JPH03117606A - Exhaust brake control device - Google Patents

Abstract

PURPOSE:To increase the braking force by controlling the opening and closing operation of a suction and exhaust valve by a solenoid valve driving device. CONSTITUTION:The braking force is generated by operating an actuator 23 according to a command of a controller 5 which has received an exhaust brake signal from an exhaust brake switch 14 to close a shutter 9 of an exhaust pipe 18. On judging that it is necessary to increase an exhaust brake according to an engine speed from a rotation sensor 13 and a car velocity detection signal from a car velocity sensor 15, the controller 5 gives a command to a valve lifter 10 to control the opening and closing operation of suction and exhaust valves 1, 2. Thus, the suction valve 1 is opened at the top dead center and closed at the bottom dead center, and the exhaust valve 2 is opened before the top dead center and closed at the top dead center, so that the large braking force can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust brake control WJ device for an engine, which is equipped with an electromagnetic valve drive device that opens and closes intake and exhaust valves using electromagnetic force.

[Conventional technology]

Conventionally, the exhaust brake has played an important role as a brake system. The principle behind the exhaust brake is that a chalet is provided in the exhaust pipe downstream of the exhaust manifold, and the brake is operated by compressing intake air.

In addition, as an engine braking device, it was
There is one disclosed in Japanese Patent No. 2547.

In this engine braking device, an intake passage, an exhaust passage, and a pressure release passage are connected to a combustion chamber of an engine body, and each of the intake passage and the exhaust passage is opened and closed by an intake valve and an exhaust valve, and the pressure release passage is connected to a combustion chamber of an engine body. A normally closed valve whose passage is always kept closed is provided, and a drive mechanism is provided that opens the normally closed valve when the piston in the combustion chamber reaches near the top dead center position of the compression stroke during engine braking operation. The drive mechanism is formed by an electromagnetic valve having a solenoid and a plunger, and the normally closed valve is linked to the operation of the plunger.

[Problem to be solved by the invention]

However, when braking is performed using the exhaust brake, closing the shutter provided on the exhaust pipe causes the exhaust gas pressure to open the exhaust valves of other cylinders that are in the intake and expansion strokes, or This may cause the air to open and flow back toward the intake port. When such a phenomenon occurs, the braking force may decrease or
Otherwise, it will have an adverse effect on the engine body.

The engine braking device disclosed in the above-mentioned Japanese Utility Model Publication No. 1983-122547 is provided with a normally closed valve in addition to the intake and exhaust valves, and the normally closed valve is actuated by an electromagnetic drive mechanism to perform brake operation. The number of parts is large and the mechanism is complicated.

The purpose of this invention is to solve the above problems,
The intake and exhaust valves are made of lightweight ceramic material, and the intake and exhaust valves are opened and closed by electromagnetic force using a solenoid valve drive device to control the valve timing and valve opening/closing period, thereby increasing the braking force of the exhaust brake. Depending on the operating condition of the engine, braking is performed using a normal exhaust brake.
At that time, the engine is operated in 4 cycles, or when increasing the braking force of the exhaust brake, the engine is operated in 2 cycles.
An object of the present invention is to provide an exhaust brake control device for an engine that increases braking force by controlling the opening and closing operations of intake and exhaust valves using an electromagnetic valve drive device so as to operate in the same manner as a cycle.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention includes a magnetic valve drive device that opens and closes intake valves and exhaust valves using electromagnetic force, a sensor that detects the operating state of the engine, a brake command means that commands brake operation, and a brake signal of the brake command means. and actuating the electromagnetic valve drive device in response to a detection signal from the sensor to open the intake valve at top dead center and close it at bottom dead center, and open the exhaust valve before top dead center; The present invention relates to an exhaust brake control device comprising a controller that controls closing at top dead center.

[Effect]

The exhaust brake control device according to the present invention is constructed as described above and operates as follows.

That is, in this exhaust brake control device, a solenoid valve drive device operates an intake valve and an exhaust valve, a sensor detects the operating state of the engine, and a brake operation command signal is used to control the intake valve in response to a detection signal from the sensor. Since the valve was opened at top dead center and closed at bottom dead center, and the exhaust valve was opened before top dead center and closed at top dead center, the valve opening/closing timing and lift of the intake and exhaust valves were controlled. The above-mentioned operation control can be performed in accordance with the engine operating state such as the braking state of the engine brake, engine rotation fluctuation, engine load fluctuation, etc., independently of the driving state of the engine, with respect to the amount, valve timing, etc.
While the exhaust brake is in operation, the intake and exhaust valves are closed by the electromagnetic valve drive device, so it is possible to obtain a braking force greater than that of a conventional exhaust brake that uses only the friction stroke and the compression stroke.

〔Example〕

Embodiments of the exhaust brake control device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing an exhaust brake control device according to the present invention.

FIG. 2 is an explanatory diagram showing an exhaust brake control device in an engine with a solenoid valve drive device in which one cylinder of the multi-cylinder engine is taken out in FIG. 1; In an engine equipped with an electromagnetic valve drive device incorporating this exhaust brake control device, a cylinder liner 4 is fitted into a cylinder 19 formed in a cylinder block 6, and a gasket 21 is provided on the upper surface of the cylinder block 6. Rad 3 is fixed to the cylinder. A piston 7 is configured to reciprocate within the cylinder liner 4.

In each cylinder 8 of this engine, a combustion chamber is a chamber surrounded by a cylinder liner 4, a cylinder head 3, and a piston 7. An intake port 12 and an exhaust port 11 are formed in the cylinder head 3, and a valve seat 22 is provided on these ports.
The valve seat 22 has an intake valve 2 that opens and closes using electromagnetic force.
is arranged, and the valve seat 22 of the exhaust port 11
An exhaust valve 1, which is opened and closed by electromagnetic force, is disposed in the exhaust valve 1. These exhaust valves 1 and intake valves 2 are operated by a valve lifter 1 of a solenoid valve drive device in response to commands from a controller 5, which will be described later.
0, they are opened and closed by electromagnetic force. Each cylinder 8
The intake pipe forming the intake boat 12 is branched from the intake manifold pipe leading to the compressor of the turbocharger 20. Further, the exhaust boat 11 of each cylinder 8 is connected to an exhaust manifold pipe, and the exhaust manifold pipe is connected to an exhaust pipe 18 provided with a shutter 9. This shutter 9 functions as an exhaust brake, and opens and closes by operating an actuator 23 in response to a command from the controller 5. Furthermore, the exhaust pipe 18 is connected to the scroll of a turbine of a turbocharger 20 and is configured to recover exhaust energy.

This'r! In the engine with an L magnetic valve drive valve drive device, the intake valve 2 and the exhaust valve 1 are operated by each valve lifter IO of the valve drive device! It is opened and closed by magnetic force. The exhaust valve 1 and the intake valve 2 are made of ceramic material, and are arranged to be slidable in the vertical direction while being guided by a valve guide fixed to the cylinder head 3. That is, the opening/closing operations of the intake valve 2 and the exhaust valve 1 are performed by passing current through the stator coil and movable coil in the pulp lifter 10 of the electromagnetic valve drive device according to commands from the controller 5, and exciting the electromagnet to drive each valve. be able to.

The controller 5 includes a rotation sensor 13 that detects the engine rotation speed, an exhaust brake switch 14 that issues an exhaust brake command, a vehicle speed sensor 15 that detects vehicle speed, a brake sensor 16 that detects the braking state of the brake, The zero rotation sensor 13, which receives detection signals from a position sensor 17 that detects the stroke position of the piston 7, that is, the crank angle, can detect engine rotation by being provided on the output shaft of the engine. The vehicle speed sensor 15 can detect vehicle speed by being provided on the drive shaft. The foot brake sensor 16 is
The braking state of the foot brake can be detected by detecting the amount of depression of the foot brake. Further, the engine position sensor 17 detects the stroke position of the piston 7, and can detect this by detecting the crank angle. As the brake command means for commanding the controller 5 to operate the exhaust brake, a signal generated by the exhaust brake inch 14 or a detection signal from the foot brake sensor 16 can be used.

The controller 5 issues a command to the pulp lifter 10 of the electromagnetic valve drive device in response to each of these detection signals. The opening/closing operation of the pulp lifter IO of this electromagnetic valve drive device is controlled in response to commands from the controller 5. That is, upon receiving the exhaust brake command signal from the exhaust brake switch 14, the controller 5 determines whether or not the engine rotation from the rotation sensor 13 and the vehicle speed detection signal from the vehicle speed sensor 15 indicate the need to increase the exhaust brake. If you compare and judge that it is necessary to increase the braking force,
In response to the detection signal, a command is issued to the pulp lifter 10 of the intake/exhaust valve 1.2 to control the opening/closing operation of the intake/exhaust valve 1.2 as described below, thereby increasing the braking force of the exhaust brake. It is something.

In this exhaust brake control device, the exhaust brake operates the actuator 23 in response to a command from the controller 5, and a braking force is generated by closing the shunter 9 of the exhaust pipe 18. When increasing the braking force of the exhaust brake, Upon receiving the engine stroke signal from the position sensor 17, the intake valve 2 is opened at the top dead center (T, D, C,) and at the bottom dead center (B, D, C,
), the exhaust valve 1 is closed at the rear point S, and the exhaust valve 1 is closed at the top dead center (T, D
, C,) and closes at top dead center (T, D, C,). That is, in the engine cycle, near top dead center (T, D, C,), the controller 5 issues a command to the pulp lifter 10 of the intake valve 2 to open the intake valve 2. The intake boat 1 is opened by opening the intake valve 2.
2 is used to introduce intake air into the cylinder 8. After the piston 7 reaches the bottom dead center (B, I), C, ), the controller 5 issues a command to the pulp lifter 10 of the intake valve 2 to close the intake valve 2. In this state, the piston 7 begins to rise, and a compression stroke in which the air in the cylinder 8 is compressed is started. The air compression action in this compression stroke acts as a braking force.
) At a nearby point P, the controller 5 issues a command to the pulp lifter 10 of the exhaust valve 1 to open the exhaust valve 1. By opening the exhaust valve 1, the compressed air in the cylinder 8 is reduced in pressure and is exhausted to the exhaust pipe 1 through the exhaust port 11. Since the shutter 9 of the exhaust pipe 18 is closed, a normal exhaust brake is applied. Piston 7 is at top dead center (T, [1, C
, ), the controller 5 issues a command to the valve lifter 10 of the exhaust valve 1 to close the exhaust valve 1. Subsequently, the above operation is repeated to increase the braking force.

Although the structure of the valve lifter in the electromagnetic valve drive device is not shown, it can be configured as follows, for example. By raising or lowering the intake and exhaust valves 1.2, the intake and exhaust valves 1,
The intake and exhaust boats 11.12 are opened and closed by the valve faces of the valves 2 and 2 coming into contact with or separating from a valve seat 22 installed on the intake and exhaust boats 11.12 of the cylinder rad 3. Therefore, the amount of air taken into the cylinder 8 of the engine is controlled by the opening/closing operation or amount of opening/closing of these intake boats 12, and the amount of compressed air from the cylinder 8 of the engine is controlled by the opening/closing operation or amount of opening/closing of the exhaust port 11. The pumping speed is controlled. Intake and exhaust valve 1.
A movable element made of a magnetic material such as soft iron is fixed to the upper end of the movable element 2, and a movable element coil is provided on these movable elements. Further, a stator made of a magnetic material such as soft iron is installed in the cylinder head 3 above the movable element, and the stator is provided with a stator coil. Therefore, when the movable coil and the stator coil are connected and disconnected by 1 t/l, the stator attracts/removes the movable element, thereby driving the intake and exhaust valves 1.2 up and down. Note that a pulp spring is disposed between the pulp spring seat formed on the upper surface of the cylinder head 3 and the mover. Therefore, the intake and exhaust valves 1.2 are normally closed by the spring force of the pulp spring. Furthermore, regarding the intake and exhaust valves 1 and 2 operated by 1iTIIi force, the material constituting the intake and exhaust valves themselves is made of ceramic material to reduce weight, and the valve face and exhaust valve of the intake and exhaust valves 1.2 are In order to prevent iron powder and the like from adhering to the sliding part of the pulp stem, it is preferable to make it from a non-magnetic ceramic material. However, if iron powder or the like is adsorbed to the sliding parts of the valve face and valve stem, the airtightness of the intake and exhaust boats 11.12 by the intake and exhaust valves 1.2 will deteriorate, and the frictional resistance of the sliding parts will increase. Unfavorable conditions such as image sticking may occur. Therefore, in order to operate the intake/exhaust valve 1.2 by electromagnetic force, a mover made of a magnetic material is separately coated on the upper end of the intake/exhaust valve 1.2. By configuring the intake and exhaust valves 1 and 2 as described above, when the controlled current from the controller 5 is energized or cut off to the mover coil and the stator coil, the stator moves the mover under the biasing force of the spring. Therefore, the intake and exhaust valves 1 and 2 move downward or upward, and the valve faces of the intake and exhaust valves 1 and 2 open or close the intake and exhaust ports (11.12). It can be carried out.

In this electromagnetic valve drive device, a controller 5 receives each detection signal detected by a rotation sensor 13, a vehicle speed sensor 15, and a position sensor 17 in response to an input from an exhaust brake switch 14, and each of the above-mentioned detection signals detects the operating state of the engine. In response to an electric signal, current is passed through the stator coil and movable coil in the valve lifter 10 of the valve drive device, and the electromagnet is energized to open and close the intake and exhaust valves 1 and 2. In some cases, the electromagnetic valve drive device can be configured to operate in response to depression of the foot brake sensor 16 to operate the exhaust brake, and by sharing the foot brake with the exhaust brake, a powerful brake can be generated. power can be secured.

Further, in this exhaust brake control device, when the foot brake is depressed, the foot brake sensor 16 detects this, and in response to the detection signal, the exhaust brake switch 14 is turned on, and the exhaust brake switch 14 is turned on in response to a command from the controller 5. By controlling the brake and fund brake to operate at the same time, sufficient braking force can be secured.
It is possible to provide a brake control device with improved braking reliability and high safety.

Furthermore, a shutter 9 is provided on the exhaust pipe 18 connected to the exhaust port 11 to apply an exhaust brake.
If a turbocharger 20 with an energy recovery device is installed in the exhaust pipe 18 downstream of this shunter 9 and compressed air is sent to the turbine of the 8-turbocharger 20,
The pneumatic energy of compressed air can be recovered as electrical energy or the like by an energy recovery device.

〔Effect of the invention〕

The exhaust brake control device according to the present invention is configured as described above and has the following effects. That is, this exhaust brake control device includes a Tt that opens and closes an intake valve and an exhaust valve using electromagnetic force, a valve drive device, a sensor that detects the operating state of the engine, a brake command unit that commands the operation of the exhaust brake, and the brake. In response to a brake signal from the command means and a detection signal from the sensor, the electromagnetic valve driving device is actuated to open the intake valve at top dead center and close it at bottom dead center, and to open the exhaust valve at top dead center. It consists of a controller that controls opening at the front and closing at top dead center.
The valve opening/closing timing, lift amount, valve timing, etc. of the intake and exhaust valves are controlled independently of the engine driving state, and the above-mentioned operations are performed depending on the engine operating state such as the braking state of the engine brake, engine speed fluctuation, engine load fluctuation, etc. Since the intake and exhaust valves are closed by the electromagnetic valve drive device while the exhaust brake is in operation, it is possible to obtain a greater braking force than that of a conventional exhaust brake that only reduces friction loss and compression stroke. I can do it. Moreover, the intake and exhaust valves of other cylinders are not forcibly opened due to back pressure, which prevents exhaust gas from flowing back toward the intake boat, preventing the exhaust braking force from decreasing, which has a negative impact on the engine itself. Never give up.

Further, when the exhaust brake control device according to the present invention is incorporated into a large-sized diesel engine or a medium-sized diesel engine, a very desirable vehicle can be provided because a strong braking force can be ensured.

Furthermore, in an engine equipped with the exhaust brake control device according to the present invention, if the exhaust brake is configured to operate simultaneously with the foot brake, braking reliability is improved and a brake system rich in safety is provided. can do.

Furthermore, an exhaust brake according to this invention! In an engine equipped with an lIm device, if a turbocharger with an energy recovery device is provided downstream of the exhaust pipe, compressed air energy can be recovered as electrical energy, for example, by the energy recovery device.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram illustrating an engine with a solenoid valve drive device incorporating an exhaust brake control device according to the present invention, and FIG. 2 is an explanation showing the operating state of the intake and exhaust valves of the exhaust brake control device of FIG. 1. It is a diagram. 1...Exhaust valve, 2-...-Intake valve, 3...
・−・・Cylinder head, 5・−・・−Controller,
7...Curved piston, 8...-- cylinder, 9...-
・-・Shutter, 10-bulb lifter, 11・
...-Exhaust port, 12--Intake boat, 13
-...Rotation sensor, 14-...Exhaust brake switch, 15-...Vehicle speed sensor, 16
...-Inner foot brake sensor, 17-Open position sensor 18--Exhaust pipe, 2o...-Turbo charging with energy recovery device.

Claims (1)

[Claims] An electromagnetic valve driving device that opens and closes the intake valve and the exhaust valve using electromagnetic force, a sensor that detects the operating state of the engine, a brake command means that commands the operation of the exhaust brake, and a brake command means that receives a brake signal from the brake command means and operates the sensor. Actuating the electromagnetic valve drive device in response to a detection signal to open the intake valve at top dead center and close it at bottom dead center, and open the exhaust valve before top dead center and close it at top dead center. An exhaust brake control device consisting of a controller that performs control.