JP2015101163A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work vehicle which is configured such that, in an operation not intended by an operator, a brake switch is not actuated, by solving such a problem that an auto-cruise function is released by the operation of a brake member not intended by the operator although the brake switch is sometimes used as a releasing method of the auto-cruise function in the work vehicle.SOLUTION: In such a working vehicle that, when either of brake pedals (16R, 16L) is operated by either of detection switches (102R, 102L), an auto-cruise function is released, a working range of the brake pedals (16R, 16L) is configured with a first dead zone (R1), a second dead zone (R2) and a brake actuation zone (R3) and a problem described above is solved by the work vehicle in which either of the detection switches (102R, 102L) is put "on" except for the first dead zone (R1).

Description

  The present invention relates to a work vehicle to which work machines for agriculture, construction, transportation, etc. are connected, and particularly to a work vehicle such as a tractor.

  The work vehicle described in Patent Document 1 describes a tractor having an auto-cruise function. As an example of releasing the auto-cruise function, when the steering switch is turned on when the brake switch is turned on, the auto-cruise is turned on. It is set to cancel the function.

JP-A-1-168530

  However, in Patent Document 1, it is not clear in which range of the brake operation the brake switch is turned on. The brake switch in such a case is usually provided at a position where it is not affected by the backlash of the brake member. However, even if it is provided in a position that is not affected by play, the brake switch is unintentionally operated by the operation of the brake member not intended by the operator, and the auto-cruise function is canceled. There was a problem. Therefore, it is a problem to be solved by the present invention to provide a work vehicle configured such that a brake switch does not operate in an operation not intended by the operator.

The present invention has taken the following technical means to solve the above problems.
That is, the invention described in claim 1 includes a vehicle body (1) provided with left and right traveling drive wheels (3R, 3L), an engine (5) and a hydraulic continuously variable transmission (34) provided in the vehicle body (1). ), The left and right brake pedals (16R, 16L) for decelerating or stopping the rotation of the traveling drive wheels (3R, 3L), and the left and right brake pedals (16R, 16L). ), And left and right detection switches (102R, 102L) that detect on / off by a predetermined depression position, and the control device (100) has an auto-cruise function for maintaining the vehicle speed, A work vehicle that releases the auto-cruise function when any of the brake pedals (16R, 16L) is operated by any of the detection switches (102R, 102L) The first dead zone (R1) where the urging force of the urging member for restoring the operating range of the left and right brake pedals (16R, 16L) to the standby position is not exerted. A second dead zone (R2) in which the urging force of the urging member is applied to the brake pedal (16R, 16L) and no braking force is applied to the traveling drive wheels (3R, 3L), and the brake pedal (16R 16L) and a brake operating band (R3) in which the urging force of the urging member is applied and the driving force is applied to each of the traveling drive wheels (3R, 3L), and the detection switches (102R, 102L) ) Is a work vehicle characterized by being “ON” except for the first dead zone (R1).

  According to a second aspect of the present invention, when the control device (100) detects that one of the detection switches (102R, 102L) is “ON” for a predetermined time, the auto-cruise function is canceled. The work vehicle according to claim 1, wherein:

  The invention according to claim 3 is characterized in that one of the detection switches (102R, 102L) is "ON" in the brake operating band (R3). It is a work vehicle.

  According to the first aspect of the present invention, any one of the left and right brake pedals (16R, 16L) is activated when any one of the detection switches (102R, 102L) is “ON” except for the first dead zone (R1). If the vehicle is not depressed more than a certain amount, the auto-cruise function is not released, and therefore the auto-cruise function is not released by the operation of the brake pedal not intended by the operator. This improves the efficiency of work using the work vehicle.

  According to the second aspect of the present invention, in addition to the effect of the first aspect of the invention, the control device (100) has one of the left and right detection switches (102R, 102L) turned on. When this is detected for a predetermined time, the auto-cruise function is canceled and the auto-cruise function is not released unless the brake pedal is operated for a certain period of time. It will not be released. Therefore, the work efficiency using the work vehicle is further improved.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, any one of the left and right detection switches (102R, 102L) is turned on in the brake operating band (R3). Therefore, since the auto-cruise function is not released unless the brake pedal is depressed more than a certain amount, the auto-cruise function is not released by the operation of the brake pedal not intended by the operator. Therefore, the work efficiency using the work vehicle is further improved.

1 is a side view of a work vehicle according to a first embodiment of the present invention. It is a top view of the work vehicle of FIG. It is explanatory drawing of the brake pedal periphery of the working vehicle of FIG. It is a power transmission mechanism diagram of the transmission of the work vehicle of FIG. FIG. 2 is a hydraulic circuit diagram of a hydrostatic continuously variable transmission for the work vehicle of FIG. 1. It is a control block diagram of the work vehicle of FIG. It is a top view of the lever guide part of the work vehicle of FIG. It is a side view of the brake pedal of the work vehicle of FIG. It is a perspective view of the handle post right side part of the work vehicle concerning a second embodiment. It is a perspective view of the handle post right side part of the work vehicle concerning a third embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In this specification, the driver who has boarded the vehicle is referred to as left and right respectively in the forward direction of the vehicle and left and right as front and rear, respectively.

  Hereinafter, a tractor will be described as an example of a work vehicle. 1 is a right side view of the work vehicle according to the first embodiment of the present invention, FIG. 2 is a plan view of the work vehicle of FIG. 1, and FIG. 3 is a view around the brake pedal of the work vehicle of FIG. An explanatory diagram is shown.

  The work vehicle according to the first embodiment includes left and right front wheels 2R and 2L at the front portion of the traveling vehicle body 1 and left and right traveling drive wheels 3R and 3L as rear wheels at the front portion. The rotational power of the mounted engine 5 is appropriately decelerated by a transmission in the transmission case 4 and transmitted to the front wheels 2R, 2L and the traveling drive wheels 3R, 3L as rear wheels. A steering handle 7 is supported on the handle post 6 at the center of the vehicle body 1, and a seat 9 on which a driver is seated is provided behind the steering handle 7.

  As shown in FIGS. 1 to 3, the work vehicle houses the fuel tank 8 in the bonnet 22, and the rear side of the fuel tank 8 main body is housed in the handle post 6. A plurality of levers are provided below the steering handle 7. A forward / reverse lever 10 that switches the traveling direction of the vehicle body 1 to the front / rear direction is provided on the left side surface of the handle post 6, and an emergency stop switch 60 is provided on the front side thereof. When the forward / reverse lever 10 is moved forward, the vehicle body 1 moves forward, and when it is moved backward, it moves backward. A throttle lever 11 for changing the engine speed is provided on the right side surface of the handle post 6. An accelerator pedal 15 is disposed at the right corner portion of the step floor 13, and a pair of right and left brake pedals 16 </ b> R and 16 </ b> L are disposed between the accelerator pedal 15 and the handle post 6.

  The accelerator pedal 15 is basically used when traveling on the road, and the control device 100 controls the engine speed according to the depression amount, and the depression amount of the accelerator pedal 15 is detected by the accelerator pedal potentiometer 76 (FIG. 6). The rotation angle of the trunnion shaft 30 (shown only in the control block diagram of FIG. 6) of the hydrostatic continuously variable transmission (HST) 34 can be changed according to the detected value of the accelerator pedal potentiometer 76. The inclination angle of the swash plate 34d (FIG. 5) is changed according to the rotation angle of the trunnion shaft 30, thereby changing the output of the HST 34 steplessly.

  The throttle lever 11 is used to change the engine speed, and is basically used during work travel. The throttle lever 11 is configured so that the position is maintained even if the hand is released at the operated position.

  On the left side of the cockpit 9, an auxiliary transmission lever 21 that can select any one of low speed, medium speed, high speed, and neutral is arranged, and behind that is mounted between the front wheels 2R, 2L and the traveling drive wheels 3R, 3L. Mid PTO shift lever 23a for turning on / off and shifting the PTO shaft of a mid working machine (moor, etc.), and a rear for turning on / off and shifting of the PTO shaft of a work machine (moor, rotary, snow remover, etc.) mounted at the rear of the machine body A PTO speed change lever 23b is provided and a 4WD lever 24 is disposed. Further, the link 31 for connecting a work machine (not shown) is provided behind the vehicle body 1.

  The operation of the left and right brake pedals 16R and 16L will be described. When the right brake pedal 16R is depressed, the brake of the right traveling drive wheel 3R acts, the rotational operation of the right traveling drive wheel 3R decelerates or stops, and when the left brake pedal 16L is depressed, the brake of the left traveling drive wheel 3L acts. Thus, the rotation operation of the left traveling drive wheel 3L is decelerated or stopped. The right brake pedal 16R is provided with a connecting bracket 101 that couples the right brake pedal 16R and the left brake pedal 16L. When traveling on a road or the like outside the farm field, the brake pedals 16R and 16L are coupled by the connecting bracket 101 to brake the left and right traveling drive wheels 3R and 3L in the same manner. The left and right brake pedals 16R and 16L are respectively provided with ON / OFF detection switches 102R and 102L that detect on / off when the brake pedals 16R and 16L are depressed to a predetermined depression position. For example, when the right brake pedal 16R is depressed by the driver and reaches a predetermined depression position, the detection switch 102R is switched ON / OFF. In this embodiment, the detection switch 102R is changed from “OFF” to “ON”. The state changes. The left brake pedal 16L has the same configuration.

  The power transmission path of the work vehicle according to the present embodiment will be described with reference to FIGS. FIG. 4 shows a power transmission mechanism diagram of the transmission of the work vehicle of FIG. 1, and FIG. 5 shows a hydraulic circuit diagram of the hydrostatic continuously variable transmission of the work vehicle of FIG. The rotational power of the engine 5 is transmitted from the HST input shaft 33 to the HST 34, and is further transmitted to the meshing transmission 38 by driving the travel output shaft 35. As shown in FIG. 5, in the HST 34, the hydraulic pump 34a is operated by the power introduced from the HST input shaft 33, and pressure oil corresponding to the inclination angle of the swash plate 34d provided in the hydraulic pump 34a is supplied to the hydraulic closed circuit 34c. To the hydraulic motor 34b, and the travel output shaft 35 for driving the travel drive wheels 3R and 3L is driven by the hydraulic motor 34b.

  The meshing transmission 38 is provided with a sub-transmission clutch 39, and the rotational output from the sub-transmission clutch 39 is transmitted to the travel drive wheels 3R and 3L via the transmission shaft 43 and the differential device 46, and the travel drive wheels 3R. , 3L are driven. Specifically, the power output from the HST 34 is transmitted from the travel output shaft 35 to the rotating shaft 36, and the gear stage by the transmission 38 is set as follows. In the sub-transmission high speed (third speed), the power shifted from the gear 38 a by the gear 38 b is transmitted to the transmission shaft 43. The sub-shift medium speed (second speed) is transmitted from the gear 38c to the gear 38d, and the sub-shift low speed (first speed) is transmitted from the gear 38e to the gear 38f. 43. These three sub-shifts are switched by operating the sub-shift lever 21 and sliding the shifter 39 left and right.

  On the other hand, the driving force for driving the working shaft is input from the HST input shaft 33 to the variable displacement hydraulic pump 34a (FIG. 5), and from the pump output shaft 51 (shown only in FIG. 4) to the PTO hydraulic clutch 54, etc. Is transmitted to the drive system for PTO provided on the PTO shaft 52 via. Power is transmitted from the PTO shaft 52 to the rear PTO shaft 55 and the mid PTO shaft 56. Further, the gear 58 on the lower side of the sub-shift of the transmission shaft 43 is transmitted to the gear 57 of the front wheel output shaft 48 via the gear 47 of the PTO shaft 52 and the gear 59 integral with the gear 47, and the front wheels 2R, 2L Is driven.

  As shown in FIGS. 2 and 7, the lever guide 12a on the right side of the cockpit 9 has a maximum speed setting dial 14a, a vehicle speed slowness response dial 14b, and a cruise travel switch 14c arranged in a line in order from the front side to the rear side.

  FIG. 6 shows a control block diagram of the work vehicle of FIG. As an input signal to the control device 100, a signal such as an accelerator pedal potentiometer 76 corresponds, and the control device 100 performs a calculation based on these input signals. The output signal corresponds to a signal to the engine 5 or the like, and the control device 100 transmits an output signal to each device based on the calculation of the control device 100.

  The operation of the trunnion shaft 30 will be described. The rotational speed of the hydrostatic continuously variable transmission (HST) 34 is determined by the rotation angle of the trunnion shaft 30 (FIG. 5), that is, the rotation angle of the swash plate 34d. That is, when the depression amount of the accelerator pedal 15 is detected by the accelerator pedal potentiometer 76, the operation amount of the trunnion shaft 30 is automatically set by the control device 100 according to the detected value of the accelerator pedal potentiometer 76, and The hydraulic output speed of the hydraulic continuously variable transmission (HST) 34 is automatically set to an appropriate value by the control device 100.

  The controller 100 sets the rotation direction of the trunnion shaft 30 of the hydrostatic continuously variable transmission (HST) 34 to the forward side or the reverse side by switching the forward / reverse switching lever 10 to the forward side or the reverse side. . The turning direction of the trunnion shaft 30 is determined by the switching valve 63 (FIG. 5), and the turning angle of the trunnion shaft 30 is determined by the amount of current to the proportional valve 65 according to the depression amount of the accelerator pedal 15. .

  In an emergency such as a valve stick, the control device 100 forcibly returns the HST trunnion shaft 30 to neutral when the brake pedals 16R and 16L in the control unit are fully depressed. Stepping on the brakes 16R, 16L means that the trunnion shaft 30 returns to neutral because the foot is released from the accelerator pedal 15, but the speed at which the trunnion shaft 30 is returned to neutral varies depending on the model.

  The control device 100 has an auto-cruise function that maintains the vehicle speed of the vehicle body 1 of the work vehicle. The maximum speed setting dial 14a, the vehicle speed slowness response dial 14b, and the cruise travel switch 14c are operation members used when executing the auto cruise function. The auto-cruise function is automatically canceled by the control device 100 when the operator depresses and operates one of the brake pedals 16R and 16L.

  The maximum speed setting dial 14a regulates the maximum speed of the vehicle body by adjusting the rotation angle of the trunnion shaft 30. In this case, even if the accelerator pedal 15 is depressed to the maximum, the work vehicle can be driven only at a speed regulated by the maximum speed setting dial 14a. The maximum speed setting dial 14a changes the rotation angle of the trunnion shaft 30 and the output of the HST 34 corresponding to the maximum speed. For example, about 15-30 km / It can be changed to a dial type in the range of h.

  The vehicle speed slowness response dial 14b changes and sets the response of the turning operation of the trunnion shaft 30. When the accelerator pedal 15 is stepped on, the target speed is determined by the accelerator pedal potentiometer 76, that is, the rotation angle of the target trunnion shaft 30 is determined, and the trunnion shaft 30 is reached by the position of the rotation angle of the target trunnion shaft 30. The time to reach is changed. For example, if the vehicle speed slowness response dial 14b is made insensitive (slow), even if the accelerator pedal 15 is stepped on quickly, the time to reach the target rotation angle of the trunnion shaft 30 will be slow, so it will accelerate slowly. To go. The change of the arrival time to the target position is performed by changing the duty ratio of the current to the proportional valve 65 (FIG. 4). The time required to reach a predetermined vehicle speed by the vehicle speed slowness response dial 14b can be changed to a dial type from about 3 seconds to about 6 seconds, for example.

  The cruise travel switch 14c is an on / off switch. When the cruise travel switch 14c is turned on while traveling at a specific speed, the trunnion is matched with the vehicle speed when the cruise travel switch 14c is turned on. The rotation angle of the shaft 30 is stopped, the output of the HST 34 is kept constant, and the vehicle speed is kept constant. With this configuration, the speed at that time is maintained even if the foot is released from the accelerator pedal 15.

  FIG. 8 shows a left side view of the left brake pedal 16L of the work vehicle according to the first embodiment of the present invention. The left brake pedal 16L is provided with an urging member 103 for recovering the left brake pedal 16L depressed by the driver to the standby position of the left brake pedal 16L. The work vehicle of this embodiment comprises the operating range of the left brake pedal 16L by the first dead zone R1, the second dead zone R2, and the brake operating zone R3. Although the left brake pedal 16L will be described, the same configuration is adopted for the right brake pedal 16R.

  The first dead zone R1 is an area of mechanical play such as a so-called pedal itself, and even if the left brake pedal 16L is returned to the standby position by the urging member 103, it is a range in which the left brake pedal 16L operates by vibration or the like. The range where the urging force of the urging member 103 does not reach is said. Unlike the mechanical backlash, the second dead zone R2 refers to a zone where the urging force of the urging member 103 reaches, but the braking force does not operate. Even if the operator depresses the left brake pedal 16L, the braking force is not increased in this region. Although not actuated, when the operator removes the leg for depressing from the left brake pedal 16L, the urging force of the urging member 103 and the range in which the left brake pedal 16L is automatically restored to the standby position by the urging member 103 Say. The brake operating band R3 is that when the operator depresses the left brake pedal 16L, the braking force is applied to the left traveling drive wheel 3L in proportion to the amount of depression, and the operator depresses from the left brake pedal 16L. If the leg is removed, the urging force of the urging member 103 is applied, and the range in which the left brake pedal 16L is automatically restored to the standby position by the urging member 103 is described.

  The left brake pedal 16L is provided with a position where the left detection switch 102L is “ON” in the brake operation band R3. When the left detection switch 102L is turned “ON” while the work vehicle is being driven using the auto-cruise function, the control device 100 cancels the auto-cruise function. By providing a position where the left detection switch 102L is “ON” in the brake operating band R3, the auto-cruise function is not released unless the operator depresses the left brake pedal 16L for a certain amount.

  Although the auto-cruise function can be canceled immediately after the left detection switch 102L is turned “ON”, the control device 100 detects that the left detection switch 102L is “ON” for a predetermined time. In such a case, the auto-cruise function may be canceled. In this case, the predetermined time is set by a timer in the control device 100. It is also possible to provide a position where the left detection switch 102L is “ON” in the second dead zone R2. In this case, by providing the position where the left detection switch 102L is “ON” on the side close to the brake operating band R3, even if the driver accidentally operates the brake pedal, the auto-cruise function is erroneously released. Can be prevented.

  Since either of the detection switches 102R and 102L is “ON” except for the first dead zone R1, the auto-cruise function is not released unless one of the left and right brake pedals 16R and 16L is depressed more than a certain amount. The auto-cruise function is not canceled by the operation of the brake pedal unintended by the user. This improves the efficiency of work using the work vehicle.

  When the control device 100 detects that either one of the left and right detection switches 102R and 102L is “ON” for a predetermined time, the brake pedal is operated for a predetermined time or more by canceling the auto-cruise function. Otherwise, since the auto-cruise function is not released, the auto-cruise function is not released by the operation of the brake pedal not intended by the operator. Therefore, the work efficiency using the work vehicle is further improved.

  Since either of the left and right detection switches 102R and 102L is “ON” in the brake operating band R3, the auto-cruise function is not released unless the brake pedal is depressed more than a certain amount. The auto-cruise function is not canceled by the operation. Therefore, the work efficiency using the work vehicle is further improved.

  In the above, when any of the detection switches 102R and 102L is “ON”, that is, the operation at the time of working in the field where the left and right brake pedals 16R and 16L can be operated independently by removing the coupling fitting 101. As described above, the auto-cruise function is canceled only when driving outside the field where the left and right brake pedals 16R and 16L are connected using the connecting bracket 101, that is, when both the detection switches 102R and 102L are turned on. It can also be configured as follows. In this case, since the auto-cruise function is not canceled even if any one of the detection switches is turned “ON”, a braking force is applied to one of the traveling drive wheels 3R, 3L to reduce the turning radius of the work vehicle. Work efficiency is improved. Furthermore, a configuration is also possible in which the auto-cruise function is canceled only when it is detected for a predetermined time that both the detection switches 102R and 102L are “ON”. Further, when the sub-shift lever 21 is in the “high speed” position, if either of the left and right detection switches 102R, 102L is “on”, the control device 100 may be configured to cancel the auto-cruise function. .

  In FIG. 9, the perspective view from the back of the handle post 6 right side part of the working vehicle concerning 2nd embodiment is shown. In the work vehicle according to the second embodiment, an auto-cruise speed increasing switch 104 and an auto-cruising speed reducing switch 105 that increase / decrease the set speed of the auto-cruise function are located on the front side of the right side of the handle post 6 and below the steering handle 7. Provide. While the auto-cruise speed increasing switch 104 is being pressed, the speed increases, and when released, the travel is continued at the current speed. While the auto-cruise deceleration switch 105 is being pressed, the speed decreases, and when released, the vehicle continues running at the current speed. By disposing at this position, the operability and visibility are improved, and it is possible to prevent the switches 104 and 105 from being accidentally touched when the handle is operated. Further, since the handle post 6 is provided, even if the handle post 6 is tilted, the position with respect to the steering handle 7 does not change, and the operability does not change.

  In FIG. 10, the perspective view from the right side rear part of the handle post 6 of the work vehicle concerning 3rd embodiment is shown. In the work vehicle according to the third embodiment, an auto-cruise acceleration / deceleration lever 106 that increases or decreases the setting speed of the auto-cruise function is provided on the right side of the handle post 6, below the steering handle 7 and above the throttle lever 11. Provide. The auto-cruise speed increasing / decreasing lever 106 increases the vehicle speed when the operator pulls it forward, and decreases the vehicle speed when pushed forward. The auto-cruise speed increasing / decreasing lever 106 has a length such that the tip of the auto-cruise speed increasing / decreasing lever 106 protrudes outside the outer periphery of the steering handle 7 in plan view. In this embodiment, the auto-cruise acceleration / deceleration lever 106 is configured to be operated in the front-rear direction. However, the auto-cruise acceleration / deceleration lever 106 may be configured to be operated in the up-down direction. it can.

DESCRIPTION OF SYMBOLS 1 Work vehicle 3R, 3L Travel drive wheel 5 Engine 16R, 16L Brake pedal 34 Hydraulic continuously variable transmission 100 Control apparatus 102R, 102L Detection switch R1 1st dead zone R2 2nd dead zone R3 Brake action zone

Claims (3)

A vehicle body (1) having left and right traveling drive wheels (3R, 3L);
A control device (100) for controlling the engine (5) and the hydraulic continuously variable transmission (34) included in the vehicle body (1);
Left and right brake pedals (16R, 16L) for decelerating or stopping the rotation of the traveling drive wheels (3R, 3L);
For each of the left and right brake pedals (16R, 16L), left and right detection switches (102R, 102L) for detecting on / off by a predetermined depression position,
The control device (100) has an auto-cruise function for maintaining the vehicle speed,
In a work vehicle that releases the auto-cruise function when any of the brake pedals (16R, 16L) is operated by any of the detection switches (102R, 102L),
The operating range of the left and right brake pedals (16R, 16L)
A first dead zone (R1) of the urging member that recovers the brake pedal (16R, 16L) to the standby position, to which the urging force does not reach;
A second dead zone (R2) in which the urging force of the urging member is applied to the brake pedal (16R, 16L) and the braking force is not operated to the respective traveling drive wheels (3R, 3L);
The brake pedal (16R, 16L) is configured with a biasing force of a biasing member and a brake operating band (R3) in which a braking force is applied to each of the traveling drive wheels (3R, 3L).
Any of the detection switches (102R, 102L) is "ON" except for the first dead zone (R1). The control device (100) is
When it is detected for a predetermined time that any of the detection switches (102R, 102L) is “ON”,
The work vehicle according to claim 1, wherein the auto-cruise function is canceled.   3. The work vehicle according to claim 1, wherein one of the detection switches (102 </ b> R, 102 </ b> L) is “ON” in the brake operation band (R <b> 3).

Images