JPS6145229Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic drive device for a centrifugal beach cleaner, which drives a working machine connected to a vehicle of the beach cleaner.

As shown in Fig. 1, the drive of the working machine of a conventional centrifugal beach cleaner, that is, the rotation of the drum, is performed by PTO6 (Power take-off, shown in chain lines), which rotates the drum 2 of the working machine L by the engine of the vehicle, as shown in Fig. 1. There are two types of systems: one is driven by a motor (as shown), and the other is an engine-driven system equipped with a dedicated small engine (not shown).

For beach cleaners that use centrifugal force to separate sand and trash, it is necessary to select the optimal rotational speed depending on the vehicle speed, depth of cleaning, wetness of the sand, and type of trash. This is an important point as it has a great influence on cleaning performance.
Through tests, we have obtained data that the optimum rotational speed is 20 to 30 rpm, and that if cleaning is performed by adjusting the rotation speed within that range, performance can be satisfied.

Since the PTO drive system uses an agricultural PTO, the PTO OUT-PUT is activated when the engine is at high idle.
(Output) rotation speed is normally set to 540 rpm.
Therefore, in order to obtain the optimum rotational speed of the drum, it is necessary to provide a gearbox on the drum side to further reduce the speed. In addition, since the PTO drive system is directly connected to the engine that is the power source of the main unit, only the rotation speed that corresponds to the gear ratio of the PTO transmission and the gearbox on the drum side is outputted, and fine adjustment is done by adjusting the engine rotation. The only way to do it is with the governor control, and the optimal rotation speed of the drum is 20.
The disadvantage is that in many cases the engine speed must be lowered to obtain ~30rpm. Reducing the engine speed results in a loss of horsepower and worsens the vehicle's maneuverability on sandy terrain, which places more stress on the undercarriage than expected. It also affects the running speed, reducing the cleaning speed and causing problems.

The engine drive system is equipped with a small engine.
Since the drum is rotated by a power source that is separate from the main power source, there are no problems like the PTO drive system, but it is wasteful and costly to install a separate power source to a vehicle that has a power source. However, it cannot be said that this method is very advantageous in terms of maintenance, and also has the disadvantage that it is difficult to make it compact due to its structure.

The present invention was made in view of the above-mentioned circumstances, and as shown in FIG. The rotational speed of the drum 2, which has a great influence on cleaning performance, is adjusted by operating a variable flow rate adjustment valve installed in the circuit of the hydraulic motor 5, and can be adjusted depending on the vehicle speed, cleaning depth, wetness of sand, and type of garbage. We provide a beach cleaner hydraulic drive system that can easily and quickly select any drum rotation speed according to your needs, and is applicable to a separate beach cleaner working machine that does not affect the vehicle power system. It is something to do.

A detailed explanation will be given below based on FIGS. 1 and 2. FIG. 1 is a side view of a beach cleaner in which a working machine is connected to a vehicle by a three-point hitch, and FIG. 2 is a hydraulic circuit diagram of the hydraulic drive system of the present invention. The vehicle main body hydraulic circuit diagram 3a and the working machine hydraulic circuit 1a shown in FIG. 2 are installed in the vehicle 3 and working machine 1 shown in FIG. The drum 2 is driven by a hydraulic motor 5. In Fig. 2, 7 is a hydraulic pump installed on the vehicle, and 4 is a control valve operated by an operator, including a lift valve 4a for the lift cylinder of the excavator, a tilt valve 4b for the tilt cylinder, and a control valve for the hydraulic cylinder of the front attachment. It is comprised of a front valve 4c and a rear valve 4d for a hydraulic cylinder of a rear attachment (for example, the hydraulic cylinder 13a of the three-point hitch 13 shown in FIG. 1). 8 is a variable flow rate adjustment valve that controls the amount of oil sent to the hydraulic motor 5 of the working machine, 9 is a filter, 10 is an oil tank, and 5 is a hydraulic motor attached to the working machine that drives the cleaning drum 2. It is attached to the frame 12 of the working machine shown in FIG. 1 and rotates the drum 2. When the hydraulic pump 7 is driven by the engine of a vehicle (not shown), the hydraulic oil sucked up from the oil tank 10 flows from the hydraulic pump 7 to the hydraulic circuit, passes through the filter 9, and circulates within the hydraulic circuit. This hydraulic circuit operates a lift cylinder, a tilt cylinder, a front attachment hydraulic cylinder, and a rear attachment hydraulic cylinder by operating a control valve 4. The hydraulic motor 5 is provided in a working machine hydraulic circuit 1a that is additionally installed in the vehicle main body hydraulic circuit 3a, and the flow rate of hydraulic oil supplied to the oil motor 5 is adjusted by a variable flow rate adjustment valve 8. By adjusting the flow rate adjustment valve 8, the required flow rate to the hydraulic motor is preferentially sent through the priority circuit 5a, and the surplus flow rate is sent to the surplus circuit 8.
a, passes through the filter 9, and returns to the oil tank 10. By operating the variable flow rate adjustment valve 8, the IN-PUT flow rate to the hydraulic motor 5 can be controlled, and the rotation speed of the hydraulic motor can be adjusted. be able to. The hydraulic motor 5 is operated and stopped by turning off the variable flow rate adjustment valve 8.

As explained in detail above, according to the hydraulic drive system of the present invention, the optimum rotational speed of the drum can be easily and quickly obtained by adjusting the variable flow rate adjustment valve without adversely affecting vehicle performance. Any drum rotation speed can be selected. Even if the IN-PUT flow rate to the hydraulic motor is reduced, the remaining flow is sent to the redundant circuit, so there is little heat generation in the hydraulic circuit. PTO
It is cheaper than the drive system and engine drive system, has a simple structure and is less likely to break down, and can use commercially available hydraulic motor flow rate adjustment variable valves.

[Brief explanation of the drawing]

FIG. 1 is a side view of a beach cleaner in which a working machine is connected to a vehicle by a three-point hitch, and FIG. 2 is a hydraulic circuit diagram of the hydraulic drive system of the present invention. 1... Work equipment, 2... Drum, 3... Vehicle, 3
a...Vehicle body hydraulic circuit, 4...Control valve, 5...Hydraulic motor, 5a...Priority circuit, 7
... Hydraulic pump, 8 ... Flow rate adjustment variable valve, 8
a... Surplus circuit.

Claims (1)

[Scope of utility model registration request] In a beach cleaner where a cleaning work machine is connected to a vehicle that has a hydraulic pump and a control valve that operates each work device, the amount of oil supplied to the drum drive hydraulic motor attached to the work machine is controlled in the vehicle body hydraulic circuit. A hydraulic drive device for a beach cleaner, characterized by being provided with a variable flow rate adjustment valve that circulates and adjusts the flow through a priority circuit and a redundant circuit.