JPH0211454A - Brake cooling system for large dump trucks - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for cooling the brakes of a large dump truck.

[Conventional technology]

The brakes of a large dump truck include a pair of left and right front brakes made of wet multi-disc brakes and a pair of left and right tow brakes.The front brake is used as a service brake, and the rear brake is used as a service brake and a retarder brake.

For this reason, when the rear brake is used as a retarder brake, it generates significant heat and reaches a high temperature, so oil is circulated through the rear brake to cool it.

[Problem to be solved by the invention]

Large dump trucks climb up and down mountain roads at mines, etc. When unloading, they use the rear brake as a retarder brake, but in the case of rain or slippery roads, the tires and road surface Due to the low contact pressure between the wheels and the road surface, it is difficult to grip the road surface, so using the rear brake as a retarder brake and braking only with the rear wheels does not provide sufficient braking, so the front brake is used in conjunction with the front brake.

In addition, when a stronger braking force is required due to a change in the road when exiting the vehicle, or when the vehicle is likely to slip, the front brake is used in conjunction with the front brake to control the vehicle speed.

As described above, the front brake is often used as an auxiliary brake when using the retarder brake, but since the conventional brake cooling system does not cool the front brake, it is likely to overheat.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a brake cooling system for a large dump truck that allows oil to flow through the front brake to prevent overheating.

[Means and effects for solving the problem] (Means) The oil from the outlet 9a of the torque converter 9 is transferred to the second inflow path 1.
1, the front brake is connected to the first inflow path 2 connected to the brake chamber 3a of the rear brake 3, and opens and closes the third inflow path 12 which is branched from the second inflow path 11. A controller 17 connected to the brake chamber 14a of 14, closes the valve 13 when a retarder use signal is input, and opens the valve 13 with priority over the retarder use signal when the front brake 14 reaches a set temperature or higher. Brake cooling system for large dump trucks equipped with

(Function) When using the retarder brake, the valve 13 is closed and the entire amount of oil from the outlet 9a of the torque converter 9 is supplied to the rear brake 3.
When the temperature of the front brake 14 reaches or exceeds the set temperature, the valve 13 opens and some of the oil from the outlet 9a of the torque converter 9 is supplied to the front brake chamber 3a.
is supplied to the brake chamber 14a.

Therefore, when the retarder brake is used, the cooling capacity of the rear brake 3 can be increased to prevent overheating, and when the retarder brake is used, the front brake 14 can be prevented from overheating.
When the front brake 14 is frequently used as an auxiliary brake, the front brake 14 can be cooled to prevent overheating.

〔Example〕

As shown in FIG. 1, the pressure oil discharged from the first pump 1 is supplied to the brake chambers 3a of the left and right rear brakes 3 through the first inflow path 2, and then flows out to the first outflow path 4. 4
flows out into a tank 7 via an oil cooler 5 and an oil filter 6.

The discharge pressure oil of the second pump 8 is supplied to the torque converter 9 and the transmission 10, and the outlet 9a of the torque converter 9 is connected to the second pump 8.
A third inflow path 12, which is connected to the first inflow path 2 through an inflow path 11 and branched from the second inflow path 11, is connected to the brake chambers 14a of the left and right front brakes 14 through a valve 13, and is connected to the brake chambers 14a of the left and right front brakes 14. The chamber 14a is connected to the inlet side of the oil cooler 5 in the first outflow path 4 through a second outflow path 15.

The valve 13 is opened when the solenoid valve 16 is demagnetized to the cutoff position I, and closed when the solenoid valve 16 is energized to the communication position (2), and the solenoid 16a of the solenoid valve 16 is controlled by the controller 17.

The controller 17 outputs an excitation signal when the retarder use signal R7 is input, and also outputs an excitation signal to the front brake 14.
When the oil temperature sensor 18 provided in the brake chamber 14a detects the set temperature, it outputs a degaussing signal regardless of the retarder use signal R1.

When the retarder is not in use, the valve 13 is open, and the pressure supplied from the second pump 8 to the torque converter 9 is supplied to the second inflow path 11 and the third inflow path 12 to the brake chamber 3a of the rear brake 3 and the front brake. 14 brake chambers 14 a l: supplied to cool both brakes.

Furthermore, when the retarder is used, the valve 13 is closed and the oil supplied from the second pump 8 to the torque converter 9 is supplied from the second inflow path 11 to the brake chamber 3a of the rear brake 3, thereby increasing the cooling capacity of the rear brake 3. Maximum.

When the front brake 14 is used in this state and generates heat, the oil temperature sensor 18 detects a temperature higher than the set temperature, and the controller 17 outputs a degaussing signal, so the valve 13 is opened and some of the oil from the torque converter 9 is supplied to the brake chamber 14a of the front brake 14 to cool the front brake 14.

In addition, an oil temperature sensor 1 for the rear brake is provided in the first outflow path 4.
9 is provided to detect the temperature of the rear brake 3, and when the temperature exceeds the set temperature, an alarm is issued to notify the operator of overheating.

〔Effect of the invention〕

When using the retarder brake, the valve 13 is closed and the entire amount of oil is supplied from the outlet 9a of the torque converter 9 to the rear brake 3.
When the temperature of the front brake 14 reaches or exceeds the set temperature, the valve 13 opens and some of the oil from the outlet 9a of the torque converter 9 is supplied to the front brake chamber 3a.
is supplied to the brake chamber 14a.

Therefore, when the retarder brake is used, the cooling capacity of the rear brake 3 can be increased to prevent overheating, and when the retarder brake is used, the front brake 14 can be prevented from overheating.
When the front brake 14 is frequently used as an auxiliary brake, the front brake 14 can be cooled to prevent overheating.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention. 2 is a first inflow path, 3 is a rear brake, 3a is a brake chamber, 9 is a torque converter, 9a is an outlet, 11 is a second inflow path, 12 is a third inflow path, 13 is a valve, 14 is a front brake, 14a is the brake chamber, and 17 is the controller.

Claims (1)

[Claims] The oil from the outlet 9a of the torque converter 9 is transferred to the second inflow path 1.
1, the front brake is connected to the first inflow path 2 connected to the brake chamber 3a of the rear brake 3, and opens and closes the third inflow path 12 which is branched from the second inflow path 11. A controller 17 connected to the brake chamber 14a of 14, closes the valve 13 when a retarder use signal is input, and opens the valve 13 with priority over the retarder use signal when the front brake 14 reaches a set temperature or higher. A brake cooling system for a large dump truck, which is characterized by being equipped with.