JP2973473B2 - Alarm device for vacuum pump - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm device for a vacuum pump, and more particularly to an alarm device for alarming an abnormal operation of a vacuum pump used in a brake booster of a vehicle.

[Prior art] In a diesel vehicle or the like, a vacuum pressure used for brake boosting is generated by a vacuum pump, and the abnormality of the vacuum system is conventionally detected by detecting a decrease in negative pressure of a vacuum tank. ing. That is, as shown in FIG. 5, the vacuum pump 4 is connected to the vacuum tank 43 via the check valve 41.
The vacuum tank 43 is connected to a booster 44 through a check valve 42.
Is in communication with The vacuum tank 43 is provided with a pressure switch 45 that closes a contact when the negative pressure falls below a certain pressure.

The abnormality is indicated by turning on the brake lamp 51 on the alarm panel 5 (FIG. 6).
The parking brake switch 3 and the brake level switch 46 are connected in parallel to the pressure switch 45 in addition to the pressure switch 45. In the figure, 7 is a meter and 6 is a battery.

[Problems to be Solved by the Invention] In the above-mentioned conventional alarm device, the malfunction of the vacuum pump 4 is indirectly detected due to a decrease in the negative pressure of the vacuum tank 43. Therefore, when an alarm is issued, the booster is no longer used. Boost function is often impaired.

Therefore, for example, Japanese Utility Model Publication No. Sho 64-7221 discloses that a suction port of a vacuum pump is provided with a pressure outlet and connected to a pressure switch so that a negative pressure drop when the pump is stopped is immediately detected to activate the pump. Those that cause defects have been proposed.

However, this also improves the instantaneousness of the alarm, but reduces the vacuum pump negative pressure immediately after the engine is started or the vacuum pump negative pressure drops due to the temporary stoppage of the vacuum pump due to the engine stall. There is a problem of falsely reporting a malfunction of the device.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide an alarm device that reliably detects a malfunction of a vacuum pump and issues an alarm.

[Means for Solving the Problems] To explain the configuration of the present invention, an alarm device for a vacuum pump 4 for supplying a negative pressure to a negative pressure pipe 43 via a check valve 41 is provided. A first negative pressure abnormality detecting means 1 for detecting a negative pressure abnormality on the upstream side and generating an output signal, and a second negative pressure detecting means for detecting a negative pressure abnormality on the downstream side of the check valve 41 and generating an output signal. Pressure abnormality detection means 45, engine operation detection means 2 for detecting the operation of the vehicle engine and generating an output signal, and parking brake non-operation detection means 3 for detecting the non-operation of the parking brake and generating an output signal
Means activated by these output signals to warn of a negative pressure abnormality upstream of the check valve 41 and a negative pressure abnormality of the downstream side of the check valve 41, The check valve 41 by the negative pressure abnormality detecting means 1
Only when a negative pressure abnormality is detected on the upstream side of the above, the check by the first negative pressure abnormality detection means 1 is performed on condition that the parking brake is not operated by the parking brake non-operation detection means 3. It is activated when all of the negative pressure abnormality upstream of the valve 41, the operation of the vehicle engine by the engine operation detecting means 2 and the non-operation of the parking brake by the parking brake non-operation detecting means 3 are detected. Alarm means 51 provided.

Accordingly, if the second negative pressure abnormality detecting means 45 detects a negative pressure abnormality downstream of the check valve 41, the parking brake non-operation detecting means 3 detects that the parking brake is not operating. Is not a condition, even when the parking brake is activated, the check valve 41
A warning of a negative pressure abnormality on the downstream side is configured to be possible.

More specifically, the logical product of the output signal of the first negative pressure abnormality detecting means 1, the output signal of the engine operation detecting means 2, and the output signal of the parking brake non-operation detecting means 3, or An alarm means 51 which is activated by an output signal of the negative pressure abnormality detecting means 45 is provided.

[Operation] In the alarm device having the above configuration, the parking brake is not activated when the engine is started, so that the parking brake non-operation detecting means 3 does not output an output signal. In this state, the first negative pressure abnormality detecting means 1 operates. No alarm is issued even if a negative pressure abnormality upstream of the check valve 41 is detected.

Further, when the vehicle engine is stopped, the engine operation detecting means 2 does not output an output signal, so that the first negative pressure abnormality detecting means 1 detects a negative pressure abnormality upstream of the check valve 41 at this time. No alarm is issued if detected.

Thus, the first negative pressure abnormality detecting means 1 detects a negative pressure abnormality on the upstream side of the check valve 41 only during normal traveling in which the engine is operating and the parking brake is not operating.
Immediate detection without being affected by the negative pressure pipe 43 separated by the check valve 41, malfunction of the vacuum pump 4 is detected, an alarm is issued, and reliable pump operation detection without erroneous detection is realized. Is done.

Further, when the second negative pressure abnormality detecting means 45 detects a negative pressure abnormality downstream of the check valve 41, an alarm is issued regardless of the operation state of the parking brake, and an alarm is issued even during parking. Can be

[Embodiment] FIG. 2 shows an alarm system of a vacuum system, and a conventional pressure switch of a vacuum tank 43 arranged downstream of a check valve 41.
In addition to the pressure switch 45, a pressure switch 1 is provided upstream of the check valve 41 and communicates with the suction port of the vacuum pump 4 by the pressure outlet pipe 12, and these pressure switches 1 and 45 are both input to the alarm panel 5. It is connected.

FIG. 1 shows a circuit configuration in the alarm panel 5. A contact 21 of the engine rotation detection sensor 2 and a contact 31 of the parking brake switch 3 are connected in series to a contact 11 of the pressure switch 1, and these are connected to a buzzer 52. Connected to the flashing relay 53.

The contact 451 of the pressure switch 45 provided in the vacuum tank 43 is directly connected to the buzzer 52 and the blinking relay 53.
The blinking relay 53 is connected to a brake lamp 51, and a contact 461 of the brake level switch 46 and another contact 32 of the parking brake switch 3 are directly connected to the brake lamp 51. The power of the battery 6 is supplied to the brake lamp 51 via the meter 7.

The contacts 11, 451 of the pressure switches 1, 45 close when the detected negative pressure drops below a predetermined pressure. The negative pressure detected by the pressure switch 1 is a negative pressure upstream of the check valve 41 that separates the vacuum pump 4 side and the vacuum tank 43 side, and is not affected by the vacuum tank 43 negative pressure. The malfunction of the vacuum pump 4 can be detected immediately. The contacts 21 and 461 of the engine circuit detection sensor 2 and the brake level switch 46 are closed when the engine is rotating and when the brake oil level is low, respectively. A pair of contacts 31 of the parking brake switch 3,
When the switch is operated, the contact 31 is opened and the contact 32 is closed.

FIG. 1 shows a state during normal running of the vehicle.
31 is closed. If the vacuum pump 4 stops in this state due to a failure of the rotation transmission system, etc.,
The suction port negative pressure of the vacuum pump 4 decreases quickly, and as a result, the pressure switch contact 11 closes to activate the buzzer 52 and to activate the brake lamp 51 via the blinking relay 53.

When the engine is started, the contact 31 is open due to the operation of the parking brake 3 (FIG. 3). In this state, even if the suction port negative pressure of the vacuum pump 4 has not yet increased and the contact 11 has been closed, The buzzer 52 and the brake lamp 51 do not blink.

If an engine stall occurs, the contact 21 of the engine rotation detection sensor 2 opens (FIG. 4). When the negative pressure drop due to the stop of the pump is detected and the contact 11 closes, the buzzer 52 and the brake lamp 51 are closed. Does not flash.

As described above, in the detection by the pressure switch 1 that exhibits the immediacy, only the negative pressure drop during the normal running of the vehicle is reported as the operation failure of the vacuum pump. Further, even when the parking brake is operating and the contact 31 of the parking brake switch 3 is open, if the negative pressure drops downstream of the check valve 41, the contact of the pressure switch 45 The 451 is closed and the buzzer 52 is operated, and the brake lamp 51 is operated to blink via the blinking relay 53. Thereby, it is possible to know the negative pressure abnormality even during parking.

The pressure switch contact of the vacuum tank may not be connected to the blinking relay, but may be directly connected to the brake lamp.

Instead of using the brake lamp as an alarm 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 vacuum pump without erroneous reporting.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is a circuit diagram showing an operation state of an alarm device, FIG. 2 is an alarm system diagram of a decrease in negative pressure, FIGS. 3 and 4 Fig. 5 is a circuit diagram showing another operation state of the alarm device, Figs. 5 and 6 show a conventional example, Fig. 5 is an alarm system diagram for a decrease in negative pressure, and Fig. 6 is a circuit diagram of the alarm device. DESCRIPTION OF SYMBOLS 1 ... Pressure switch, (1st negative pressure abnormality detection means) 2 ... Engine rotation detection sensor (vehicle engine operation detection means) 3 ... Parking brake switch (parking brake non-operation detection means) 4 ... Vacuum pump 43 … Vacuum tank (negative pressure piping) 45… Pressure switch (second negative pressure abnormality detecting means) 5… Alarm panel 51… Brake lamp (alarm means)

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Noboru Ikoma 1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-59-26354 (JP, A) JP-A-58- 35245 (JP, A) JP-A-51-35865 (JP, A) JP-A-60-156990 (JP, A) Japanese Utility Model Application Laid-Open No. 61-10265 (JP, U) (58) Fields investigated (Int. ⁶ , DB name) B60T 17/22 F04C 25/02 F04C 29/10

Claims (1)

(57) [Claims] An alarm device for a vacuum pump for supplying a negative pressure to a negative pressure pipe through a check valve, wherein the alarm device detects a negative pressure abnormality upstream of the check valve and generates an output signal.
Negative pressure abnormality detecting means, second negative pressure abnormality detecting means for detecting a negative pressure abnormality downstream of the check valve and generating an output signal, and detecting an operation of the vehicle engine to generate an output signal. Engine operation detecting means, parking brake non-operation detecting means for detecting the non-operation of the parking brake and outputting an output signal, and a negative pressure abnormality on the upstream side of the check valve activated by these output signals; Means for warning of a negative pressure abnormality downstream of the check valve, and only when the first negative pressure abnormality detection means detects a negative pressure abnormality upstream of the check valve. A condition that the parking brake is not operated by the parking brake non-operation detecting means, and a negative pressure abnormality upstream of the check valve by the first negative pressure abnormality detecting means; A vacuum pump, comprising: an alarm unit that is activated when all of the operation of the vehicle engine by the engine operation detection unit and the non-operation of the parking brake by the parking brake non-operation detection unit are detected. Alarm device.