KR20000055665A - Exhaust brake system for vehicle - Google Patents

Abstract

PURPOSE: An exhaust brake system for automotive vehicle is provided to prevent an impact within a combustion chamber caused by a pressure of exhaust gas and achieve an improved performance of exhaust brake while allowing a precise control by a hydraulic control system. CONSTITUTION: A system comprises a silence valve(20) installed to an intake manifold(16), an exhaust brake valve(22) installed to an exhaust manifold(18), first and second control cylinders(12, 14) for operating the silence valve(20) and the exhaust brake valve(22), respectively, an oil pump(4) connected to the first and second control cylinders(12, 14) through an oil hose(6) so as to supply necessary oil pressure to the first and second control cylinders(12, 14), proportional control valves(8, 10) installed respectively at a portion of the oil hose(6) connecting the oil pump(4) and first and second control cylinders(12, 14) so as to control the oil pressure to be supplied by stages from the oil pump(4) to control cylinders(12, 14) according to time sequence, and a control unit for controlling an amount of current supplied to the proportional control valves(8, 10) so that the valves(8, 10) are operated by stages.

Description

Vehicle exhaust brake system {EXHAUST BRAKE SYSTEM FOR VEHICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle exhaust brake system, and more particularly, to a vehicle exhaust brake system capable of improving operation performance and reducing shock generated during brake operation.

In general, an exhaust brake is an auxiliary brake that generates a braking force by using the back pressure generated in the volume between the exhaust manifold and the exhaust brake valve when performing the exhaust stroke.

4, the exhaust brake valve 108 is installed at one side of the exhaust manifold 102, and the intake manifold 104 reduces the air intake noise generated when the exhaust brake is operated. And a control cylinder 112 and 114 for operating the exhaust brake valve 108 and the silencer valve 110 are installed on one side of the intake and exhaust manifolds 104 and 102, respectively. And a three-way solenoid valve 116 or the like installed on the air pipe 124 between the cylinders 112 and 114 and the air tank 118 to control the air supplied to the control cylinders 112 and 114.

The three-way solenoid valve 116 is in accordance with the electrical signal of the electronic control unit (ECU) when the exhaust brake switch 120 is on, the clutch switch 122 is off, the engine RPM is 900 or more, and the like conditions Open pipe 124.

When the three-way solenoid valve 114 is opened under the above conditions, the exhaust brake supplies air from the air tank to operate the control cylinders 112 and 114, and according to the operation of the control cylinders 112 and 114, the sirens valve 110. And when the exhaust brake valve 108 is operated in a direction in which the intake and exhaust manifolds 104 and 102 are closed, negative pressure is generated in the combustion chamber 106 to perform a braking action.

However, in the exhaust brake system as described above, since the 3-way solenoid valve is controlled on / off according to the signal of the electronic control unit, the compressed air of the air tank is instantaneously supplied to the control cylinder. Since the operation of the valve is made suddenly, there is a problem that a shock occurs due to the rapid increase or decrease of exhaust gas in the combustion chamber.

In addition, since the operation of the exhaust brake is made of pneumatic pressure using air, there is a problem in that the accuracy of the operation is lowered.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to allow the operation of the sirens valve and the exhaust brake valve to be performed step by step with a certain delay time, so that the shock inside the combustion chamber due to the pressure of the exhaust gas. To provide a vehicle exhaust brake system that can be prevented.

Another object of the present invention is to provide an exhaust brake for a vehicle capable of improving operating performance since the brake is operated using oil hydraulic pressure.

1 is a block diagram of an exhaust brake system according to the present invention.

2 is a cross-sectional view of a proportional control valve of the exhaust brake system according to the present invention.

Figure 3 is a block diagram showing the control means of the exhaust brake system according to the present invention.

4 is a configuration diagram of an exhaust brake system according to the prior art.

In order to achieve the above object, the present invention provides a silencer valve installed in the intake manifold to open and close the intake manifold, an exhaust brake valve installed in the exhaust manifold to open and close the exhaust manifold, and First and second control cylinders installed at one side of the lance valve and the exhaust brake valve to operate the sirens valve and the exhaust brake valve, respectively, and connected to the first and second control cylinders by an oil hose, It is installed on each side of the oil pump for supplying the hydraulic pressure required to the second control cylinder, and the oil hose connecting between the oil pump and the first and second control cylinder, the hydraulic pressure supplied to each control cylinder from the oil pump is time Proportional control valve for controlling to be supplied step by step according to the control, and by controlling the amount of current supplied to the proportional control valve It provides a vehicle exhaust brake system comprising a control means for causing the proportional control valve to be operated in stages.

In the exhaust brake system configured as described above, the oil pressure pumped from the oil pump is controlled by the proportional control valve, and is supplied step by step to each control cylinder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an exhaust brake system according to the present invention, in which an oil tank 2 in which oil is stored, an oil pump 4 for pumping this oil, and a proportional control valve 8, 10 for stepwise controlling operating hydraulic pressure are illustrated. And control cylinders 12 and 14 for operating the silencer valve 20 and the exhaust brake valve 22 according to the hydraulic pressure.

The oil tank 2 and the oil pump 4 are preferably used jointly with those used in the existing power steering system without the need for additional installation.

The sirens valve 20 is a valve installed at one side of the intake manifold 16 to open and close, and serves to reduce air intake noise generated when the exhaust brake is operated.

The exhaust brake valve 22 is provided on one side of the exhaust manifold 18, and when the exhaust brake is operated, the exhaust manifold 18 is closed to increase the pressure in the exhaust pipe to perform a braking action.

The control cylinders 12 and 14 consist of a first control cylinder 12 for operating the sirens valve 20 and a second control cylinder 14 for operating the exhaust brake valve 22, and the oil pump 4. ) And the oil hose (6), when the hydraulic pressure is supplied according to the pumping action of the oil pump (4), the two pistons (20, 22) are operated while the internal pistons (24, 26) move linearly. Let's do it.

Proportional control valves (8, 10) are installed on one side of the oil hose (6) connecting between the oil pump (4) and each control cylinder (12, 14), respectively, the first and second control cylinders (12, 14) ) Is a valve for controlling the hydraulic pressure supplied to the step by step so that the first and second control cylinders (12, 14) are operated slowly with a predetermined delay time, it is operated in accordance with the electrical signal of the control means.

As shown in FIG. 2, the proportional control valves 8 and 10 are provided with a first port 30 to which hydraulic pressure pumped from the oil pump 4 is supplied, and a second port 32 connected to the control cylinder 12. ), A valve body 28 each having a third port 34 drained to the oil tank 2, a valve spool 42 in which the inner circumference of the valve body 28 is slidably fitted, and the valve One side of the spool 42 is composed of a solenoid 44 for moving the valve spool 42 in accordance with the electrical signal of the control means.

One end of the valve spool 42 is provided with an elastic member 36 between the inner surface of the valve body 28, and the other end thereof is connected to the solenoid 44, and has a first opening / closing action of the second port 32. A land 38 is formed, and a second land 40 which opens and closes the second port 40 at a predetermined distance from the first land 38 is formed.

The operating state of the proportional control valve configured as described above will be described below.

When the current controlled differently according to the operation time is applied to the solenoid 44 in the control means, the solenoid 44 pushes the valve spool 42 step by step according to the amount of current. Then, the first land 38 moves in a direction of gradually opening the second port 32, and the second land 32 moves in a direction of gradually closing the third port 34. The hydraulic pressure supplied to the 34 is gradually increased in flow rate supplied to the control cylinder 12 through the second port 32 with time, and drained to the oil tank 2 through the second port 32. The flow rate decreases in stages.

As shown in FIG. 3, the control means for controlling the proportional control valves 8 and 10 includes an engine RPM sensor 46, a clutch switch 50, an exhaust brake switch 48, and an accelerator switch for detecting engine RPM. An electronic control unit (ECU) receiving a signal such as 52 controls the amount of current supplied to the solenoid 44 of the proportional control valve in accordance with the signal.

That is, when any one of the engine RPM is 900 or more, the clutch switch off, exhaust brake switch on, the accelerator switch off state is applied, the electronic control unit (ECU) is applied to the solenoid 44 according to the signal. In this case, the electronic control unit (ECU) controls the amount of current applied to allow the proportional control valves 8 and 10 to be operated in stages.

The operation of the exhaust brake system made as described above is described below.

When signals such as sensors and switches of the control means described above are applied to the electronic control unit ECU, the electronic control unit ECU applies power to the solenoid 44 of the proportional control valve in accordance with the signal. At this time, the electronic control unit ECU controls the amount of current to be supplied step by time. Then, the solenoid 44 moves the valve spool 42 of the proportional control valve, so that the second port 32 is gradually opened, and the third port 34 is gradually closed.

That is, the oil pressure pumped from the oil pump 4 gradually increases the flow rate supplied to the control cylinders 12 and 14 through the second port 32, and to the oil tank 2 through the third port 34. The drain flow rate gradually decreases. Then, when the pistons 24 and 26 of the first and second control cylinders 12 and 14 operate the sirens valve 20 and the exhaust brake valve 22, the intake manifold 16 and the exhaust manifold 18 ) Is stepwise closed with time, and back pressure is applied to the combustion chamber 25 to perform a braking action.

Exhaust brake system according to the present invention made as described above by adjusting the hydraulic pressure supplied to the control cylinder from the proportional control valve over time, so that the closing action of the intake and exhaust manifold is made to reduce the shock in the combustion chamber In addition, the hydraulic system using oil instead of the conventional air pressure is made to operate the brake system to enable precise control to improve the operating performance.

Claims (3)

A silencer valve installed at the intake manifold to open and close the intake manifold; An exhaust brake valve installed at the exhaust manifold to open and close the exhaust manifold; First and second control cylinders installed at one side of the sirens valve and the exhaust brake valve to operate the sirens valve and the exhaust brake valve, respectively; An oil pump connected to the first and second control cylinders by an oil hose and supplying hydraulic pressure required to the first and second control cylinders; A proportional control valve installed at one side of an oil hose connecting the oil pump and the first and second control cylinders to control the oil pressure supplied from the oil pump to each control cylinder in steps according to time; And control means for controlling the amount of current supplied to the proportional control valve so that the proportional control valve is operated in stages. The valve body of claim 1, wherein the proportional control valve includes: a valve body having a first port connected to the oil pump, a second port connected to the control cylinder, and a third port connected to the oil tank; A first land slidably fitted to an inner circumference of the valve body, a first land for opening and closing the second port, a second land for opening and closing the third port are formed, and an elastic member between the valve body and the inner circumference of the valve body. A valve spool interposed therebetween; And a solenoid connected to the other side of the valve spool to move the valve spool step by step according to an electrical signal of the control means. The control means according to claim 2, wherein the electronic control unit (ECU) controls the amount of current applied to the solenoid step by step according to the operation signal of the engine RPM sensor, clutch switch, accelerator switch, exhaust brake switch An exhaust brake system for a vehicle.