JP2816341B2 - Snow removal vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow removal vehicle having a snow removal grader blade provided below a vehicle body at an intermediate portion between a front wheel and a rear wheel of the vehicle body.

[0002]

2. Description of the Related Art In a snow removing vehicle provided with a snow removing grader blade below a vehicle body at an intermediate portion between a front wheel and a rear wheel of the vehicle body, the pressing force of the grader blade against a snow surface is automatically adjusted during snow removing work. A configuration capable of adjustment is already disclosed in Japanese Utility Model Laid-Open No. 5-49823.

FIG. 9 shows a schematic configuration of the above proposed snow removal vehicle.
Will be described with reference to the side view of FIG. A snow removal vehicle indicated generally by reference numeral 10 includes a chassis frame 12, a cab 14 mounted on the upper front end of the chassis frame 12, and a front wheel 1
6 and a rear wheel 18. The rear wheel 18 includes a front rear wheel, that is, a rear front wheel 18f, and a rear rear wheel, that is, a rear rear wheel 18r. Also, the chassis frame 1 behind the cab 14
The loading platform 20 is mounted on the loading platform 2, and the hydraulic platform 2 is mounted on the loading platform 20.
2 and a fuel tank 24 and a weight or additional weight 26 are provided. (Note that in this specification, the underframe 12 and the cab 14 mounted thereon are
The carrier 20 and the like may be collectively referred to as a vehicle body in some cases. )

At the front end of the chassis frame 12, a snow plow 28 extending forward of the vehicle body is provided.
A grader blade 30 is disposed below the vehicle body at an intermediate portion of the rear wheel 18. The snow plow 28 is
The grader blade 30 is mainly used for removing fresh snow, and is used for scraping and removing snow that has been partially crushed by a wheel or the like of an automobile and partially hardened into an ice shape.

As described later, the grader blade 30 is set to a state in which the vehicle is forwarded, waited, grounded, pressed, and the like by an operation from the driver's seat side in the cab 14. When pressing the grader blade 30 against the snow surface to remove snow,
If the pressing force is too strong or the road surface condition changes, the running resistance increases and the tires of the front wheels 16 and / or the rear wheels 18 slip, causing the vehicle body to skid and reducing the snow removal efficiency, or It may hinder the running of the vehicle.

In order to prevent the lateral slip of the vehicle body by controlling the pressing force of the grader blade 30 against the snow surface to an optimum value, a configuration shown in FIG. 10 has been proposed. In the figure, reference numeral 32 denotes an oil pump driven by an engine (not shown) of a vehicle, reference numeral 34 denotes a hydraulic adjustment device for adjusting the pressure of hydraulic oil discharged from the oil pump 32, and reference numeral 36 denotes the hydraulic adjustment device. Receiving the working pressure oil at a pressure controlled by
0 is pressed against the snow surface S, and the hydraulic cylinder 36 causes the grader blade 30 to
When pressed down, the pressing force increases, and when it rises and retracts on the snow surface S, the pressing force decreases.

The hydraulic pressure adjusting device 34 is temporarily controlled by a first controller (ECU) 38. The controller 38 includes a lever of a mode switching device 40 provided near the driver's seat in the cab 14. A command signal is supplied by the operation. The mode switching device 40 is used to forward the vehicle,
The state of standby, ground contact, and pressing can be selected, and the pressing state can be selected from several levels of pressing force. The selection mode is displayed near the driver's seat, for example, by a monitor 42 provided on an instrument panel.

On the other hand, the vehicle is provided with a non-contact type vehicle speed detector 44 using radar, ultrasonic waves, etc., which detects the actual speed, and the rear wheels 18 detect the respective rotational speeds. Wheel speed detectors 46a and 46b are provided. These vehicle speed detector 44 and wheel speed detector 46
The vehicle speed signal and the wheel speed signal detected by the a and 46b are supplied to a second controller (ECU) 48, which detects the slip ratio of the vehicle based on the two speed signals and detects the slip rate of the vehicle. To the control signal.

The snow removing vehicle 10 is an all-wheel drive vehicle having a so-called part-time type front wheel drive device, in which the front wheels 16 and the rear wheels 18 rotate at the same speed. Therefore,
In order to detect the slip ratio of the vehicle, it is necessary to provide a vehicle speed detector 44 of a radar system, an ultrasonic system, or the like. Further, the first and second controllers 38 and 48 can be replaced by one common controller.

A snow removal operation mode using the grader blade 30 of the above-mentioned proposed snow removal vehicle 10 will be described with reference to FIG. First, the driver operates the operation lever of the mode switching device 40 to set the pressing pressure of the grader blade 30 against the snow surface S to a desired pressure among a plurality of stages, and sets the vehicle 10 according to the condition of the snow surface S. Appropriate speed (usually 20 to
40 km / hr).

[0011] and a signal indicating the actual vehicle speed V _t from the vehicle speed detector 44, a signal indicative of the rotational speed V _w rear wheel 18 from the wheel speed detector 46b is inputted to the second controller 48,
The controller 48 calculates the slip ratio. Result of the operation, when the wheel speed V _w is not greater than the vehicle speed V _t, i.e., if the slip is not generated, is in a state where the pressing force of the snow S for grader blade 30 by the hydraulic cylinder 36 is insufficient From the second controller 4
A pressurizing command is supplied from 8 to a hydraulic adjusting device 34, and the hydraulic cylinder 36 presses the grader blade 30 to the set pressing pressure.

[0012] As a result of the above-mentioned operation, the wheel speed _{V w} is the vehicle speed _{V t}
If it is larger, that is, if a slip has occurred, the second controller 48 determines whether the slip rate is within a range of an optimum slip rate appropriate for snow removal work. When the slip ratio is within the optimum range, the hydraulic pressure supplied to the hydraulic cylinder 36 is maintained in that state.

On the other hand, as a result of the calculation, if the slip ratio exceeds the optimum range, a pressure reducing command is supplied from the controller 48 to the hydraulic pressure adjusting device 34, and the hydraulic pressure supplied to the hydraulic cylinder 36 is reduced. Grader blade 3
The pressing force on the snow surface S of 0 is reduced, and problems such as skidding of the vehicle due to an excessive slip ratio are eliminated.

[0014]

In the above-mentioned proposed snow removing vehicle, when the snow is removed from the hard snow layer using the grader blade, the slip ratio is detected from the actual vehicle speed and the wheel speed of the vehicle. By controlling the pressing force of the grader blade so that the slip ratio falls within the optimum range, there is an advantage that effective snow removal can be performed without causing a problem such as a side slip of the vehicle regardless of a change in the road surface condition. However, in order to detect the actual vehicle speed of the vehicle, there is a problem that a complicated and expensive vehicle speed detector using radar or ultrasonic waves and requiring a great deal of labor for maintenance is required.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and effectively controls the pressing force of a grader blade against a snow surface without using a complicated and expensive vehicle speed detector. The main object of the present invention is to provide an inexpensive, highly reliable and durable, easy-to-maintain snow removal vehicle capable of efficiently removing a hard snow layer without causing problems such as side slip. Things.

According to the present invention, a driver's work load is small in snow removal work, and a variation in impact force at the time of snow removal based on a partial difference in frozen hardness of the snow layer is absorbed to improve ride comfort. It is another object of the present invention to provide a snow removing vehicle with less driver fatigue.

Further, the present invention provides a distributing machine having a differential mechanism and a differential lock mechanism in a transmission system for transmitting the power of the engine to the front wheels and the rear wheels, thereby reducing the slip state of the vehicle during snow removal. Still another object of the present invention is to provide a snow removal vehicle that can be detected by an inexpensive device and that has excellent running performance and easy snow removal workability such as normal running such as forwarding and escape from a muddy place. is there.

In order to achieve the above object, the present invention provides a front wheel propeller shaft and a rear wheel propeller in which the power of an engine drives a front wheel and a rear wheel from a transmission via a distributor provided with a differential mechanism. While being transmitted to the shaft, a grader blade for snow removal is disposed below the vehicle body between the front wheel and the rear wheel,
A front wheel speed detector for detecting a rotation speed of the front wheel, wherein the grader blade is pressed against the snow surface via a hydraulic cylinder operated by a hydraulic pressure supplied from a hydraulic source mounted on the vehicle body; A rear wheel speed detector that detects a rotation speed of the rear wheel; and a controller that calculates a wheel speed difference between the front wheel and the rear wheel based on output signals detected by the two detectors. The present invention also proposes a vehicle for snow removal, wherein the supply hydraulic pressure supplied to the hydraulic cylinder device is controlled according to an output signal based on the wheel speed difference.

[0019]

In the snow removing vehicle according to the present invention, a distributor having a differential mechanism is provided in a transmission system for transmitting the power of the engine to the front wheels and the rear wheels. Are disposed on the front wheel and the rear wheel, and the slip state of the vehicle can be detected from the speed difference between the front wheel and the rear wheel. Therefore, no special vehicle speed detector is required. Further, when the anti-skid brake device is employed for the front wheels and the rear wheels, the wheel speed detector of the anti-skid brake device can be used as it is as the wheel speed detector, thus further simplifying the structure. Can be planned.

Further, as a transmission interposed in a transmission system for transmitting the power of the engine to the front wheels and the rear wheels, a torque converter, a multi-plate clutch device and a brake device, and one or more planetary gear devices are incorporated. By adopting a hydraulic automatic transmission, the driver's gear shifting operation can be omitted and the work load can be greatly reduced.In addition, during snow removal work, shocks due to the difference in partial frozen hardness of the snow layer can be reduced. It can relax and improve the ride.

Further, by providing a differential lock mechanism in the differential mechanism, it is possible to improve running performance such as forward running and escape from a muddy place.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. (Note that members and portions substantially the same as or corresponding to those of the proposed snow removal vehicle described with reference to FIGS. 9 and 10 are denoted by the same reference numerals in principle, and overlapping descriptions will be omitted. First, in the schematic side view of the entire vehicle shown in FIG. 1, an engine 50 is mounted on the chassis frame 12 below the cab 14, and a fluid transmission 52 is connected to the engine 50. The engine 50 is usually a diesel engine, and the hydraulic transmission 52 is a known type that incorporates a torque converter, a hydraulically operated multi-plate clutch device and a brake device, and one or more planetary gear devices. It is of the structure.

A distributor 54 shown in the schematic diagram of FIG. 2 and the side view of FIG. 3 is connected to the output side of the transmission 52. The distributor 54 includes a casing 56, which is composed of an upper casing 58 and a lower casing 60 having a small dimension in the vehicle longitudinal direction. An input shaft 62 for inputting the power of the engine 50 to the distributor 54 via the transmission 52 is provided as an example of the upper casing 58.
(Ie, the output shaft of the transmission 52). Also,
A planetary gear type differential mechanism 64 is provided inside the upper casing 58. The differential device 64 includes a carrier 66 connected to the input shaft 62. A plurality of planetary gears 68 are rotatably supported on the carrier 66, and a ring gear 70 meshes with the planetary gear 68. The ring gear 70 has a first output shaft 72 for driving rear wheels.
One end of the first output shaft 72 protrudes outside the upper casing 58, and a rear wheel output flange 74 is provided at the protruding end.

A sun gear 76 meshes with a planetary gear 68 supported by the carrier 66.
The drive gear 78 is fixed to the. The drive gear 78 meshes with an output gear 82 housed in the lower casing 60 via an idler gear 80, and the output gear 82 is fixed to a second output shaft 84 for driving the front wheels or integrally with the output shaft 84. Is formed. One end of the second output shaft 84 protrudes outside the lower casing 60, and a front wheel output flange 86 is provided at the protruding end.

Further, a differential lock mechanism 88 for locking the differential between the second output shaft 84 for driving the front wheels and the first output shaft 72 for driving the rear wheels by the differential mechanism 64 is stored in the upper casing 58. Have been. The above differential lock mechanism 8
8 rotates the first output shaft 72 for driving the rear wheels and the second output shaft 84 for driving the front wheels at the same speed in the locked position, as is well known in the art; The differential rotation of the first output shaft 72 and the second output shaft 84 is permitted depending on the condition of the road surface.

As shown in the overall side view of FIG.
The output flange 74 of the first output shaft 72 is connected to the front end of a rear-wheel propeller shaft 88 that extends rearward while being inclined downward at an angle θ with respect to the chassis frame 12, and the rear end of the propeller shaft 88 is connected to the rear end. It is connected to a differential 92f on a rear shaft 90f for the front wheel 18f, and the differential 92f is further connected to a propeller shaft 9 for the rear rear wheel 18r.
4, and is connected to a differential 92r of the rear shaft 90r. On the other hand, a front wheel output flange 86 of the second output shaft 84 is connected to a rear end of a propeller shaft 96 for driving front wheels, and a front end of the propeller shaft 96 is connected to a differential 100 of a front shaft 98.

The grader blade 30 is disposed below the chassis frame 12 at the rear of the distributor 54. FIG. 4 is a side view showing a support device of the grader blade 30, and FIG. 5 is a plan view of a main part of the above-mentioned grader blade support device, with a part thereof omitted. As shown in FIG. 5, the grader blade support devices indicated generally by the reference numeral 102 are mounted on the left and right side rails 12 'of the chassis frame 12 at different positions in the vehicle longitudinal direction. The left and right support devices 102 have substantially the same structure. The grader blade 30
Two portions in the vehicle width direction are supported by the left and right support devices 102, and are supported below the vehicle body at an appropriate inclination angle θg suitable for snow removal with respect to a center line oo in the vehicle front-rear direction. (Note that, in FIG. 5, the grader blade 30 is shown in a rest position where the attitude is substantially parallel to the road surface.)

As best shown in the side view of FIG.
The support device 102 has a rectangular base plate 104 arranged substantially vertically, and a link arm 106 and a yoke 108 are arranged on the base plate 104 at intervals in the vehicle longitudinal direction. The link arm 106 is supported by a bracket 110 so as to be able to rotate around a substantially horizontal axis a-a extending in the vehicle front-rear direction, and the yoke 108 is fixed by a bracket 112 to the axis a-a. It is supported so as to be able to pivot about a substantially parallel axis bb.

A pair of trunnions 118 projecting from the cylinder 116 of the first hydraulic cylinder device 114 in the vehicle width direction are pivotally supported on the yoke 108. Therefore, the hydraulic cylinder device 114 has the axis bb Can be freely rotated around an axis perpendicular to (i.e., an axis extending in the vehicle width direction). A substantially vertical holder 122 is pivotally attached to a shaft 120 of the piston slidably fitted in the cylinder 116 by a pin 124 extending in the vehicle width direction. Further, the holder 122 has a pair of upper and lower arms 126 and 128 forming a parallel link mechanism.
Is connected to a pin 130 extending in the vehicle width direction, and the other end of each of the arms 126 and 128 is connected to the link arm 106 by a pin 132 extending in the vehicle width direction.
It is pivotally attached to the upper and lower ends.

A tilt bracket 134 is supported by a pin at a lower end portion of the holder 122, and a mounting bracket 136 of the tilt bracket 134 has a mounting bracket 138 fixed to an arc-shaped or arcuately curved grader blade 30 on a convex rear surface thereof. Are pivotally connected by a fulcrum pin 140. Further, the chilled bracket 134 is pivotally supported by a trunnion 146 protruding from the cylinder 144 of the second hydraulic cylinder device 142 so as to extend in the vehicle width direction. It can rotate about the axis of the trunnion 146.
A shaft 148 of a piston slidably fitted in the cylinder 144 is pivotally attached to a protruding arm 150 protruding from the rear surface of the grader blade 30 by a pin 152 extending in the vehicle width direction. .

Therefore, the first hydraulic cylinder device 114
By controlling the supply and discharge of hydraulic oil to and from the cylinder 116, the piston shaft 120 is extended from the cylinder 116 or retracted into the cylinder 116, thereby tilting the holder 122 and the holder 122 through the parallel link mechanism. The grader blade 30 supported via the bracket 134 can be lowered toward the snow surface S or raised in a direction away from the snow surface. Also, the link arm 106 and the first hydraulic cylinder device 114 of the parallel link mechanism on the chassis frame 12 side are respectively provided with horizontal axes aa, b.
-B, so that the grader blade 30 can move up and down by the same amount in the left and right directions, that is, can be displaced up and down in the same posture with respect to the snow surface S. By operating the device 114 independently or changing the stroke of the piston shaft 120 of both cylinder devices 114, the grader blade 3 against the snow surface S
The angle between the lower edge of the zero and the snow surface S can be changed as appropriate.

Further, the supply and discharge of working pressure oil to and from the second hydraulic cylinder device 142 is controlled to control the piston shaft 148.
Extend from the cylinder 144, or
4, the grader blade 30
By rotating the blade 30 around the fulcrum pin 140, the blade 30 is moved to a use position shown by a solid line in FIG. 4 and a rest position or a desired intermediate position shown by a two-dot chain line in FIG. Can be done.

A first hydraulic cylinder device 114 for controlling the vertical position of the grader blade 30 and a second hydraulic cylinder device 114 for selectively positioning the blade 30 in an operating position or a rest position.
The operation of the hydraulic cylinder device 142 will be described with reference to FIGS.
This will be described with reference to FIG. (In the following description, when it is necessary to distinguish the left and right members and devices with respect to the center line in the vehicle longitudinal direction, the left and right symbols are denoted by L,
The right side adds R. For example, the left first hydraulic cylinder device is 114L, and the right first hydraulic cylinder device is 114L.
Represented by R. )

As shown in the grader blade elevating and turning control chart of FIG. 6, a front wheel speed detector 154 is provided on each of the left and right front wheels 16 of the snow removal vehicle 10, and a rear wheel speed is provided on the rear wheel 18. A detector 156 is provided, and the speed signals of both speed detectors 154 and 156 are provided to second controller 48. For the front wheel speed detector 154 and the rear wheel speed detector 156, a wheel speed detector in an anti-skid brake device that has been widely used in the past can be used, and a vehicle without an anti-skid brake device can be used. In the case of, a well-known non-contact type rotation speed sensor including a ring having a number of teeth or projections that rotate integrally with the wheel and a pickup opposed to the ring, and other appropriate speed detection devices are appropriately employed. be able to. Further, in the case of a rear two-axle vehicle shown in the figure, the rear wheel speed detector 156 is preferably provided on the rear rear wheel 18r where a change in speed appears greatly during turning or the like.

The snow removal work by the grader blade 30
Since the differential lock mechanism 88 of the distributor 54 is unlocked and the differential between the first output shaft 72 for the rear wheel and the second output shaft 84 for the front wheel is permitted, the above-mentioned front wheel and By comparing the output signals of the rear wheel speed detectors 154 and 156, the controller 48 can detect the slip ratio of the vehicle during the snow removal operation. (Note that the first controller 38 and the second controller 48 cooperating with the mode switching device 40 are integrated into a single controller or control means, and the output signal of the mode switching device 40 is (It goes without saying that the output signals of the front and rear wheel speed detectors 154 and 156 can be processed.)

A signal representing the slip ratio detected by the controller 48 is supplied to the hydraulic pressure adjusting device 34,
The hydraulic pressure supplied to the left and right first hydraulic cylinder devices 114L and 114R is controlled so that the grader blade 30 is moved up and down to obtain an optimum slip ratio that enables the snow removal operation to be performed most efficiently. The pressing force of the grader blade 30 against the snow surface S is controlled. The above-mentioned slip ratio is usually determined by the speed detector 1 for the left and right front wheels.
This is detected by comparing the average value of the output signal of the output signal 54 and the average value of the output signal of the speed detector 156 of the left and right rear wheels 18. However, if necessary, the slip ratio of the front wheel detected by comparing the signals of the left and right front wheel speed detectors 154L and 154R, and the signal of the left and right rear wheel speed detectors 156L and 156R are detected. Based on the rear wheel side slip rate
The hydraulic cylinder devices 114L and 114R can be vertically moved independently or simultaneously by the same amount or simultaneously by different amounts.

Next, the first hydraulic cylinder device 114L
And 114R, the second hydraulic cylinder devices 142L and 14R
An example of the 2R hydraulic circuit will be described with reference to FIG. In the figure, reference numeral 158 denotes an oil tank that stores hydraulic oil, 160 denotes an oil pump that pressurizes and feeds hydraulic oil in the oil tank 158, and 162L denotes a left first hydraulic cylinder device 114.
162R is a three-position electromagnetic switching valve that controls the operation of the right first hydraulic cylinder device 114R, and 164 is a three-position electromagnetic switching valve that controls the left and right second hydraulic cylinder devices 142L and 142R. The three-position electromagnetic switching valve 166L that simultaneously expands or contracts is a pilot check valve interposed between the left first hydraulic cylinder device 114L and the three-position electromagnetic switching valve 162L, and 166R is the right first hydraulic cylinder device 114R. And three-position electromagnetic switching valve 162
R, a pilot-type check valve interposed between the left and right second hydraulic cylinder devices 142L and 142R and the three-position electromagnetic switching valve 164, a pilot-type check valve 170L, 170R is a pressure sensor for detecting the operating oil pressure in the pressure chamber on the extension side of the left and right first hydraulic cylinder devices 114L and 114R, that is, on the blade pressing side.
And 174 are ordinary relief valves.

The oil pump 160 can be driven by the engine 50 of the vehicle 10, or is driven by a motor 176 which is energized by an onboard power supply. The output signals of the pressure sensors 170L and 170R enter the hydraulic pressure adjusting device 34, which controls the three-position electromagnetic switching valves 162L, 162R and 164.

In FIG. 8, all three-position solenoid-operated switching valves 16
2L, 162R and 164 are shown in neutral position,
At this time, none of the first hydraulic cylinder devices 114L and 114R and the second hydraulic cylinder devices 142L and 142R operate and are stationary. Therefore, first, the three-position electromagnetic switching valve 1
When the cylinder 64 moves rightward from the illustrated position, hydraulic pressure oil is supplied to the extension-side pressure chambers of the second hydraulic cylinder devices 142L and 142R, the piston shaft 148 extends from the cylinder 144, and the grader blade 30 4 is rotated counterclockwise in FIG.
Can rotate to a substantially horizontal rest position, and when the three-position electromagnetic switching valve 164 moves leftward from the position in FIG.
The operating pressure oil is supplied to the contraction side pressure chambers of the second hydraulic cylinder devices 142L and 142R, and conversely, the grader blade 30 rotates around the fulcrum pin 140 clockwise in FIG. It can pivot to the operating position shown by the solid line inside. Further, the three-position electromagnetic switching valve 1
64 is moved leftward or rightward as described above, and then returned to the neutral position after a suitable time, so that the intermediate position between the rest position shown by the two-dot chain line and the operating position shown by the solid line in FIG. Can be stopped at any position.

Similarly, when the three-position electromagnetic switching valve 162L is moved to the right, the operating pressure oil is supplied to the extension side pressure chamber of the first hydraulic cylinder device 114L, and the left portion of the grader blade 30 faces the snow surface S. When the pressing force increases and the three-position solenoid-operated switching valve 162L moves to the left, the operating pressure oil is supplied to the contraction side pressure chamber of the first hydraulic cylinder device 114L, and the left portion of the grader blade 30 is moved. Since it rises from the snow surface S, the pressing force against the snow surface decreases. Similarly, the first hydraulic cylinder device 114R connected to the right portion of the grader blade 30 also has a three-position electromagnetic switching valve 16R.
The expansion and contraction is controlled by the 2R, and the pressing force against the snow surface S of the right side of the grader blade 30 is increased or decreased.

When the slip rate calculated and detected by the controller 48 exceeds an appropriate slip rate set in advance,
When the state continues for the first set time T ₁ (preset according to the thickness of snow on a snowy road, the weight of the vehicle, the running speed at the time of snow removal, etc.), a signal is output to the hydraulic pressure adjusting device 34. You. The hydraulic adjusting device 34 both the 3-position solenoid switching valve 162L and 162R, or either one, to reduce the pressing force by shifted leftward the second set time T ₂ by the switching valve which is set in advance. If after a second set time T ₂ still slip ratio is not greater than the proper slip rate that state continues first set time T ₁ or more, again both or either one of the second set time T of the change-over valve _The pressing force is further reduced by moving leftward by _{2 and} the same operation is repeated until the slip ratio of the vehicle reaches the appropriate slip ratio. The adjustment of the pressing force is, of course, performed by the mode switching device 40 in advance based on a certain pressing force appropriately selected from a plurality of stages of the pressing force depending on the snow condition or the like. Moreover, beyond the slip ratio is properly slip rate of the vehicle during snow removal, and the state is first set time T ₁
When the continuation is continued, the three-position electromagnetic switching valve 164 is moved leftward by the second setting time T2 to rotate the grader blade 30 counterclockwise around the fulcrum pin 140, and the lower edge of the blade 30 with respect to the snow surface S The angle formed by the second hydraulic cylinder device 142 can be controlled by adjusting the angle formed by the grader blade 30 with the snow surface S by the same operation as the control of the pressing force. And an appropriate slip ratio can be obtained. Further, the control of the pressing force by the expansion and contraction control of the first hydraulic cylinder devices 114L and 114R and the angle control of the blade by the expansion and contraction control of the second hydraulic cylinder device 142 are appropriately performed according to the amount of snow, snow quality, road conditions, and the like. Can be selected or used in combination.

According to the configuration of the present invention described above, the distributor is interposed in the power transmission system of the vehicle, and inexpensive speed detectors are mounted on the front and rear wheels, and the speed is detected by these speed detectors. Based on the wheel speeds of the front and rear wheels, since the slip rate of the vehicle during snow removal work is detected, the manufacturing cost is lower than the above-described proposed device that requires a vehicle speed detection device using radar or ultrasonic waves, In addition, the wheel speed detector has a simple structure, has few failures, and has excellent durability. Therefore, there is an advantage that maintenance is easy and reliability is improved. Furthermore, since the hydraulic cylinder devices for pressing the grader blade against the snow surface are arranged on both sides of the longitudinal centerline of the vehicle body and are controlled by separate hydraulic control valves, the left and right hydraulic cylinder devices can be simultaneously or independently. It can be operated, and the pressing force of the grader blade against the snow surface can be finely controlled, so that there is an advantage that snow can be efficiently removed without causing a problem such as side slip. Furthermore, by using a fluid automatic transmission as a transmission interposed in a power transmission system that transmits the power of the engine of the vehicle to the wheels, a driver's gear shifting operation work during snow removal work can be omitted and steering operation can be performed. Also, when it is possible to concentrate on the operation of the mode switching device, it is possible to reduce the impact of the vehicle body based on the change of the acting force required for snow removal of the grader blade and improve the riding comfort, thereby reducing the occupant fatigue. However, there is an advantage that the snow removal work efficiency can be improved. In addition, since a distributor equipped with a differential mechanism and a differential lock mechanism is interposed in a power transmission system for transmitting the power of the engine to the wheels, by locking the differential lock mechanism, the front wheel propeller shaft is driven. And the rear wheel propeller shaft can be driven synchronously, and there is an advantage that it is possible to provide a snow-removing vehicle that is easy to run in normal running such as forwarding and escape from a muddy place and has excellent running performance.

The present invention can be implemented by adding various changes and modifications to the above embodiment within the scope of the claims. For example, the rear axle of the vehicle can be changed from two rear axles to a single rear axle, and one oil pump 160 is used as a hydraulic source for supplying hydraulic pressure to the first and second hydraulic cylinder devices. However, two or more oil pumps can be provided, and a three-position electromagnetic switching valve 162L, 1 exemplarily illustrated as a hydraulic control valve.
Instead of 62R and 164, other appropriate switching valves can be used instead.

[0044]

As described above, in the snow removal vehicle according to the present invention, the propeller for the front wheels drives the front wheels and the rear wheels of the engine through the distributor provided with the differential mechanism from the transmission. The transmission is transmitted to the shaft and the rear wheel propeller shaft, and a grader blade for snow removal is disposed below the vehicle body between the front wheel and the rear wheel, and the grader blade is provided from a hydraulic source mounted on the vehicle body. A front wheel speed detector for detecting the rotation speed of the front wheel, and a rear wheel speed detector for detecting the rotation speed of the rear wheel, wherein the front wheel speed detector detects the rotation speed of the front wheel. And a controller that calculates a wheel speed difference between the front wheel and the rear wheel based on the output signals detected by the two detectors, and the controller calculates the wheel speed difference based on the wheel speed difference calculated by the controller. Hydraulic syringe It is characterized by controlling the supply hydraulic pressure supplied to the, effectively controlling the pressing force of the grader blade against the snow surface, efficiently removing snow without causing problems such as side slip. There is an effect that this kind of vehicle which can be performed at low cost, has excellent reliability and durability, and is easy to maintain can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an entire vehicle showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a distributor 54 interposed in a power system of the vehicle shown in FIG.

FIG. 3 is a side view of the distributor 54 shown in FIG.

FIG. 4 is a side view showing a vehicle body mounting structure of the grader blade 30 in FIG.

5 is a schematic plan view of the grader blade mounting structure shown in FIG.

FIG. 6 is a view showing a control procedure for raising and lowering and rotating the grader blade.

FIG. 7 is an arrangement and control system diagram of a lifting / lowering and rotation control device of the grader blade.

FIG. 8 shows first and second hydraulic cylinder devices 1 in FIG.
FIG. 14 is a hydraulic circuit diagram for controlling operations of 14 and 142.

FIG. 9 is a schematic side view showing a proposed snow removing vehicle.

FIG. 10 is an elevational control diagram of the grader blade in FIG. 9;

[Explanation of symbols]

10: snow removal vehicle, 12: chassis frame, 16: front wheel,
18 rear wheel, 30 grader blade, 50 engine, 52 transmission, 54 distributor, 64 differential mechanism, 8
8: Differential lock mechanism, 34: Hydraulic adjusting device, 38 and 4
8 ... controller, 114 ... first hydraulic cylinder device, 1
42 ... second hydraulic cylinder device, 160 ... oil pump (hydraulic power source), 162L and 162R ... 3-position electromagnetic switching valve (hydraulic control valve), 164 ... 3-position electromagnetic switching valve (hydraulic control valve)

──────────────────────────────────────────────────続 き Continuing on the front page (73) Patent holder 000006286 Mitsubishi Motors Corp. 5-33-8, Shiba, Minato-ku, Tokyo (72) Inventor Masami Onizawa (72) Inventor Shigeo Sawaguchi 8-3-3, Kikusui, Shiroishi-ku, Sapporo City, Hokkaido 325-13 Nishinomiyazawa, Teine-ku, Sapporo-shi 325-13 (72) Inventor Takemi Somazawa 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Akira Motooka Minato-ku, Tokyo Shiba 5-chome 8-3 Mitsubishi Motors Corporation (72) Inventor Hideaki Hiragun 5-33-8 Shiba 5-chome, Minato-ku, Tokyo Mitsubishi Motors Corporation (58) Field surveyed (Int.Cl. ^6, D Name) E01H 5/06 E01H 5/04

Claims (7)

(57) [Claims] 1. The power of an engine is transmitted from a transmission via a distributor provided with a differential mechanism to a front-wheel propeller shaft and a rear-wheel propeller shaft for driving front and rear wheels.
A grader blade for snow removal is disposed below the vehicle body between the front wheel and the rear wheel, and the grader blade is mounted on the snow surface via a hydraulic cylinder device operated by a hydraulic pressure supplied from a hydraulic source mounted on the vehicle body. A front wheel speed detector that detects the rotation speed of the front wheel, a rear wheel speed detector that detects the rotation speed of the rear wheel,
A controller that calculates a wheel speed difference between the front wheel and the rear wheel based on the output signals detected by the two detectors, and the hydraulic cylinder according to an output signal based on the wheel speed difference calculated by the controller. A snow removing vehicle, wherein the supply hydraulic pressure supplied to the device is controlled. 2. The front wheel speed detector and the rear wheel speed detector are provided on each of the left and right wheels, and the controller calculates the wheel speed difference by an average value of output signals from the left and right front wheel speed detectors and the left and right wheels. 2. The snow removal vehicle according to claim 1, wherein the vehicle calculates a difference from an average value of output signals from the rear wheel speed detector to generate an output signal indicating a slip state of the vehicle. 3. The hydraulic cylinder device according to claim 1, wherein the grader blade is disposed on the lower side of the vehicle body with an inclination with respect to a center line in the front-rear direction of the vehicle body. 2. The snow removing vehicle according to claim 1, wherein at least one of the left and right sides is disposed, and a hydraulic control valve is interposed between each hydraulic cylinder device and the hydraulic pressure source. 4. The snow removing vehicle according to claim 1, wherein the transmission is a hydraulic automatic transmission. 5. A differential lock mechanism is provided in a differential mechanism of the distributor, and the front wheel propeller shaft and the rear wheel propeller shaft are synchronously driven when the differential lock mechanism is locked. The snow removing vehicle according to claim 1 or 2, wherein: 6. A mode switching device for manual operation is connected to the controller, and the pressing force of the grader blade generated by the hydraulic cylinder device for pushing down the grader blade is controlled in a plurality of stages by operating the mode switching device. The snow removal vehicle according to claim 1 or 2, wherein 7. A propeller for a rear wheel, wherein the rear wheel comprises two shafts.
The axle is connected to the front rear wheel axle and the rear rear wheel axle.
3. The snow removing vehicle according to claim 1, wherein the wheel speed detector is configured to detect a rotation speed of the rear rear wheel .