JP3997414B2 - Sweeper brush rotation hydraulic control circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control circuit for a hydraulic motor for rotating a brush of a sweeper.
[0002]
[Prior art]
In the sweeper, the brush rotation speed is controlled according to the degree of dirt on the road surface. For example, in Patent Document 1, after the pressure oil sent from the brush pump passes through the switching valve, a part of the pressure oil is returned to the tank by the flow rate adjustment valve, and the remaining oil passes through the hydraulic motor to drive the hydraulic motor. It is designed to return to the tank via the return circuit. The number of rotations of the hydraulic motor is variable by appropriately changing the throttle amount (the amount of pressure oil returned to the tank) by the flow rate adjusting valve.
In Patent Document 2, the pressure oil pumped from the pump flows to the hydraulic motor through the on-off valve and the flow rate adjustment valve. When the flow rate adjustment valve is fully opened, the entire amount of pressure oil flows to the hydraulic motor. The maximum speed is achieved, and when it is at the throttle side, the hydraulic motor rotates at the throttled flow rate.
Patent Document 3 discloses a sweeper having side brushes on the left and right sides.
[0003]
[Patent Document 1]
Japanese Patent Publication No. 60-37243 [Patent Document 2]
Japanese Patent Laid-Open No. 7-310310 [Patent Document 3]
Japanese Patent Laid-Open No. 2002-021032
[Problems to be solved by the invention]
In Patent Document 1, the rotation speed of the hydraulic motor can be changed by appropriately changing the throttle amount (return amount of pressure oil to the tank) by the flow rate adjustment valve, and the brush rotation speed can be set according to dirt on the road surface or the like. However, if the hydraulic motor is rotated at the maximum flow rate, the flow rate adjustment valve must be adjusted one by one. Further, in Patent Document 2, when the flow rate adjustment valve is set to the throttle side, the pump pumps up a certain amount of oil, which is not preferable because it receives resistance at the throttle, and there is no escape point for pressure oil and the oil temperature rises.
The present invention provides a sweeper brush rotating hydraulic motor that does not cause an increase in oil temperature and can be switched between a maximum rotation speed and a preset low-speed rotation speed with a single touch. A control circuit is to be provided.
[0005]
[Means for Solving the Problems]
In the sweeper hydraulic control circuit of the sweeper of the present application, a supply side circuit that connects the hydraulic pump and the brush rotation hydraulic motor, a return circuit that connects the brush rotation hydraulic motor and the tank, and a bypass circuit that connects the supply side circuit and the return circuit In the sweeper brush hydraulic control circuit of the sweeper, the flow rate adjusting valve is provided in the bypass circuit, and the rotation speed of the brush rotating hydraulic motor is variable by changing the throttle amount by the flow rate adjusting valve . Corresponding to the side brush, the left and right supply side circuits connecting the left and right hydraulic pumps and the left and right side brush brush rotation hydraulic motors, and the left and right common return circuits connecting the left and right brush rotation hydraulic motors and the same tank And left and right bypass circuits for connecting the left and right supply side circuits and the left and right common return circuits, respectively. In the left and right bypass circuits, the flow of pressure oil toward the return circuit in a non-energized state is blocked in series with the flow rate adjusting valve, and the pressure oil is opened in the energized state to flow through the return circuit. An electromagnetic opening / closing valve is provided, and a switch for turning ON / OFF the energization of each electromagnetic opening / closing valve is provided in each driver's seat .
According to this configuration, the bypass circuit is shut off when the electromagnetic on-off valve is closed by turning off the switch in the driver's seat, so that the entire amount of pressure oil sent from the hydraulic pump flows into the brush rotation hydraulic motor. The brush rotating hydraulic motor rotates at the maximum speed. When the solenoid on / off valve is opened by turning on the switch in the driver's seat, a part of the pressure oil is returned directly to the tank via the flow adjustment valve of the bypass circuit, and the remaining amount of pressure oil rotates the brush rotation hydraulic motor. Is done. Therefore, the brush rotating hydraulic motor rotates at an appropriate set rotational speed determined by the amount of pressure oil released through the flow rate adjusting valve. Thus, the brush rotation is switched between the maximum rotation speed and the set rotation speed only by switching the electromagnetic on-off valve. Further, since the rotation of the left and right brushes can be controlled separately, it is possible to cope with cases where the degree of dirt on the cleaning surface differs between the left and right sides of the sweeper.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a plan view of the sweeper 1. 2 is the vehicle body, 3 is the driver's seat, 4R and 4L are the left and right side brushes provided on the lower side of the vehicle body 2 and closer to the driver's seat 3, and 5R and 5L are also provided at the lower part of the vehicle body 2 behind it. Left and right auxiliary brushes. 6 is a main brush, and the left and right side brushes 4R and 4L and the auxiliary side brushes 5R and 5L are grounded on the road surface and rotate inward about the vertical axis to sweep the dust on the road surface to the center of the vehicle body. The main brush 6 sweeps up from the road surface to the front upper side of the vehicle body and is collected in a hopper via an elevator (not shown). Such a structure is well known.
[0007]
FIG. 2 shows a hydraulic control circuit for driving the four side brushes 4R, 4L, 5R, and 5L. The left side brush 4L and the auxiliary brush 5L are connected to the output rotation shafts of the left brush rotating hydraulic motors 6L and 7L, respectively. The right side brush 4R and the auxiliary side brush 5R are connected to the output rotation shafts of the right brush rotating hydraulic motors 6R and 7R, respectively. On the right side (left side) of the hydraulic control circuit, the brush rotation hydraulic motors 6R and 7R (brush rotation hydraulic motors 6L and 7L) are connected in series. In the right circuit, the discharge port 9R of the hydraulic pump 8R is connected to the inflow port 11R of the brush rotating hydraulic motor 6R via the supply side circuit 10R. A discharge port 12R of the brush rotating hydraulic motor 7R is connected to the tank 14 via a common return circuit 13 on the left and right. Similarly, in the left side circuit, the discharge port 9L of the hydraulic pump 8L is connected to the inflow port 11L of the brush rotating hydraulic motor 6L via the supply side circuit 10L. The discharge port 12L of the brush rotating hydraulic motor 7L is piped to the tank 14 via a common return circuit 13 on the left and right.
[0008]
In the left and right circuits, the supply side circuits 10R and 10L and the return circuit 13 are connected by bypass circuits 15R and 15L, respectively. The bypass circuits 15R and 15L are provided with variable flow rate adjusting valves 16R and 16L on the side close to the pumps 8R and 8L. Further, electromagnetic on-off valves 17L and 17R are connected in series to the flow rate adjusting valves 16R and 16L at positions between the flow rate adjusting valves 16R and 16L and the return circuit 13 in the bypass circuits 15R and 15L. The electromagnetic on-off valves 17L and 17R incorporate check valves, and block the flow from the flow rate adjusting valves 17L and 17R toward the return circuit 13 in a non-energized state.
[0009]
The electromagnetic on / off valves 17R and 17L are connected to a power source via switches 18R and 18L, respectively. When the switches 18R and 18L are turned on, the solenoid is excited to open the on / off valves 17R and 17L and the switches 18R and 18L are turned off. Thus, the on-off valves 17R and 17L can be switched to the check valve side. The switches 18R and 18L are provided in the driver's seat 3.
[0010]
The operation will be described with the circuit on the right side. When the switch 8R is turned on and the pump 8R is operated with the electromagnetic on-off valve 17R opened, a part of the pressure oil discharged from the pump 8R flows into the bypass circuit 15R and returns to the return circuit 13 via the flow rate adjustment valve 16R. The remaining pressure oil that has not entered the bypass circuit 15R is supplied to the brush rotating hydraulic motors 6R and 7R. When the throttle of the flow rate adjusting valve 16R is adjusted in this state, the amount of oil flowing into the brush rotating hydraulic motors 6R, 7R is determined, so that the flow rate adjusting valve is set so as to obtain a desired side brush rotational speed (set rotational speed). A diaphragm level of 16R is determined. Further, the pressure oil discharged from the pump 9R is throttled by the flow rate adjusting valve 16R of the bypass circuit 15R, but the remaining pressure oil is directed to the brush rotating hydraulic motors 6R and 7R, so there is no escape place for the pressure oil. Can suppress the temperature rise of pressure oil.
[0011]
Next, when the switch 18R is turned OFF, the electromagnetic on-off valve 17R is closed, so that all the oil discharged from the pump is supplied to the brush rotating hydraulic motors 6R, 7R, and the brush rotating hydraulic motors 6R, 7R The side brush 4R and the auxiliary brush 5R rotate at a high speed. Thereafter, when the switch 18R is turned ON and OFF, the rotation speed of the side brush 4R and the auxiliary brush 5R can be switched between the set rotation speed and the maximum rotation speed set previously.
Corresponding to the left and right side brushes 4R, 4L and the auxiliary side brushes 5R, 5L, each is provided with a hydraulic circuit, and the bypass circuits 15R, 15L of each hydraulic circuit are provided with separate electromagnetic on-off valves 17R, 17L. The electromagnetic on-off valve 17L can be closed and the right electromagnetic on-off valve 17R can be opened. In this case, the left side brushes 4L and 5L rotate at the maximum rotation speed, and the right side brushes 4R and 5R rotate at the set rotation speed.
The flow rate adjustment valve in the present embodiment may be a manual adjustment valve or an electromagnetic type. When an electromagnetic flow rate adjusting valve is employed, it is convenient to provide an operation switch for adjusting the flow rate at the driver's seat.
[0012]
【The invention's effect】
As described above, in the present application, the brush can be easily switched between the maximum number of rotations and the set number of rotations lower than that by only switching the on-off valve while suppressing the temperature rise of the pressure oil. Further, since the rotation of the left and right brushes can be controlled separately, it is possible to cope with the case where the degree of dirt on the cleaning surface differs between the left and right sides of the sweeper.
[Brief description of the drawings]
FIG. 1 is a plan view of a sweeper.
FIG. 2 is a hydraulic control circuit for a side brush.
[Explanation of symbols]
1 Sweeper 4R / 4L Side Brush 5R / 5L Auxiliary Side Brush 6R / 6L / 7R / 7L Brush Rotating Hydraulic Motor 8R / 8L Hydraulic Pump 10R / 10L Supply Side Circuit 13 Return Circuit 14 Tank 15R / 15L Bypass Circuit 16R / 16L Flow Rate Regulating valve 17R / 17L Solenoid valve

Claims (1)

A supply side circuit connecting the hydraulic pump and the brush rotating hydraulic motor, a return circuit connecting the brush rotating hydraulic motor and the tank, and a bypass circuit connecting the supply side circuit and the return circuit are provided, and the flow rate is adjusted in the bypass circuit. In the sweeper hydraulic control circuit of the sweeper where the rotation speed of the hydraulic motor for brush rotation is variable by changing the throttle amount by the flow adjustment valve , the right and left hydraulic pressures correspond to the left and right side brushes. Left and right supply side circuit connecting the pump and the brush rotating hydraulic motor of the left and right side brush, left and right common return circuit connecting the left and right brush rotating hydraulic motor and the common tank, and the left and right supply side circuit common Left and right bypass circuits, respectively, and flow control valves are provided in the left and right bypass circuits, respectively. In series with the regulating valve, there is an electromagnetic on-off valve that shuts off the flow of pressure oil toward the return circuit in a non-energized state and opens the energized state to allow pressure oil to flow through the return circuit. A sweeper hydraulic pressure control circuit for a sweeper, characterized in that a switch for turning on and off the power supply is provided in the driver's seat .

Images