JPH08197984A - Motive power transmitting device of rotary snowplow - Google Patents

Abstract

PURPOSE: To provide a motive power transmitting device of a rotary snowplow by which safe braking can be performed by generating a sufficient effect of an ABS device. CONSTITUTION: Clutches 19 are arranged in a transmission 12 to transmit motive power for travel from a hydraulic continuously variable transmission (HST) 20 to front and rear wheels 10 and 11. The clutches 19 have a directional control valve 21 becing a control valve. When a brake pedal 5 is stepped, its signal is sent to an ABS controller 30, and at the same time, it is sent to a power shift directional control valve controller 33, and a speed change signal to the directional control valve 21 is controlled, and the clutches 19 are disengaged from each other. Therefore, an action of the HST 20 is not transmitted to the front and rear wheels 10 and 11 at braking time, and an influence is not exerted on an ABS device, and an effect of the ABS device is sufficiently exhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for a rotary snow removal vehicle, and more particularly to a power transmission device for a rotary snow removal vehicle equipped with an ABS device.

[0002]

2. Description of the Related Art A rotary snow removal vehicle normally uses a single engine to drive the vehicle and to drive a snow removal device. This is because the running speed during snow removal is very slow, most of the engine power can be consumed to drive the snow removal device, and no snow removal power is required during forwarding, and all engine power can be used for running. is there. The traveling speed is controlled separately from the engine speed, and the traveling speed and the working speed can be separately controlled. This is for keeping the snow throwing distance by the snow removing device constant regardless of the magnitude of the snow removing load.

In a general rotary snow plow, the power generated by the engine is divided into a driving power and a working power by a power distributor. The driving power is a hydrostatic transmission using hydraulic pressure from a power distributor:
It is transmitted to the transmission (sub-transmission) via the HST and is further transmitted to the front and rear wheels. HST
Includes at least one of a variable displacement hydraulic pump and a hydraulic motor, and controls the flow rate of the hydraulic pump or hydraulic motor to control the traveling speed.

[0004] When the rotary snow plow vehicle travels, the transmission gear is set to an arbitrary gear, and the accelerator pedal is depressed while controlling the HST (while controlling the flow rate of the hydraulic pump or hydraulic motor). When the HST is set to the stop position during traveling, the deceleration is sufficient to stop the vehicle.

When braking a rotary snow plow, the HST is generally set to the stop position and the brake pedal is depressed to stop the vehicle. However, since the deceleration exerted by the HST is large, the HST can be stopped when there is a leeway. The vehicle can be stopped only by the deceleration action.

By the way, when abrupt braking is applied on a frozen road surface or a snowy road where a rotary snow plow operates, a slip state occurs like a general vehicle. Further, the sudden deceleration by HST is in a better condition than the brake braking, but the slip still occurs. If the vehicle slips during braking, the steering wheel cannot be operated, which is dangerous. Therefore, it is conceivable to install an ABS device (Anti-skid Brake System) for preventing slip during braking. Conventionally, a general ABS device uses an anti-skid system in which the number of rotations of a wheel is counted, a deceleration state of a vehicle body is simulated to obtain a virtual slip ratio, and a brake pressure is adjusted to prevent the wheel from locking. .

[0007]

However, in the case of a rotary snow removal vehicle, it is common to use both brake braking and deceleration by HST in an emergency. If the ABS device is provided, the ABS device operates due to the sudden braking, but the normal ABS device does not operate due to the deceleration action of the HST. Therefore, even when the ABS device is activated during the sudden braking, when the deceleration by the HST is performed, a rapid deceleration occurs on the power generation side, the wheels are locked, and the slip state occurs, and the ABS device has no effect. There was a problem.

It should be noted that, when the ABS device is operated during braking, it is sufficient to control the deceleration by the HST so as not to impair the effect of the ABS device according to the deceleration of the vehicle, but the operation is extremely difficult and practical. is not.
Further, when deceleration by the HST is started after the brake braking, the ABS device has a speed increasing action when the brake pressure is reduced (brake is released), and the ABS device is not sufficiently effective.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the conventional power transmission system for a rotary snow plow, and to generate a sufficient effect of the ABS system so as to perform safe braking. It is to provide a device.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a power transmission device for a rotary snow removal vehicle, which transmits traveling power through a hydraulic continuously variable transmission, the rotary snow removal device including an ABS device. A power transmission device for a vehicle is provided with clutch means for connecting / disconnecting traveling power from the hydraulic continuously variable transmission, and control means for controlling to disconnect the clutch means when the ABS device operates. .

[0011]

When the rotary snow plow is suddenly braked, the ABS device is actuated and at the same time, the clutch means is disengaged to release the power transmission (including acceleration and deceleration) from the hydraulic continuously variable transmission to the wheels (driving wheels). . This prevents the influence of the hydraulic continuously variable transmission during braking from affecting the ABS device and impairing the effect of the ABS device.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a power transmission mechanism of a rotary snow plow equipped with a power transmission device according to an embodiment of the present invention. In this figure, the power generated by the engine 6 is transmitted to the power distributor 7 and divided into work power and travel power. The work power is taken out from the power distributor 7 and reaches the power transmission unit 15, which is divided into two and one system has a blower 1
8 and the other system goes through chain transmission 16 and auger 1
Drive 7

The motive power for traveling is H which is composed of a power distributor 7, a variable displacement hydraulic pump 8 and a hydraulic motor 9.
It is transmitted to the transmission 12 via ST20 and is transmitted to the front and rear wheels 10 and 11 via the front and rear wheel differentials (differential) 13 and 14.

By the way, the rotational speed adjusting mechanism of the engine 6 is provided with two systems, an accelerator pedal 1 and an accelerator lever 2. The accelerator pedal 1 is used at the time of forwarding a rotary snow removal vehicle. The accelerator lever 2 is used during snow removal work, is fixed to a full throttle in most cases, and adjusts the rotation speed of the engine 6 at the vehicle speed so that the work can be performed at the rotation speed at which the engine torque becomes maximum, that is, the most efficient rotation speed. To be done.

Further, the HST 20 is provided with a forward / reverse control lever 3, and the transmission 12 is provided with a travel control lever 4. The forward / reverse control lever 3 is a lever that controls the discharge amount and the discharge direction of the hydraulic pump 8 by controlling the swash plate of the hydraulic pump 8 of the HST 20, and is used for controlling the traveling speed and switching between forward and reverse movements. When the lever 3 is returned to the neutral position during traveling, the HST 20 becomes the stop position, and the deceleration sufficient to stop the vehicle is exhibited. Further, the travel control lever 4 is a lever for switching the shift speed of the transmission 12, and when the snow plow vehicle is running, the travel control lever 4 allows the shift speed of the transmission 12 to be set to an arbitrary speed and the forward / reverse control lever 3 to be operated. While depressing accelerator pedal 1, the car runs.

The transmission 12 has a clutch 19 called a power shift transmission for shifting gears, and a control valve (power shift switching valve) 21 of the clutch 19 is provided. When the power shift switching valve 21 is set to the neutral position, the clutch 19 is disengaged and the power transmission to the front and rear wheels is discontinued.

FIG. 2 is a system diagram showing the braking system of the rotary snow removal vehicle. The brake pedal 5 provided in a driver's seat (not shown) is connected to the brake valve 22. The brake valve 22 has an air compressor 23.
From the air tank 24, a predetermined air pressure is supplied. The brake valve 22 is connected to the air master 25 to form a braking pneumatic circuit. Reference numeral 27 in the drawing is a pressure gauge, and reference numeral 28 is a pressure governor.
In addition, a braking hydraulic circuit for actuating front and rear wheel brakes (not shown) includes an air master 25 and a safety cylinder 26.
It is composed of a and b and ABS hydraulic units 31 and 32. Reference numeral 29 in the figure is an oil reservoir.
Since the hydraulic units 31 and 32 as the ABS device can adopt the configuration of a conventionally known ABS device, detailed description thereof will be omitted. Further, an electric signal indicating that the brake pedal 5 has been depressed is sent to the controller 30 of the ABS device, and the ABS hydraulic units 31 and 32 perform braking by the conventionally known ABS device. An electric signal indicating that the brake pedal 5 is depressed is also sent to the controller 33 of the power shift switching valve 21 at the same time to control the signal of the power shift switching valve 21 by the travel control lever 4.

In this braking system, hydraulic pressure corresponding to the depression amount of the brake pedal 5 is supplied to the brakes (not shown) on the front and rear wheels to exert the braking force. And ABS
The hydraulic units 31 and 32 control the hydraulic pressure supplied to the brakes to unlock the wheels during sudden braking. By the way, in the present embodiment, the brake pedal 5
When is depressed, the power shift switching valve 21 is switched to the neutral position by the control signal of the power shift switching valve controller 33. As a result, the clutch 19 is disengaged, and the power transmission from the HST 20 to the front and rear wheels is discontinued. Therefore, even if the HST 20 is located at any position or is switched to any position during braking by the brake, the action of the HST 20 is AB.
It does not affect the S device and does not impair the effect of the ABS device. Therefore, it is possible to prevent the vehicle from slipping by producing a sufficient effect of the ABS device when braking with the brakes and to perform safe braking.

In addition, when braking with the brake, the HST20
Does not affect the ABS device, and since it is not necessary to operate the forward / reverse control lever 3 during braking, it is possible to obtain the same braking feeling (brake feeling) as a general vehicle equipped with the ABS device. .

[0021]

As described above, according to the power transmission device for a rotary snow removal vehicle of the present invention, the action of the HST does not affect the ABS device during braking by the brake, so that the ABS device has a sufficient effect. It is possible to prevent the vehicle from slipping. Further, it is possible to obtain the same brake feeling as that of a general car.

[Brief description of drawings]

FIG. 1 is a plan configuration diagram showing a power transmission mechanism of a rotary snow plow equipped with a power transmission device according to an embodiment of the present invention.

FIG. 2 is a system diagram showing a braking system of the rotary snow removal vehicle.

[Explanation of symbols]

 1 accelerator pedal 2 accelerator lever 3 forward / backward control lever 4 travel control lever 5 brake pedal 8 hydraulic pump 9 hydraulic motor 12 transmission 19 power shift transmission 20 HST 21 power shift switching valve 30 ABS controller 31, 32 ABS hydraulic unit 33 power shift Switching valve controller

Claims (1)

[Claims] 1. A power transmission device for a rotary snow removal vehicle, which transmits traveling power through a hydraulic continuously variable transmission, comprising:
In a power transmission device for a rotary snow plow equipped with a device, there are provided clutch means for connecting and disconnecting traveling power from the hydraulic continuously variable transmission, and control means for controlling to disconnect the clutch means when the ABS device operates. A power transmission device for a rotary snow removal vehicle, comprising: