JP2002178781A - Gear shift control device of work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and efficiently perform temporary stop of a car body during running and restart of the stopping car body in relation to a work vehicle having a switch type gear shift operating part in a gear shift lever. SOLUTION: The side surface of a grip 33 of the gear shift lever 18 is provided with an up switch 34 for raising the present gear position and a down switch 35 for lowering it. A stop/start switch 37 of the car body is disposed on the back surface of a grip 33, and, every time the stop/start switch 37 is operated, a command for temporarily stopping the car body during running and a command for restarting the car body during the temporary stopping are alternately outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a work vehicle, and more particularly to a shift control for a work vehicle provided with a pair of switch-type shift operation sections for instructing a shift lever to increase or decrease a current shift position. It concerns the device.

[0002]

2. Description of the Related Art
This type of work vehicle such as an agricultural tractor is provided with a shift lever for switching a shift position of a transmission, and a pair of switch-type shift operation units for increasing or decreasing the current shift position. There is known a device in which an actuator is driven in accordance with the switch signal to switch the transmission. Since the transmission provided with such a switch-type shift operation section can perform a shift operation with only one hand of an operator, the shift operation of a multi-stage transmission can be performed easily and efficiently.

However, in order to temporarily stop the running vehicle body or restart the temporarily stopped vehicle body, it is necessary to perform an operation of disengaging the clutch or an operation of switching the forward / reverse switching lever. The operation is complicated because the operator is required to perform both-hand operation and stepping operation. Then, when the vehicle body is restarted, it is necessary to sequentially switch the transmission from the low-speed position to the high-speed position again, and it is troublesome to reset to the original transmission position. Further, when stopping the vehicle body, the vehicle body may start to move if the clutch is in the disengaged state, and there is a problem in terms of safety.

Therefore, in a work vehicle provided with a switch-type shift operation portion in a shift lever, a technique to be solved in order to easily and efficiently perform operations of temporarily stopping a running vehicle body and restarting the stopped vehicle body. Issues arise.
An object of the present invention is to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and a pair of shift levers 18 for switching the shift position of a transmission is provided with a command for increasing or decreasing the current shift position. In a shift control device for a work vehicle that switches the transmission by driving an actuator in accordance with a switch signal of the shift operation unit 34, 35, the transmission lever 18 Means 30 for providing a vehicle body stop / start switch 37 for stopping the running vehicle body by operating the stop / start switch 37, and means 30 for starting the stopped vehicle body by operating the stop / start switch 37 And a means 30 for storing the current shift position during traveling, and stopping the vehicle body by operating the stop / start switch 37 When the vehicle is starting with operation of the stop-start switch 37 after the shift control device for a working vehicle provided with a means 30 for returning the shift position said storage,
In addition, when the vehicle body is stopped by operating the stop / start switch 37, the forward / reverse switching device 42 is set to a neutral state, and the shift control device for the working vehicle is provided that activates the left and right brake devices 91L and 91R. Things.

[0006]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show an agricultural tractor 10 as an example of a working vehicle, in which an engine 11 is mounted on a front portion of a vehicle body, and the rotational power of the engine 11 is appropriately changed by various transmissions in a transmission case 12 as described later. After shifting, the two rear wheels 13, 13 or the rear wheels 13,
13 and the four front wheels 14, 14. A working machine 16 such as a rotary is pulled through a link mechanism 15 at the rear of the vehicle body.

On the other hand, on the right side of the driver's seat 17, there are provided a shift lever 18 for switching the shift position of the transmission, a position lever 19 for changing the height of the work machine 16, and sub-con- verters 20, 20 for operating additional equipment. Various operation levers are arranged. In this way, by arranging various operation levers frequently used by the operator on the right side of the driver's seat 17, the operator's attention can be limited to the right side portion, and operability can be improved. .
A handle post 24 is provided in front of the driver's seat 17, and a steering handle 25 is mounted on the handle post 24. The steering handle 25
, The front wheel 14, which is a steered wheel, turns and the vehicle body turns.

A forward / reverse switching lever 26 protrudes from a side surface of the handle post 24. The forward / reverse clutch 47, which will be described later, is switched by operating the forward / reverse switching lever 26 to select forward traveling or reverse traveling of the vehicle body. I do. Further, a meter panel 2 is provided in front of the steering handle 25.
7 and pedals such as a clutch pedal 28 and a left and right brake pedal 29 are provided below the steering handle 25. Reference numeral 30 denotes a controller serving as control means described later, and reference numeral 31 denotes a lift arm angle sensor for detecting the height of the work implement.

As shown in FIGS. 2 and 3, the speed change lever 18 protrudes upward from an inverted h-shaped lever guide 32, and is located at a "low speed" position inside the vehicle front and a "medium speed" outside the vehicle front. The transmission has a three-stage shift pattern of a position and a “high-speed” position on the outer rear side of the vehicle body. It is configured to manually switch to any of “low speed”, “medium speed”, and “high speed” via As described above, the shift pattern of the shift lever 18 is configured so as not to be shifted to the rear inside the vehicle body, and only the "low speed" position, which is less frequently used, is arranged inside the front of the vehicle body. Even when the various operation levers are arranged in a concentrated manner on the right side of the seat 17, there is no danger that the speed change lever 18 will be too close to the driver's seat 17 and erroneous operation will be performed. Operability does not deteriorate.

On the side surface of the grip 33 of the shift lever 18, an up switch 3 which is a pair of switch-type shift operation sections for raising or lowering the current shift position is provided.
4 and a down switch 35 are provided to move up or down from a current position a main speed change pattern in which a first main speed change device 41 and a second main speed change device 43 described later are combined in cooperation. Also, the first main transmission 41 is set at the “high speed” position or the “low speed” on the head of the grip 33 of the transmission lever 18.
A seesaw type high / low switch 36 for instructing the position to go up or down is provided. Further, a stop / start switch 37 of the vehicle body is provided on the rear surface of the shift lever 18.
The stop / start switch 37 is a single momentary switch that serves both as a stop switch and a start switch. Each time the stop / start switch 37 is operated, a command to stop the running vehicle body and a command to start the temporarily stopped vehicle body by operating the stop / start switch 37 are alternately described, as described later. Output to

As shown in FIGS. 4 to 8, the rotational power of the engine 11 is intermittently operated by a main clutch 40 in a clutch housing, and the first main transmission 41 in the transmission case 12 sequentially switches between forward and reverse. The transmission is transmitted to the device 42, the second main transmission 43, and the auxiliary transmission 44.

[0012] The first main transmission 41 is "high speed""lowspeed"
This is a transmission having a wet-type multi-plate Hi-Lo clutch 47 for switching between the two gear sets 45 and 46. When the Hi-Lo clutch valve 48 is switched to the "high speed" position by the controller 30 as control means. , Said Hi
-Lo clutch 47 is "on" on the Hi side, and power is transmitted at "high speed" via one gear set 45. Also,
When the Hi-Lo clutch valve 48 is switched to the “low speed” position, the Hi-Lo clutch 47 “turns on” to the Lo side.
Thus, power is transmitted at "low speed" via the other gear set 46 having a higher reduction ratio than the one gear set 45. As described above, the first main transmission 41 has two shift positions of high and low, and the rotational power shifted by the first main transmission 41 is transmitted to the forward / reverse switching device 42.

The forward / reverse switching device 42 is a transmission having a wet-type multi-plate forward / reverse clutch 51 for switching between two forward and backward gear sets 49, 50. Is being operated by
Alternatively, the forward / reverse position sensor 52 detects whether the vehicle is being operated on the reverse side. Then, based on this detection result, a signal is sent from the controller 30 to the forward solenoid or the reverse solenoid of the forward / backward valve 54, and the forward / backward clutch 51 becomes “on” in “forward” or “reverse”, and the gear set 49, Power is transmitted to the second main transmission 43 through one of the transmissions 50. When the forward / reverse switching lever 26 is at the neutral position, the forward / reverse clutch 51 is "disengaged", the rotational power is cut off, and the second main transmission 4
3 is not transmitted.

The second main transmission 43 is a synchromesh gear type transmission composed of four gear sets. The second main transmission 43 transmits the rotational power output from the forward / reverse switching device 42 to the fourth speed gear set 56, 3 High speed gear set 57, second speed gear set 5
8, the auxiliary transmission 4 through one of the first-speed gear sets 59
Transmit to 4. A shifter ring having a synchromesh mechanism is provided between the drive side gears of the fourth speed gear set 56 and the third speed gear set 57, and this shifter ring is slid forward and backward by expansion and contraction of a first shift hydraulic cylinder 60 which is a shift actuator. Similarly, a shifter ring having a synchromesh mechanism is also provided between the driving side gears of the second speed gear set 58 and the first speed gear set 59, and this shifter ring is used as a speed change actuator. The two-speed hydraulic cylinder 61 is configured to slide back and forth by expansion and contraction.

[0015] From the controller 30, the main shift "3-4th speed"
When a signal is sent to the fourth speed solenoid of the valve 62, the first
When the transmission hydraulic cylinder 60 is extended, power is transmitted through the fourth-speed gear set 56 to become “fourth-speed”, and when a signal is sent to the third-speed solenoid of the main-transmission “3-4th-speed” valve 62, Due to the contraction of the first shift hydraulic cylinder 60,
Power is transmitted via the third-speed gear set 57 to “third speed”.
Becomes In addition, the controller 30 sends the main transmission “1-2”
When a signal is sent to the second speed solenoid of the "speed" valve 63,
By the extension of the second shift hydraulic cylinder 61, power is transmitted through the second speed gear set 58 to become “second speed”, and a signal is sent to the first speed solenoid of the main shift “1-2 speed” valve 63. Power is transmitted via the first-speed gear set 59 by the contraction of the second speed-change hydraulic cylinder 61, and "1"
Speed. As described above, the second main transmission 43 has four shift positions from “first speed” to “fourth speed”, and the rotational power shifted by the second main transmission 43 is transmitted to the subtransmission 44. Is transmitted to

The sub-transmission 44 is a sliding mesh gear type transmission which is switched via a link mechanism by manual operation of the transmission lever 18, and is "low speed".
It has three gear positions: a “medium speed” gear set 64, 65 and a “high speed” (directly connected) gear set 66. The rotational power shifted by the second main transmission 43 is further shifted by the auxiliary transmission 44.

The rotational power shifted by the sub-transmission 44 is transmitted to the rear wheels 13 via a rear differential 67 and a four-wheel drive switching clutch 68
Is switched to "constant speed" or "increased speed", and transmitted to the front wheels 14 via the front differential device 69. Further, the rotational power of the engine 11 is
PTO take-off shaft 71 which is branched to a PTO system at the front stage of the vehicle, is connected / disconnected by a PTO clutch 70 and protrudes from the rear of the vehicle body.
Is transmitted to

The second main transmission 43 includes a main transmission "1-N-2" as a means for detecting a gear combination.
Speed "position sensor 72 and a main speed" 3-N-4 speed "position sensor 73, and the auxiliary speed change device 44 has a sub speed" low speed "position sensor 7 as means for detecting a gear combination.
4, a sub-shift "medium speed" position sensor 75, and a sub-shift "high speed" position sensor 76 are provided. The depression operation of the clutch pedal 28 is detected by a clutch pedal sensor 77, and the depression operation of the left and right brake pedals 29 is detected by a brake pedal sensor 78. In addition, 7
9 is a vehicle speed sensor for detecting the running speed of the vehicle body, 80 is an engine speed sensor, and 81 is a running / work mode switch. The detection signals of the switches 34 to 37, the forward / backward position sensor 52, and the sensors 72 to 80 are sent to the controller 30.

In this way, the first main transmission 41 and the second main transmission 43 are linked to obtain an eight-speed main transmission pattern, and the three sub-transmission patterns of the sub-transmission 44 are combined. , 24-speed shift patterns can be obtained.
By operating the up switch 34 or the down switch 35 provided on the grip 33 of the speed change lever 18 described above, the main speed change pattern in which the first main speed change device 41 and the second main speed change device 43 are combined in cooperation with each other is displayed. The first main transmission 41 is moved up or down to the "high speed" position or the "low speed" position by operating the height change switch 36. And
The controller 30 determines the current shift position based on the detection signals of the switches and sensors, and displays the current shift position on a shift position indicator 82 provided on the meter panel 27.

On the other hand, the main pump 8
5 and the sub-pump 86 are driven, and the hydraulic oil discharged from the main pump 85 is sent to the lift cylinder 88 for lifting and lowering the work implement through the sub-con- trol circuit 87 and to the rolling cylinder 89 for horizontal control. A part of the operating oil of the main pump 85 passes through the pressure reducing valve 90 to the four-wheel drive switching clutch 68 and the first speed changing hydraulic cylinder 60.
And the second shift hydraulic cylinder 61, the left and right brake cylinders 91L and 91R, the forward / reverse clutch 51, and the PTO clutch 70. The hydraulic oil discharged from the sub pump 86 is supplied to the power steering device and the main clutch 4.
0 is supplied.

Here, the grip 3 of the shift lever 18
The control procedure in the case where the stop / start switch 37 provided in the control unit 3 is operated will be described with reference to the flowcharts in FIGS. First, the controller 30
Determines whether the traveling / work mode switch 81 is in the traveling mode or the working mode, and monitors the pushing operation of the stop / start switch 37 in the working mode (step 1). When the stop / start switch 37 is pressed (step 2), the controller 30 determines whether the forward / reverse switching device 42 is in a neutral state (step 3). When it is determined from the detection signal of the forward / reverse position sensor 52 that the forward / reverse switching device 42 is not in the neutral state, the vehicle is considered to be traveling and the means for stopping the vehicle is activated (step 4). When it is determined that the forward / reverse switching device 42 is in the neutral state, the vehicle body is regarded as being stopped and the means for starting the vehicle body is activated (step 5).

Note that the shift control of the present invention is not executed during the running mode in step 1. This is dangerous if the vehicle body is stopped by the pressing operation of the stop / start switch 37 by mistake while the vehicle is traveling at high speed in the traveling mode, and the safety is ensured. Similarly, if the vehicle speed is relatively low,
For example, when the sub-transmission 44 is in the "low speed" position (gears 1-8)
The shift control according to the present invention is performed only when the vehicle is operating, and the shift control by pressing the stop / start switch 37 is not performed to prevent danger when the vehicle speed is high.

When the means for stopping the vehicle body is activated in step 4, first, the controller 30 stores the current gear position during traveling as M (step 41). Subsequently, the forward / reverse clutch 51 is disengaged to bring the forward / reverse switching device 42 into the neutral state (step 42), and the left and right brake cylinders 91L and 91R are operated to apply braking to the vehicle body to temporarily stop the vehicle body from traveling. (Step 4
3). Thus, the operator can stop traveling of the vehicle body only by one-handed operation of the shift lever 18 without performing the clutch disengagement operation or the switching operation of the forward / reverse switching lever. Further, when the vehicle body is temporarily stopped by pressing the stop / start switch 37, the brake is operated in conjunction with the disengagement operation of the forward / reverse clutch 51. Therefore, even when the vehicle body is on a slope, the vehicle is stopped. There is no danger of the car body moving inside.

On the other hand, when the means for starting the vehicle body is operated in step 5, the controller 30 first determines whether or not the current shift position matches the stored value M (step 51). When the current shift position does not match the stored value M, the Hi-Lo clutch 47, the first main shift hydraulic cylinder 60, and the second main shift hydraulic cylinder 61 are used.
Are operated to switch the shift position to match the stored value M (step 52). And the forward / reverse switching device 4
2 to the original state (forward or backward) (step 5
3). Further, the left and right brake cylinders 91L and 91R are released to restart the vehicle body (step 54). At this time, the stored value M is cleared (step 55). Thus, when the vehicle body temporarily stopped by the pressing operation of the stop / start switch 37 starts again by the pressing operation of the stop / start switch 37, the operator manually manually shifts the transmission from the low-speed position to the high-speed position. There is no need to switch to, and it is possible to automatically return to the original shift position and start traveling.

In this embodiment, the forward / reverse switching device 42 is set to the neutral state in step 42 in order to stop the traveling of the vehicle body. When the boost control is performed, the forward gear set 4
9 and the rotational resistance of the reverse gear set 50, the second main transmission 4
There is a problem that the synchronization time of the synchromesh of No. 3 becomes long and that the load on the clutch is large because the relative rotation difference between the forward clutch and the reverse clutch is large. Therefore, if the forward / reverse clutch 51 is configured to perform only the switching of “on” and “off” and the Hi-Lo clutch 47 is configured to perform the boost control, the high-speed gear set 45 and the low-speed gear set 46 rotate in the same direction. Therefore, the rotation difference is reduced, the synchronization time of the synchromesh of the second main transmission 43 is shortened, and the load on the clutch is reduced.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0027]

According to the present invention, as described in detail in the above embodiment, the invention according to claim 1 is a shift control device in which a shift lever is provided with a switch for instructing a shift position to be up or down. Since the shift lever is provided with a stop / start switch for the vehicle body, the stop / start switch can be operated to temporarily stop and restart the vehicle body, thereby eliminating the need for both-hand operation and stepping operation by the operator. Properties can be significantly improved.

According to a second aspect of the present invention, when the vehicle is restarted by operating the stop / start switch, the current shift position during traveling is stored, and the stored shift position is automatically returned to the original shift position. As a result, in addition to the effect of the first aspect, it is not necessary for the operator to manually reset the shift position.

The invention according to claim 3 is characterized in that the above-mentioned stop /
3. When stopping the vehicle body by the start switch, the forward / reverse switching device is set to the neutral state, and the left and right brake devices are operated, so that the stopped vehicle body does not have the possibility of accidentally traveling. In addition to the effects of the invention, safety at the time of stopping the vehicle body can be ensured.

[Brief description of the drawings]

 The figure shows an embodiment of the present invention.

FIG. 1 is a side view of a tractor.

FIG. 2 is a partially cutaway plan view of a driver's seat.

FIG. 3 is a perspective view of a transmission lever.

FIG. 4 is a block diagram of a shift control system.

FIG. 5 is a diagram showing a power transmission path.

FIG. 6 is a list showing shift patterns of the transmission.

FIG. 7 is a front view of an indicator showing a shift position.

FIG. 8 is a hydraulic circuit diagram.

FIG. 9 is a flowchart showing the overall procedure of a shift control.

FIG. 10 is a flowchart showing a procedure of operation of a stopping means.

FIG. 11 is a flowchart showing a procedure of starting means operation.

[Explanation of symbols]

 Reference Signs List 10 Tractor 18 Shift lever 30 Controller 34 Up switch 35 Down switch 37 Stop / start switch 42 Forward / reverse switching device 91L, 91R Brake cylinder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B60T 7/08 B60T 7/08 B F16H 59/10 F16H 59/10 F-term (Reference) 3D040 AA12 AA22 AA35 AB04 AC02 AD13 3D041 AA12 AA30 AB01 AC01 AC17 AC18 AC24 AD31 AD41 AE31 AE33 AE41 3J552 MA04 MA13 MA24 MA26 NA05 NB01 PA01 PB10 RB03 RB17 SB02 TA10 UA05 VA62Z VA64Z VA65Z VA70Z VB01Z VC01Z

Claims (3)

[Claims] A shift lever for switching a shift position of a transmission is provided with a pair of switch-type shift operation sections for raising or lowering a current shift position. In a shift control device for a work vehicle that switches the transmission by driving an actuator according to a signal, the transmission lever 18
Means 30 for stopping the running vehicle by operating the stop / start switch 37 and means for starting the stopped vehicle by operating the stop / start switch 37 30. A shift control device for a work vehicle, wherein 30 is provided. 2. A means 30 for storing a current shift position during traveling.
2. The device according to claim 1, further comprising: means for returning to the stored shift position when the vehicle is started by operating the stop / start switch after the vehicle is stopped by operating the stop / start switch. Transmission control device for work vehicle. 3. When the vehicle is stopped by operating the stop / start switch 37, the forward / reverse switching device 42 is set to a neutral state, and the left and right brake devices 91L, 9
The shift control device for a work vehicle according to claim 1 or 2, wherein the 1R is operated.