JPH0528351Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust brake device that reinforces braking force.

[Prior Art] For example, in an exhaust brake device disclosed in Japanese Patent Application Laid-Open No. 58-220937, pressurized air from an air tank, which serves as an air pressure source for an air brake, is supplied to an upstream side of an exhaust pipe from an exhaust brake valve. By doing so, the back pressure of the engine is increased and a large braking force is obtained, but it cannot be applied to vehicles without an air tank.

[Problems to be solved by the invention] In view of the above-mentioned problems, the purpose of the invention is to provide an exhaust brake device that increases the braking force by using intake air from a forced supercharger attached to an engine. It is in.

[Means for Solving the Problem] In order to achieve the above object, the configuration of the present invention is such that there is a gap between the portion of the intake pipe downstream of the forced supercharger and the portion of the exhaust pipe upstream of the exhaust brake valve. A conduit is connected to the conduit, and a brake control valve, which is normally closed and opens when the exhaust brake is activated, is inserted and connected to the conduit.

[Operation] When the exhaust brake is activated, the discharge air from the forced supercharger connected to the engine is supplied to the exhaust pipe upstream of the exhaust brake valve, so the back pressure of the engine is effective even when the engine is running at low speed. This increases the exhaust braking force.

[Embodiment of the invention] A forced supercharger 4 (for example, a Roots blower) driven by a crankshaft 3 is connected to the internal combustion engine 2, and air sucked from an intake port 5 passes through an intake pipe 6 to an intake port of the engine 2. supplied to exhaust pipe 15
is equipped with a known exhaust brake valve 16, and a portion of the exhaust pipe 15 upstream of the exhaust brake valve 16,
A conduit 13 is connected between the intake pipe 6 and a portion downstream of the forced supercharger 4 . A brake control valve 7 is provided in the middle of the conduit 13, preferably at the connection with the intake pipe 6.
is provided and normally closes the entrance to conduit 13. Preferably, a check valve 14 is provided at the connection between the conduit 13 and the exhaust pipe 15 to allow air to flow from the conduit 13 to the exhaust pipe 15. In the illustrated embodiment, the brake control valve 7 is configured as an electromagnetic on-off valve, and is connected to the manual brake switch 1 from the battery 12.
1, accelerator switch 10, clutch switch 9
When the electromagnetic on-off valve is energized through the valve body 7a, the valve body 7a opens the conduit 13.

The exhaust brake valve 16 is connected to a known pneumatic actuator, and when the exhaust pipe 15 is normally in an open state and the solenoid valve that controls the pneumatic circuit of the pneumatic actuator is energized when the exhaust brake is activated, the pneumatic actuator is activated. The exhaust brake valve 16 is closed.

The clutch switch 9 is closed when the clutch is in the engaged state, and the accelerator switch 10 is closed when the accelerator pedal is released.

Now, when the exhaust brake is operated, when the brake switch 11 is closed, electricity is applied from the battery 12 to the brake control valve 7, and the valve body 7a is opened. Therefore, air from the forced supercharger 4 driven by the engine 2 is supplied to the intake pipe 6 and at the same time is supplied to the exhaust pipe 15 via the conduit 13, so the back pressure of the engine 2 increases and the exhaust gas Braking force is increased. The check valve 14 prevents air from flowing back into the conduit 13 when the discharge pressure of the forced supercharger 4 becomes lower than the internal pressure of the exhaust pipe 15 .

According to the present invention, when the exhaust brake is activated, even when the engine 2 is running at low speed, as shown in FIG. Since the exhaust braking force can be increased, the exhaust braking force can be increased. In high-speed operation of engine 2,
Engine 2 back pressure may become too high, causing bounce on the exhaust valve. At this time, by opening the manual brake switch 11 and closing the brake control valve 7, an abnormal increase in the back pressure of the engine 2 can be avoided.

Furthermore, even when the engine 2 is operated under partial load (when the exhaust brake is not activated), the amount of intake air sent from the forced supercharger 4 to the cylinders of the engine 2 may become excessive, resulting in a large pumping loss. At this time as well, if the brake control valve 7 is opened and the air is bypassed to the exhaust pipe 15 via the conduit 13, the pumping loss of the forced supercharger 4 can be reduced, and a loss in fuel efficiency can be avoided.

It should be noted that if the valve body 7a of the brake control valve 7 is of a poppet type, a quick response to the brake operation can be obtained.

[Effects of the invention] As mentioned above, the invention uses the discharge air of the forced turbocharger connected to the engine, and does not require a special air pressure source, so it can be applied to small and medium-sized vehicles. When the exhaust brake is activated, the back pressure of the engine is effectively increased even when the engine is running at low speed, and the exhaust brake force is increased.

When the vehicle is decelerating, even if the transmission is not downshifted, when the accelerator pedal is released, engine power is absorbed by the forced supercharger, and a rapid braking effect is activated at the beginning of the exhaust brake activation, resulting in smooth deceleration and acceleration. You can continue driving, and the burden of operating the transmission is reduced.

In other words, if the exhaust brake is effective when the engine is operated at low speed, the usable rotation range per gear will be expanded, and you will not have to operate the transmission frequently (change gears) when driving downhill for a long time. Since the transmission can continue to operate at a higher speed, fuel efficiency improves as shown by the broken line in FIG. 3 (the solid line is for the conventional example).

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the exhaust brake device according to the present invention, and Fig. 2 is a diagram showing the relationship between the rotation speed and exhaust braking force of an engine equipped with the exhaust brake device according to the present invention in comparison with a conventional example. , FIG. 3 is a diagram showing the performance of an engine equipped with an exhaust brake device according to the present invention in comparison with a conventional example. 4... Forced supercharger, 6... Intake pipe, 7... Brake control valve, 11... Manual brake switch, 1
3... Conduit, 15... Exhaust pipe, 16... Exhaust brake valve.

Claims (1)

[Scope of utility model registration request] A conduit is connected between the intake pipe downstream of the forced supercharger and the exhaust pipe upstream of the exhaust brake valve, and a brake control valve that is normally closed and opens when the exhaust brake is activated is inserted into the conduit. An exhaust brake device characterized by being connected.