JPS6095610A - Electromagnetic driven controlling electronic system provided with self-diagnostic function - Google Patents

Abstract

PURPOSE:To simplify a constitution of the whole system by connecting selectively a solenoid driving circuit to an electromagnetic driving power source and a fault diagnosing power source, respectively, and diagnosing a fault by operating and non-operating states of this driving circuit. CONSTITUTION:A relay device RY is inserted between solenoids SOL1-4 and a driving power source VS. When a diagnostic mode setting signal SD is applied to an input terminal C, a digital controller COL becomes a diagnostic mode for inspecting a faulty state of an electromagnetic driving system, and simultaneously, a movable contact of said relay device RY is switched to a diagnostic side terminal tc. As a result, on and off signals are supplied to solenoid driving circuits TR1-TR4 from the digital controller COL, and its operating state and non-operating state are formed. In both these states, a voltage level variation of a diagnostic line is monitored by a voltage level detector VD, and the diagnosis is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic control system for an electromagnetic drive device of a construction machine such as a hydraulic crane, and more particularly to an electronic control system having a self-diagnosis function to check the failure state of the electromagnetic drive device. Regarding control systems.

In general, construction machinery, such as hydraulic cranes, use a large number of electromagnetic drive devices to rotate, raise and lower the boom, extend and contract, move the winch up and down, move the accelerator up and down, etc. That is, a solenoid energizing circuit for a hydraulic control electromagnetic valve or an electromagnetic relay is provided. In such construction machinery, in order to improve work efficiency or prevent danger,
It is extremely advantageous to have self-diagnosis capabilities in the electronic control system of an electromagnetic drive.

"([phlegm lヱ") Figure 1 is a block circuit diagram of an electronic control system 10 for electromagnetic drive control equipped with a conventional self-diagnosis function. In the figure, 5OL1 and S Q L 2 are These are solenoids of electromagnetic valves that control, for example, the amount of movement of the boom of a hydraulic crane in right or left rotation by energization: vS is a power source for driving solenoid 9; TR1 and TR2 are transistors, for example. COL is a digital controller composed of, for example, a microcomputer, which controls the operation of the solenoid drive circuits TRi and TR2 in either the drive control mode or the diagnostic mode 1-'; ZDl and Zn2
is a Zener diode for high-level voltage setting of the diagnostic line and input protection of the controller COL; F (i and R2 are
D1 and D2 are surge voltage protection diodes; MPX is a multi-solexer; AD is an analog-to-digital converter.

In such an electronic control system 10, if the solenoids 5OL1 and 5OL2 are electromagnetic valve solenoids for controlling the boom rotation of a hydraulic crane, the input terminals a and b each correspond to the amount of boom rotation requested by the worker. An analog signal SA indicating the target value of the valve stroke and an analog signal SB indicating the current value of the valve stroke during turning are input. It is applied via AD to the digital controller COL.

When the digital controller COL is in drive control mode, it compares the coded signals SA and SB,
Depending on the sign and absolute value of the difference signal, the operation of the solenoid I and the % dynamic circuits TRi and TR2, which are transistor circuits as shown in FIG. 2, is controlled. That is, 5A-
If 8B>O, the controller COL applies an ON signal to the drive circuit TR1 to make the transistor circuit conductive for a period corresponding to the absolute value of the difference signal, and at the same time gives an OFF signal to the drive circuit TR2 to make the transistor circuit conductive. The transistor circuit is brought into a non-conducting state. As a result, an energizing current is supplied from the drive power source VS to the solenoid 5OLi connected to the drive circuit TR1, and the boom is rotated to the right.

On the other hand, if 5iA-8B (Q), the controller CO
L gives an OFF signal to the drive circuit TR1 to make the transistor circuit non-conductive, and at the same time turns the drive circuit TR1 into a non-conductive state.
An ON signal is applied to 2 to make the transistor circuit conductive. Therefore, an energizing current is supplied from the drive power source 8 to the solenoid 5QL2 connected to the drive circuit TR2, and the boom is turned to the left. Of course, 5A-8
At B, the boom rotation is stopped.

Next, when the diagnostic mode setting signal SD is given to the input terminal C by the worker, the target value signal SA and the current value signal S
Irrespective of B, the digital controller COL enters a diagnostic mode for testing the electromagnetic drive system for fault conditions.

The diagnostic mote 9 appropriately supplies ON and OFF signals from the digital controller COL to the solenoid drive circuits TR1 and TR2, and monitors voltage level changes in the diagnostic lines 1 and 2 provided corresponding to each electromagnetic drive system. It is executed by Specifically, diagnosis is performed according to the following steps.

([) All solenoid drive circuits TR are turned OFF.
When a signal is applied, if each electromagnetic drive system is normal, a circuit is formed that connects the drive power supply 8 to the Zener diode ZD via the solenoid SQL and the resistor R. Therefore, by detecting the terminal voltage of the Zener diode ZD, that is, the voltage level of each diagnostic line, the following diagnosis is possible.

cL) Diagnostic line high level: Normal state h) Diagnostic line low level: Disconnection of the solenoid or the wiring to the solenoid, or short circuit to ground in the solenoid drive circuit Failure state (2) Electromagnetic signal that indicates a normal state according to step (1) If an ON signal is given to the solenoid drive circuit only for the drive system, if the electromagnetic drive system is normal, the drive power supply ■
8, a circuit is formed which is grounded by the drive circuit TR via the solenoid (solenoid) SQL. Therefore, by detecting the voltage level of the diagnostic line, the following diagnosis is possible. □a) Diagnostic line high level: Disconnection/failure in the solenoid drive circuit b) Diagnostic line low level: Normal status (3) As a result of the comprehensive diagnosis in steps (1) and (2), each electromagnetic drive system is completely normal. Determine the condition.

As detailed above, in the conventional electronic control system shown in Fig. 1, the case of two solenoids was explained, but in actual construction machinery, a large number of solenoids are provided, and electromagnetic drive It is clear that systems are arranged in parallel depending on the number of systems, and their drive control involves selectively energizing a large number of solenoids in response to input signals depending on the type of work, and diagnosis. The above steps are simply repeated.

The results of the diagnosis, that is, the voltage level detection signals of each diagnostic line output from the digital controller COL, can be transmitted to the operator by creating an external indicator via an appropriate output drive device. can be easily notified.

Disadvantages of the Prior Art According to the conventional electronic control system shown in Fig. 1, which has a self-diagnosis function to check the failure state of the electromagnetic drive system, it is necessary to provide diagnostic lines depending on the number of electromagnetic drive systems. Therefore, when a large number of electromagnetic drive systems are used, such as in actual construction machinery, parts such as Zener diodes 1 and ZD, current limiting resistors R, etc. connected to diagnostic lines are connected to Renoi 1. The same number of circuits as sOL are required, and the controller CO
Since L also checks the same number of diagnostic lines as solenoid 9, the circuit for checking becomes complicated.
Moreover, it is clear that the system price increases significantly.

Purpose of the Invention Accordingly, the present invention provides an electronic control system equipped with a solenoid drive circuit such as a large number of solenoid valves and solenoid relays.
The purpose of the present invention is to provide a self-diagnosis function that can inspect all electromagnetic drive systems for failure conditions using a minimum number of components, regardless of the number of loads being driven.

□ Description of a preferred embodiment of the invention FIG. 6 is a block circuit diagram showing a first embodiment of an electronic control system for electromagnetic drive control equipped with a self-diagnosis function according to the present invention. Circuit elements that are the same as those in the illustrated electronic control system 10 are given the same symbols. As is clear from a comparison with the configuration of FIG. 1, in the present invention,
A relay device RY is inserted between the solenoids 5QL1 to 5QL4 and the driving power source 8. i.e., solenoi)"5
The common connection point of QL1 to QL4 is connected to the fixed contact of the relay device RY, and the movable contact is connected to the drive control side terminal tS connected to the drive power supply ■8 and the control system power supply V via the resistor R3. . Diagnosis side terminal t connected to.

It can be switched between. Diagnosis side terminal t. is connected to the digital controller COL via a voltage sensor VD which monitors the voltage novel at that point.

In Figure 6, four solenoids SQL 1 to 5OL
4 is shown in order to clarify by comparison with the configuration of FIG. 1 that the present invention requires only a single diagnostic line despite the increased number of solenoids. can be,
For example, solenoids 5OLi and 5QL2 are solenoids for controlling the rotation of the boom, and solenoids SQL and 5OL4 are solenoids for controlling the expansion and contraction of the seam. Therefore, the input terminals σ1 and hl are supplied with a valve stroke target value signal SA corresponding to the zoom turning amount requested by the operator.
1 and the current value signal SB1 of the valve stroke during turning are respectively input, and on the other hand, input terminals LL2 and h2 are
A target value signal SA2 of the valve stroke corresponding to the amount of expansion and contraction of the boom requested by the worker car and a current value signal SB□ of the valve stroke during expansion and contraction are respectively input.

The operation when the digital controller COL is in the drive control mode is similar to the description in connection with FIG. 1, and therefore the operation in the diagnostic mode of the invention shown in FIG. 6 will be described below. .

When a diagnostic mode setting signal SD is applied to the input terminal C by an operator, the digital controller COL enters the diagnostic mode for inspecting the failure state of the electromagnetic drive system, and at the same time, the movable contact of the relay device RY is set to the diagnostic side. terminal t. can be switched to After that, specific diagnosis is performed using the digital controller COL.
A power supply V for the control system supplies ON and OFF signals to the solenoid drive circuits TRi to TF14 as appropriate, and also functions as a diagnostic line. This is carried out by passing a current through the resistor R6 and monitoring the change in the voltage level of the diagnostic line due to the voltage drop across this resistor using the voltage detector VD.

The solenoid drive circuits TR1 to TR4 are drive circuits using np and n-type transistors as shown in FIG.

Next, the specific procedure of the electronic control system of the present invention in the diagnostic mode will be explained according to the flowchart of the diagnostic subroutine shown in FIG.

(1) Start diagnosis by inputting the diagnostic mode setting signal SD (401), 1. - Devices R and Y are connected to the diagnostic side terminal t.
. (402).

(2) Supply OFF signals from the digital controller COL to all solenoid drive circuits TR1 to TR4.
03), the voltage level detector VD detects the diagnostic line voltage (404), and provides the detected value as digital data to the controller COL.

(3) The diagnostic line voltage ■ is approximately the control system power supply voltage ■. Judgment is made as to whether or not it is equal to (VT
05).

(If the judgment in 41(3) is No, that is, VT\■o, this means that the solenoid drive circuit TR (rL) (in this example, Le = 1 to 4) is in a non-conductive state. Therefore, it means a failure state in which either the electromagnetic drive line is short-circuited to ground or the solenoid drive circuit TR is short-circuited to ground.

(4) It is determined whether the -1 diagnostic line voltage ■1 is approximately equal to zero (vT=8=O?) (406).

+41-2 (4) If the judgment of -1 is NO, that is, ■7
\O means that this fault condition is displayed by an appropriate external output device (407), and the diagnosis ends (409).
.

(4)-3 If the judgment in (4)-1 is YES, that is, ■T
If key 00, this means that the electromagnetic drive line is shorted to ground, and this fault condition should not be indicated separately.
), the diagnosis ends (409).

+51 If the judgment in (3) is YES, that is, during VT ■.

, this means an apparently normal state.

(6) In order to sequentially diagnose each electromagnetic drive system,
Set the count value of the counter (Rue = 4) (410
).

(7) Supply an ON signal to the solenoid drive circuit TFll (411), detect the diagnostic line voltage (1) by the voltage level detector VD (412), and provide the detected value to the controller COL as digital data.

(8) Diagnostic line voltage ■1 is approximately the control system power supply voltage V. It is determined whether or not it is equal to (■T'Fv.?) (413).

(9) (If the judgment in 81 is YES, that is, vTki ■).

In the case of , this means that the solenoid drive circuit TR1 is in a conductive state or in an operating state, so the solenoid 5OL1 is disconnected,
This means a disconnection failure in the electromagnetic drive line, such as a disconnection in the drive circuit, and this failure state is displayed (414), and the diagnosis ends (415).

(to) If the judgment in (8) is NC), that is, ■. ＼■
In the case of o, it is determined whether the diagnostic line voltage (■1) is approximately equal to zero (■Tki07) (416).

old) If the judgment in (10) is YES, that is, V,'FO
If so, this means a short-circuit failure of the solenoid (eSOLi), this failure condition is displayed (417), and the diagnosis ends (418).

Ru.

(131 (After checking that the electromagnetic drive line related to solenoid "5OLi" is normal according to the procedure of 121, an OFF signal is given to the solenoid drive circuit TR1 in order to prepare for the next diagnosis of the electromagnetic drive line (419),
The circuit is rendered non-conductive or inactive, and the count value of the loop counter is decremented by one (420).

04) It is determined whether the count value L of the loop counter is zero (1L=0?') (421).

(+51) If the judgment in (Im) is NO, that is, if it is \O, repeat the steps (7) to (+3) described above in order to execute the diagnosis of the next electromagnetic drive line.

+16) If the judgment of (+4) is YES, that is, n-[
In case 1, this means that all electromagnetic drive systems have been diagnosed and
Moreover, it means that the diagnosis result is normal, and this normal state is displayed (422).

a) At the same time as the normal state is displayed, the relay device RY is switched to the drive control side terminal [S (423), the diagnosis mode 1. The process returns to the drive control program (424).

FIG. 5 is a block circuit diagram showing a second embodiment of an electronic control system for electromagnetic drive control equipped with a self-diagnosis function of the present invention. As mentioned above, in the electronic control system O shown in FIG. 6, the solenoid drive circuits TR1 to TR4 are
Although the explanation has been made as a drive circuit using crane-type transistors as shown in FIG. 2, the electronic control system 50 in FIG. In addition, a pnp type transistor is used in the output stage as shown in FIG. The operation of electronic control system 50 is basically the same as system 0 of FIG. 6, and therefore can be readily understood from the description associated with FIGS. 6 and 4.

Effects Although the embodiment of the present invention has been specifically described in detail for the case where there are four solenoids, according to its operating principle, even if there are a large number of drive circuits such as electromagnetic valves or electromagnetic relay devices,
Only one diagnostic line is sufficient, and unlike conventional systems, there is no need to provide diagnostic lines depending on the number of drive circuits.
Therefore, the configuration of the entire system becomes simple, and the advantages especially in terms of price are immeasurable (・0

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of a conventional electromagnetic drive control electronic system with a self-diagnosis function. FIG. 2 shows a solenoid drive circuit that can be used in the system of FIG. FIG. 6 is a block circuit diagram showing a first embodiment of an electromagnetic drive control electronic system having a self-diagnosis function according to the present invention. FIG. 4 is a flowchart illustrating the diagnostic procedure in the system shown in FIG. FIG. 5 is a block circuit diagram showing a second embodiment of an electromagnetic drive control electronic system having a self-diagnosis function according to the present invention. FIG. 6 shows a solenoid drive circuit that can be used in the system of FIG. (Explanation of symbols) 10.1, 50: Electronic control system 5OLi~SQL, 4: Solenoid TRi~TR4, TR1'~TR4': Solenoid drive circuit vS2 Solenoid drive power supply o2 Control system power supply COL: Digital control MPX: Multiplexer AD: Analog-to-digital converter D1-D4: Diode R1-R6: Resistor ZD1. Z
D2: Zener diode RY: Relay device Patent applicant Sanwa Seiki Co., Ltd. (4 others)

Claims (1)

[Scope of Claim] An electronic system for electromagnetic drive control equipped with a self-diagnosis function for inspecting failure states of a plurality of electromagnetic drive devices, comprising: an electromagnetic drive power source, a failure diagnosis power source, and a plurality of electromagnetic drive devices. a plurality of solenoid drive circuits connected to each other; and a switching device commonly connected to the plurality of solenoid drive circuits and selectively connecting each of the solenoid drive circuits to the electromagnetic drive power source and the failure diagnosis power source. a voltage level detector for detecting a voltage change on the fault diagnosis power source side of the switching device; and a voltage level detector that detects a voltage change on the fault diagnosis power source side of the switching device; switch the electronic system from the drive control mode to the diagnostic mode, and then, with the plurality of sensor drive circuits inactive, detect the first fault based on the voltage detection value of the voltage sensor. A diagnosis is performed, and then a second fault diagnosis is performed based on the detected value of the voltage sensor while the plurality of solenoid drive circuits are kept in an operating state (based on the first and second fault diagnoses). An electronic system for electromagnetic drive control, comprising: a controller that performs comprehensive failure diagnosis of the plurality of electromagnetic drive devices.