JP2623596B2 - Accumulator pressure controller - Google Patents

Description

Description: Object of the Invention [Industrial Application Field] The present invention relates to a pressure of an accumulator for accumulating and controlling a pressure in an accumulator used in a hydraulic circuit such as an accelerating slip control device to a predetermined pressure. It relates to a control device.

[Prior Art] Conventionally, as a pressure control device for keeping the pressure in an accumulator at a predetermined pressure, a pump switch is turned on when a pressure in the accumulator becomes lower than a predetermined pressure, thereby driving a pump motor. A device is known in which the pressure in the accumulator is increased and the pressure switch is turned off to stop the driving of the motor when the pressure in the accumulator becomes higher than a predetermined pressure (Japanese Patent Laid-Open No. 58-1339).
No. 45).

[Problems to be Solved by the Invention] However, the following problems have been considered in the conventional pressure control device.

That is, the conventional pressure control device cannot detect a short-circuit state when a short-circuit fault occurs in the pressure switch or when a power supply line to the pressure switch short-circuits. Therefore, the motor continues to be driven even though the pressure in the accumulator is higher than the predetermined pressure, causing the problem that the pressure in the accumulator becomes abnormally high and the problem that the motor is overloaded and leads to failure. It was thought to make it.

An object of the present invention is to provide a pressure control device for an accumulator which solves the above-mentioned problem and performs more accurate and safe accumulator pressure control.

Configuration of the Invention [Means for Solving the Problems] A pressure control device for an accumulator according to the present invention has a pressure detection means for outputting a detection signal corresponding to the pressure in an accumulator as exemplified in FIG. And when the detection signal from the pressure detecting means indicates that the pressure in the accumulator is equal to or less than a predetermined value,
And a pressure increasing control means for driving pressure increasing means for increasing the pressure in the accumulator, wherein the pressure increasing means comprises: When the pressure is increased, the abnormality determining means determines that an abnormality has occurred in the pressure detecting means. When the abnormality determining means determines that an abnormality has occurred, the pressure increasing control means And a drive stopping means for stopping the driving of the pressure increasing means.

[Operation] In the pressure control device for an accumulator according to the present invention having the above-described configuration, the pressure detection means outputs a detection signal corresponding to the pressure in the accumulator, and the detection signal from the pressure detection means determines the pressure in the accumulator. Is less than or equal to a predetermined value, the pressure increase control means drives the pressure increase means for increasing the pressure in the accumulator. By driving the pressure increasing means in this way, the pressure in the accumulator is maintained near the predetermined value.

Here, when the pressure increasing means is driven for a predetermined time or more, the abnormality determining means determines that an abnormality has occurred in the pressure detecting means, and the abnormality determining means determines that the abnormality has occurred. When it is determined that the pressure has occurred, the drive stopping means stops the driving of the pressure increasing means by the pressure increasing control means.

Therefore, according to the pressure control device of the present invention, due to the abnormality of the pressure detecting means, the pressure increasing means continues to be driven even though the pressure in the accumulator is higher than the predetermined value, and the pressure in the accumulator becomes abnormal. It can solve the problem of becoming expensive. As a result, the pressure control of the accumulator can be performed safely.

Next, a preferred embodiment of the present invention will be described with reference to the drawings.

An accumulator pump control device according to an embodiment of the present invention includes:
As shown in FIG. 2, roughly, an accumulator 1 for accumulating brake oil used in a hydraulic circuit of an acceleration slip control device mounted on a vehicle, and a motor 2 for accumulating brake oil in the accumulator 1 to a predetermined pressure or more. An electronic control unit 3 for driving and controlling the motor, a pump 4 driven by the motor 2 to supply brake oil to the accumulator 1, and a motor 2
And a relay 5 for supplying drive power to the power supply. The solenoid valve 6 is for supplying brake oil in the accumulator 1 to a hydraulic circuit of an acceleration slip control device (not shown).

The accumulator 1 includes a pressure switch 10 that opens a contact when the brake oil inside the accumulator 1 becomes higher than a predetermined reference pressure,
A pressure switch 10 and a resistor R1 connected in parallel are provided. One end of the pressure switch 10 is connected to the electronic control unit 3.
Are connected to the negative input terminals of the comparators 30 and 31, respectively, and to the positive side of a vehicle-mounted battery BT as a power supply via a resistor R2 of the electronic control unit 3.
On the other hand, the other end of the pressure switch 10 is grounded. Thereby, when the contact of the pressure switch 10 is in the open state,
That is, when the brake oil in the accumulator 1 is equal to or higher than a predetermined reference pressure, the potential on the power supply side of the pressure switch 10 is expressed by the following equation (1).
5 shows a predetermined potential V1 according to an equation. When the contact of the pressure switch 10 is in a closed state, the potential on the power supply side of the pressure switch 10 indicates zero.

V1 = VBT × R1 / (R1 + R2) (1) Here, VBT is a positive potential of the battery BT (hereinafter, referred to as “VBT”).
Battery potential).

The electronic control unit 3 is a microprocessor unit (hereinafter referred to as a processor) incorporating a well-known ROM and RAM.
32, the comparators 30 and 31, the transistor TR1, the resistor R2, the resistors R3 to R5 connected in series, and the like.

The output of each of the comparators 30 and 31 is
The input terminals are connected to the 32 input ports PI1 and PI2, and the positive input terminals thereof are respectively given a predetermined reference potential by resistors R3 to R5 for dividing the potential of the battery BT. That is,
The plus side input terminal of the comparator 30 connected to the plus side of the battery BT via the resistor R3 is supplied with a reference potential V2 according to the following equation (2), and the plus side of the battery BT and the resistor R3
The reference potential V3 according to the following equation (3) is applied to the plus-side input terminal of the comparator 31 connected via R4 and R4.

V2 = VBT × (R4 + R5) / RT (2) V3 = VBt × R5 / RT (3) where RT = R3 + R4 + R5 In this embodiment, the battery potential VBT and the values of the resistors R1 to R5 are respectively , 12 [V], 470 [Ω], 360 [Ω],
1.3 [KΩ], 3.9 [KΩ], and 2.4 [KΩ] are set. Accordingly, the reference potential V2 indicates 9.9 [V] from the equation (2), and the reference potential V3 indicates 3.8 [V] from the equation (3). Further, the predetermined potential V1 indicates 6.8 [V] from the equation (1).

On the other hand, the collector of the transistor TR1 whose base is connected to the output port PO1 of the processor 32 is connected to the battery BT.
The emitter is grounded via the exciting coil 5a of the relay 5. As a result, the processor 32 can supply drive power to the motor 2 by setting the output port PO1 to high level, turning on the transistor TR1, and closing the switch 5b of the relay 5. The power supply side of the motor 2 is also connected to the input port PI3 of the processor 32. Therefore, the processor 32
The drive of the motor 2 can be detected by determining the voltage level of the input port PI3.

Next, the operation of the present embodiment having the above configuration will be described by referring to a “pump control routine” shown in FIG.
Short-circuit detection process ".

When the processing performed by the processor 32 shifts to the “pump control routine” shown in FIG. 3, it is first determined whether or not the output of the comparator 31 is at a low level (step 50). In this case, when the pressure switch 10 is operating normally, when the pressure switch 10 is closed, a potential of zero [V] is applied to the negative input terminal of the comparator 31, and the pressure switch 10
Is opened, a predetermined potential V1 (6.8 in the present embodiment).
[V]). Therefore, when the output of the comparator 31 is low compared to the reference potential V3 (3.8 [V] in the present embodiment), it means that the brake oil pressure in the accumulator 1 is higher than the predetermined reference pressure. On the other hand, when the output of the comparator 31 indicates a high level, it is a case where the output is lower than the predetermined reference pressure.

For this reason, if a negative determination is made in step 50, the processor 32 keeps the brake fluid pressure in the accumulator 1 higher than the predetermined reference pressure, that is, the comparator 31.
The process of turning on the transistor TR1 is performed until the output of the transistor TR1 indicates the low level (steps 50 and 60).

On the other hand, if a positive determination is made in step 50, the transistor TR1 is turned off (step 70), and the process proceeds to the subsequent step 80. In step 80, the "disconnection / short detection processing" shown in FIG. 4 is executed. This process is periodically executed by a method such as a hardware interrupt.

When the processing shifts to this processing, first, it is determined whether or not the output of the comparator 30 is at a high level (step 100).

When the output of the comparator 30 does not indicate the high level, it means that the power supply line of the pressure switch 10 is disconnected. That is, when the line connecting the resistor R2 of the electronic control unit 3 and the power supply side of the pressure switch 10 of the accumulator 1 or the line connecting the ground side of the pressure switch 10 and the ground is disconnected, the comparator 30 Indicates the battery potential VBT, and the output of the comparator 30 is at a low level.

If an affirmative determination is made in step 100 that there is no disconnection, it is subsequently determined whether or not the input port PI3 indicates a high level, that is, whether or not drive power is being supplied to the motor 2 (step 100). Step 110). Here, the motor 2
If a positive determination is made that drive power is supplied to
Subsequently, it is determined whether or not the time for supplying the driving power has passed the predetermined time T (step 120). The predetermined time T is set as follows.

The predetermined time T is set to a value slightly larger than the maximum drive time of the motor 2 until the brake oil pressure in the accumulator 1 becomes close to a predetermined pressure equal to or higher than a predetermined reference pressure. That is, even if the normal solenoid valve 6 is turned on and the brake oil stored in the accumulator 1 is used in a large amount for the acceleration slip control, the accumulator 1
The drive control time of the motor 2 until the brake oil pressure in the inside becomes approximately equal to or higher than a predetermined reference pressure at which the pressure switch 10 is opened does not exceed the predetermined time T.

As a result, if a positive determination is made in both steps 110 and 120, the motor 2
Is drive-controlled. The abnormal causes include the following.

(A) When the pressure switch 10 closes its contact, that is, when the brake switch in the accumulator 1 is equal to or higher than a predetermined reference pressure, that is, when the pressure switch 10 is short-circuited, (b) When the power supply line to the pressure switch 10 is short-circuited between the power supply side and the ground side, (c) When the motor 2 is driven despite the output of the comparator 31 indicating a low level, That is, when the transistor TR1 or the relay 5 is in an abnormal state and is in a conductive state.

Therefore, if an affirmative determination is made in step 120, a command for turning off the transistor TR1 is output (step 130), and in a subsequent process, a process of outputting a signal indicating an abnormality (NG signal) to the outside from the output port PO2 is performed. Perform (Step 140).

On the other hand, even if a negative determination is made in step 100 that there is a disconnection, a process of outputting an abnormality signal is performed in step 140.

After the processing of step 140, or if a negative determination is made in step 110 or 120, the processing exits to "RETURN".

As described above, according to the accumulator pump control device of the present embodiment described in detail, the short circuit of the pressure switch 10 or the short circuit of the power supply line to the pressure switch 10 is detected,
The driving of the motor 2 can be stopped. This allows
As in the related art, it is possible to prevent the problem of abnormally increasing the pressure in the accumulator 1 and the problem of overloading the motor 2 and further enhance the reliability of the control device using the accumulator 1. Has the effect. Further, in the present embodiment, it is possible to detect not only a short circuit of the pressure switch 10 but also a disconnection of a power supply line to the pressure switch 10 or an abnormality of the transistor TR1 and the relay 5, for example. I'm playing.

In this embodiment, the pressure switch 10, the resistor R1,
And the resistor R2 correspond to pressure detection means, the processing of steps 50 and 60 in FIG. 3 corresponds to pressure increase control means, and the processing of steps 110 and 120 in FIG. 4 correspond to abnormality determination means, The processing of step 130 in FIG. 4 corresponds to the drive stopping means.

Further, the present invention is not limited to the above-described embodiment at all, and can be implemented in various modes without departing from the gist of the present invention. For example, as shown in FIG.
After an affirmative determination in step 120 of the `` short circuit detection process '', a process for determining the output of the comparator 31 is added, and whether the abnormal cause is a short circuit of the pressure switch 10 or the power supply line,
Alternatively, it may be configured to judge whether it is due to an abnormality of the transistor TR1 or the relay 5.

According to the pressure control device for an accumulator of the present invention, it is possible to detect that an abnormality has occurred in the pressure detection unit that outputs a detection signal corresponding to the pressure in the accumulator, and to stop driving the pressure increase unit. Can be. This prevents the problem of abnormally increasing the pressure in the accumulator and the problem of overloading the motor as the pressure increasing means, as in the past, and further enhances the reliability of the control device using the accumulator. It has an excellent effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the basic configuration of an accumulator pump control device according to the present invention, FIG. 2 is a schematic circuit diagram illustrating the configuration of an accumulator pump control device according to one embodiment of the present invention, and FIG. FIG. 4 is a flowchart showing a process of "control routine", and FIG. 4 is a flowchart showing a process of "disconnection / short detection process". DESCRIPTION OF SYMBOLS 1 ... Accumulator, 2 ... Motor 3 ... Electronic control device, 4 ... Pump 10 ... Pressure switch, 30, 31 ... Comparator 32 ... Microprocessor unit (processor)

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-57-99448 (JP, A) JP-A-58-8452 (JP, A) JP-A-62-175249 (JP, A) JP-A 61-99249 193961 (JP, A) JP-A-57-158152 (JP, A) JP-A-58-47553 (JP, U)

Claims (1)

(57) [Claims] 1. A pressure detecting means for outputting a detection signal corresponding to a pressure in an accumulator; and wherein the detection signal from the pressure detecting means indicates that the pressure in the accumulator is equal to or less than a predetermined value. And a pressure increasing control means for driving pressure increasing means for increasing the pressure in the accumulator, wherein the pressure increasing means comprises: When the pressure is increased, the abnormality determining means determines that an abnormality has occurred in the pressure detecting means. When the abnormality determining means determines that an abnormality has occurred, the pressure increasing control means A pressure control device for an accumulator, comprising: driving stop means for stopping driving of the pressure increasing means.