JP3199640B2 - Tractor tread adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tractor tread adjusting device.

[0002]

2. Description of the Related Art A conventional tractor tread adjusting device is:
For example, this conventional device is disclosed in Japanese Patent Application Laid-Open No. 3-182808. In this conventional device, an axle case of a rear wheel is made extendable and contractable, and a hydraulic cylinder for extending and contracting the axle case is provided. The switching valve is provided so that the switching can be manually performed by lever operation.

[0003]

According to the above prior art, in order to obtain a desired tread width, it is necessary to measure the tread width while operating a lever, and the operation is very complicated. It was difficult to do. Therefore,
The inventors of the present invention provide a setting operation unit that can be manually operated to set the tread widths of the left and right rear wheels of a tractor in a predetermined setting range in a stepless manner or in a plurality of steps. A tread adjusting device that moves a wheel in the tread direction so that the wheel automatically reaches the target tread width by setting the setting operation unit to a position indicating the target tread width by combining with a hydraulic device that moves in the direction. Was developed.

[0004] However, the tractor is mounted with various wide and narrow wheels according to the working form, and the difference between the wide and narrow wheels is relatively large. When the tread adjusting device is designed so that the tread width can be set, if the tread width is set to the narrowest tread width in the adjustment range designed when a wide wheel is mounted, the wheel hits a fender or the like of the tractor. There is a problem. On the other hand, if the tread width is designed to be set within a range required when a wide wheel is mounted, the tread width of the wheel cannot be sufficiently reduced when the narrow wheel is mounted.

As described above, the width of the wheel cannot be neglected in the tractor especially when tread adjustment is performed. Accordingly, the present invention provides a tread adjustment operation that can be performed easily and quickly and has a simple structure, but only within a setting range of a tread width required when a wide wheel is mounted and when a narrow wheel is mounted. It is intended to be able to operate.

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention has taken the following technical means. That is, the tread adjusting device of the present invention is provided with a setting operation unit that can be manually operated to set the tread width of the left and right wheels of the tractor to a stepless or multiple steps within a predetermined setting range, and A hydraulic device for moving the wheels in the tread direction, and a setting limit width of the tread width is set to the predetermined value.
In order to be switched to a plurality of types within the constant range, and is provided so as to be repositionable mounting regulating member for regulating the operating range of the setting operation unit.

When the operator operates the setting operation section to a position indicating the target tread width, the hydraulic device is operated so that the tread width is attained, and the wheels are moved in the tread direction. This tread adjustment operation is easy and quick. Can be done. When a wide tire is mounted, a restricting member is attached so that the setting range of the tread width is narrowest, and when a narrow tire is mounted, the restricting member is mounted so that the setting range of the tread width is widest. The setting operation unit can be operated only within an appropriate tread width setting range, regardless of whether a wide or narrow wheel is mounted.

As means for operating the hydraulic device by the setting operation section, for example, the setting operation section is constituted by a dial provided so as to protrude from a casing provided in the vicinity of a driver's seat of a tractor. A first rotor that rotates integrally with the setting operation unit, a reel that rotates according to the actual tread width of the left and right wheels, and a second rotor that rotates integrally with the reel are provided.
What is necessary is just to arrange | position a 2nd rotor and a reel on the same axis, and just to comprise an electric contact for controlling the hydraulic system of a wheel between a 1st rotor and a 2nd rotor.

Further, if the regulating member is removably attached to a mounting hole provided in the casing, and the first rotor is provided with an engaging portion which engages with the regulating member to regulate the operation range, the attaching and detaching of the regulating member can be achieved. Work can be done very easily.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Right and left front wheels 12 and left and right rear wheels 13 are mounted on the front and rear of the vehicle body 11 of the tractor 10 shown in FIGS. 22 and 23, respectively. The rear wheel 13 is covered with a fender 16.

An engine is mounted on the front of the vehicle body 11,
The engine is covered with a hood 17. Although not shown, a three-point link mechanism for mounting various working devices is provided at a rear portion of the vehicle body 11, and the mechanism is configured to be able to move up and down by a hydraulic elevating device. A cabin 18 is mounted on the vehicle body 11, and a driving control section is provided in the cabin 18. That is, a driver's seat 19 is provided in the cabin 18, a steering handle 20 is provided in front of the driver's seat 19, and various operation levers (not shown) are provided near the driver's seat 19.
Are arranged.

FIG. 1 to FIG. 13 show a tread adjusting device according to an embodiment of the present invention. To be described below, as shown in FIG.
The transmission case 21 is mounted on the left and right sides of the rear of the transmission case 21 via a brake case 22, a rear axle case 23, and a rear axle 24. The rear axle case 23 includes a fixed case 25
And a movable case 26 slidably provided in the left-right axial direction.
Is fixed to the transmission case 21 via the brake case 22.

A brake 28 is provided in the brake case 22 for braking a differential yoke shaft 27 projecting right and left outward from a rear wheel differential device in the transmission case 21. It is operatively connected to the axle 24. The rear axle 24 has a planetary reduction gear 29
Is connected to a transmission shaft 30 connected to the tractor body 11 via a spline cylinder shaft 31 so as to be movable in the axial direction which is the left-right direction with respect to the tractor body 11. The transmission shaft 30 is supported by a fixed case 25 via a bearing 32, and the rear axle 24 is supported by a movable case 26 via bearings 33 and 34, and a flange 35 at the outer end of the rear axle 24.
The disk 13a of the rear wheel 13 is mounted on the rear wheel.

On the rear side of the rear axle case 23, a rear wheel 13 is provided.
A hydraulic cylinder 36 (hydraulic device) for moving the rear axle 24 in the axial direction in order to move the rear axle 24 in the tread direction is disposed in parallel and housed in a holding case formed integrally with the fixed case 25. . The hydraulic cylinder 36
Piston rod 38 whose inner end is fixed to fixed case 25
And the piston 3 fixed to the outer end of the piston rod 38
9 and a cylinder body 40 slidably fitted to the piston 39 and the piston rod 38.
The piston rod 38 has a cylindrical shape, and an inner cylinder 41 is inserted through the piston rod 38 so as to form an oil passage inside and outside, and the oil passage is provided in each oil chamber in a cylinder body 40 defined by a piston 39. 42 and 43 are connected.

An interlocking body 44 fixed to the outer end of the movable case 26 is fixed to the outer end of the cylinder body 40. The cylinder body 40, the movable case 26 and the rear axle 24 are fixed via the interlocking body 44. And are integrally linked.
A cylindrical stopper 45 is loosely fitted in the oil chamber 43 of the cylinder body 40.

The structure inside the rear axle case 23 is the same for both the left and right wheels, and the right and left rear wheels 13 can be changed in tread independently of each other by moving the respective hydraulic cylinders 36 in and out. FIG. 12 shows a hydraulic circuit including left and right hydraulic cylinders 36. In this hydraulic circuit, a hydraulic pump 50 is configured to supply hydraulic oil in an oil tank 51 through an oil filter 52 to a hydraulic device for lifting and lowering a work implement provided at a rear portion of a tractor, and to hydraulic cylinders 36 on right and left rear axles. And is driven by an engine mounted on the front of the tractor body 11.

A priority valve 54 composed of a flow control valve is provided at an intermediate portion of the oil supply path 53 to the hydraulic cylinder 36, and a part of the hydraulic oil supplied from the hydraulic pump 50 is supplied to the left and right axles by hydraulic pressure. The oil is supplied to a cylinder 36 and other oil is supplied to a hydraulic elevating device at the rear of the tractor 10. For example, if the capacity of the hydraulic pump 50 is 6
The amount of hydraulic oil supplied to the hydraulic cylinders 36 on the left and right axles is 3 liters / minute.

A relief valve 55 is provided on the downstream side of the priority valve 54 and on the upstream side of the cylinder 36 to prevent the pressure in the hydraulic cylinder 36 and the pressure in the oil supply pipe from abnormally increasing. The hydraulic cylinders 36 are connected in series, with the hydraulic cylinder 36 on the left axle located upstream and the hydraulic cylinder 36 on the right axle located downstream. Each hydraulic cylinder 36 is provided with a corresponding three-position switching type electromagnetic switching valve 56. These electromagnetic switching valves 56 are provided with a solenoid 57 for extending the hydraulic cylinder 36 and a solenoid 58 for shortening.
The switching operation is performed from the neutral position by exciting either the extension solenoid 57 or the compression solenoid 58.

In the vicinity of the driver's seat 19, there is provided a tread setting operation section 61 which can be manually operated and a casing 63 provided with an actual tread width display section 62 by the operation section 61. With the extension solenoid 57
Alternatively, the hydraulic cylinder 36 (hydraulic device) can be controlled by exciting one of the compression solenoids 58.

In this embodiment, as shown in FIGS. 22 and 23, a casing 63 is provided on the left side of the driver's seat 19, so that the operator on the driver's seat 19 can easily manually operate the setting operation section 61. In addition, the actual tread width display portion 62 is made visible. Note that the casing 63 may be disposed on the right side of the driver's seat 19 or on the front and rear sides. As shown in FIGS. 1 to 5, the casing 63 is formed of a heat-resistant resin such as an ABS resin in the shape of a rectangular box that is open downward.
Bolt holes 6 for mounting are provided in the corners of the casing 63.
4 are provided. A pair of tread setting operation sections 61 are provided side by side on this single casing 63, and each operation section 61 corresponds to a change in the tread of the left and right rear wheels 13 respectively. The rear wheels 13 are configured to be independently movable in the left-right width direction (tread direction).

Each of these tread setting operation sections 61 is constituted by a dial which is rotated by manual operation, and a maximum of 1540 m is obtained by rotating the dial 61.
m, 10 in the range of 1280 mm (minimum width tire)
The tread width of each of the left and right rear wheels 13 can be set in mm units. It is preferable that the setting operation unit 61 is configured to be switchable in a plurality of steps as described above. However, the setting operation unit 61 can be switched in a stepless manner.

The casing 63 is provided with a regulating member 65 for regulating the operation range of the setting operation section 61 so that the position can be changed so that the minimum setting limit width of the tread width can be switched to a plurality of types. The regulating member may be configured to be detachably attached to the setting operation unit 61. As shown in FIGS. 4 and 9, the regulating member 65 is formed of a long pin. A short pin 65a is integrally connected to the pin 65, and is detachably attached to a pair of mounting holes 67 provided in the casing 63 for inserting and supporting the pins 65a and 65b. The short pin 65a serves to prevent the restriction member 65 from being accidentally displaced from the mounting hole 67. Further, by replacing the positions of the long pin 65 and the short pin 65a and mounting the short pin 65a in the mounting hole 67, the minimum set limit width of the tread width can be switched to a plurality of types. Note that the regulating member 65 can be configured by a single pin without providing the short pin 65a. Further, the regulating member may be constituted by a member other than the pin.

An operation unit 61 is provided on a first rotor 70 described later.
An engagement portion 66 that engages with the regulating member 65 is provided in order to regulate the range of the rotation operation. When a wide rear wheel 13 is mounted, the rear wheel 13 and the fender 16
In order to avoid the contact with the short pin 65a, the mounting position of the restricting member 65 is exchanged with the position of the short pin 65a to restrict the minimum setting width by the dial 61 to 1320 mm. It is to be noted that a rotation regulating engagement portion 66 for the regulation member 65 is provided.
Is provided on the first rotor 70 in the present embodiment, but may be provided on the dial 61.

Further, as shown in FIG.
A scale 62 constituting a real tread width display portion is provided around the dial 61 on the outer surface of the box (the upper surface in the illustrated example), and each real tread of the left and right rear wheels 13 corresponding to the set position of the dial 61 is provided. The widths are displayed, so that the driver's seat 19 can easily recognize the current tread width of the left and right rear wheels 13.

In the box-shaped casing 63, each operation unit 61 is provided.
Rotor 70, second rotor 71, and reel 73 of Bowden wire 72, which is linked to rear axle 24.
Are each stored. One set of the first rotor 70, the second rotor 71, and the reel 73 are arranged on the same axis. The first rotor 70 is rotatably accommodated in a cylindrical holding portion 63a formed in the casing 63,
At the center of the rotor 70, a top plate 63 of a casing 63 is provided.
b, a shaft 74 protruding upward from the shaft 7 is provided.
A setting operation section 61 is detachably attached to the operation section 4, and the operation section 61 and the first rotor 70 are connected so as to rotate integrally. The stopper pin 65 is detachable by removing the setting operation section 61 from the shaft section 74.

A latch (not shown) is formed on the inner periphery of the holding portion 63a, and a positioning mechanism 75 for engaging with the latch is provided on the outer periphery of the rotor 70 (see FIG. 3). 1 pitch of operation unit 61 (1 tread width)
The operability is improved by making it possible to reliably perform the rotation operation by 0 mm). The illustrated positioning mechanism 75 is composed of a steel ball that engages with the latch and a coil spring that urges the ball in a direction that engages with the latch, but may have another structure. .

The second rotor 71 is disposed below and opposed to the first rotor 70, and is externally rotatably fitted to a boss 80 provided at the center of the first rotor 70 so as to project downward. I have. The second rotor 71 is received from below by a substrate 82 fitted into the casing 63 from below and fixed by tapping screws 81, and a boss provided at the center of the second rotor 71 so as to protrude downward. The portion 83 is rotatably inserted into and supported by a support hole 84 provided in the substrate 82.

As shown in FIGS. 1 and 3, a second rotor 71 is provided between the first rotor 70 and the second rotor 71.
There is provided an operation angle restricting means for restricting the rotation operation angle of the first rotor 70 to a predetermined range. The means comprises an engagement pin 85 provided on the first rotor 70 so as to protrude downward, and an engagement hole 86 provided on the second rotor 71 so that the pin 85 engages. The engagement hole 86 is formed in the shape of a long hole extending in the circumferential direction.
0 is rotatable with respect to the second rotor 71.

The reel 73 is disposed below the substrate 82 and has a bolt 8 with respect to a boss 83 of the second rotor 71.
8 are integrally attached and fixed. On the outer circumference of the reel 73, a winding groove 89 for guiding and holding the inner 72a of the Bowden wire 72 is provided, and a locking portion 90 for locking and holding a connector attached to the inner 72a is provided. An end of the outer 72 b of the Bowden wire 72 is attached to a substantially central portion of the side wall of the casing 63 in the left-right direction.

As shown in FIGS. 10 and 11, an outer end 72b of the Bowden wire 72 is fixedly attached to the tractor body 11 via a long plate-shaped bracket 91, and an inner end 72a is connected to the inner end 72a. It is attached and fixed to the interlocking body 44 fixed to the outer end of the rear axle 24 via an L-shaped bracket 92. The outer 7 to the bracket 91
By adjusting the attachment of the inner tread 2b or the attachment of the inner 72a to the bracket 92, the tread width indicated by the actual tread display portion 62 can be adjusted to be the true actual tread width. .

The reel 73 has an inner 7
A torsion coil spring 95 (urging means) for urging the reel 73 to rotate in the direction of winding the 2a is mounted. One end of the spring 95 is connected to the reel 7.
3 and the other end is locked to a projection 96 provided on the casing 63. It should be noted that a through hole 97 of the projection 96 is formed in the substrate 82.

Therefore, when the rear axle 24 moves left and right outward, the inner 72a is unreeled from the reel 73, and the reel 73 and the second rotor 71 are rotated in that direction. When moved inward, the reel 73 is biased by the spring 95.
And the second rotor 71 is rotated in the winding direction so that the reel 7
3, the inner 72a is wound up. In this way,
In the present embodiment, a feedback unit that feeds back the actual tread width of each of the right and left rear wheels 13 to the setting operation unit 61 is configured as a mechanical type mainly including the Bowden wire 72 described above.

When the setting operation section 61 and the display section 62 indicate the actual tread width, the first rotor 70, the second rotor 71, and the substrate 82 are electrically disconnected from each other, and the value indicated by the display section 32 is displayed. Is provided with a contact (switch) that is electrically connected when is different from the actual tread width. These contact points are connected to the extension solenoid 57 and the compression solenoid 58 of the above-mentioned left and right electromagnetic switching valves 56, so that the hydraulic cylinder 24 can be controlled by the setting operation section 61.
A control circuit including the contact (118) will be described later.

That is, on the upper surface of the second rotor 71 (the surface facing the first rotor 70), as shown in FIG. 6, a central positive side conducting portion 101 made of a copper plate is formed. In addition, two semicircular arc-shaped negative conducting portions 102 and 103 are formed on the outer peripheral side of the conducting portion 101 so as to face each other. A slight space is provided between the ends of the pair of negative-side conducting portions 102 and 103 to form an insulating portion 104.

On the other hand, the first rotor 70 has the structure shown in FIGS.
As shown in the figure, the positive-side conductive portion 101 and the negative-side conductive portion 10
A conductive member 105 is provided for electrically connecting either one of the second and third members. This conductive member 105
Is made of a copper plate having a width extending over the positive-side conductive portion 101 and the negative-side conductive portions 102 and 103.
And is urged in a direction of pressing against the conductive portions 101, 102, and 103 by a spring 107 housed at the back of the recess 106.

When the actual tread width display section 62 indicates the actual actual tread width of the right and left rear wheels 13, the display section 6 is positioned so that the conductive member 105 is located on the insulating section 104.
2 corresponds to the insulating portion 104. Therefore, as shown in FIG.
4, when the display unit 62 is displaying the actual tread width, the positive conduction unit 101 and the negative conduction units 102 and 103
Is electrically disconnected, and the setting operation unit 6 is switched from the neutral position.
When the first member 1 is rotated or the second rotor 71 is rotated together with the reel 73, the positive-side conducting portion 101 is electrically connected to one of the negative-side conducting portions 102 and 103.

On the upper surface of the substrate 82 (the surface facing the second rotor 71), as shown in FIG. 8, a ring-shaped positive conducting portion 111 on the center side and a semicircular pair on the outer peripheral side are formed. Are formed. This substrate 82
Positive-side conductive portion 111 of the second rotor 71 and the positive-side conductive portion 10 of the second rotor 71
1 is conducted through a coil spring 114 and a conductive member 115 mounted on the second rotor 71, and similarly, the respective negative-side conducting portions 112 and 113 of the substrate 82 are connected to the corresponding second rotor 71. The conduction is made to the negative conduction parts 102 and 103, respectively. The conductive portions 111 of these substrates 82,
Conductive wires 116 are connected to 112 and 113, respectively. These conductive wires 116 are bundled and pulled out of the casing 63, and a connector 117 is provided at an end thereof.
It is detachably connectable to a wiring connector on the tractor vehicle body 11 side.

Through such wiring, the positive-side conducting portion 111 is connected to a power source mounted on the tractor body 11, one of the negative-side conducting portions 112 and 113 is connected to the extension solenoid 57, and the other is the compression solenoid 58. Connected to
In order to control the hydraulic cylinder 24 by the setting operation unit 61, a contact 118 (switch) provided in a power supply path to the solenoids 57 and 58 for expanding and contracting the electromagnetic switching valve is configured.

The telescopic solenoid 5 using the contact 118
FIG. 13 shows a first embodiment of the control circuits 7 and 58. In the hydraulic circuit of FIG. 12 described above, since one of the left and right hydraulic cylinders 36 is connected in series, it is necessary to operate only one of them. Therefore, in the control circuit of the present embodiment, when the left and right contacts are energized, the left telescopic solenoids 57 and 58 are operated with priority.

That is, the telescopic solenoid 5 for the right axle
A relay 120 is provided in the middle of the power supply path to the power axles 7 and 58. The relay 120 is activated when the telescopic solenoids 57 and 58 for the left axle are energized and operates when the telescopic solenoids 57 and 58 for the right axle are energized. The power supply path to the solenoids 57 and 58 is cut off. An alarm device 121 is connected to the control circuit of the present embodiment, indicating that the telescopic solenoids 57 and 58 are being excited, that is, that the hydraulic device 36 for changing the tread is being operated. The alarm device 121 is provided near the driver's seat 19. Preferably, the alarm device 121 is provided on the casing 63. As such an alarm device, a lamp, a buzzer, or the like can be employed.

The alarm device 121 includes telescopic solenoids 57 and 58 for the left axle and telescopic solenoids 5 for the right axle.
Each of the solenoids 57 and 58 is electrically connected in parallel, and informs the operator that any one of these solenoids 57 and 58 is operating.
According to the tread adjusting device according to the first embodiment, since the hydraulic pump 50 is not operated while the engine is stopped, the hydraulic cylinder 36 expands and contracts even when the setting operation unit 61 is operated to connect the contact 118. No operation is performed, and the tread width of each rear wheel 13 is not changed. If the tread width is not changed, the reel 73 and the second rotor 71 connected to the rear axle 24 via the Bowden wire 72 do not rotate, so that the rotation operation angle with respect to the second rotor 71 is restricted. The setting operation section 61 can be prevented from being largely turned while the engine is stopped, and the rear wheel 13 and the rear axle 24 can be prevented from being moved unexpectedly and largely when the engine is started. The first rotor 70 with respect to the second rotor 71
Is preferably one pitch (for a tread width of 10 mm) in each of the tread expanding and contracting directions, but may be two pitches or the like.

When the setting operation section 70 is rotated by one pitch in either the tread expanding direction or the reducing direction for adjusting the tread of each rear wheel 13 after the engine is started, the transmission member provided on the first rotor 70 is provided. The positive-side conductive portion 101 of the second rotor 71 and one of the negative-side conductive portions 102 and 103 are electrically connected to each other via 115 (that is, the contact 11
8 is closed), and the extension solenoid 57 or the compression solenoid 5
8, the electromagnetic switching valve 56 is operated, and pressure oil is supplied to one of the oil chambers 42 and 43 of the hydraulic cylinder 36,
The rear axle 24 is moved in the axial direction by one pitch (10 mm).

Then, the reel 73 and the second rotor 71 are rotated in accordance with the movement of the rear axle 24, and the second rotor 7
When the first insulating portion 104 is positioned on the conductive member 115 of the first rotor 70, the contact 118 is opened and the solenoid 5 is opened.
The energization to 7, 58 is cut off. Here, the actual tread width of the rear wheel 13 is not correctly fed back due to a maladjustment of the Bowden wire 72 or a failure of each part. If the energization is continued, the alarm device 121 operates continuously, so that the operator can recognize that the maintenance is required, and it is possible to prevent the relief valve 55 from continuing to operate for an abnormally long time, and to prevent malfunction. Reduction is also achieved.

As described above, by feeding back the actual tread width of the rear wheel 13 to the setting operation section 61, the required tread width can be easily and reliably set to the required tread width with a simple operation. The actual tread width of the left and right rear wheels 13 can be displayed by the actual tread width display portion 62 provided around the left and right wheels. Further, even when the rear wheel 13 hits a rock, a curb or the like during traveling and the rear axle 24 is temporarily moved in the axial direction, the reel 73 and the second rotor 71 rotate accordingly. The contact 118 is connected, the hydraulic cylinder 36 is controlled to expand and contract so as to have the correct actual tread width set by the setting operation unit 61, and the reliability of the actual tread width indicated by the actual tread width display unit 62 can be secured.

FIG. 14 shows a second embodiment of the control circuit for the telescopic solenoids 57 and 58. The difference from the first embodiment is that the alarm device 121 is replaced by a solenoid 5
An automatic power supply disconnecting device 130 is provided for forcibly disconnecting power to the solenoids 57 and 58 after a predetermined time has elapsed from the start of power supply to the solenoids 7 and 58. The device 130
Telescopic solenoids 57, 58 and their common ground 13
1 and the relay 132 is operated for a predetermined time after the energization of one of the relays 132 and one of the telescopic solenoids 57 and 58 is started.
And a timer 133 for connecting to the earth 131. The time for operating the telescopic solenoids 57, 58 is set to, for example, 5 seconds.

According to the control circuit of the second embodiment, the continuous operation of the relief valve 55 due to the improper adjustment of the Bowden wire 72 can be reliably prevented. FIG. 15 shows a telescopic solenoid 5
7 shows a third embodiment of the control circuits 7 and 58, which differs from the first embodiment in that the alarm device 121 is not provided, and the other configuration is the same, so that detailed description is omitted. I do.

The present invention is not limited to the above embodiment, and can be appropriately designed and changed. 16 and 17 show a comparative example of the present invention,
The difference from the above-described embodiment is that the regulating member 65 is not provided, the large-diameter dial is adopted as the setting operation unit 61, and the rotation range of the first rotor 70 with respect to the second rotor 71 is different. This is the point that the engaging pin 85 and the engaging hole 86 for regulating are not provided. The other configurations are the same, so the same reference numerals are given and the detailed description is omitted.

FIG. 18 shows still another comparative example.
Telescopic solenoids 57, 58 by microcomputer
Is shown. This tread adjustment device
The control unit 140 includes a central processing unit (CPU). The control unit 140 includes the left and right hydraulic cylinders 36.
Are connected to a stroke sensor 141, a buzzer 142 and left and right lamps 143 that constitute an alarm device, and an extension solenoid 57 and a compression solenoid 58 for the left and right rear axles 24, and are provided in the casing 63. A pair of left and right volumes (not shown) are connected. The control unit 140 has a built-in timer.

The setting operation unit 61 is mounted on the above-mentioned volume, and when the resistance value of the volume is changed by rotating each setting operation unit 61, the expansion / contraction of the hydraulic cylinder 36 is controlled in accordance with the change. It is designed to energize the solenoids 57 and 58. Note that the actual tread width of each of the left and right rear wheels 13 is fed back to the setting operation unit 61 by an electric signal from the stroke sensor 141,
The extendable solenoids 57 and 58 are controlled so that the fed-back actual tread width signal and the volume of the setting operation unit 61 match.

FIG. 19 shows an example of a flowchart of a program for operating the control unit 140. In this flowchart, the left rear wheel 13 detected by the stroke sensor 141 attached to the left hydraulic cylinder 36
Is the first actual tread width LH, the actual tread width displayed by the actual tread width display 62 on the left side of the casing 63 is the second actual tread width LS,
Stroke sensor 14 attached to right hydraulic cylinder 36
1 is the first actual tread width RH of the right rear wheel 13 detected by the first actual tread width RH, and the actual tread width displayed by the actual tread width display section 62 on the right side of the casing 63 is the second actual tread width RS. And

This program has an initialization program executed first when the engine is started. That is, when starting the engine, first, it is checked whether the first actual tread widths LH, RH of the left and right rear wheels 13 and the second actual tread widths LS, RS match, and if they match, the lamp 143 is turned on. If not, the corresponding lamp 143
Is controlled and the buzzer 142 is operated to notify the operator that the setting operation section 61 is being operated while the engine is stopped. When the operator operates the setting operation section 61 to match the first actual tread widths LH and RH with the second actual tread widths LS and RS, and the left and right lamps 143 are both turned on, the buzzer 142 is activated. Is stopped, and the initialization process ends.

By performing such initialization processing, even if the setting operation section 61 is operated accidentally while the engine is stopped, it is possible to prevent the tread width from being changed when the engine is started. After the completion of the initialization processing, first, the first actual tread width LH and the second actual tread width LS of the left wheel 13 are compared, and if they are different, the timer is initialized and then the extension solenoid 57 Alternatively, one of the compression solenoids 58 is excited, and when the widths LH and LS match, the power supply to the solenoids 57 or 58 is stopped. Also, for a predetermined time,
For example, if the widths LH and LS do not match even after 5 seconds or more, it is considered that the maintenance is defective, and an error process is performed. The content of the error processing may be any. For example, the power supply to all the solenoids 57 and 58 is stopped and the buzzer 142 notifies the operator. First actual tread width L of left wheel 13
When H and the second actual tread width LS match, the first actual tread width RH and the second actual tread width R of the right wheel 13 are determined.
The same processing is performed for S. In this way, the movement control of the left rear axle 24 is performed with priority over the right side.

FIGS. 20 and 21 show a mounting structure of the front wheel 12, in which a left and right front axle case 161 is provided in a front wheel differential case 160 provided at a front portion of the tractor body 11. As shown in FIGS. The front axle case 161 includes a fixed case 162 fixed to the differential case 160 and the fixed case 16.
The movable case 16 is inserted into the inside 2 so as to be movable in the left-right axial direction.
3

A gear case 164 accommodating the final reduction gear is fixed to the outer end of the movable case 163, and a guide pin 165 projecting inward in the left-right direction is fixed. It is inserted and guided by a guide portion 166 provided on a side portion of the fixed case 162. A bracket 167 for fixing the movable case 163 is attached to the gear case 164. The bracket 167 is made of a long plate-shaped steel plate, and has a fixed case 162.
Is arranged on the upper surface side. The bracket 167 is provided with a plurality of mounting holes 168 in the left-right direction. Further, a tapered bolt hole is also provided on the upper surface of the fixed case 162, and the movable case 163 is fixed to the fixed case 162 by inserting and fastening the tapered bolt 171 by aligning one of the mounting holes 168 with the bolt hole. Fixed.

As described above, the detachable taper bolt 17
By using No. 1, even if the mounting hole 168 and the bolt hole are slightly displaced, these holes are forcibly matched by fastening the tapered bolt 171, so that the tread changing operation of the front wheel 12 can be facilitated and quick. Can be achieved. A front wheel case 174 is attached to the gear case 164 via a bracket 173 so as to be rotatable around a king pin 172, and the front wheel 12 is mounted on the case 174.

The tractor vehicle body 11 is provided with a hydraulic cylinder 175 of a power steering device. The hydraulic cylinder 175 includes a piston rod 176 projecting in both left and right directions.
Are connected to the bracket 173 via tie rods 177. The work of changing the tread of the front wheels 12 can be performed using the hydraulic cylinder 175 of the steering device.

[0057]

According to the present invention, the tread adjustment operation can be performed easily and quickly, and the setting operation section can be performed only within the setting range of the tread width required when any of the wide and narrow wheels is mounted with a simple structure. Can be operated. Further, in a configuration in which a contact point for controlling the hydraulic device is provided between the first rotor and the second rotor that are arranged to face each other, and the actual tread width is fed back to the second rotor, the setting is performed by the setting operation unit. Hydraulic equipment can be controlled accurately to achieve the tread width, while simplifying the configuration,
Cost can be reduced. Further, in the case where the regulating member is constituted by a pin and attached to the mounting hole provided in the casing, the operation of changing the position of the regulating member can be easily performed, and the operability of the setting operation section regulated by the regulating member is improved. Can also be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a casing according to an embodiment of the present invention.

FIG. 2 is a side view of the casing.

FIG. 3 is a front view showing a right half of the casing in cross section.

FIG. 4 is a side sectional view of the casing.

FIG. 5 is a bottom view of the casing, and left reels are indicated by phantom lines.

FIG. 6 is a top view of the second rotor.

FIG. 7 is a bottom view of the first rotor.

FIG. 8 is a top view of the substrate.

FIG. 9 is a simplified perspective view showing a mounting structure of a stopper pin.

FIG. 10 is a perspective view showing a structure for attaching a Bowden wire to a rear axle case.

FIG. 11 is a plan sectional view of a rear axle case.

FIG. 12 is a hydraulic circuit diagram of a rear axle moving hydraulic device.

FIG. 13 is an electric circuit diagram showing a first embodiment of a control circuit of the hydraulic device for moving the rear axle.

FIG. 14 is an electric circuit diagram showing the second embodiment.

FIG. 15 is an electric circuit diagram showing the third embodiment.

FIG. 16 is a plan view showing a casing of a comparative example for the present invention.

FIG. 17 is a front view showing a right half of the casing in cross section.

FIG. 18 is a simplified electric circuit diagram showing another comparative example.

FIG. 19 is a flowchart of a control program of the comparative example.

FIG. 20 is a simplified plan view showing a mounting structure of a front wheel.

FIG. 21 is a simplified rear view showing the same structure.

FIG. 22 is an overall side view of the tractor.

FIG. 23 is an overall plan view of the tractor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tractor 13 Wheel (rear wheel) 19 Pilot driver's seat 36 Tread changing hydraulic device 61 Setting operation part 63 Casing 65 Restriction member 66 Engaging part 67 Mounting hole 70 First rotor 71 Second rotor 73 Reel 118 Contact

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-195002 (JP, A) JP-A-3-182807 (JP, A) JP-A-3-182808 (JP, A) JP-A-10-108 44707 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60B 35/12-35/14

Claims (3)

(57) [Claims] 1. A setting operation unit (61) which can be manually operated to set a tread width of left and right wheels (13) of a tractor (10) in a predetermined setting range in a stepless manner or in a plurality of steps; 61) a hydraulic device (36) for moving the wheel (13) in the tread direction in accordance with the position of (61), and setting the tread width within the predetermined setting range.
In order to be switched to a plurality of types, the regulating member for regulating the operating range of the setting operation section (61) (65) taken in
A tread adjusting device for a tractor, wherein the tread adjusting device is provided so as to be capable of changing a mounting position. 2. A tractor (10) comprising a setting operation section (61).
The casing (6) provided near the driver's seat (19)
3) It is composed of a dial protruding from
Inside the casing (63), a first rotor (70) that rotates integrally with the setting operation section (61), and the left and right wheels (1).
3) Reel (73) that rotates according to the actual tread width
And a second rotor (71) that rotates together with the reel (73). The first rotor (70) and the second rotor (71) are disposed on the same axis so as to face each other.
2. An electric contact (118) for controlling a hydraulic device (36) of a wheel (13) between the rotor (70) and the second rotor (71).
A tread adjusting device for a tractor according to claim 1. The regulating member (65) includes a casing (6).
The first rotor (70) includes a pin detachably attached to a mounting hole (67) provided in 3).
The tread adjusting device according to claim 2, further comprising an engaging portion (66) that engages with the regulating member (65) to regulate an operation range.