JPH0443888A - Alarm device of vacuum pump - Google Patents

Abstract

PURPOSE:To surely detect and report the actuation failure of a vacuum pump through the output signal of each means by providing means for detecting the operation failure of the vacuum pump, that for detecting actuation of a vehicle engine, and that for detecting the non-actuation of a parking brake. CONSTITUTION:Because a parking brake is actuated at the start of an engine, a parking brake non-actuation detecting means 3 does not yield an output signal and under these conditions an alarm is not given even with detection of the operation failure of a vacuum pump 4. When a vehicle engine is stopped an engine operation detecting means 2 does not yield an output signal and thereby an alarm is not given even with detection of the operation failure of the vacuum pump 4. The operation failure of the vacuum pump 4 is thus detected and an alarm means 51 is actuated only during normal operation of the vehicle in which the engine is operated but the parking brake is not actuated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a warning device for a vacuum pump, and more particularly to a warning device for warning of abnormal operation of a vacuum pump used in a brake booster of a vehicle.

[Prior Art] In diesel vehicles, etc., a vacuum pump is used to generate the vacuum pressure used to boost the braking force of the brakes. Conventionally, abnormalities in the vacuum system have been detected by detecting a drop in negative pressure in the vacuum tank. ing. That is, as shown in Figure 5,
The vacuum pump 4 passes through a check valve 41 to a vacuum tank 43.
The vacuum tank 43 is connected to a booster 44 via a check valve 42. The vacuum tank 43 has a pressure switch 4 whose contact closes when the negative pressure drops below a certain pressure.
5 is provided, which is input connected to the alarm panel 5.

The emergency display is performed by lighting up the brake lamp 51 on the alarm panel (Fig. 6).
In addition to the pressure switch 45, a parking brake switch 3 and a brake level switch 46 are connected to the brake lever 1 in parallel.

In the figure, 7 is a meter and 6 is a battery.

[Problems to be Solved by the Invention] By the way, in the conventional alarm device described above, malfunction of the vacuum pump 4 is indirectly detected by a decrease in negative pressure in the vacuum tank 43, so when an alarm is issued, the booster is no longer activated. The boosting function of is often impaired.

For example, Japanese Utility Model Publication No. 64-7221 discloses that by providing a pressure outlet in the suction port of a vacuum pump and connecting it to a pressure switch, a drop in negative pressure when the pump is stopped is immediately detected and the pump is activated. Some have been proposed that generate defects.

However, although this improves the immediacy of the alarm, the vacuum pump negative pressure is insufficient immediately after the engine starts, and the vacuum pump negative pressure decreases due to W or temporary stoppage of the vacuum pump due to engine stall. There is a problem in that the vacuum pump is incorrectly reported as malfunctioning.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and an object of the present invention is to provide an alarm device that reliably detects malfunction of a vacuum pump and provides an alarm.

[Means for Solving the Problems] To explain the present invention in detail, the alarm device for a vacuum pump includes means 1 for detecting malfunction of the vacuum pump 4 and emitting an output signal, and means 1 for detecting operation of the vehicle engine. It comprises means 2 for issuing an output signal, means 3 for detecting non-operation of the parking brake and issuing an output signal, and alarm means 51 activated by the logical product of these output signals.

[Function] In the alarm device configured as described above, since the parking brake is activated when the engine is started, the parking brake non-operation detection means 3 does not issue an output signal, and in this state, malfunction of the vacuum pump 4 is detected. No warning will be issued.

Further, when the vehicle engine is stopped, the engine operation detection means 2 does not issue an output signal, so that no alarm is issued even if malfunction of the vacuum pump 4 is detected at this time.

In this way, malfunction of the vacuum pump is detected and an alarm is issued only during normal driving when the engine is running and the parking brake is not operating, thereby achieving reliable detection of pump operation without false detection.

[Embodiment] FIG. 2 shows a vacuum system alarm system, in which, in addition to the conventional pressure switch 45 of the vacuum tank 43, a pressure switch 1 is provided which communicates with the suction port of the vacuum pump 4 through a pressure outlet pipe 12. , these pressure switches 1.45 are all input connected to the alarm panel 5.

FIG. 1 shows the circuit configuration inside the alarm panel 5, and the contact 11 of the pressure switch 1 is connected to the contact 21 of the engine rotation detection sensor 2 and the contact 31 of the parking brake switch 3.
are connected in series, and these are the buzzer 52 and the blinking relay 5.
Connected to 3.

Contact 451 of the pressure switch 45 provided in the vacuum tank 43
is directly input connected to the buzzer 52 and blinking relay 53. In addition, the flashing relay 53 is connected to the brake lamp 5.
1, and a contact 461 of the brake level switch 46 and another contact 32 of the parking brake switch 3 are directly input connected to the brake lamp 51.

Power from a battery 6 is supplied to the brake lamp 51 via a meter 7.

Note that each contact 11.451 of the pressure switch 1.45 closes when the detected negative pressure falls below a predetermined pressure. Also, an engine rotation detection sensor 2 and a brake level switch 4
Each contact 21.461 of 6 is closed when the engine is rotating and when the brake oil level is low. A pair of contacts 31 and 32 of the parking brake switch 3 are interlocked, and when the switch is activated, the contact 31 is opened and the contact 32 is closed.

FIG. 1 shows the state when the vehicle is normally running, and shows the contacts 21 of the engine rotation detection sensor 2 and the parking brake 3.
31 are all closed. If the vacuum pump 4 stops in this state due to a failure in the rotation transmission system, etc., the suction port negative pressure of the vacuum pump 4 quickly decreases, and as a result, the pressure switch contact 11 closes and the buzzer 5
At the same time, the brake lamp 51 is made to blink via the blinking relay 53.

When the engine is started, the contact 31 is open due to the operation of the handbrake 3 (Fig. 3), and in this state, even if the negative pressure at the suction port of the vacuum pump 4 has not yet increased and the contact 11 is closed, The buzzer 52 and brake lamp 51 are not dimmed.

In addition, when an engine stall occurs, the contact 21 of the engine rotation detection sensor 2 opens (Fig. 4). Even if the negative pressure drop due to the pump stop is detected and the contact 11 closes, the buzzer 52 and the brake lamp 51 will not blink.

In this way, only a decrease in negative pressure during normal vehicle running is reported as a malfunction of the vacuum pump.

In the above example, malfunction of the vacuum pump is caused by
Instead of detecting a decrease in negative pressure using a pressure switch, it is also possible to detect a stoppage of the pump rotating shaft or the like.

It is also possible to connect the pressure switch contact of the vacuum tank directly to the brake lamp without connecting it to the blinking relay.

Instead of sharing the brake lamp as a warning display, a separate dedicated lamp may be provided, and various types of engine rotation detection sensors can be used.

[Effects of the Invention] As described above, according to the alarm device of the present invention, it is possible to reliably detect and notify the malfunction of the pump without falsely reporting it.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, FIG. 1 is a circuit diagram showing the operating state of the alarm device, FIG. 2 is a negative pressure drop alarm system diagram, and FIGS. 3 and 4 5 is a circuit diagram showing other operating states of the alarm device, FIGS. 5 and 6 show a conventional example, FIG. 5 is an alarm system diagram for negative pressure drop, and FIG. 6 is a circuit diagram of the alarm device. 1... Pressure switch (vacuum pump operation detection means) 2... Engine rotation detection sensor (vehicle engine operation detection means) 3... Parking brake switch (parking brake operation detection means) 4... Vacuum pump 5. ...Alarm panel 51... Brake lamp (alarm means) Fig. 1 Fig. 2] Fig. 3 Fig. 4

Claims (1)

[Claims] means for detecting malfunction of a vacuum pump and emitting an output signal; means for detecting operation of a vehicle engine and emitting an output signal; means for detecting non-operation of a parking brake and emitting an output signal; and these output signals. An alarm device for a vacuum pump, comprising an alarm means activated by the logical product of