JPS6228667Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an exhaust brake control device for an automobile.

For automobiles equipped with a diesel engine, a shutter is installed in the middle of the exhaust pipe, and by closing this shutter when the vehicle decelerates, the exhaust work during the piston exhaust stroke is rapidly increased, increasing the effectiveness of engine braking. Exhaust brakes are often installed.

A conventional exhaust brake control circuit is, for example, as shown in FIG.

1 is the engine key switch, 2 is the exhaust brake switch, 3 is the clutch switch (turns on when you release the clutch pedal), and 4 is the accelerator switch (turns on when you release the accelerator pedal). When all of these switches are turned on, The magnetic valve 5 is switched to send pressurized air from the air tank 6 into the working chamber 7A of the air cylinder 7, and the piston 10 is actuated to close the exhaust shutter 9 provided in the middle of the exhaust pipe 8. let

In this case, the exhaust brake is effective because
This is when the driver turns on the exhaust brake 2 during engine braking when both the clutch pedal and the accelerator pedal are released, that is, the engine is under no load and the clutch is engaged.

However, in such a configuration, the driver has to operate the exhaust brake switch 2 every time, even when driving downhill, for example when it is preferable to apply the exhaust brake, resulting in a heavy operational burden on the driver. Although there was a problem, the present applicant proposed a device aimed at solving the problem in Utility Application No. 56-60642. However, another problem was that it was not possible for the following vehicle to recognize when the exhaust brake was suddenly applied to decelerate.

Furthermore, in terms of the circuit configuration, since the operating current of the magnetic valve is passed through a plurality of switches, the switches have a large contact load and must be expensive.

This invention was proposed to solve this problem, and by selecting between automatic and manual exhaust brake switch, when automatic, the foot brake can be operated once when driving downhill. To provide an exhaust brake control device which enables an exhaust brake to be effective and which separates a magnetic valve drive circuit from various switches in circuit terms.

Hereinafter, embodiments of the present invention will be described based on the drawings.

In Figure 2, transistor Tr ₁ is on when accelerator switch 4 is on;
Tr ₂ is on when clutch switch 3 is on,
Furthermore, the transistor Tr ₃ is connected to the accelerator switch 4.
When the brake switch 12 is turned on while the brake switch 12 is turned on, it is turned on via the thyristor SCR, and when all of these are turned on, the transistor Tr ₄ is turned off (these constitute a discrimination circuit).

The current from the power supply terminal (+) flows through each resistor when the above transistors Tr ₁ to _{Tr 3} are non-conducting.
It is applied to the base of transistor Tr ₄ via R ₅ , R ₆ , R ₇ and diodes D ₁ , D ₂ , D ₃ .

The brake switch 12 is turned on during braking in conjunction with the foot brake, and at this time the stop lamp 13 lights up.

The exhaust brake switch 14 as a selection circuit has a manual contact M and an automatic contact A, each of which is connected to the base of a switching transistor Tr ₅ constituting a drive circuit for the magnetic valve 5 via diodes D ₄ and D ₅ . .

When the transistor Tr ₅ becomes conductive, a current from the power terminal (+) flows through the relay L through the resistor R ₉ , closes its contact a, energizes the magnetic valve 5 , and causes the air cylinder 7 to receive pressure from the air tank 6 . Switch to supply compressed air.

The manual contact M side of the exhaust brake switch 14 is connected to a resistor R ₈ and a diode from the middle.
said transistor Tr ₃ and thyristor through D ₆
When the switch 14 is connected to the SCR and the manual contact M is connected, the transistor Tr ₃ is turned on.

Similarly, on the auto contact A side, there is a slope detection switch 15 as a means for detecting a downhill slope on the way.
is installed and turns on when driving downhill. Incidentally, the inclination detection switch 15 may be, for example, a deceleration switch that senses deceleration.

On the other hand, when the transistor Tr ₄ is non-conductive, the switching transistor Tr ₅ is connected to the switching transistor Tr 5 via the resistor R ₉ .
A power supply voltage is applied to the circuit, but when conduction occurs, the power supply voltage is grounded.

In addition, in the figure, R ₁ to _{R 4} are each transistor Tr ₁
~ indicates the resistance that controls the applied current to Tr ₃ and the thyristor SCR.

Next, the operation will be explained.

When the exhaust brake is to be applied during deceleration of the vehicle, the exhaust brake switch 14 is turned on to the manual contact M.

Transistors Tr ₁ and Tr ₂ are in a state where there is no load and the clutch is not connected, that is, accelerator switch 4 and clutch switch 3 are both turned on and conductive, and at the same time transistor Tr ₃ is conductive, so the base of transistor Tr ₄ is The potential is grounded and the transistor Tr ₄ is switched to non-conduction.

Due to the connection of the above manual contact M, the base potential of the switching transistor Tr ₅ increases, so when the transistor Tr ₄ is turned off, a current flows between the collector and emitter of the transistor Tr ₅ via the resistor R ₉ , and the relay Excite L and close its contact a.

As a result, the magnetic valve 5 is energized,
Since the air cylinder 7 is switched to feed air from the air tank 6, the exhaust shutter 9 closes the exhaust pipe 8 and the exhaust brake is applied.

To release the exhaust brake, simply return the exhaust brake switch 14 to the off position.

In addition, this exhaust brake switch 14
If you leave it connected to manual contact M, the exhaust brake will always work during deceleration.

Next, if you want to automatically apply the exhaust brake only on downhill slopes, such as when driving on a road that includes many downhill slopes, the exhaust brake switch 14 is switched to auto contact point A.

Since the slope detection switch 15 is turned on on a downhill slope, a high potential is applied to the base of the transistor _Tr5 .

In the downhill deceleration state, both the accelerator switch 4 and the clutch switch 3 are on, and when the footbrake is operated at this time, the stop lamp 13 lights up and the gate of the thyristor SCR opens, and the transistor Tr is connected via the accelerator switch 4 and the resistor _R3 . A base voltage of _{Tr 3} is applied, and this transistor Tr ₃ becomes conductive.

As a result, the base potential of the transistor Tr ₄ is grounded and becomes non-conductive, and from this moment on, the transistor Tr ₅ is turned on in the same way as above, the relay L is energized, the magnetic valve 5 is switched, and the exhaust shutter 9 is turned on. This activates and applies the exhaust brake.

In this case, the thyristor SCR that turns on the transistor Tr ₃ will not conduct unless the foot brake is operated, so when applying the exhaust brake on a downhill slope, the stop lamp 13 will always light up, making the following vehicle aware of the braking state. It will be done.

Furthermore, once the brake is applied, the thyristor SCR remains conductive, so the exhaust brake continues to work even after the brake pedal is released.

The thyristor SCR returns to a non-conductive state when the accelerator switch 4 is turned off, and turns off the transistor Tr ₃ until the next gate voltage is applied.

When the vehicle shifts from a downhill slope to a flat road, the slope detection switch 15 is turned off, so the transistor Tr ₅ becomes non-conductive and the exhaust brake is released.

When you do not want to apply the exhaust brake, keep the exhaust brake switch 14 in the OFF state, and the transistor Tr ₅ will be kept non-conductive, so even if other conditions are satisfied to apply the exhaust brake, Exhaust brake never works.

Also, except when decelerating, no matter which position the exhaust brake switch 14 is turned on, the transistor
Since one of Tr ₁ to Tr ₃ is turned off,
Similarly, the exhaust brake will not work.

As described above, according to the present invention, the exhaust brake switch is provided with manual and automatic contacts,
When in auto mode, the exhaust brake is automatically activated when driving downhill, so when driving on a road that includes many downhill slopes, the exhaust brake must be applied on downhill slopes without having to operate the switch each time. This reduces the burden on the driver.

Furthermore, in this case, since the operation of the foot brake is required, the following vehicle can be made aware of the braking action.

The energizing circuit for the magnetic valve is separated from the signal circuits for the accelerator switch, clutch switch, brake switch, etc.
Another effect is that the current load on the various switches can be reduced, making them more compact and lower in cost.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional device. FIG. 2 is a circuit diagram showing an embodiment of the present invention. 3...Clutch switch, 4...Accelerator switch, 5...Magnetic valve, 6...Air tank, 7...Air cylinder, 8...Exhaust pipe, 9...
...Exhaust shutter, 12...Brake switch, 13...Stop lamp, 14...Exhaust brake switch, 15...Tilt detection switch, Tr ₁ to Tr ₅ ...Transistor, SCR...Thyristor, L...Relay, R ₁ ~ _R10 ...Resistance.

Claims (1)

[Scope of utility model registration request] A selection circuit for manual and auto exhaust brakes, and a discrimination circuit that determines the operation of the exhaust brake by fully closing the accelerator and connecting the clutch when the selection circuit is manual, and by operating the foot brake in addition to these when the selection circuit is automatic. Exhaust brake control characterized by comprising: an inclination detection circuit that identifies running; and a drive circuit that operates the exhaust brake using only the output of the discrimination circuit when in manual mode and the output of the discrimination circuit and the inclination detection circuit when in auto mode. Device.