Work vehicle

Abstract

To provide a work vehicle that can travel more safely by allowing an operator to easily grasp operation of a main shift lever and a behavior of a machine body.SOLUTION: A work vehicle includes: a travelling vehicle body that travels by rotational power of an engine; a main transmission device for performing stepless gear change according to operation of a main shift lever; a control part for controlling main transmission by the main transmission device and storing an operation position of the main shift lever; and a main transmission memory switch that is depression-operated when the control part is caused to store the operation position of the main shift lever. By long time depression of the main transmission memory switch, the control part stores the operation position of the main shift lever as a stored operation position, and by short time depression of the main transmission memory switch, the control part executes main transmission reproduction mode for reproducing a state of main transmission at the stored operation position. In the main transmission reproduction mode, the control part keeps the state of the main transmission according to the stored operation position even when the main shift lever is operated to a higher speed side than the stored operation position.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] Conventionally, in a work vehicle equipped with a continuously variable transmission (main transmission) that changes the traveling speed of the vehicle body steplessly, and an actuator that controls the shift position of the main transmission, a technology is known in which, when a shift position is stored, even if the shift position is subsequently operated to a different shift position, the actuator automatically reproduces the memorized shift position by operating a shift position reproduction switch (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-298099 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, while the above-mentioned conventional technology can easily reproduce the shift position even in a continuously variable transmission in which it is difficult to reproduce the shift position, if the operating position of the shift operation lever (main shift lever) does not match the actual shift position, it may be difficult for the driver to grasp the operation of the main shift lever and the behavior of the vehicle, which may hinder safe driving.

[0005] The present invention has been made in consideration of the above, and aims to provide a work vehicle that allows the driver to easily understand the operation of the main shift lever and the behavior of the vehicle, thereby enabling safer travel. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a work vehicle (1) according to an embodiment includes a traveling body (2) that travels with the rotational power of an engine (E) and a main transmission (30) that changes the traveling speed of the traveling body (2) steplessly in response to the operation of a main transmission lever (15). The work vehicle (1) includes a control unit (100) that controls main shifting by the main transmission (30) and stores the operation position (P) of the main transmission lever (15), and a main transmission memory switch (56) that is pressed when the operation position (P) of the main transmission lever (15) is to be stored in the control unit (100). The control unit (100) stores the operation position (P) of the main transmission lever (15) in a stored operation position (P) by pressing and holding the main transmission memory switch (56) for a predetermined period of time or longer. M ) and the main shift memory switch (56) is pressed for less than the predetermined time to store the memory operation position (P M A main shift reproduction mode is executed to reproduce the state of the main shift at the stored operation position (P M ) to the higher speed side, the memory operation position (P M ) and maintains the main speed change state according to the Effect of the Invention

[0007] According to the work vehicle according to this embodiment, the driver can easily grasp the operation of the main shift lever and the behavior of the vehicle body, allowing for safer travel. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic side view showing a work vehicle according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing the configuration of the transmission. [Diagram 3] FIG. 3 is an explanatory diagram (part 1) of the operation section of the tractor. [Figure 4] FIG. 4 is an explanatory diagram (part 2) of the operation section of the tractor. [Diagram 5]FIG. 5 is a schematic explanatory diagram of the main shift reproduction mode. [Figure 6A] FIG. 6A is a flowchart (part 1) showing an example of a processing procedure of the main shift reproduction mode. [Figure 6B] FIG. 6B is a flowchart (part 1) showing an example of a processing procedure of the main shift reproduction mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a work vehicle disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment described below.

[0010] <Overview of the work vehicle> First, an overview of a work vehicle 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic side view showing a work vehicle 1 according to an embodiment.

[0011] In addition, each figure may show a three-dimensional Cartesian coordinate system including a Z-axis with the positive direction being vertically upward (upward). For ease of explanation, the positive direction of the X-axis is defined as the left, the negative direction of the X-axis as the right, the positive direction of the Y-axis as the forward direction, and the negative direction of the Y-axis as the backward direction, and the X-axis direction is referred to as the left-right direction, the Y-axis direction as the front-back direction, and the Z-axis direction as the up-down direction.

[0012] In addition, the tractor 1, which is an example of a work vehicle, can travel on roads and fields using the power of a prime mover such as an engine E, which is a drive source, and can perform specified tasks in the field by freely attaching and detaching multiple types of work machines (not shown) that perform ground tasks.

[0013] In the following description, the work vehicle (tractor) 1 or the traveling vehicle body 2 described below may be referred to as the "machine body".

[0014] As shown in Fig. 1, the tractor 1 is equipped with an engine E mounted inside a bonnet 2a at the front of the vehicle body. Rotational power from the engine E is transmitted to a transmission 3, which is a speed change device including a main speed change device 30 described below, and is then reduced in speed by the transmission 3 before being transmitted to the traveling wheels, i.e., the front wheels 4 and rear wheels 5 of the tractor 1.

[0015] A driver's seat 7 is provided inside a cabin 6 at the rear of the aircraft. A steering wheel 8 for steering the front wheels 4 is provided in front of the driver's seat 7. A meter panel 9 and the like are provided in front of the steering wheel 8.

[0016] A working machine such as a rotary working machine is coupled to the rear of the body of the tractor 1. The working machine is driven by a PTO (Power Take-Off) shaft 150 protruding rearward from a casing (transmission case) of the transmission 3.

[0017] In addition, around the driver's seat 7 within the cabin 6, there are provided a steering wheel 8, a meter panel 9, various operating pedals such as an accelerator pedal 10, a clutch pedal 11, and a brake pedal 12, various operating levers such as a forward / reverse lever 14, a main shift lever 15, and an auxiliary shift lever (not shown), and various operating devices (not shown).

[0018] The forward / reverse lever 14 is an operating tool operated to operate a forward / reverse clutch that switches the vehicle between "forward," "neutral," and "reverse." The main speed change lever 15 is an operating tool operated to operate a main transmission 30 that changes the vehicle travel speed. The main speed change lever 15 is operated to move from the neutral position to the speed increase side or the speed decrease side.

[0019] The tractor 1 can perform automatic gear shifting by controlling the transmission 3 according to the rotation speed of the engine E. Also, the tractor 1 can switch the main gear shift only by operating the accelerator pedal 10 or the main gear shift lever 15, as described later.

[0020] <Transmission configuration> Next, the power transmission configuration of the work vehicle 1 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing the configuration of the transmission 3 (power transmission diagram).

[0021] The tractor 1 is equipped with a hydrostatic continuously variable transmission (hereinafter referred to as HST (Hydro Static Transmission)) 31 having a hydraulic pump 311 and a hydraulic motor 312, and a hydromechanical continuously variable transmission (hereinafter referred to as HMT (Hydro Mechanical Transmission)) 30 that combines a planetary gear (planetary gear mechanism 33).

[0022] The main transmission, HMT30, combines the HST31 and the planetary gear mechanism 33, making it possible to start, accelerate (increase speed), and decelerate the machine by operating only the lever or pedal, and also enables the machine to run with higher transmission efficiency than a transmission configuration with only the HST 31. Furthermore, by combining the HMT30 with electronic control, it makes it possible to perform constant speed running (cruise control) that runs the machine at a constant speed (constant speed).

[0023] 2, in the transmission 3, the HST 31 includes a variable displacement hydraulic pump 311 and a fixed displacement hydraulic motor 312. The hydraulic pump 311 and the hydraulic motor 312 are accommodated in a housing (not shown) of the HST 31. A pump output shaft 32 is inserted into the hydraulic pump 311 along the rotation axis of the hydraulic pump 311. The pump output shaft 32 transmits power from the engine E to the hydraulic pump 311, the planetary gear mechanism 33, and the PTO shaft 150.

[0024] The transmission 3 is housed in a transmission case (not shown). In addition to the pump output shaft 32, the transmission 3 is provided with a motor output shaft 34, an output shaft 35, a sub-speed change shaft 37a, a PTO shaft 150, and the like, all of which are rotatable. The transmission 3 is also provided with a planetary gear mechanism 33. The planetary gear mechanism 33 is disposed on the rear side (downstream side in the transmission direction) of the HST 31. The planetary gear mechanism 33 includes a sun gear 331, a planetary gear 332, a ring gear 333, and a carrier.

[0025] A forward / reverse clutch 36 is provided on the rear side (downstream side in the transmission direction) of the planetary gear mechanism 33. The forward / reverse clutch 36 includes a front clutch 361 and a rear clutch 362. The forward / reverse clutch 36 switches between an HST mode and an HMT mode. The forward / reverse clutch 36 transmits power to the output shaft 35 according to the two modes (HST mode and HMT mode), and transmits the power to an auxiliary transmission shaft 37a via the auxiliary transmission mechanism 37.

[0026] A pump side input gear 38 is provided on the pump output shaft 32. The pump side input gear 38 meshes with a gear of a carrier 334 that is loosely fitted concentrically with the sun gear 331, thereby driving the carrier 334 to rotate. The carrier 334 is provided with a plurality of planetary gears 332 that mesh with the sun gear 331 and the ring gear 333. In this manner, the planetary gear mechanism 33 is composed of the sun gear 331, the plurality of planetary gears 332, the ring gear 333, the carrier 334, etc.

[0027] In the planetary gear mechanism 33, the sun gear 331 is loosely fitted on the output shaft 35, and the planetary gear 332 meshes with the sun gear 331 and the ring gear 333. The planetary gear 332 is rotatably supported by a carrier 334 that is loosely fitted on the output shaft 35, and is configured to revolve around the sun gear 331 while rotating on its own axis.

[0028] A motor-side input gear 39 is provided on the motor output shaft 34. The motor-side input gear 39 drives a sun gear 331 to rotate.

[0029] The sub-speed change mechanism 37 transmits power to the sub-speed change shaft 37a by connecting the sub-speed change clutch. The sub-speed change shaft 37a is configured to be able to transmit power to the rear wheel differential 40 via a pinion provided on the sub-speed change shaft 37a. The sub-speed change shaft 37a is also configured to be able to drive the front wheels 4 via a 4WD clutch 41 and a front wheel differential 42.

[0030] Here, each transmission configuration in the HST mode and the HMT mode will be described. In the HMT mode, in the forward / reverse clutch 36, the front clutch 361 is connected and the rear clutch 362 is disconnected.

[0031] At this time, the sun gear 331 of the planetary gear mechanism 33 is rotationally driven by the rotational power of the pump output shaft 32. Due to the rotation of the sun gear 331, the rotations of the carrier 334 and the sun gear 331 are combined and transmitted to the planetary gear 332. The power transmitted to the sun gear 331 is transmitted to the ring gear 333.

[0032] In the HMT mode, the front clutch 361 of the forward / reverse clutch 36 is controlled to be connected, so that the rotational power of the ring gear 333 is transmitted to the output shaft 35. The power of the output shaft 35 is transmitted to the rear wheels 5 and the front wheels 4 via the auxiliary transmission mechanism 37.

[0033] On the other hand, in the HST mode, in the forward / reverse clutch 36, the rear clutch 362 is connected and the front clutch 361 is disconnected. In the HST mode, the rotational power of the motor output shaft 34 is transmitted to the output shaft 35. The power of the output shaft 35 is transmitted to the rear wheels 5 and the front wheels 4 via the auxiliary transmission mechanism 37.

[0034] In the HST mode, the rotational power of the engine E is transmitted to the rear wheels 5 and the front wheels 4 without passing through the planetary gear mechanism 33. That is, the power of the engine E rotates the carrier 334 via the pump output shaft 32, but since the carrier 334 only rotates idly, the power is changed in speed by the HST 31 and transmitted from the motor output shaft 34 to the output shaft 35, and then transmitted to the rear wheels 5 and the front wheels 4 via the sub-transmission mechanism 37.

[0035] In addition, the rotational power from the pump output shaft 32 is also output toward the PTO shaft 150 via the PTO clutch 43 and the PTO conversion unit 44 .

[0036] As shown in Figures 3 and 4, various operation levers and various operation switches are provided on the operation unit 50 of the work vehicle (tractor) 1. Figures 3 and 4 are explanatory diagrams of the operation unit 50 of the work vehicle (tractor) 1. Note that Figure 2 is a perspective view showing the operation unit 50 of the work vehicle (tractor) 1. Also, Figure 3 is a plan view showing the operation unit of the work vehicle (tractor) 1.

[0037] 3 and 4, in the tractor 1 (see FIG. 1), an operation unit 50 provided to the right of the driver's seat 7 is provided with a PTO switch 51, a PTO changeover switch 52, a one-touch tilling switch 53, a preference changeover switch 54, a tilling adjustment dial 55, a main speed change memory switch 56, a main speed change lever 15, a work implement lever 57, an accelerator memory switch 58, an HMT sensitivity adjustment dial 59, etc. These various operation levers and various operation switches in the operation unit 50 are connected to a control unit 100 of the tractor 1.

[0038] The tractor 1 includes a control unit 100. When the main shift lever 15 is operated, the control unit 100 outputs a shift command value corresponding to the operation position P (see FIG. 5) of the main shift lever 15 to the HMT 30, which is the main shift device. In this manner, the HMT 30 is controlled by the control unit 100. The control unit 100 controls the main shift by the HMT 30, which is the main shift device. The control unit 100 stores the operation position P of the main shift lever 15 and the rotation speed of the engine E.

[0039] The control unit 100 is a computer equipped with a processing device such as a CPU (Central Processing Unit), a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a HDD (Hard Disk Drive), and further an input / output device.

[0040] The control unit 100 includes a driving system ECU (Electronic Control Unit) that controls the driving system, an engine ECU as an engine control unit that controls the engine E, and a work machine lifting system ECU that controls the lifting and lowering of a work machine such as a rotary tiller.

[0041] Connected to the control unit 100 are an electronic governor (actuator) that controls the rotation speed of the engine E, a detection sensor that detects the rotation speed of the engine E (output shaft of the engine E), and a lever position detection sensor that detects the operation position (shift position) P (see FIG. 5) of the main shift lever 15. Note that the lever position detection sensor may be, for example, a potentiometer that detects the rotation angle of the main shift lever 15.

[0042] In addition, the control unit 100 is connected to a forward / reverse lever position detection sensor that detects the operating position of the forward / reverse lever 14 (see FIG. 1), a detection sensor that detects the rotational speed of the motor output shaft 34, a speed change actuator that controls the swash plate of the hydraulic pump 311, and a solenoid valve that connects / disconnects the forward / reverse clutch 36.

[0043] In this way, the control unit 100 feedback controls the inclination angle of the movable swash plate of the hydraulic pump 311 via the shift actuator so that the traveling speed (vehicle speed) of the tractor 1 becomes the shift command value corresponding to the operating position P of the main shift lever 15, based on the operating position P of the main shift lever 15 and the detection value of the detection sensor.

[0044] In the gear shift control of the control unit 100, for example, the HMT mode is executed in the medium to high speed range, and the HST mode is executed in the low speed range, and two driving modes are automatically switched in accordance with the gear shift command value.

[0045] The forward / reverse lever 14 is operated to operate the forward / reverse clutch 36. The forward / reverse clutch 36 switches the vehicle between "forward", "reverse" and "neutral". The control unit 100 is capable of controlling the forward / reverse clutch 36.

[0046] When the forward / reverse lever position detection sensor detects that the operational position of the forward / reverse lever 14 is "forward," the control unit 100 controls the speed change actuator so that the movable swash plate of the hydraulic pump 311 is within the range of the forward position. When the control unit 100 detects that the operational position of the forward / reverse lever 14 is "reverse," the control unit 100 controls the speed change actuator so that the movable swash plate of the hydraulic pump 311 is within the range of the reverse position.

[0047] Furthermore, when the control unit 100 detects that the operation position of the forward / reverse lever 14 is "neutral", it controls the speed change actuator to hold the movable swash plate of the hydraulic pump 311 in the neutral position and controls so as not to rotate the output shaft 35. Note that the forward / reverse lever position detection sensor may be, for example, a potentiometer that detects the rotation angle of the forward / reverse lever 14, or a switch having contacts corresponding to each of the positions of "forward", "reverse", and "neutral".

[0048] Also connected to the control unit 100 is a main shift memory switch 56 that is operated to store the operation position P of the main shift lever 15. The main shift memory switch 56 is operated by the driver of the tractor 1 or the like when storing the operation position P of the main shift lever 15 detected by the lever position detection sensor.

[0049] As described above, the control unit 100 outputs a gear change command value corresponding to the operation position P of the main gear change lever 15 to the HMT 30, and also stores the operation position P of the main gear change lever 15 when the main gear change memory switch 56 is operated. By storing the operation position P of the main gear change lever 15, the control unit 100 causes the tractor 1 to travel at a constant speed corresponding to the stored operation position P (referred to as the stored operation position).

[0050] <Main shift reproduction mode> Next, the main speed change reproduction mode by the control unit 100 will be described with reference to Fig. 5. Fig. 5 is a schematic explanatory diagram of the main speed change reproduction mode.

[0051] The main shift memory switch 56 is pressed when the operation position P of the main shift lever 15 is to be stored in the control unit 100. As shown in Fig. 5, when the main shift memory switch 56 is pressed and held for a predetermined time (e.g., 2 seconds) or more, the control unit 100 (see Figs. 3 and 4) stores the operation position P of the main shift lever 15 in the stored operation position P. M In addition, the control unit 100 stores the main shift memory switch 56 in the storage operation position P M A main speed change reproduction mode is executed to reproduce the state of the main speed change in the tractor 1 at a constant speed.

[0052] In the main shift reproduction mode, the control unit 100 controls the main shift lever 15 to the stored operation position P M Even if the speed is increased to the higher speed side, the stored operation position P M The main gear is maintained in a state according to the above.

[0053] For example, as shown in FIG. 5, when the main shift lever 15 can be operated between "D (drive) mode position PD," "neutral position P0," and "maximum position P1," the control unit 100 determines whether the operation position P of the main shift lever 15 is a position where the output of the HMT 30 is 30% (memory operation position P M ) to store the data, the memory operation position P MEven if the main shift lever 15 is operated to a higher speed than this, the operation position P of the main shift lever 15 is maintained in the main shift state where the output of the HMT 30 is 30%.

[0054] According to this configuration, in the main shift reproduction mode, the main shift lever 15 is in the stored operation position P M Even if the aircraft is operated to the higher speed side than the stored operation position P M Since the main shift lever 15 is kept in a state that corresponds to the vehicle speed, unintended speed increases by the driver can be suppressed. In other words, the driver can easily grasp the operation of the main shift lever 15 and the vehicle behavior, allowing for safer driving.

[0055] In addition, the control unit 100 determines whether the operation position P of the main shift lever 15 is the memory operation position P M When the main shift lever 15 is operated to a position different from the stored position P M The main shift is controlled in accordance with the operating position P of the main shift lever 15 until it coincides with the

[0056] For example, when the main shift memory switch 56 is pressed briefly, that is, when the high-speed regulation mode for regulating high-speed driving is activated, the operation position P of the main shift lever 15 is set to the memory operation position P M When the speed is higher than the speed limit, the operation position P of the main shift lever 15 is changed to the storage operation position P M However, in the case of the work vehicle 1, the operation position P of the main shift lever 15 is set to the stored operation position P M Since activation of the high-speed regulation mode is suspended until it coincides with the vehicle speed, the driver can easily grasp the operation of the main shift lever 15 and the behavior of the vehicle, and can travel more safely.

[0057] In the main shift reproduction mode, the control unit 100 also detects whether the main shift lever 15 is in the stored operation position P M When the main shift lever 15 is operated to a lower speed than the above, the main shift is controlled in accordance with the operation position P of the main shift lever 15.

[0058] According to such a work vehicle 1, even when the main gear shift reproduction mode is being executed, the driver can freely perform operations on the deceleration side, which allows for safer travel.

[0059] The tractor 1 also includes an accelerator memory switch 58 (see Figs. 3 and 4). The accelerator memory switch 58 is operated when recalling the rotation speed (memorized rotation speed) of the engine E (see Fig. 2) stored in the control unit 100. By pressing and holding the main transmission memory switch 56, the control unit 100 stores the rotation speed of the engine E as the stored rotation speed.

[0060] Even when the main shift reproduction mode is executed by a short push of the main shift memory switch 56, the control unit 100 does not execute the recall of the stored rotation speed until the accelerator memory switch 58 is operated.

[0061] According to this configuration, the control unit 100 stores the rotation speed of the engine E together with the operation position P of the main shift lever 15, making it possible to reproduce the traveling speed (vehicle speed) in the main shift reproduction mode. In addition, by pressing and holding the main shift memory switch 56, the operation position P of the main shift lever 15 (stored operation position P M Since the control unit 100 simultaneously stores the rotation speed of the engine E (stored rotation speed) and the rotation speed of the engine E, the operation of storing the rotation speed of the engine E in the control unit 100 can be performed by a simpler operation.

[0062] Furthermore, when the vehicle is operated manually (manual driving) during work travel, the rotational speed of the engine E is usually determined, and the determined rotational speed is fixed while the main shift lever 15 is operated to increase or decrease the vehicle speed. However, with this configuration, the reproduction of the rotational speed of the engine E (memorized rotational speed) and the operation position P (memorized operation position P) of the main shift lever 15 are required. M ) can be reproduced in a separate operation from the reproduction of the driving speed (vehicle speed) according to normal procedures.

[0063] Next, an example of a processing procedure of the main shift reproduction mode will be described with reference to Figures 6A and 6B. Figures 6A and 6B are a flow chart showing an example of a processing procedure of the main shift reproduction mode.

[0064] As shown in FIG. 6A, in the main shift reproduction mode, when the main shift memory switch 56 is pressed and held from the main shift memory OFF state (initial state) in which the operating position P of the main shift lever 15 is not stored (steps S101, S102), the control unit 100 determines whether the state of the tractor 1 is the main shift memory "OFF", the sub-shift "neutral", and the main shift "other than D (drive)" (step S103).

[0065] In the process of step S103, if the control unit 100 determines that the state of the tractor 1 is the main shift memory "OFF", the auxiliary shift "neutral", and the main shift "other than D (drive)" (step S103: Yes), it determines whether the one-touch tilling switch 53 is "other than neutral" and the attention changeover switch 54 has switched to "attention 1 or 2" (step S105). In addition, if the control unit 100 determines that the state of the tractor 1 is not the main shift memory "OFF", the auxiliary shift "neutral", and the main shift "other than D (drive)" (step S103: No), it does not store the operation position P of the main shift lever 15 and ends the main shift reproduction mode (step S104).

[0066] In the processing of step S105, when the control unit 100 determines that the one-touch tilling switch 53 is "other than neutral" and the preference change switch 54 has not switched to "preference 1 or 2" (step S104: No), it stores the operating position P of the main shift lever 15 as the main shift memory ON state (step S105).

[0067] After the process of step S106, i.e., after the main shift memory is set to ON, if the main shift memory switch 56 is short-pushed (step S107), the control unit 100 sets the main shift memory to OFF (step S108). After executing the process of step S108, the control unit 100 causes the tractor 1 to travel at a constant speed (executes the main shift reproduction mode). Furthermore, even if the sub-shift lever is operated to the neutral position (step S107) after the process of step S106 (after the main shift memory is set to ON), the control unit 100 sets the main shift memory to OFF (step S108).

[0068] On the other hand, when the control unit 100 determines in the processing of step S105 that the one-touch tilling switch 53 is "other than neutral" and the special preference switching by the special preference switching switch 54 is "special preference 1 or 2" (step S105: Yes), it stores the operating position P of the main shift lever 15 as the special preference main shift memory ON state (step S109).

[0069] After the process of step S109, that is, after the particular main shift memory is set to ON, when the main shift memory switch 56 is short-pushed (step S110), the control unit 100 sets the main shift memory to OFF (step S108). When the control unit 100 executes the process of step S109, the control unit 100 performs constant speed traveling of the tractor 1 (executes the main shift reproduction mode). In addition, even if the auxiliary shift lever is operated to the neutral position (step S110) after the process of step S109 (after the particular main shift memory is set to ON), the control unit 100 sets the main shift memory to OFF (step S108). Note that, when the control unit 100 executes the process of step S108 after the process of step 107 or step S110, the control unit 100 may set the main shift memory to OFF in step S108 via a process of setting the main shift memory to OFF in the safety operation (step S111).

[0070] Furthermore, after executing the process of step S109, when the one-touch tilling switch 53 or the attention changeover switch 54 is operated (step S112), the control unit 100 judges whether to transition to "attention 1 or 2" (step S113). If the control unit 100 transitions to "attention 1 or 2" (step S113: Yes), the control unit 100 cancels the main shift memory (step S114). After executing the process of step S114, the control unit 100 sets the main shift memory to OFF for safety operation (step S115). Note that the control unit 100 may switch to the attention main shift memory after executing the process of step S114 (step S115).

[0071] In the process of step S113, if the control unit 100 does not transition to "preference 1 or 2" (step S113: No), it judges whether to transition from "preference 1 or 2" (step S114). In the process of step S114, if the control unit 100 transitions from "preference 1 or 2" (step S114: Yes), it cancels the main shift memory (step S118). After executing the process of step S118, the control unit 100 sets the main shift memory of the safety operation to OFF (step S119). Note that the control unit 100 may switch to the preference main shift memory after executing the process of step S118 (step S120).

[0072] When the control unit 100 does not transition from "Preference 1 or 2" in the process of step S114 (step S114: No), the control unit 100 stores the operation position P of the main shift lever 15 as a main shift memory ON state (step S121).

[0073] As shown in FIG. 6B, after executing the processing of step S108, i.e., after setting the main transmission memory to the OFF state, when the main transmission memory switch 56 is short-pressed (step S122), the control unit 100 determines whether the state of the tractor 1 is the main transmission memory "OFF", the sub transmission "neutral", and the main transmission "other than D (drive)" (step S123).

[0074] In the process of step S123, if the control unit 100 determines that the state of the tractor 1 is the main shift memory "OFF", the auxiliary shift "neutral", and the main shift "other than D (drive)" (step S123: Yes), it determines whether the one-touch tilling switch 53 is "other than neutral" and the attention changeover switch 54 has switched to "attention 1 or 2" (step S125). In addition, if the control unit 100 determines that the state of the tractor 1 is not the main shift memory "OFF", the auxiliary shift "neutral", and the main shift "other than D (drive)" (step S123: No), it does not store the operation position P of the main shift lever 15 and ends the main shift reproduction mode (step S124).

[0075] When the control unit 100 determines in the processing of step S125 that the one-touch tilling switch 53 is "other than neutral" and the preference change switch 54 has not switched to "preference 1 or 2" (step S125: No), it stores the operating position P of the main shift lever 15 as the main shift memory ON state (step S127).

[0076] Furthermore, if the control unit 100 determines in the process of step S125 that the one-touch tilling switch 53 is "other than neutral" and the preference changeover switch 54 has not switched to "preference 1 or 2" (step S125: No), it goes into a standby state to enter a state in which the main shift memory is ON (step S128). After executing the process of step S128, if the one-touch tilling switch 53 or the preference changeover switch 54 is operated (step S129), the control unit 100 goes into a state in which the main shift memory is OFF (step S130).

[0077] In the processing of step S125, when the control unit 100 determines that the one-touch tilling switch 53 is "other than neutral" and the preference change switch 54 has switched to "preference 1 or 2" (step S125: Yes), if the sub-speed change lever is operated to a position other than high speed (step S126), the control unit 100 goes into a standby state in which the main speed change memory is ON (step S131).

[0078] When the control unit 100 is in a standby state (step S131) ​​in which the main speed change memory is ON, and any of the one-touch tilling switch 53, the attention to detail switch 54, and the main speed change memory switch 56 is operated (step S132), the control unit 100 switches to the main speed change memory OFF state (step S130).

[0079] After executing the process of step S131, the control unit 100 sets the particular main shift memory to ON (step S133). After executing the process of step S131, the control unit 100 sets the state to a standby state for entering the state of the main shift memory to ON (step S134). When any of the one-touch tilling switch 53, the particular changeover switch 54, and the main shift memory switch 56 is operated (step S135) in the standby state for entering the state of the main shift memory to ON (step S134), the control unit 100 sets the state to the main shift memory to OFF (step S130). Note that the control unit 100 may set the particular main shift memory to ON (step S133) after executing the process of step S134.

[0080] According to the embodiment described above, the following work vehicle 1 is realized.

[0081] (1) A work vehicle 1 having a traveling body that travels using the rotational power of an engine and a main transmission that changes the traveling speed of the traveling body steplessly in response to operation of a main transmission lever, the work vehicle 1 being equipped with a control unit that controls main transmission by the main transmission and stores the operating position of the main transmission lever, and a main transmission memory switch that is pressed when the operating position of the main transmission lever is to be stored in the control unit, the control unit stores the operating position of the main transmission lever as a stored operating position by pressing and holding the main transmission memory switch for a predetermined period of time or longer, and executes a main transmission reproduction mode in which the main transmission state at the stored operating position is reproduced by pressing and holding the main transmission memory switch for a short period of time or shorter, and in the main transmission reproduction mode, maintains the main transmission state corresponding to the stored operating position even if the main transmission lever is operated to a higher speed than the stored operating position.

[0082] In this type of work vehicle 1, in the main shift reproduction mode, even if the main shift lever is operated to a higher speed than the stored operation position, the vehicle is maintained in a main shift state corresponding to the stored operation position, so that unintended speed increases by the driver can be suppressed. In other words, it becomes easier for the driver to grasp the operation of the main shift lever and the behavior of the vehicle, allowing for safer driving.

[0083] (2) In the above (1), when the main shift lever is operated to a position different from the stored operation position when the main shift memory switch is briefly pressed, the control unit controls the main shift in accordance with the operation position of the main shift lever until the operation position of the main shift lever coincides with the stored operation position.

[0084] With such a work vehicle 1, activation of the high-speed restriction mode is suspended until the operating position of the main shift lever matches the stored operating position, making it easier for the driver to understand the operation of the main shift lever and the behavior of the vehicle, allowing for safer driving.

[0085] (3) In the work vehicle 1 described above in (2), when the main shift lever is operated to a lower speed side than the memorized operating position in the main shift reproduction mode, the control unit controls the main shift in accordance with the operating position of the main shift lever.

[0086] According to such a work vehicle 1, even when the main gear shift reproduction mode is being executed, the driver can freely perform operations on the deceleration side, which allows for safer travel.

[0087] (4) In the work vehicle 1 described above in (1) to (3), the control unit stores the engine speed as the stored speed by pressing and holding the main transmission memory switch.

[0088] According to such a work vehicle 1, the control unit stores the engine speed together with the operating position of the main shift lever, thereby making it possible to reproduce the traveling speed (vehicle speed) in the main shift reproduction mode. In addition, by pressing and holding the main shift memory switch, the control unit simultaneously stores the operating position of the main shift lever (stored operating position) and the engine speed (stored speed), so that the operation of storing the engine speed in the control unit can be performed with a simpler operation.

[0089] (5) In the work vehicle 1 described above in (4), an accelerator memory switch is further provided which is operated when recalling the memorized rotation speed stored in the control unit, and the control unit does not recall the memorized rotation speed until the accelerator memory switch is operated, even when the main shift reproduction mode is executed by a short press operation of the main shift memory switch.

[0090] With such a work vehicle 1, the engine speed (memorized speed) and the operation position of the main shift lever (memorized operation position) can be reproduced as separate operations, and the traveling speed (vehicle speed) can be reproduced according to normal procedures.

[0091] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0092] 1. Work vehicle (tractor) 2 Running vehicle 15 Main gear shift lever 30 Main Transmission (HMT) 56 Main speed memory switch 58 Accelerator memory switch 100 Control section E-Engine P operation position PM Memory operation position

Claims

1. A work vehicle including a traveling body that runs on the rotational power of an engine and a main transmission that changes the traveling speed of the traveling body steplessly in response to the operation of a main transmission lever, a control unit that controls a main speed change by the main speed change device and stores an operation position of the main speed change lever; a main shift memory switch which is pressed when the operating position of the main shift lever is to be stored in the control unit; Equipped with The control unit is By pressing and holding the main shift memory switch for a predetermined period of time or longer, the operation position of the main shift lever is stored as a stored operation position, a main shift reproduction mode is executed in which the state of the main shift at the memory operation position is reproduced by a short pressing operation of the main shift memory switch for less than the predetermined time; In the main shift reproduction mode, even if the main shift lever is operated to a higher speed than the stored operation position, the main shift state corresponding to the stored operation position is maintained. A work vehicle characterized by:

2. The control unit is When the operation position of the main shift lever is operated to a position different from the stored operation position at the time of the short press operation of the main shift memory switch, the main shift is controlled according to the operation position of the main shift lever until the operation position of the main shift lever coincides with the stored operation position.

2. The work vehicle according to claim 1 .

3. The control unit is In the main shift reproduction mode, when the main shift lever is operated to a lower speed side than the stored operation position, the main shift is controlled according to the operation position of the main shift lever.

3. The work vehicle according to claim 2.

4. The control unit is The engine speed is stored as a memory speed by the long press operation of the main shift memory switch.

4. A work vehicle according to claim 1, wherein the work vehicle is a vehicle having a structure similar to that described above.

5. An accelerator memory switch operated when the stored rotation speed is to be recalled in the control unit. Further equipped with The control unit is Even when the main shift reproduction mode is executed by the short push operation of the main shift memory switch, the stored rotation speed is not recalled until the accelerator memory switch is operated.

5. The work vehicle according to claim 4.

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