JPH082014Y2 - Brake mechanism - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] <Industrial Application Field> The present invention relates to a brake mechanism used in a vehicle or the like,
In particular, the present invention relates to a brake mechanism that supplies high pressure hydraulic fluid accumulated in an accumulator to a modulator unit and a master cylinder to control a brake fluid pressure supplied to a brake means.

<Prior Art> A brake mechanism including a booster using hydraulic pressure to operate a brake of an automobile or the like has been conventionally known. For example, Japanese Patent Application Laid-Open No. 60-135359 discloses a brake device for an automobile which supplies hydraulic pressure from an accumulator to a brake booster to boost a master cylinder.

This accumulator is generally supplied with high-pressure hydraulic oil from a pump driven by an electric motor and accumulates pressure. The drive control of the pump is performed by the control unit appropriately connecting and disconnecting the switch means connected to the electric power supply line to the electric motor according to the internal pressure of the accumulator.

Further, in the anti-lock brake mechanism for adjusting the hydraulic pressure supplied to the braking means of each wheel, Japanese Patent Laid-Open No. 61-1
As disclosed in Japanese Patent No. 13542, etc., when each wheel is on the verge of being locked, high pressure hydraulic oil from the accumulator, which is also accumulated by the intermittent operation of the switch means, distributes the braking fluid pressure to each wheel. Supplied to the modulator unit.

<Problems to be solved by the invention> By the way, the above-mentioned anti-lock brake mechanism does not always operate, and even if it breaks down properly, it does not directly affect the braking performance in normal driving, so that the failure of the above switch means. Is difficult to detect.

Therefore, an object of the present invention is to improve the reliability of a brake mechanism equipped with a switch means for connecting and disconnecting the electric motor of a pump that supplies high-pressure hydraulic fluid to an accumulator, and to make it relatively easy to fail. Is configured to be able to self-diagnose and issue a warning or the like.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, such a purpose is to accumulate braking fluid pressure supply means to the brake means and supply pressure to the braking fluid pressure supply means. An accumulator, a pump for supplying high-pressure hydraulic fluid to the accumulator, an electric motor for driving the pump, and a switch means provided on a power supply line for supplying electric power to the electric motor. A brake mechanism comprising a control unit for connecting and disconnecting the switch means in accordance with the internal pressure of the accumulator, wherein the switch means comprises a solid relay, and a power source side terminal connected to at least a power source of the solid relay And a detection means for detecting a voltage level between a motor-side terminal connected to the electric motor and the motor-side terminal. Is accomplished by providing a brake mechanism, characterized in that.

<Operation> In this way, by detecting the output level of the terminal connected to the power source of the solid state relay called solid state relay and the terminal connected to the motor, the failure state and the cause can be relatively easily diagnosed. Can be dealt with effectively. Moreover, since the solid-state relay is a non-contact relay, it has higher durability than a contact relay.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 schematically shows the structure of a vehicle brake mechanism having an antilock function to which the present invention is applied. A brake pedal 1 arranged in a vehicle compartment is connected to a brake booster 4 which is integrally connected to a master cylinder 3 having a reserve tank 2 which stores brake fluid. The master cylinder 3 is connected to a modulator unit 7 having a brake fluid reserve tank 6 via two conduits 5a and 5b. The brake booster 4 is
It is connected to an accumulator control unit 9 which supplies hydraulic pressure via two pipe lines 8a and 8b. The master cylinder 3 including the brake booster 4 and the modulator unit 7 constitute a braking fluid pressure supply means for the braking means.

The modulator unit 7 has two sets of modulators for front wheels and rear wheels connected to the pipelines 5a and 5b, respectively, and each modulator has brake means 11FL and 11FR for each wheel via the pipelines 10a to 10d. , 11RL, 11RR. Each of the modulators is connected to a control unit described later. An accumulator control unit 9 is connected to the modulator unit 7.

The accumulator control unit 9 includes an accumulator 12
And a hydraulic control circuit 15 including a pressure switch 13 for monitoring the accumulated pressure of the accumulator 12 and a control valve 14 and the like. The accumulator 12 has a line 17 provided with a check valve 16.
It is connected to the reserve tank 6 via. A pump 18 is installed in the pipe line 17 and is driven by an electric motor 19 to supply high-pressure brake fluid to the accumulator 12. The high-pressure brake fluid accumulated in the accumulator 12 is pressure-controlled by the hydraulic control circuit 15 and supplied to the brake booster 4 via the pipelines 8a and 8b, and also supplied to the modulator unit 7 via the pipeline 20. Also, the hydraulic control circuit 15 is connected to the reserve tank 6 via a pipe line 21.

The pressure switch 13 is connected to the control unit 23 via two signal lines 22a and 22b, and is also connected to the ground line.
Grounded via 22c. When the pressure in the accumulator 12 drops below a predetermined value, a signal is output from the pressure switch 13 to the control unit 23 via the signal line 22a or 22b. Further, the accumulator 12 is provided with an accumulator switch 24 that detects the position of the bladder, and is connected to the control unit 23 via a signal line 25.

The electric motor 19 has power lines 26a and 26b as power supply lines.
Is connected to the positive terminal of the battery 27 via the and is grounded via the ground wire 28. A solid state relay 29 (SSR) as a switch means is provided on the power supply lines 26a and 26b. A fuse 30 and a fail-safe contact type relay 34 are provided on a power line 26b connecting the solid-state switch 29 and the positive terminal of the battery 27. The relay 34 has a contact that connects and disconnects the power supply line 26b, and is connected to the control unit 23 by a signal line 35. Solid state relay 29
Are connected to the control unit 23 via four signal lines 31a to 31d. The control unit 23 is connected to the battery 27 via an ignition switch 32 in the vehicle compartment, and a warning lamp on the instrument panel.
Connected to 33.

FIG. 2 shows an embodiment of the solid state relay 29 used in the brake mechanism of FIG. The solid state relay 29 has an n-channel MOS type FET (field drop transistor) 41,
The gate is connected to the driving unit 42. The drain of the FET 41 is connected to the battery 27 via the power line 26b when the power source side terminal 43 is connected.
Of the signal line 31a
Is connected to the control unit 23 via. The power supply voltage level from the battery 27 is output from the output terminal 44 as the signal S1. As for the source of the FET 41, the motor side terminal 45 is connected to the motor 19 via the power supply line 26a, and the output terminal 46 is connected to the control unit 23 via the signal line 31b.
It is connected to the. The voltage level to the motor 19 is output from the output terminal 46 as the signal S2.

On the other hand, the drive unit 42 has its input side terminal 47 and output side terminal.
Reference numeral 48 is connected to the control unit 23 via signal lines 31c and 31d, respectively, and receives a signal from the control unit 23 to drive the FET 41. A diode 49 is connected between the output side of the drive unit 42 and the source of the FET 41.

In the brake mechanism of the present embodiment, when the normal brake pedal 1 is stepped on, the brake booster 4 boosts the master cylinder 3 by the hydraulic pressure supplied from the accumulator control unit 9, and the brake fluid flows through the pipe lines 5a and 5b. It is supplied to the modulator unit 7. The modulator unit 7 supplies the brake fluid to each brake means 11FL via the pipelines 10a to 10d based on the output pressure from the master cylinder 3.
Brakes the wheels by pumping to 11FR, 11RL, 11RR.

The control unit 23 constantly detects the braking state from the sensor means provided on each wheel. When the wheels are about to lock, the brake fluid pressure to the corresponding braking means is reduced by supplying high pressure brake fluid from the accumulator 12 to the modulator unit 7 to prevent wheel lock. When the risk of wheel locking disappears, the supply of high pressure brake fluid from the accumulator 12 is stopped and the brake fluid pressure to the brake means is restored.

When the high pressure brake fluid is supplied from the accumulator 12 to the brake booster 4 or the modulator unit 7 and the internal pressure of the accumulator 12 drops to a predetermined first reference pressure (for example, 190 atmospheric pressure) or less, the pressure switch 13 turns on the ON signal. And an OFF signal for driving the motor 19 is output from the signal line 22a to the control unit 23. The control unit 23 receiving the OFF signal outputs a drive signal to the solid-state relay 29 to apply a positive voltage from the drive unit 42 to the gate of the FET 41. When the solid state relay 29 is turned on in this manner, a current flows from the battery 27 to the electric motor 19, the pump 17 is driven, and the high pressure brake fluid is supplied to the accumulator 12.

When the internal pressure of the accumulator 12 becomes equal to or higher than the first reference pressure, the pressure switch 13 sends an ON signal to the control unit 23 again. As a result, the control unit 23 turns off the solid-state relay 29 to turn on the electric motor 19.
To stop driving.

The control unit 23 is an output terminal of the solid-state relay 29.
It has a function of detecting the connection state of at least the power supply lines 26a, 26b to the solid-state relay 29 based on the level of the signals output from 44, 46, whereby the flow of FIGS. 3 to 8 will be described below. As explained using the figure,
Self-diagnosis of motor drive control system failure. In the present embodiment, for example, regarding the internal short circuit or the internal open of the solid state relay 29, the disconnection of the power line 26b on the battery side, the disconnection of the signal line 31c to the solid state relay 29, the overcurrent to the electric motor 19, and the pump drive time over. Fault diagnosis is performed.

FIG. 3 is a flow chart showing a self-diagnosis process for an internal short-circuit failure of the solid state relay 29 in the control unit 23. When the signal sent from the pressure switch 13 to the control unit 23 changes from off to on, it is determined whether the drive signal sent from the control unit 23 to the solid state relay 29 is on. When the drive signal is off, the level of the signal S2 sent from the output terminal 46 is determined. If signal S2 is low or off, solid state relay 29
Is off and the electric motor 19 is stopped, which is normal. However, when the signal S2 is at a high level, that is, on, the electric motor 19 continues to operate with the solid state relay 29 remaining in the on state. Therefore, the control unit 23 is a solid state relay.
It is determined that there is an internal short circuit failure in 29, and the down lamp counts for a fixed time, for example, 2 minutes, and then the warning lamp 33 is turned on. At the same time, the relay 34 can be operated to cut off the power supply line 26b and stop the electric motor 19.

However, when the electric motor 19 is still operating, the fuse 30 of the power line 26b is cut off and the electric motor 19 is cut off.
Can be stopped. If the signal S2 is turned off before the counter has counted 2 minutes, it means that the electric motor 19 has stopped, so it is judged that the internal short-circuit failure has been resolved and the warning lamp 33 is not turned on. .

FIG. 4 shows a self-diagnosis process for an internal open failure of the solid state relay 29. When the signal S2 is at a low level, that is, in spite of the ON signal being sent from the control unit 23 to the solid state relay 29, the electric motor 19 is not energized. Therefore, the control unit 23 determines that there is an internal open failure of the solid state relay 29, and the down counter counts, for example, for 2 minutes, and then the warning lamp 33 is turned on. Also, after counting for 2 minutes, the accumulator
If the internal pressure of 12 falls below a predetermined second reference pressure (for example, 160 atm), the pressure switch 13 causes the signal line 22
A warning signal is output to the control unit 23 via b.

FIG. 5 shows a self-diagnosis process for a disconnection failure of the battery side power supply line 26b. Output terminal of solid state relay 29 regardless of output from control unit 23 to solid state relay 29
When the signal S1 output from 44 is at a low level, the down counter counts, for example, for 2 minutes and then diagnoses a disconnection failure of the power line 26b on the battery side, and turns on the warning lamp 33.

In FIG. 6, the disconnection failure of the signal line 31c for driving the solid state relay 29 is determined. When the control unit 23 outputs the ON signal for driving the solid-state relay 29, but the signal is not output from the terminal 48 of the drive unit 42, the down counter counts, for example, for 2 minutes, and then the signal line. It is judged that the wire 31c is broken, and the warning lamp 33 is turned on.

In FIG. 7, an overcurrent from the battery 27 to the electric motor 19 is self-diagnosed. When the solid state relay 29 is turned on by the drive signal from the control unit 23 and the electric motor 19 is operating, the time when the potential difference between the output terminals 44 and 46 is a certain set value, for example, 0.2 V or more is counted. Then, the state in which it lasts for a certain time, for example, 2 seconds or more is counted. It is judged that this is an overcurrent to the electric motor 19, and if such a state continues for three times, for example, a warning lamp
33 is turned on and relay 34 is activated at the same time to turn on power line 26b.
Shut off. If the fuse 30 is blown by the overcurrent before the warning lamp 33 is turned on, it is determined that the solid relay 29 has an internal short circuit failure, and the warning lamp 33 is turned on.

In the self-diagnosis processing shown in FIG. 8, first, the continuous operation time of the pump 17 and the electric motor 19 is counted. Even if the pump 17 is continuously operated for a certain period of time, if the pressure inside the accumulator 12 does not reach the specified value and the ON signal is not output from the pressure switch 13, the operation of the electric motor 19 is stopped.
That is, when an ON signal is sent from the control unit 23 to the solid-state relay 29, the duration is counted, and if it is, for example, 2 minutes or more, it is judged that the pump drive time is over, the warning lamp 33 is turned on, and at the same time the relay 34 is turned on. To cut off the power supply line 26b.

The above embodiment is merely a typical example of the present invention and does not limit the technical scope thereof. For example, the solid-state relay 29 can use various relay means other than the configuration shown in FIG. Further, the present invention is not limited to the above-described automobile brake mechanism,
It can be applied to various brake mechanisms that can adjust the brake fluid pressure by supplying high-pressure hydraulic fluid using an accumulator.

[Effects of the Invention] As described above, according to the present invention, in order to control the driving motor of the pump that supplies the high-pressure brake fluid to the accumulator, a solid state relay is connected between the motor and the power source and the pressure switch is connected. Based on the signal level output from the solid-state relay for pump / motor drive control by controlling the control unit to turn it on and off based on the signal input from the controller and connecting each output terminal of the solid-state relay to the control unit. Therefore, the failure can be relatively easily self-diagnosed and effectively dealt with.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a brake mechanism of an automobile to which the present invention is applied. FIG. 2 is a schematic diagram showing the structure of a solid state relay used in the present invention. 3 to 8 are flow charts showing the self-diagnosis processing of the failure in the control unit. 1 ... Brake pedal, 2 ... Reserve tank 3 ... Master cylinder, 4 ... Brake booster 5a, 5b ... Pipe line, 6 ... Reserve tank 7 ... Modulator unit 8a, 8b ... Pipe line 9 ... Accumulator control unit 10a to 10d …… Pipe lines 11FL, 11FR, 11RL, 11RR …… Brake means 12 …… Accumulator, 13 …… Pressure switch 14 …… Control valve, 15 …… Control circuit 16 …… Check valve, 17… … Pipeline 18 …… Pump, 19 …… Electric motor 20,21 …… Pipeline, 22a-22c …… Line 23 …… Control unit 24 …… Accumulator switch 25 …… Signal line, 26a, 26b …… Power line (Power supply line) 27 …… Battery, 28 …… Ground line 29 …… Solid relay (switch means), 30 …… Fuse 31a to 31d …… Signal line 32 …… Ignition switch 33 …… Warning lamp, 34 …… Relay 35 …… signal line, 41… FET 42 ...... drive unit, 43 to 48 ...... terminal 49 ...... diode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Horiuchi 840 Kazabu, Kazabu, Ueda, Nagano Prefecture, Nisshin Kogyo Co., Ltd. (72) Mutsu Shimizu, 840 Kazabu, Kudabu, Ueda, Nagano, Nisshin Kogyo Co., Ltd.

Claims (1)

[Scope of utility model registration request] Claim 1: Brake means (11FL, 11FR, 11RL, 11RR)
Brake fluid pressure supply means (3.7) and an accumulator (12) for accumulating the supply pressure to the brake fluid pressure supply means
A pump (18) for supplying high-pressure hydraulic fluid to the accumulator, an electric motor (19) for driving the pump, and a power supply line (26a, 26b) for supplying electric power to the electric motor. ) Provided with switch means (29),
A brake mechanism comprising: a control unit (23) for connecting and disconnecting the switch means in accordance with the internal pressure of the accumulator, wherein the switch means comprises an individual relay and a power source connected to at least the power source of the solid state relay. Side terminal (43)
A brake mechanism, wherein the control unit is provided with detection means for detecting a voltage level between a motor side terminal (45) connected to the electric motor.