JP3378025B2 - Electronic control unit for hydraulic circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive circuit used for a hydraulic machine such as a hydraulic excavator and a hydraulic crane, and a control device such as a prime mover, and more particularly to a control device including a plurality of control units. The configuration of the electronic control device. 2. Description of the Related Art In recent years, a construction machine driven by a hydraulic device such as a hydraulic shovel or a hydraulic crane for driving a working device has been required to have higher functions, improved operability, energy saving, etc. for adapting to various works. Electronic control of hydraulic drive units, prime movers and the like has been promoted for the purpose. FIG. 12 shows an electronic control device for a hydraulic circuit, which is one example. The electronic control unit is supplied to a hydraulic pump 2, a hydraulic actuator 2 driven by pressure oil discharged from the hydraulic pump 1, and connected between the hydraulic pump 1 and the hydraulic actuator 2. A control valve 3 for controlling the flow rate of pressure oil, a control unit 12, a control unit 13, and a changeover switch 14. The hydraulic pump 1 transmits signals from a pressure detector 5 and a swash plate position detector 6 to a control unit 12,
The control unit 12 sends the signal to the swash plate position control device 8 according to the signal.
To control the position of the swash plate 1a to control the displacement, that is, the discharge flow rate. The control valve 3 receives signals from the control unit 13 by the operation lever 4 and receives the signals from the control units 13, 3 R, 3 R, and the opening thereof is controlled, thereby controlling the direction and flow rate of pressure oil to the actuator 2 or the tank 9. . The changeover switch 14 instructs the control units 12 and 13 to switch the control state, for example, between the control in the normal mode and the control in the fine operation mode. FIG. 13 shows the structure of the control unit 12.
The control unit 12 receives the pressure signal pd of the pressure detector 5 and the swash plate position signal θ from the swash plate detector 6, converts the A / D converter 20d into a digital signal, and a central processing unit (C).
PU) 21d and a read-only memory (ROM) for storing control procedure programs and basic data necessary for control
22d, a random access memory (RAM) 23d for temporarily storing numerical values during the operation, an interface (I / O) 24d for output, and an amplifier 25 for outputting a swash plate drive signal to the swash plate control device 8. A digital input interface (D / I) 29d for inputting a switch signal Sw from the changeover switch 14. FIG. 14 shows the configuration of the control unit 13.
In the figure, the same parts as those of the control unit 12 are indicated by the same numbers as those in FIG. The operation signal X of the operation lever 4 is converted into a digital signal by the A / D converter 20e. The digital switch signal Sw from the changeover switch 14 is input by a digital input interface (D / I) 29e. The D / A converter 26e converts the digital signals back into analog signals.
L, 28R and output to the solenoid valves 3L, 3R. FIG. 15 shows the ROM 22d of the control unit 12.
4 shows a flowchart of a control procedure stored in the control program. First,
In step 100, the pressure signal pd and the swash plate position signal θ are read via the A / D converter 20d. Next, in step 101, the switch signal Sw is read via the digital input interface (D / I) 29d. Next, step 102
, The target hydraulic pump absorption torque Tr for control in the normal mode or control in the fine operation mode is set in the RAM 23d in accordance with the switch signal Sw. Further, in step 110, the target tilt angle θr is calculated by substituting the pressure signal pd and the value of the hydraulic pump target absorption torque Tr previously stored in the RAM 23d into the following equation. Θr = C · Tr / pd At this time, Tr is a unique value depending on the type of the hydraulic circuit and the switch signal Sw at that time. Next, in step 120, a drive signal is output to the swash plate control device 8 so that the swash plate position signal θ matches the target tilt angle θr. FIG. 16 shows the ROM 22e of the control unit 13.
4 shows a flowchart of a control procedure stored in the control program. First,
In step 200, the operation signal X is read via the A / D converter 20e. Next, in step 201, the switch signal Sw is supplied to the digital input interface (D / I) 29e.
Read through. Next, in step 202, in accordance with the switch signal Sw, the operation coefficient Ky for the control in the normal mode or the control in the fine operation mode and the value Xo of the dead zone are stored in the RAM 23e.
Set to. Next, in step 210, the operation signal X, the operation coefficient Ky previously stored in the RAM 23e, and the value X of the dead zone
Using o, the valve operation amounts Y1 and Y2 are calculated. When X ≧ 0, Y1 = Ky · (X−Xo) Y2 = 0 When X <0 Y1 = 0 Y2 = Ky · (| X | −Xo) At this time, Ky and Xo are determined by the hydraulic circuit. It becomes a unique value depending on the model used and the switch signal Sw at that time. Next, in step 220, the valve operation amounts Y1 and Y2 are output via the D / A converter 26e and the amplifiers 28L and 28R. [0013] There are the following five problems in the control device having these configurations. First, the following problems arise when the number of control units is plural or one. (1) Since the control units 12 and 13 perform all of the input of the detection signal, the processing of the data, and the output of the device drive signal, the A / D converter 20d or 20e,
Alternatively, expensive input / output devices such as the I / O interface 24d and an amplifier are required. In addition, a large-capacity power supply and a large-area substrate are required, and the unit price of the control unit becomes high. Therefore, when the basic data is changed to improve the performance, the expensive control unit 12 or 13 itself needs to be replaced each time, which is uneconomical. [0015] (2) system is control unit 12 and 13 in accordance with the model which the hydraulic circuit is used, the basic data Tr used in the calculation as shown above in FIG. 15, in FIG. 16, Ky, Xo
Is different. Therefore, despite the fact that the control programs are common, various types of control units must be prepared for each model, which complicates the production management. In addition, when a plurality of control units are provided,
Problems include: (3) Since there are various types of control units for each model for the reason (2), there is a possibility that the combination of the control units 12 and 13 may be mistaken at the time of assembly. (4) The control unit 12 or 1
A similar error can occur when replacing 3. (5) When the wiring from the changeover switch 14 to one of the control units is cut, the control mode of the other control unit does not match, and the operation of the vehicle body becomes abnormal. It is a first object of the present invention to provide an electronic control unit for a hydraulic circuit, which can replace a control unit for improving performance at low cost. A second object of the present invention is to reduce the complexity of having to produce many types of control units only for differences in basic data in an electronic control unit for a hydraulic circuit, and to facilitate production management. To provide an electronic control device. A third object of the present invention is to provide an electronic control device for a hydraulic circuit.
Even if there are multiple control units,
Incorrect combination of control unit models for repair
Electronic control that is unlikely to cause control state mismatch
It is to provide a control device. [0021] In order to achieve the first, second and third objects, the present invention provides a hydraulic circuit for a hydraulic machine.
A plurality of first control units that respectively control the plurality of devices; and a switching signal generator that instructs switching of a control state of the plurality of first control units .
The first control unit includes a model of the hydraulic machine,
Basic data set as a value specific to the control state at that time
Control operation using the data to control the plurality of devices.
The electronic control system for a hydraulic circuit, wherein the plurality of first control unit provided with a second control unit of the basic data storage management dedicated separately, the second control unit, the said hydraulic machine model Specific to each of multiple control states
The set as a value, means for storing the basic data used in each of the control operation of the plurality of first control unit, means for inputting a signal of the switching signal generator, when the input signal is changed Of the stored basic data
Select the one corresponding to the control state indicated by the signal
Having a first communication means for transmitting to each of the previous SL plurality of first control units, and the plurality of first control units, respectively, the signal of the switching signal generator changes and
A second communication means for receiving the basic data transmitted when the basic data is transmitted,
Means for storing, and using the stored basic data,
Means for performing a control operation . In the present invention configured as described above, only the second control unit stores the basic data corresponding to the model and the state of control, and the first control unit needs to store the basic data. It is enough to prepare one common to all models. Therefore, the first control unit can be mass-produced and can be manufactured at low cost. Further, the second control unit does not include expensive input / output devices and accessories, and can be manufactured at low cost. Therefore, the cost of the entire control unit can be reduced, and the replacement of the control unit for the purpose of improving the performance can be achieved by replacing only the inexpensive second control unit, and the replacement of the control unit can be reduced. Further, in the present invention, only the second control unit stores the basic data corresponding to the model and the control state, and the first control unit does not need to store the basic data. You just need something. Therefore, the production management of the control unit is facilitated. Next, the first control unit is common to all the models with respect to the second control unit storing the basic data, so that an erroneous combination can be prevented. Even when the wiring from the changeover switch to the second control unit is cut off, the control modes of both control units match, so that no abnormal operation occurs in the hydraulic circuit. An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows an overall configuration diagram of the electronic control device of the present embodiment. This electronic control unit includes a hydraulic pump 1, a hydraulic actuator 2 driven by hydraulic oil discharged from the hydraulic pump 1, and a hydraulic oil connected between the hydraulic pump 1 and the hydraulic actuator 2 and supplied to the hydraulic actuator 2. A control valve 3 for controlling the flow rate of the above, a control unit 7, a control unit 10, a control unit 11, and a changeover switch 14 are provided. The control unit 11 is a control unit for storing basic data, and is separate from the other control units 7 and 10.
And communicates data with the control units 7 and 10 . In the hydraulic pump 1, signals from the pressure detector 5 and the swash plate position detector 6 are transmitted to the control unit 7, and the control unit 7 uses the signals to control the position of the swash plate 1a through the swash plate position control device 8. The displacement is controlled, i.e. the discharge flow rate is controlled. The control valve 3 receives signals from the control unit 10 by the operation lever 4 and receives the signals from the control units 10 by the solenoid valves 3L and 3R. . The changeover switch 14 instructs the control unit 11 to switch the control state, for example, between the control in the normal mode and the control in the fine operation mode. FIG. 2 shows the configuration of the control unit 7. The control unit 7 receives the pressure signal pd of the pressure detector 5 and the swash plate position signal θ from the swash plate detector 6 and converts the A / D converter 20a into a digital signal, and a central processing unit (CPU).
And a read-only memory (ROM) 22a for storing a control procedure program and basic data necessary for control.
A random access memory (RAM) 23a for temporarily storing numerical values during the operation, an output interface (I / O) 24a, an amplifier 25 for outputting a swash plate drive signal to the swash plate control device 8, and a control unit. Units 10, 11 and C
And a serial interface (SI / O) 27a for performing data communication according to a PU command. FIG. 3 shows the configuration of the control unit 10. In the figure, the same parts as those of the control unit 7 are indicated by the same numbers as those in FIG. The operation signal X of the operation lever 4 input to the A / D converter 20b is converted into a digital signal. D / A converter 2
6b reconverts the digital signal into an analog signal, and these analog signals are amplified by the amplifiers 28L and 28R and output to the solenoid valves 3L and 3R. The serial interface (SI / O) 27b communicates data with other control units 7 and 11 in accordance with instructions from the CPU. FIG. 4 shows the configuration of the control unit 11. C
The PU 21c, the ROM 22c, and the RAM 23c are the same as the other control units 7, 10. The serial interface (SI / O) 27c is connected to the other control units 7, 10 and C
Data communication is performed by the PU command. The digital input interface (D / I) 29c inputs the switch signal Sw of the changeover switch 14. Serial interface (SI / O) 2
FIG. 5 shows an example of a communication method using the communication protocol 7c. The figure shows communication from the control unit 11 to the control unit 7. The SI / O 27c of the control unit 11 is a CPU
One parallel data sent from the communication unit 21c is converted into time-series data for each bit, and the S
Communicate to I / O 27a. The SI / O 27a that has received the serial data converts the data received in a time series one bit at a time into one parallel data again. The CPU 21a of the control unit 7 monitors the state of the SI / O 27a, and reads parallel data when it is input. By repeating the above operation, communication of a plurality of data can be performed. These SI / Os can be easily obtained as commercially available LSIs. The control procedure stored in the ROMs 22a to 22c of each control unit will be described with reference to FIGS. FIG. 6 shows a control procedure of the control unit 11. First, in step 300, the switch signal Sw of the changeover switch 14 is read by the digital input interface (D / I) 29c to determine whether the state of Sw has changed. If not, return to the beginning and repeat.
If it is determined in step 300 that Sw has changed, step 310
Go to In step 310, the state of Sw is determined. If Sw is ON, it is determined that the control is in the normal mode, and the process proceeds to step 320. In step 320, basic mode Tr in the normal mode is communicated to the control unit 7 via the I / O 27c. Next, in step 330, the SI / O 27
The control unit 10 communicates the basic data Ky and Xo in the normal mode to the control unit 10 via c. At this time, Tr, Ky, and Xo are a group and correspond to a specific model and a control mode at that time. FIG. 7 shows details of the control procedure 320 of the control unit 11 shown in FIG. In step 321, Tr data is communicated to the control unit 7 via the serial interface (SI / O) 27c. FIG. 8 shows the configuration of the communication data at this time. At this time, as shown in FIG. 8A, a start code which is the start of data and a destination address for identifying that the control unit that has received the data is transmission to itself (in this case, No.), Tr data, and an end code indicating the end of the data are transmitted as a set of data. That is, the CPU 21c and the serial interface (SI /
O) 27c and serial interface (SI / O)
27a, the communication procedure with the CPU 21a is performed four times: a start code, a destination address, Tr data, and an end code, and transmitted. Next, the process proceeds to step 322 to determine whether a response from the control unit 7 has been received. As will be described later, the control unit 7 returns a response to the data received from the control unit 11. As shown in FIG. 8B, the response data is a set of data including a start code, a source address indicating which control unit is the response, a response code, and an end code. At this time, the communication procedure shown in FIG. 5 is reversed four times to receive one set of data. When it is confirmed in step 322 that the response from the control unit 7 has been received, the flow proceeds to step 330 to communicate the data Ky and Xo to the control unit 10. This procedure is similar to that shown in procedure 320. However, the data transmitted from the control unit 11 to the control unit 10 is as shown in FIG. 8C, and the destination address is the control unit 10 and two data of Ky and Xo are transmitted. It becomes a set of data. The response data from the control unit 10 is the same as that of FIG. 8 except that the source address is changed to the control unit 10 as shown in FIG.
This is the same configuration as (a). When the procedure 330 ends, the procedure returns to the first procedure 300. In step 310, the switch signal Sw becomes O
If it is FF, it is determined that the control is in the fine operation mode, and the routine goes to step 340. In step 340, the basic data Tr in the fine operation mode is transferred to the serial interface (SI /
O) Communicate to control unit 7 via 27c. The communication method is the same as the procedure 320 described above. Next, in step 350, the basic data Ky of the fine operation mode
, Xo to the serial interface (SI / O) 27
and communicate to the control unit 10 via c. When the procedure 350 ends, the procedure returns to the initial procedure 300. As described above, the control unit 11 performs the procedure 3
Steps 00 to 350 are always repeated. FIG. 9 shows a control procedure of the control unit 7.
Here, the difference from the control procedure of the control unit 12 shown in FIG.
0,140 is the added point. In step 130, it is determined whether or not there has been communication from the control unit 11 via the serial interface (SI / O) 27a. If there is no communication, the process moves to step 100 and normal control is continued.
If it is determined in step 130 that there has been communication, the process proceeds to step 140. In step 140, the serial interface (S
The target absorption torque Tr of the hydraulic pump, which is basic data used for control calculation from the control unit 11 via the I / O 27a, is read and stored in the RAM 23a. This procedure 1
Details of 40 are shown in FIG. First, in step 141, FIG.
In the data shown in (a), the destination address is itself,
That is, it is determined whether or not the control unit 7 is used. If it is determined that the address is not itself, proceed to step 100 and proceed to the normal
Continue control . If it is determined that the address is itself, the process proceeds to step 142. In step 142, the Tr data shown in FIG. 8A is stored in the RAM 23a. Next, the procedure proceeds to step 143, where the response shown in FIG. 8B is transmitted to the control unit 11, and the procedure proceeds to step 100 to start normal control. In the next step 110, the target tilt angle θr is calculated using Tr stored in the RAM 23a. FIG. 11 shows a control procedure of the control unit 10. Here, the difference from the control procedure of the control unit 13 shown in FIG. 16 is that the procedures 201 and 202 are first eliminated and the procedures 230 and 240 are added as in the case of the control unit 7. In step 230, it is determined whether or not there has been communication from the control unit 11 via the serial interface (SI / O) 27b. If there is no communication, the procedure moves to step 200 and normal control is continued. If it is determined in step 230 that there has been communication, the process proceeds to step 240. Step 2
For 40, serial interface (SI / O) 27b
The control unit 11 reads the operation coefficient Ky and the dead zone value Xo, which are basic data used for the control operation, via the control unit 11 and stores them in the RAM 23b. This procedure is the same as that shown in FIG. 10. The received data is as shown in FIG. 8C, the stored data is Ky and Xo, and the response to the control unit 11 is shown in FIG. 8 (d) only. In step 210, the valve operation amounts Y1 and Y2 are calculated using Ky and Xo stored in the RAM 23b. In the above, the control units 7, 10
Since different data is not required for each model, it is possible to use the same data for all models. Therefore, the control units 7 and 10 can be mass-produced and can be manufactured at low cost. Further, since the control unit 11 does not include expensive input / output devices and devices attached thereto,
It can be manufactured at low cost. Therefore, according to the present embodiment, it is possible to reduce the cost of the control units 7, 10, 11 as a whole. In the replacement of the control unit for improving the performance, it is sufficient to replace only the inexpensive control unit 11,
Since it is unnecessary to replace the control units 7 and 10 having expensive input / output mechanisms, the control units can be replaced at low cost. In addition, these effects are obtained when one control unit is used.
That is, the same applies to the case of only the control unit 7 or only the control unit 10. Further, according to the present embodiment, only the control unit 11 stores basic data corresponding to the model and the control state, and the control units 7 and 10 do not need to store the basic data and share the same data for all models. Since it is sufficient to prepare these, it is possible to avoid the complexity of producing many types of these two control units for each model, and it becomes easy to control the production of the control units. Next, in the production / assembly of a certain model, since the control units 7 and 10 are common to all the models, respectively, for the control unit 11 storing the basic data unique to the model, the control unit of another model is It is possible to prevent an error that causes the combination of 7 and 10. Further, the control states of the control unit 7 and the control unit 10 are less likely to be mismatched. In the above embodiment, the function of SI / O in the communication procedure of the basic data does not restrict the present invention. For example, an LSI used for a LAN or the like, a method of communicating with a parallel signal, or the like may be used. Other means may be used. The configuration of the communication data is not limited to that shown in the present embodiment, and the start code and the end code are omitted as a fixed data length, or all the data are converted into character codes for communication between the control units. Any configuration may be used as long as matching is achieved. In this embodiment, the control unit for the hydraulic pump and the control valve has been described. However, the present invention can also be applied to other control units that can be considered as construction machines, for example, for an engine or for monitor display. In addition, although a manually operated switch is shown for switching the control mode, another switching signal such as a signal from another control unit may be used. According to the present invention, it is sufficient to replace only the inexpensive second control unit when replacing the control unit for improving the performance, so that the control unit can be replaced at low cost. . Further, since the first control unit is common to all models and can be mass-produced, the cost of the entire control unit can be reduced. Further, according to the present invention , the first control unit
Suffices to be common to all models, so that control management of the control unit can be easily performed. Also , the plurality of first control units are
Even if it does, errors in the combination of the corresponding models of the control unit during assembling and repair hardly occur, and the reliability can be improved. Furthermore, it is less likely that the control states of the respective control units will be inconsistent due to a wrong combination of the corresponding models .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram of an electronic control device according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a control unit. FIG. 3 is a configuration diagram of a control unit. FIG. 4 is a configuration diagram of a control unit. FIG. 5 is a diagram illustrating an example of a communication method using a serial interface. FIG. 6 is a flowchart showing a control procedure stored in a ROM of the control unit. FIG. 7 is a flowchart showing details of a control procedure. FIG. 8 is a diagram showing a configuration of communication data in a communication method. FIG. 9 is a flowchart showing a control procedure stored in a ROM of the control unit. FIG. 10 is a flowchart showing details of a control procedure. FIG. 11 is a flowchart showing a control procedure stored in a ROM of the control unit. FIG. 12 is an overall configuration diagram of a conventional electronic control unit for a hydraulic circuit. FIG. 13 is a configuration diagram of a control unit. FIG. 14 is a configuration diagram of a control unit. FIG. 15 is a flowchart showing a control procedure stored in a ROM of the control unit. FIG. 16 is a flowchart showing a control procedure stored in a ROM of the control unit. [Description of Signs] 7 Control unit 10 Control unit 11 Control units 21a to e Central processing unit (CPU) 22a to e Read only memory (ROM) 23a to e Random access memory (RAM) 27a to c Serial interface (SI / O) )

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-155654 (JP, A) JP-A-4-191135 (JP, A) JP-A-2-70203 (JP, U) JP-A-62 72234 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F15B 11/00-11/28 E02F 9/20-9/22

Claims (1)

(57) [Claims] [Claim 1] Each of a plurality of devices of a hydraulic circuit of a hydraulic machine
A plurality of first control unit which is controlled, and a switching signal generator for indicating the switching of the control state of the plurality of first control unit, said plurality of first control unit,
The model of the hydraulic machine and the control state at that time
Control operation using basic data set as unique values
An electronic control unit for a hydraulic circuit for controlling the plurality of devices , wherein a second control unit dedicated to basic data storage management is provided separately from the plurality of first control units. , the and the hydraulic machine of the model
Set as a unique value for each of the multiple control states,
Means for storing basic data to be used in each of the control operation of the plurality of first control unit, means for inputting a signal of the switching signal generator, the input signal is changed
Is indicated by the signal of the stored basic data.
Having a first communication means for transmitting to each of the first control unit of the plurality prior Symbol select the one corresponding to the control state that the plurality of first control units, respectively, the switching
Second communication means for receiving the basic data transmitted when the signal of the signal generator changes , means for storing the received basic data,
Means for performing the control calculation using the stored basic data .