JPH0115703Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a speed control device for a snowplow vehicle that automatically controls the traveling speed according to the snow removal load.

In general, a snowplow has a structure in which a single engine operates a snow removal device and a hydraulic pump, and a hydraulic motor, which is rotated by the hydraulic pump, drives a traveling device, and the snow removal device removes snow while moving. ing. However, in conventional snowplows, the snow removal device and the traveling device are operated separately by the operator, making it difficult to always maximize the engine's performance. Ta. In addition, the worker manually adjusts the traveling speed by operating a control lever in the driver's cab, which imposes a heavy labor burden on the worker.

The present invention solves the above-mentioned conventional dissatisfaction by automatically controlling the running speed according to the snow removal load so that the engine load is always at its maximum allowable load, improving engine utilization efficiency, Another object of the present invention is to provide a speed control device for a snowplow that can significantly reduce the labor burden on workers. Hereinafter, the present invention will be explained in detail based on the drawings.

The figure shows one embodiment of the present invention, in which numeral 1 is the engine of a rotary snowplow. The output shaft 1a of this engine 1 is connected to a well-known gear device 2,
A snow removal device 3 and a hydraulic pump 4 are connected to this gear device 2. The snow removal device 3 includes a reducer 3a that reduces the rotational power from the gear device 2, a blower 3b attached to the reducer 3a, and an auger 3d attached to the reducer 3a via a chain transmission 3c. The snow shoveled by the auger 3d is sent to a chute (not shown) by the blower 3b for snow removal. Further, the hydraulic pump 4 is driven by the rotational power from the gear device 2 to operate the hydraulic motor 5 for traveling, and the power of the hydraulic motor 5 is sent to the gear device 6 for traveling to operate the hydraulic motor 5 as appropriate. The speed is changed and the traveling device 7 is operated. Note that the gear device 6 for traveling is also connected to the gear device 2 connected to the engine 1, and when only driving without performing snow removal work, the power of the engine 1 is directly applied to the traveling device. It has become possible to convey up to 7.

The speed control device of the present invention includes a sensor 8 attached to the output shaft 1a of the engine 1, and a sensor 8 attached to the output shaft 1a of the engine 1.
a calculation means 9 for calculating an increase/decrease ΔV in the traveling speed V to be controlled based on the output signal of the calculation means 9;
and an output means 10 for automatically controlling the traveling speed V based on the calculation results at.

Here, the sensor 8 is attached to the output shaft 1a via a pair of gears 11, and detects the rotation speed of the engine 1. The calculation means 9 is composed of a microcomputer or the like, and detects the actual running speed V based on the swash plate angle θ of the hydraulic pump 4 detected by the swash plate angle sensor 12, and The engine load L is calculated from the rotation speed n of the engine 1 obtained by
Traveling speed V to make the engine load L equal to the maximum allowable load Lm compared to the maximum allowable load Lm of
This is to calculate the increase/decrease ΔV of . The increase/decrease ΔV in the traveling speed V obtained by this calculation means 9 is D−
The A converter 13 converts the digital signal into an analog signal and sends it to the output means 10.

This output means 10 is a motor drive unit 10.
A and a servo motor 10b, the signal of increase/decrease ΔV in the traveling speed V is sent to the motor drive unit 10a, and the motor drive unit 10
When the driver a drives the servo motor 10b, the servo motor 10b moves the swash plate of the traveling hydraulic pump 4 to change the traveling speed V by the amount of increase/decrease ΔV.

In addition, 14 in the figure is a changeover switch for switching between automatic operation and manual operation. When this changeover switch 14 is turned on, the electromagnetic clutch 15 attached to the output shaft of the servo motor 10b is connected, and the traveling speed V is changed. It will be automatically controlled, and conversely, if this is turned off, the electromagnetic clutch 15 will be disengaged, resulting in manual operation. In addition, reference numeral 16 in the figure is an operating lever that is mechanically connected to the swash plate of the hydraulic pump 4 for traveling, and is used for manual operation. A switch is built in, and when the operator grasps the operating lever 16 with his/her hand, this switch is actuated and the electromagnetic clutch 15 is disengaged, thereby switching from automatic to manual mode.

Next, the operation of the present invention will be explained.

In the case of the speed control device of the present invention, the changeover switch 14 is normally turned on to enter the automatic control state and start snow removal work. Snow removal work is performed by a worker as usual by operating a snow removal device 3 such as an auger 3d.
At that time, the traveling speed V is automatically controlled according to the snow removal load. That is, the rotation speed n of the engine 1 is detected by the sensor 8, and the engine load L is detected.
In addition, the swash plate angle sensor 12 is connected to the traveling hydraulic pump 4.
The traveling speed V is indirectly detected by detecting the swash plate angle θ. Then, the calculation means 9 compares the engine load L with the maximum allowable load Lm of the engine 1,
When the load L is lower than the maximum allowable load Lm, an increase amount ΔV in the running speed V that makes these equal is calculated and sent to the output means 10 via the DA converter 13.
The output means 10 moves the swash plate of the traveling hydraulic pump 4 based on this signal to increase the traveling speed V.
On the other hand, if the traveling speed V is large and the engine load L exceeds the maximum allowable load Lm, then the traveling speed V
decrease. In this way, the traveling speed V is controlled according to the snow removal load so that the engine load L always becomes the maximum allowable load Lm.

In addition, the operator can use the changeover switch 14 as necessary.
or in case of an emergency, by grasping the operating lever 16, the automatic operation can be canceled and switched to manual operation. Manual operation is the same as before using control lever 1.
However, since the operating lever 16 is mechanically connected to the swash plate of the travel hydraulic pump 4, there is no need to interrupt the work even if there is a failure in the electrical system.

As described above, according to the present invention, there is provided a snowplow equipped with one engine that drives a snow removal device and a hydraulic pump, and a hydraulic motor that is operated by the hydraulic pump and drives a traveling device. A sensor detects the rotation speed, and the travel speed of the traveling device is detected based on the swash plate angle of the hydraulic pump.The engine load is calculated based on the rotation speed detected by the sensor, and this engine load is set to the maximum of the engine. It consists of a calculating means for calculating an increase or decrease in the traveling speed to match the allowable load, and an output means for automatically controlling the traveling speed by moving the swash plate of the hydraulic pump based on the increase or decrease obtained by the calculating means. Therefore, the traveling speed can be controlled so that the engine load, which is the sum of the loads of the snow removal device and the traveling device, matches the maximum allowable load of the engine. Moreover, it is possible to change the traveling speed to the target traveling speed with a single command to change the traveling speed by the amount of increase and decrease, and while changing the traveling speed sequentially, the engine load is controlled to match the maximum allowable load. It is possible to change the traveling speed more accurately in a shorter time than in the case of a conventional vehicle. Furthermore, since the engine load is calculated based on the engine speed, the calculation is simple, and from this point of view as well, the engine load can be calculated and the traveling speed can be changed in a short time. Therefore, even if the engine load changes suddenly, the engine load will match the maximum allowable load.
The running speed can be changed in a short time.

Therefore, the engine that serves as the power source for snow removal work can always be operated at its maximum allowable load, and the power of the engine can be used extremely effectively. Furthermore, the labor burden on the worker can be significantly reduced. Further, it is easy to switch to manual operation as needed, and this manual operation has the advantage that it can be performed even in the event of an electrical failure.

[Brief explanation of the drawing]

The figure is a drive system diagram of a rotary snowplow, showing one embodiment of the present invention. 1... Engine, 3... Snow removal device, 4... Hydraulic pump, 5... Hydraulic motor, 8... Sensor, 9...
...Arithmetic means.

Claims (1)

[Scope of utility model registration request] A snow removal vehicle including one engine that drives a snow removal device and a hydraulic pump, and a hydraulic motor that is operated by the hydraulic pump to drive a traveling device, a sensor that detects the rotation speed of the one engine, and a sensor that detects the rotation speed of the one engine, Detects the traveling speed of the traveling device based on the swash plate angle of the pump, calculates the engine load based on the rotation speed detected by the sensor, and increases or decreases the traveling speed to match the engine load with the maximum allowable load of the engine. 1. A speed control device for a snowplow, comprising: a calculation means for calculating the amount; and an output means for automatically controlling the traveling speed by moving the swash plate of the hydraulic pump based on the increase or decrease obtained by the calculation means.