body 3, and the output pulse of the rotary encoder 15 is checked to adjust the HST17 to the neutral state. That is, the data (output pulse) from the rotary encoder 15 is checked, and the control device 56 instructs the adjustment motor 49 so that the pulse width of the output pulse takes a value that the output rotation of the HST is 0.

When the HST 17 is outputting the rotational driving force in the reverse direction of the body 3, the adjustment motor 49 is instructed to rotate in the direction of increasing the length of the main transmission rod 33, and the HST trunnion 36 is set. H by swinging downward
Adjust the output rotation of ST17 to the forward side of the machine 3,
Adjust HST17 to the neutral state as above.

When the machine body 3 is decelerating, the rotational movement of the traveling device 2 accompanying the decelerating machine body 3 is fed back to the output side of the HST 17. Therefore, in this embodiment, the control device 56 (microcomputer unit 57) checks whether or not the vehicle body 3 is decelerating.
The data is checked by the rotary encoder 15 to detect the rate of change in acceleration / deceleration on the output side of the HST 17.

On the other hand, if the neutral flag is not set (reset) in the check of the neutral flag, it is determined that the main gear shift lever 14 is not in the neutral position, and whether or not the machine body 3 is decelerating. If the machine body 3 is decelerating as described above in the check, it is determined that the machine body 3 is operating, and if the rotation drive force output of the HST 17 is not output in the check, the main shift lever is output. It is judged that the neutral position of 14 and the HST 17 match each other, and an adjustment control is not performed and an instruction not to rotate the adjustment motor 49 is issued to the adjustment motor 49 side.

As described above, when the neutral position of the main speed change lever 14 and the neutral state of the HST 17 are not matched by the control device 56, the length of the main speed change rod 33 is automatically adjusted at the neutral position of the main speed change lever 14. Since the HST 17 is adjusted to the neutral state by the error in the neutral position of the main shift lever 14 and the neutral state of the HST 17, the error between the main shift lever 14 and the neutral state becomes smaller than that of the conventional one, and the HS with respect to the swing amount of the main shift lever 14 is reduced.
Since the operation amount of T17 (the trunnion shaft 34) becomes accurate, the gear ratio of HST17 corresponding to the swing setting position (shift position) of the main transmission lever 14 becomes accurate, and the machine body 3 corresponds to the setting of the main transmission lever 14. While traveling at the specified speed, the neutral position of the main transmission lever 14 and the HS
No deviation of the neutral position of T17 occurs.

That is, the structure is such that the control of the length of the main transmission rod 33 is automatically performed by the information from the above-mentioned sensors (rotary encoder 15, potentiometer 30, neutral switch 18) and the like. In addition, the load applied to the main transmission lever 14 or the reverse load from the HST 17 may be added as a control condition to this automatic control. Further, in the present embodiment, the example in which the HST 17 is set to the neutral state at the neutral position of the main transmission lever 14 has been described, but when the combine is stopped on a slope or the like,
A predetermined output may be generated from the HST 17 in the upward direction of the slope of the machine body 3.

Since the control system 56 employs a protection system constituted by checking whether or not the engine has just been started and checking whether or not the vehicle body 3 is being decelerated, the electrical system immediately after the engine is started is adopted. During the unstable period and during deceleration of the machine body 3, the control for adjusting the length of the main transmission rod 33 (rotation control of the adjustment motor 49) is not performed, and the neutral position of the main transmission lever 14 and the HST 17 are more reliably controlled. Neutral states can be matched (with less error).

On the other hand, FIGS. 3 (a), 3 (b) and 4 (a),
As shown in (b), the above-described gear 37 meshes with a gear 62 fixed to the counter shaft 61 rotatably supported by the bracket 27 so as to rotate integrally with the counter shaft 61. The gear 62 is connected to an assist motor 64 attached to the bracket 27 via a gear 63 integrally fixed to the counter shaft 61 together with the gear 62. At this time, the assist motor 64 and the gear 63 are connected via the output gear 65 provided on the assist motor 64.

At this time, the assist motor 64 is connected to the output side of the microcomputer unit 57 as shown in FIG. 6, and the control device 56 causes the main shift lever 14 to swing in the front-back direction. Is checked by the potentiometer 30 and the rotational direction of the output rotation of the HST 17 is checked by the rotary encoder 15,
The swing angle of the main shift lever 14 in the direction that assists the swing of the main shift lever 14, that is, the HST 17
A rotation instruction is given to the assist motor 64 according to the load applied from the side to rotate the assist motor 64.

Assist motor 6 by this controller 56
By the rotation control of No. 4, the operator assists with the assist motor 64, and the HST 17 generated when the HST 17 is operated by the main speed change lever 14 is added to the braking force or the like which is generally given to the main speed change lever 14 in advance. The operating load that is increased by the reaction force (load) of the HST trunnion 36 that returns to the neutral position is reduced by the assistance of the assist motor 64, and the main shift lever 1
The rocking operation of 4 can be easily performed. Then, in particular, depending on the swing angle of the main transmission lever 14, the assist motor 64
Since the rotation instruction is issued to the vehicle, it is possible to more effectively prevent an increase in the operating load of the main transmission lever 14 due to the reaction force that increases as the main transmission lever 14 is swung to the high speed side.

[0049]

According to the present invention configured as described above, the operation instruction based on the neutral position of the shift lever and the output rotation of the hydraulic continuously variable transmission is provided by the control device based on the information from the position detecting means and the output detecting means. Since it is given to the drive actuator from the gear shift lever, the coupling can be adjusted by the adjusting portion so that the output rotation of the hydraulic continuously variable transmission at the neutral position of the speed change lever has a predetermined value. Since it is possible to reduce the operation error of the continuously variable transmission and to accurately adjust the operation amount of the hydraulic continuously variable transmission with respect to the swing amount of the speed change lever, the aircraft is said to travel at a speed corresponding to the setting of the main speed change lever. effective.

Further, the neutral position of the speed change lever is judged by the position detection means and the output detection means having a plurality of detection means which operate corresponding to the swing position of the speed change lever, and thus the above three or more detections are performed. The neutral position of the gear shift lever can be accurately detected even if a malfunction, a failure, a wiring abnormality, or the like occurs in one of the means, and the adjustment of the coupling tool can be performed more accurately.

Further, since the control device is provided with the protection system, even if the gear shift lever is in the neutral position, the adjustment of the connecting tool is not performed when the vehicle is decelerating, and the above adjustment is performed after the vehicle is stopped. Done. Therefore, it is possible to accurately and stably adjust the connecting member in the neutral position of the speed change lever, and to adjust the operation amount of the hydraulic continuously variable transmission with respect to the swing amount of the main speed change lever with a smaller error. There are also advantages.

[Brief description of drawings]

FIG. 1 is a perspective view of a combine.

FIG. 2 is a perspective view of an operation panel portion of the combine.

3A is a front view of a main part of a transmission portion, and FIG. 3B is an enlarged view of a main part of FIG.

4A is a right side view of a main part of a transmission portion, and FIG. 4B is an enlarged view of a main part of FIG.

FIG. 5 is a partial plan view of a main shift lever guide.

FIG. 6 is a block diagram of a control device.

FIG. 7 is an operation flowchart of the determination system.

FIG. 8 is an operation flowchart of adjustment control.

[Explanation of symbols]

3 aircraft 14 Gear shift lever 15 Rotary encoder (output detection means) 17 HST (hydraulic continuously variable transmission) 18 Neutral switch (detection means) 30 Potentiometer (detection means) 33 Main speed change rod (connector) 34 Trunnion shaft (operating shaft) 46 Turnbuckle (adjustment part) 49 Adjustment motor (drive actuator) 56 Control device

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 20/00-20/08 F16H 59/00-59/12 G05G 1/00-25/04

Claims (3)

(57) [Claims] 1. A hydraulic continuously variable transmission (17) for continuously changing the rotational driving force of an engine, and a speed change lever (14) for performing a speed change operation of the hydraulic continuously variable transmission (17) are provided. Shift lever (14) and hydraulic continuously variable transmission (17)
A connecting tool (33) is provided for connecting between the operating shafts (34) of the gear shift lever (1).
4) is provided on the coupling tool (33) side for adjusting the connection relationship between the hydraulic continuously variable transmission (17) and the gear ratio of the hydraulic continuously variable transmission (17) is set to that of the speed change lever (14). In a work vehicle in which stepless speed change is performed by setting steplessly according to the swing angle, position detecting means for detecting the neutral position of the speed change lever (14) and hydraulic continuously variable transmission (17) are provided. Output detecting means (15) for detecting output rotation
And a drive actuator (49) for operating the adjusting section (46), and the drive actuator (4) according to the detection information of the position detecting means and the output detecting means (15).
Control device and provided (56) for controlling the 9), shift lever
In the neutral position of (14), the hydraulic continuously variable transmission (1
The connector (33) so that 7) is in a neutral state.
An adjusting device for a continuously variable transmission mechanism in a work vehicle in which a control device (56) automatically adjusts and controls the length of the . 2. The position detecting means is a shift lever (1
4) A plurality of detecting means (1) which operate corresponding to the swing position of (4)
8) and (30), the control device (56) detects the neutral position of the speed change lever (14) by the position detecting means and the output detecting means (15), and detects a plurality of detecting means (18) of the position detecting means. ), (30) and the output detection means (15), the control device is provided with a determination system for confirming the neutral position of the speed change lever (14) by the operation of at least two detection means. Adjusting device for transmission mechanism. 3. The control device (56) is a transmission lever (14).
The work according to claim 1 or 2, wherein the control device (56) is provided with a protection system that detects deceleration traveling or stoppage of the airframe (3) in the neutral position and deactivates the drive actuator (49) during deceleration traveling. Adjustment device for continuously variable transmission in a vehicle.