JP5251017B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle such as an agricultural tractor, a riding management machine, or an aerial work vehicle.

  2. Description of the Related Art Conventionally, a technique for changing and adjusting a tread of a wheel pivoted on a vehicle is widely known, for example, as disclosed in Japanese Patent Application Laid-Open No. 2000-301906 (see Patent Document 1). In addition, there is a known technique filed by the present applicant.

  A tread changing device for a work vehicle described in the publication includes a hydraulic cylinder that changes a tread of a front wheel or a rear wheel of the vehicle, and a stroke sensor that detects the tread. Alternatively, when it is detected that the tread of the rear wheel is in the changed state, the left and right rear wheels are operated until the on / off switch for changing the tread is changed from [On] to [Off] and from [Off] to [On]. The brake is activated to temporarily check the start of the vehicle.

As described above, the known technique is a technical means for ensuring the safety of the subsequent traveling accompanying the change of the tread.
JP 2000-301906 A

  A configuration in which tread adjustment of left and right wheels axially mounted on a vehicle is normally performed using a hydraulic cylinder is widely known. Then, when the connected hydraulic valve is switched based on the control signal and changed to the zoom output side, the hydraulic cylinder is supplied with hydraulic oil and zoomed to the expansion side or the contraction side while the wheel of the wheel is operated. A tread change will be made.

  In this way, the hydraulic cylinder performs zoom operation while high pressure hydraulic oil is supplied in a relief state, and when the output operation is completed, the internal pressure remains in the cylinder until the next zoom operation. I will wait. Then, the internal pressure remaining in the hydraulic cylinder gradually increases as time passes, and when the oil temperature rises in relation to the ambient temperature, the pressure further increases due to the influence of the internal pressure. It will be. As a result, the hydraulic cylinder has a problem that there is a risk that the internal pressure is applied to the pipes in the communication state to cause breakage or the like.

In order to solve the above-mentioned problem, the invention described in claim 1 is a hydraulic cylinder (3) for changing and adjusting the treads of the left and right wheels (2, 2) pivoted on the vehicle (1). , 3), and the hydraulic cylinder (3, 3) is configured to change and operate the tread by hydraulic oil fed from the hydraulic valve (4, 4) that operates based on a control signal. (4, 4) supplies the hydraulic oil to the hydraulic cylinders (3, 3) to perform the desired tread change output, and then outputs the output in the direction opposite to the tread change output for a set time (T) and configured to output between,
By outputting the output in the direction opposite to the tread change output for the set time (T), if it is more than a certain value away from the preset target tread width, it will automatically be corrected to the target tread width,
The hydraulic valve (4, 4) supplies hydraulic oil to the hydraulic cylinder (3, 3) and compares it with the oil temperature when the tread change output is performed. When the oil temperature rises above a set value, the hydraulic valves (4, 4) output alternately to the expansion side and the contraction side for a set time (T2) with respect to the hydraulic cylinder (3, 3). age,
By alternately outputting to the expansion side and the contraction side for the set time (T2), it is configured to automatically correct the target tread width when it deviates from a preset target tread width by a certain value or more. This is a working vehicle characterized by the above.

The hydraulic valves (4, 4) supply hydraulic oil to the hydraulic cylinders (3, 3) and complete the adjustment to change the tread of the left and right wheels (2, 2), and then output in the opposite direction to the output. When it is output for a set time (T) and deviates from a preset target tread width by a certain value or more, the internal pressure remaining in the cylinder decreases. Further, when the oil temperature rises to reach a temperature that affects the rise of the internal pressure, the hydraulic valves (4, 4) are set on the expansion side and the contraction side with respect to the hydraulic cylinders (3, 3) for a set time (T2). When the output is alternated between and a predetermined value or more away from the preset target tread width, the increase in internal pressure is resolved. By reducing the internal pressure, the safety of the piping is ensured. In advance spillover of the pipe which is in communication with a proof resign shall. When a predetermined value or more is deviated from a preset target tread width, the target tread width is automatically corrected.

Next, the invention described in claim 2, wherein the hydraulic valve (4,4), after outputting during the set time (T), when bets Red change output is not output over a certain time, the hydraulic The valves (4, 4) are configured to output alternately for a set time (T1) to the expansion side and the contraction side of the tread with respect to the hydraulic cylinder (3, 3) ,
By alternately outputting to the expansion side and the contraction side of the tread for the set time (T1), when the predetermined tread width deviates from a preset target tread width, the target tread width is automatically corrected. The work vehicle according to claim 1, wherein the work vehicle is configured as described above.

  The hydraulic cylinder that adjusts and adjusts the tread zooms and adjusts the tread of the wheel while the high pressure hydraulic oil is supplied with the relief applied at the time of output. There is a tendency for the pressure to gradually increase with this.

Accordingly, the invention of claim 2, in order to protect the piping which is in communication with the hydraulic cylinder, since the last tread regulation, when the output of the bets red regulation is not more than a predetermined time, the hydraulic cylinders (3,3) On the other hand, the output is alternately output for the set time (T1) on the expansion side and the contraction side, and the pressure that remains in the cylinder and gradually increases is eliminated to prevent the ripples from spreading to the surrounding piping. It is.

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In the first aspect of the invention, after the hydraulic valves (4, 4) supply hydraulic oil to the hydraulic cylinders (3, 3) and adjust the treads of the left and right wheels (2, 2). By outputting the output in the opposite direction to the output for the set time (T), the target tread width set in advance is deviated by a certain value or more. As a result, the internal pressure remaining in the hydraulic cylinder is reduced. By reducing the internal pressure, it has a feature that it can be safely protected by preventing ripples to the surrounding piping in communication. And if it deviates more than a predetermined value from the target tread width set in advance to reduce the internal pressure, the tread width is automatically corrected, so that the tread width is protected and the actual work is not affected. .
In addition, when the oil temperature rises to reach a temperature that affects the rise of the internal pressure, there is an effect of securing the safety of the pipes in the communication state by trying means for eliminating the rise of the internal pressure. In other words, the output is alternately performed for the set time (T2) on the expansion side and the contraction side, thereby deviating from a preset target tread width by a certain value or more. Thereby, an increase in the internal pressure in the hydraulic cylinder can be avoided. By reducing the internal pressure, there is a feature that prevents ripples to surrounding piping. And if it deviates more than a predetermined value from the target tread width set in advance to reduce the internal pressure, the tread width is automatically corrected, so that the tread width is protected and the actual work is not affected. .

The invention of claim 2, in order to protect the piping of communication to the hydraulic cylinders (3,3), after the previous tread regulation, the output of the bets Red adjusted (extension side or the contraction side) is fixed time When there is no more, the output is alternately output for the set time (T1) to the expansion side and the contraction side for the hydraulic cylinder (3, 3), so that a constant value is obtained from the preset target tread width. Leave more. As a result, the internal pressure remaining in the hydraulic cylinder and gradually increasing can be eliminated . By reducing the internal pressure, there is a feature that prevents ripples to surrounding piping. And if it deviates more than a predetermined value from the target tread width set in advance to reduce the internal pressure, the tread width is automatically corrected, so that the tread width is protected and the actual work is not affected. .

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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a tread adjusting device equipped in an agricultural tractor shown in the drawings will be described in detail below.
First, as shown in FIGS. 2 and 3, the tractor 5 has an engine 7 mounted in a front bonnet 6, and a clutch housing and a gear-type transmission that houses a main clutch at the rear of the engine 7. The mission case 8 to be connected is integrally connected. A rear axle case 9 capable of tread adjustment is provided on both the left and right sides of the mission case 8, and wheels 2 and 2 are provided on the ends of the case 9 on both the left and right sides.

A front axle case is provided below the engine 7 so as to be able to roll around the front and rear axis, and a front wheel 10 is provided to be steerable at both side ends.
The cockpit 11 is provided in a cabin 12 mounted on the vehicle body, and has a configuration in which a meter panel 13, a steering handle 14, and operation levers are concentrated on the front side. Further, various setting devices such as a tread adjustment set switch 15 and a tread width setting dial 16 which will be described later (see FIG. 4) are provided in the vicinity of the levers, and these setting signals are a control unit below the cockpit 11. The input to the controller 17 is configured.

  In FIG. 2, a cylinder case 18 having a hydraulic cylinder for raising and lowering the work implement is provided at the upper rear portion of the transmission case 8. The lift arm 19 is configured to move up and down by extending and contracting the piston of the hydraulic cylinder in the cylinder case 18 and to move up and down the rear rotary tiller 20 connected thereto. One of the lift arms 19 is provided with a potentiometer-type lift arm angle sensor for detecting the height of the work implement, and the detection position of the potentiometer of the work implement lift lever and the rotation setting position of the lift arm 19 are as follows. The switching control valve for raising or lowering the work implement in the hydraulic circuit is switched by a control signal from the controller for raising / lowering control so as to match.

Next, the tread adjusting device will be described.
First, in FIG. 1, drive shafts 26, 26 extended from the rear wheel differential mechanism 25 disposed at the center to the left and right sides are respectively connected to left and right transmission cylinders 29 via brake devices 27, 27 and speed reducers 28, 28. , 29 is configured to transmit traveling power. On the other hand, as shown in the drawing, the left and right wheels 2 and 2 are pivotally attached to the wheel shafts 30 and 30, respectively, and the wheel shafts 30 and 30 are supported by the wheel support cases 31 and 31. It has become.

  As shown in FIG. 1, the wheel shafts 30, 30 are arranged such that the wheels 2, 2 at the front end portions (outside) can be expanded and contracted with respect to the transmission cylinders 29, 29 on the vehicle 1 side. The rear wheel differential mechanism 25 can be slid freely by spline fitting so that traveling power can be transmitted from the rear wheel differential mechanism 25 to the wheels 2 and 2. The hydraulic cylinders 3 and 3 for adjusting the tread fix the cylinder lot 33 to the housing case 34 (on the inner transmission cylinder 29 side), and are provided between the transmission cylinders 29 and 29 and the wheel support cases 31 and 31. The cylinder left chamber 3L and the cylinder right chamber 3R are configured such that the tread can be adjusted by an expansion / contraction operation between the chambers 3L and 3R.

The hydraulic cylinders 3 and 3 in FIG. 1 show a state where the left side is contracted and a state where the right side is extended.
In this case, as shown in FIG. 1, the left and right hydraulic valves 4, 4 are connected to the oil tank T (pump P) and both chambers 3L, 3R on the hydraulic cylinder 3, 3 side by pipes 35, 35, respectively. The cylinder left chamber 3L is supplied and drained from the left pipe 35, and the cylinder right chamber 3R is supplied and discharged from the right pipe 35 to expand and contract.

  1 and 4, reference numerals 36 and 36 denote stroke sensors, which are configured to measure the expansion / contraction strokes of the hydraulic cylinders 3 and 3 and input them to the controller 17. An input shaft rotation sensor 37 detects the rotation of the wheels 2 and 2.

  The tread adjusting device configured as described above is controlled by the controller 17 shown in FIG. 4, and a tread width to be adjusted is set in advance by the tread width setting dial 16, and then the tread adjustment set switch 15 is turned on. It is set as the structure which can be performed by.

  Then, the controller 17 performs a zoom output in which the hydraulic valves 4 and 4 supply hydraulic oil to the hydraulic cylinders 3 and 3 to widen the tread. The configuration is such that the output on the side opposite to the output direction (opposite direction) (the side on which the trace is narrowed) is executed for a set time (T). In this case, in the embodiment, “T = 80 msec,” and the output is performed for an extremely short time. In this short time, the tread is not changed.

  As described above, the tread adjusting device configured as described above first sets the tread width to be adjusted by operating the tread width setting dial 16. Subsequently, when the operator turns on the tread adjustment set switch 15, the controller 17 confirms the detection information of the rotation sensor 37 and outputs a control signal only when the wheels 2 and 2 are rotating. The tread adjustment is performed by controlling and switching the valves 4 and 4. The hydraulic cylinders 3 and 3 are supplied with hydraulic oil via the hydraulic valves 4 and 4 and move the wheels 2 and 2 to a set position while zooming.

  When the set tread adjustment is completed, the controller 17 subsequently outputs a control signal to perform the zoom output on the side opposite to the zoom output direction, and controls the hydraulic valves 4 and 4 to control the hydraulic cylinder. 3 and 3 are zoomed. In this case, the zoom output on the opposite side is performed for “T = 80 msec”.

  In this manner, in the embodiment, after the hydraulic valves 4 and 4 supply the hydraulic oil to the hydraulic cylinders 3 and 3 to adjust the treads of the left and right wheels 2 and 2, the zoom on the side opposite to the zoom output is performed. It is possible to output the output, lower the internal pressure remaining in the cylinders 3 and 3, prevent the ripples to the surrounding pipes 35 and 35 in communication, and protect them safely.

  In the case of the embodiment, the controller 17 outputs the zoom output in the opposite direction to the hydraulic valves 4 and 4 as described above, and then outputs to adjust the next tread (extension side or contraction side). Is not output for 30 minutes or more, a control signal is output to the hydraulic valves 4 and 4, and the output is alternately output to the hydraulic cylinders 3 and 3 this time on the expansion side and the contraction side, “T1 = 80 msec. The control operation to output is performed.

  As described above, in the embodiment, as a second stage, a means for avoiding an increase in the internal pressure remaining in the hydraulic cylinders 3 and 3 is taken, and the pipes 35 and 35 in communication with the hydraulic cylinders 3 and 3 are protected. Can do.

  As described above, the controller 17 according to the embodiment automatically outputs and remains in the cylinders 3 and 3 when there is no zoom output for 30 minutes or more after the previous tread adjustment until the next tread adjustment. The internal pressure which is gradually increasing is eliminated, and the ripples to the surrounding pipes 35 and 35 are prevented in advance.

  The controller 17 according to the embodiment compares the oil temperature of the hydraulic oil when the hydraulic valves 4 and 4 are switched and hydraulic oil is supplied to the hydraulic cylinders 3 and 3 to perform zoom output. Thereafter, when the oil temperature of the hydraulic oil changes by + 20 ° C. or more, the hydraulic valves 4 and 4 alternately output to the expansion side and the contraction side with respect to the hydraulic cylinders 3 and 3, “T2 = 80 msec. , And a means for automatically avoiding a rise in internal pressure accompanying a rise in temperature is automatically exercised, and adverse effects on each communicating part are eliminated.

  As described above, in the embodiment, in order to eliminate the natural increase in the internal pressure remaining in the hydraulic cylinders 3 and 3, the controller 17 automatically outputs the zoom output and automatically operates the hydraulic valves 4 and 4, Even if the hydraulic oil is supplied to the hydraulic cylinders 3 and 3 even for a very short time, the tread width set and adjusted in advance may be changed. In such a case, the controller 17 according to the embodiment, when the tread width set with the tread width setting dial 16 is deviated more than a certain amount in advance, protects the tread width set as a configuration in which the correction automatically works, Measures are taken so that there is no obstacle to actual work.

  Furthermore, the tread width set by the operator (the width set by the tread width setting dial 16) is not erased even if the power is turned off after the work, and is stored in the EPROM and can be set at the next restart.

Next, an embodiment of the tread adjusting / fixing device for the front axle 40 shown in FIGS. 5 and 6 will be described.
First, as shown in the drawing, the front axle 40 that supports the front wheels is tread-adjusted from a support member 42 on the vehicle body 41 side by three members: a transmission device 43 in the center, a guide case 44 on one side, and an adjustment fixture 45 on the other side. It is configured to be possible. Reference numeral 46 denotes a fixing screw.

  Then, as shown in FIG. 5, when adjusting the tread with respect to the support member 42 of the vehicle body 41, the front axle 40 extends and contracts the transmission device 43 while sliding the guide case 44, and adjusts the adjustment fixture 45. Then, the adjustment position is selected, and the adjustment fixing screw 46 is used to fix the adjustment position.

  Thus, the embodiment has a configuration in which the guide case 44 is disposed on one side and the adjustment fixture 45 is disposed on the other side with the transmission device 43 in between, and the load is distributed and received in three. Are better.

Next, an embodiment shown in FIGS. 7 and 8 will be described for the zoom weight device.
In many cases, work vehicles are attached with weights corresponding to the type of work implement to be mounted on the vehicle body and the attachment site, and work is performed while ensuring the overall vehicle body balance. And regarding weight mounting apparatus, Unexamined-Japanese-Patent No. 2005-263122 is published before application.

  First, as shown in FIGS. 7 and 8, base machine frames 50, 50 have bases attached to both sides of a transmission case 51 mounted on the vehicle body of a work vehicle, and further forward than the front wheel support portion 52. It is made to extend and protrude. The weight hitch 53 is supported by being laid over and supported by the front portions of the left and right base machine frames 50, 50, and a weight (bumper weight or the like) 54 can be inserted into the weight.

The zoom mechanism 55 is connected to zoom hydraulic cylinders 56, 56 provided outside the base portions of the base machine frames 50, 50, and is disposed on the front side of the weight hitch 53. The zoom operation can be performed forward from the weight hitch 53. In this case, as will be understood from the drawings, the zoom mechanism 55 is supported and guided by a plurality of rollers 57, 57 pivoted on the outside of the base machine frames 50, 50, and is extended forward. A plurality of weights 54, 54 can be attached freely.

  As shown in FIG. 8, the weight hitch 53 is configured such that when the zoom mechanism 55 is moved forward, a mounting space 57 is formed on the front side, and the weight 54 can be mounted.

  As described above, the zoom mechanism 55 is advantageous in that it can be used in various ways by combining with the weight hitch 53. Further, the zoom mechanism 55 can zoom back and forth with the weight 54 placed thereon, and has an advantage that the weight balance of the vehicle body can be adjusted.

Horizontal cross section of rear axle case showing tread adjuster Overall side view of tractor Rear view of tractor Schematic showing the control mechanism of the tread adjuster Front axle tread adjustment and fixing device slope view Partial cross-sectional view of previous Fig. 5 Slope view of weight zoom mechanism The action slope figure of a weight zoom mechanism.

1 Vehicle 2, 2 Left and right wheels 3, 3 Hydraulic cylinder 4, 4 Hydraulic valve T Set time T1 Set time T2 Set time

Claims (2)

A hydraulic cylinder (3, 3) is provided for changing and adjusting the tread of the left and right wheels (2, 2) pivoted on the vehicle (1). The hydraulic cylinder (3, 3) is controlled based on a control signal. The hydraulic valve (4, 4) is configured to change and operate the tread by the hydraulic oil fed from the hydraulic valve (4, 4). The hydraulic valve (4, 4) supplies the hydraulic oil to the hydraulic cylinder (3, 3). After supplying and performing the desired tread change output, the output in the opposite direction to this tread change output is output for the set time (T) ,
By outputting the output in the direction opposite to the tread change output for the set time (T), if it is more than a certain value away from the preset target tread width, it will automatically be corrected to the target tread width,
The hydraulic valve (4, 4) supplies hydraulic oil to the hydraulic cylinder (3, 3) and compares it with the oil temperature when the tread change output is performed. When the oil temperature rises above a set value, the hydraulic valves (4, 4) output alternately to the expansion side and the contraction side for a set time (T2) with respect to the hydraulic cylinder (3, 3). age,
By alternately outputting to the expansion side and the contraction side for the set time (T2), it is configured to automatically correct the target tread width when it deviates from a preset target tread width by a certain value or more. A working vehicle characterized by that. The hydraulic valve (4,4), after outputting during the set time (T), when bets Red change output is not output over a certain time, the hydraulic valves (4,4), said hydraulic cylinder ( 3, 3), it is configured to output alternately for a set time (T1) to the expansion side and the contraction side of the tread ,
By alternately outputting to the expansion side and the contraction side of the tread for the set time (T1), when the predetermined tread width deviates from a preset target tread width, the target tread width is automatically corrected. The work vehicle according to claim 1, wherein the work vehicle is configured as follows .

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