JP2014008836A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device simplified in a configuration and capable of being inexpensively achieved by using an existing brake pedal shaft as an HST (hydrostatic continuously variable transmission) pedal shaft.SOLUTION: This invention includes HST forward and reverse drive pedals (19F) and (19B) which perform forward and reverse drive control by stepping operation, and brake pedals (17L) and (17R) which brake right and left traveling brakes (16) and (16) by stepping operation. The HST forward and reverse drive pedals (19F) and (19B) are constructed on the same axis core by using a turning fulcrum shaft (18) of the brake pedal (17).

Description

  The present invention relates to a work vehicle including a forward / reverse transmission means for performing forward / reverse control by operating an HST pedal and a braking means for braking left and right traveling brakes by operating a brake pedal.

  The technique disclosed in Patent Document 1 has a configuration in which the pedal shaft of the HST pedal and the arm shaft of the brake arm are mounted on separate shafts.

JP 2005-225349 A

In the conventional configuration, since the HST pedal shaft and the brake arm shaft are separate shaft configurations, the configuration is complicated, the number of parts is large, and the cost is difficult to implement.
An object of the present invention is to solve the above problems by using an existing brake pedal shaft as an HST pedal shaft.

In order to solve the above problems, the present invention has taken the following technical means.
That is, according to the present invention, the HST forward / reverse pedals (19F) and (19B) that perform forward / reverse control by the depression operation and the brake pedals that brake the left and right traveling brakes (16) and (16) by the depression operation are provided. (17L), (17R), and the HST forward / reverse pedal (19F), (19B) is mounted on the same axis using the pivot point (18) of the brake pedal (17). It is characterized by being.

The brake pedals (17L) and (17R) brake the left and right traveling brakes (16) and (16) by stepping on the brake pedal shaft (18) as a rotation fulcrum.
The HST forward / reverse pedals (19F) and (19B) are stepped on the same axis as that of the brake pedal shaft (18) as a rotation fulcrum, so that the aircraft moves forward and backward. That is, when the forward pedal (19F) is depressed, the aircraft advances under the control of the hydraulic continuously variable transmission (HST), and when the backward pedal (19B) is depressed, the aircraft moves backward.

  According to the above configuration, the rotation fulcrum shaft of the HST forward / reverse pedal uses the existing rotation fulcrum shaft of the brake pedal, so there is no need to provide a separate fulcrum shaft dedicated to HST as in the prior art. Therefore, it can be implemented at low cost.

  According to a second aspect of the present invention, in the first aspect, a potentiometer (21) for detecting an operation angle of each pedal is provided on a side portion of the HST forward pedal (19F) and the reverse pedal (19B). It is characterized by being.

  According to the said structure, it can control accurately, detecting the operation depression angle of each forward / reverse pedal by the potentiometer (21) arrange | positioned at the side part of each pedal. Moreover, although two potentiometers are used, the link configuration of the pedal is simplified compared to the use of one potentiometer, which is advantageous in terms of cost.

  The present invention according to claim 3 is configured to be controllable so that, when the HST forward / reverse pedals (19F) and (19B) are depressed simultaneously, the travel of the airframe is automatically stopped. It is characterized by being.

According to the above configuration, if both the left and right forward and backward pedals are depressed simultaneously during forward and backward control, the aircraft stops automatically without moving forward or backward.
In short, if the forward / reverse judgment cannot be made, the aircraft will automatically stop, so it is safe.

  According to the first aspect of the present invention, since the pivot fulcrum shaft of the HST forward / reverse pedal uses the existing pivot fulcrum shaft of the brake pedal, a dedicated fulcrum shaft dedicated to HST is provided separately as in the prior art. There is no need, the number of parts is small, and it can be implemented at low cost.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, the potentiometer is arranged on the side portion of each pedal, and the operation depression angle of each forward / reverse pedal is detected. It becomes possible.

  According to the third aspect of the present invention, in addition to the effect of the first or second aspect, if the left and right forward / reverse pedals are operated simultaneously and the forward / backward judgment cannot be made, the aircraft automatically Since it stops, the work can be performed safely.

Side view of tractor Rear view of the main part Side view of the main part Rear view of the main part of the tractor Rear view of part of tractor Side view of HST forward / reverse pedal operation Side view of the main part of another example Side view of the main part of another example Side view of the main part of another example Perspective view of the main part of the operating mechanism of the HST forward / reverse pedal Perspective view of the main part Side view of the main part Perspective view of the main part of the tractor operation section

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a tractor as an example of a work vehicle. The tractor T has an engine E mounted in the hood 1 at the front of the vehicle body, and the rotational power of the engine E is supplied to a hydraulic continuously variable transmission (HST). ) Is transmitted to the transmission in the mission case 2 via 10, and the rotational power decelerated by this transmission is transmitted to the front wheels 3 and the rear wheels 4. A steering handle 5 for steering the front wheels 3 and 3 is provided behind the engine E, and a driver's seat 6 is installed behind the steering handle 5. A hydraulic cylinder case 7 is mounted on the rear upper part of the mission case 2, and lift arms 8 and 8 that constitute a part of the hydraulic lifting mechanism are pivotally supported on the left and right sides of the cylinder case 7. Has been. When hydraulic oil is supplied to the working machine lifting / lowering hydraulic cylinder 9 housed in the cylinder case 7, the lift arms 8 and 8 are rotated upward, and when discharged, the lift arms 8 and 8 are lowered.

A work machine R such as a rotary tiller is mounted on the rear part of the vehicle body via a three-point link mechanism including a top link 11 and a lower link 13 that moves up and down via a lift rod 12.
Further, on the left side of the operation column 14, brake pedals 17L and 17R for braking the left and right traveling brakes (left and right rear wheels 4 and 4) 16L and 16R of the vehicle by a stepping operation are disposed above the step floor 15. . The brake pedals 17L and 17R are configured so as to be able to be depressed with a brake pedal shaft 18 pivoted in the left and right lateral directions above the step floor 15 as a pivotal fulcrum.

  On the right side of the operation column 14, on the step floor 15, there are HST forward / reverse pedals 19F, 19B for controlling the forward and backward movement of the vehicle. By operating the left forward pedal 19F and the right reverse pedal 19B, the operation rod is Thus, the trunnion shaft 20 of the HST 10 is controlled to rotate so as to continuously change from the neutral position to the forward acceleration position and the reverse acceleration position. These forward / reverse pedals 19F and 19B are provided side by side on the same axis as the brake pedal shaft 18 installed in the lateral direction.

  Potentiometers 21 and 21 for detecting operation angles of the pedals 19F and 19B are provided on the sides of the forward / reverse pedals 19F and 19B. The potentiometer 21 is configured to accurately perform forward / reverse control by detecting the operation depression angle of each forward / backward pedal. In the above configuration, in order to ensure safety, when the left and right forward / reverse pedals 19F and 19B are depressed simultaneously, the forward / reverse control is not activated and the aircraft is automatically stopped. Can do.

  In the configuration of an HST forward / reverse pedal that uses two potentiometers for two pedals, a check device can be provided so that both the left and right pedals cannot be operated simultaneously. For example, as shown in FIG. 4, bevel gears G1 and G2 are provided facing each other at the end of the hub 24 of each pedal 19F and 19B, and pinion bevels G3. G4 is installed and linked. According to this, when the pedal on one side is stepped down, the pedal on the other side reverses and reverses upward.

  In the example of FIG. 5, either the forward pedal 19F or the reverse pedal 19B is mounted on the brake pedal shaft 18, and the other pedal is attached to another rotating shaft 25 having an appropriate distance from the brake pedal shaft 18. The link interlocking means 26 for operating the forward / reverse pedal in opposite directions is provided in the space between the two axes.

  Further, in the example of FIG. 6, in the configuration in which the forward pedal shaft 25 and the reverse pedal shaft 18 are mounted at a predetermined interval and a pedal interlocking device is provided between the two shafts, the spur gear 27 a, 27b is engaged so as to be interlocked.

  As shown in the example of FIG. 7, a link plate 28 a having a long hole 29 is attached to one pedal hub 24, and a link plate 28 b having pins 30 is attached to the other pedal hub 24. And it can also comprise so that the movement of a pedal may be interlocked | inserted by inserting the pin 30 in the elongate hole 29. FIG.

  In the example of FIG. 8, arm plates 31 a and 31 b with pins 30 are attached to both pedal hubs 24 and 24, and the arm plates 31 a and 31 b with pins are interlocked by a connecting plate 32.

  In the embodiment shown in FIG. 9, a neutral cam plate 33 is installed on one of the pedal hubs 24 in a configuration in which means for interlocking the forward pedal and the reverse pedal is provided in the space between the forward pedal shaft 25 and the reverse pedal shaft 18. The pedal is configured to return to neutral by pressing the cam roller 35 of the neutral arm 34 that can be rotated independently. The rotation fulcrum shaft of the neutral arm 34 is shared with the forward pedal shaft 25. As a means for obtaining the pressing force of the neutral arm 34, a torque spring, a gas damper 36, or the like can be used.

  The embodiment shown in FIGS. 10, 11 and 12 will be described. The forward / reverse pedals 19F and 19B include a swing link 38 that swings back and forth around the longitudinal support shaft 37 in the middle portion, and a forward / backward pedal arm. It is linked and linked via a link mechanism comprising reciprocating links 39L and 39R that can be moved back and forth to be connected to both ends of the swing link 38, and when one pedal is depressed, the other pedal moves in the opposite direction. It is configured. According to this, the pedal on the other side moves in the opposite direction in conjunction with the depression of the pedal on one side, so that both pedal positions are aligned when neutral, improving visibility, operability and safety. improves.

  An angle detection sensor 40 is provided near the vertical support shaft 37 of the swing link 38, which detects the pedal depression angle, and controls the opening of the trunnion according to the pedal depression amount. It is configured to do. The vertical support shaft 37 is configured to be slidable in the front-rear direction, and is normally configured to always be urged forward by a tension spring 41. When both pedals are depressed simultaneously, the longitudinal support shaft portion 37 slides backward, the slide pin 44 slides in the guide groove 43 of the sensor arm 42 of the angle detection sensor 40, and the angle of the sensor arm 42 is neutral. You can keep the position.

  Further, a detection switch 45 for detecting that the substantially vertical support shaft portion is pushed in is provided on the back side of the slidable vertical support shaft portion 37. Therefore, when both pedals are depressed at the same time, the longitudinal support shaft portion 37 slides backward, so that the angle detection sensor maintains the neutral position, and the detection switch 45 on the back side is pushed and turned on, thereby turning the HST on. It can be used as an input signal for control to forcibly return to neutral, or to operate the brake to stop the machine body, and the control can be expanded.

  The configuration example shown in FIG. 13 relates to the structure of the differential lock pedal 47 protruding from the front cover 46 below the driver's seat. In order to secure a step space, the differential lock pedal is formed by a round bar and comes out of the guide hole 48. It is configured to be bent sideways at a location. When the diff lock pedal is stepped on, it is possible to secure a space for the heel if the front cover 46 where the heel of the foot hits is partially bent backward.

10 HST (hydraulic continuously variable transmission)
16 Traveling brake 17 Brake pedal 18 Brake pedal shaft 19F HST forward pedal 19B HST reverse pedal 21 Potentiometer

Claims (3)

  HST forward / reverse pedals (19F), (19B) that perform forward / reverse control by depressing operation, and brake pedals (17L), (17R) that brake left and right traveling brakes (16), (16) by depressing operation, The work vehicle characterized in that the HST forward / reverse pedals (19F) and (19B) are mounted on the same axis using the rotation fulcrum shaft (18) of the brake pedal (17).   The work vehicle according to claim 1, wherein a potentiometer (21) for detecting an operation angle of each pedal is provided on a side portion of the HST forward pedal (19F) and the reverse pedal (19B).   The work according to claim 1 or 2, wherein when the HST forward / reverse pedals (19F) and (19B) are depressed simultaneously, the vehicle can be controlled to automatically stop traveling. vehicle.

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