JP3131297B2 - Electronic control unit for hydraulic circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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 or a hydraulic crane, and a control device such as a motor, and more particularly to a structure of an electronic control device having a plurality of control units.

[0002]

2. Description of the Related Art In recent years, a construction machine driven by a hydraulic drive system such as a hydraulic shovel or a hydraulic crane for driving a working device has a hydraulic function for adapting to various works, improving operability, saving energy, and the like. Electronic control of driving devices, prime movers, and the like has been promoted. FIG. 25 shows an example of an electronic control unit for a hydraulic circuit.

[0003] The electronic control unit includes a prime mover 13 (hereinafter referred to as an engine) such as an engine, a hydraulic pump 1 driven by the engine 13, a hydraulic actuator 2 driven by hydraulic oil discharged from the hydraulic pump 1, A control valve 3 connected between the pump 1 and the hydraulic actuator 2 for controlling the flow rate of pressure oil supplied to the hydraulic actuator 2, a control unit 17, and a control unit 18
And a control unit 19.

[0004] The speed of the engine 13 is controlled by a governor 13a. The setting of the rotation speed at this time is governor 1
This is performed by changing the angle of the governor lever 13b built in 3a. The governor lever 13b is provided with a governor lever angle detector 15 for detecting the angle of the governor lever 13b. The signal monitored by the governor lever angle detector 15 and the signal of the throttle lever 16 are transmitted to the control unit 19, and the control unit 19 drives the motor 14 based on those signals to control the angle of the governor lever 13b. 13 is controlled.

The hydraulic pump 1 transmits signals from the pressure detector 5 and the swash plate position detector 6 to the control unit 18,
Based on the signal, the control unit 18 controls the swash plate position control device 8.
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 17 by the operating lever 4 and receives the signals from the control units 17, 3 L and 3 R, and controls the opening thereof to control the direction and flow rate of pressure oil to the actuator 2 or the tank 9. .

FIG. 26 shows the structure of the control unit 18.
The control unit 18 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 20e into a digital signal, and a central processing unit (C).
PU) 21e and a read-only memory (ROM) for storing control procedure programs and basic data necessary for control
22e, a random access memory (RAM) 23e for temporarily storing numerical values in the middle of calculation, an output interface (I / O) 24e, an amplifier 25 for outputting a swash plate drive signal to the swash plate control device 8, and control. A digital input interface (D / I) 29e for inputting the operation state signal Lv from the unit 17.

FIG. 27 shows the structure of the control unit 17.
In the figure, the same parts as those of the control unit 18 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 20f. The D / A converter 26f converts the digital signal back into an analog signal,
These analog signals are amplified by the amplifiers 28L and 28R and output to the solenoid valves 3L and 3R. Further, an operation state signal Lv indicating the operation state of the operation lever 4 is output to the control units 18 and 19 via the digital output interface (D / O) 30.

FIG. 28 shows the structure of the control unit 19.
In the figure, the same parts as those of the control unit 18 are indicated by the same numbers as those in FIG. Throttle signal N of throttle lever 16
L, governor lever angle signal Ng of governor lever angle detector 15
Is converted into a digital signal by the A / D converter 20g. The signal to the motor 14 is output to the output interface (I
/ O) 24g and output via the motor driver 31. Also, like the control unit 18, the control unit 17
Is input through a digital input interface (D / I) 29g.

FIG. 29 shows the ROM 22e of the control unit 18.
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 20e. Next, in step 101, the operation state signal Lv from the control unit 17 is read via the digital input interface (D / I) 29e.

Next, in step 102, the operation state signal Lv
The pump tilt angle maximum value θmax is set in accordance with The details are shown in FIG. First, in step 102a, it is determined whether the operation state signal Lv is in the "ON" state. If the operation state signal Lv is "ON", that is, if the operation is being performed, the procedure goes to step 102b to set the maximum value θmax1 during operation of the actuator as the maximum pump tilt angle θmax.

At step 102a, the operation state signal Lv is turned "ON".
If not, that is, if it is determined that the operation has not been performed, the procedure goes to step 102c, where the pump tilt angle maximum value θma
The standby flow rate θmax2, which is the maximum value when the actuator is not operated, is set in x.

Next, in step 110, the target tilt angle θr of the pump is calculated. The details are shown in FIG. First, in step 110a, a target tilt angle θr1 is calculated from the pressure signal Pd and the value of the hydraulic pump target absorption torque Tr. θr1 = C · Tr / Pd Next, in step 110b, the target tilt angle θr1 is compared with the pump tilt angle maximum value θmax. Procedure 1 when θr1 ≧ θmax
At 10c, the final target tilt angle θr is set to θr = θmax. If θr1 <θmax, in step 110d, θr =
θr1.

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. 32 shows the ROM 22f of the control unit 17.
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 20f. Next, in step 201, the operation signal X is determined, and the operation state signal Lv is set. Fig. 3 shows the details.
3 is shown.

First, in step 201a, the absolute value of the operation signal X is compared with the dead zone value Xo. If | X | ≧ Xo, that is, if it is determined that the operation lever is operated, the procedure goes to step 201b, where the operation state signal Lv is set to “ON”.

If | X | <Xo, it is determined that the operation lever is not operated, and the procedure goes to step 201c to set the operation state signal Lv to 'OFF'. At this time, the value of Xo is a value unique to the model. Next, in step 202, the control unit 1 is controlled via the digital output interface (D / O) 30.
An operation state signal Lv is output to 8 and 19. Next, step 21
At 0, the valve operation amounts Y1 and Y2 are calculated using the operation signal X, the operation coefficient Ky, and the value Xo of the dead zone.

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 is a unique value depending on the model used. Next, in step 220, the valve operation amounts Y1 and Y2 are output via the D / A converter 26f and the amplifiers 28L and 28R.

FIG. 34 shows the ROM 22g of the control unit 19.
4 shows a flowchart of a control procedure stored in the control program. First,
In step 300, the throttle signal NL and governor lever angle signal Ng are read via the A / D converter 20g. Next, in step 310, the digital input interface (D
/ I) Read the operation state signal Lv from the control unit 17 via 29g.

Next, in step 320, the operation state signal Lv
Is determined and the target governor lever angle Nr is set. FIG.
5 shows the details of the procedure 320.

First, in step 320a, the operation state signal L
judge v. If it is determined in step 320a that Lv = 'OFF', that is, the operation lever 4 has not been operated, the flow proceeds to step 320c. In step 320c, the throttle signal NL
And a preset standby rotation speed Nmin2 which is a minimum value when the actuator is not operated. NL ≧ Nmin
In the case of 2, go to step 320d, and set the target governor lever angle Nr.
To Nmin2. If it is determined in step 320c that NL <Nmin2, Nr = NL in step 320e.

If it is determined in step 320a that Lv = 'ON', that is, that the operation lever 4 has been operated, step 320
Go to b. As in the case of Lv = 'OFF', the throttle signal NL is compared with Nmin1, which is virtually set at a position slightly higher than the set value of the maximum engine speed in advance. In this case, NL <Nmin1 is always satisfied. Procedure 32
At 0b, Nr = NL.

The values of Nmin1 and Nmin2 are unique values depending on the specifications of the vehicle body in which the engine is used. Finally, in step 330, control is performed so that the target governor lever angle Nr matches the governor lever angle signal Ng.

[0024]

Problems to be Solved by the Invention There are the following problems in the control device having these configurations. (1) For example, in the prior art example, signals are exchanged between the control units only between the control units 17 and 18 and between the control units 17 and 19. As the number increases, the wiring becomes complicated. Therefore, the probability of wiring failure increases, and it becomes difficult to find the failure.

(2) When the wiring from the control unit 17 to the other control unit 18 or 19 is cut off, the control with the other control unit becomes inconsistent and the operation of the vehicle body becomes abnormal.

(3) The control units 17, 18 and 19
Since all of the input of the detection signal, the processing of the data, and the output of the device drive signal are performed, the A / D converter 20
e, f, g, or output interface (I / O)
Expensive input / output devices such as 24e and 24g, amplifiers, and the like are required, and accordingly, a large-capacity power supply and a large-area substrate are required, and the unit price of the control unit becomes expensive. Therefore, when the basic data is changed to improve the performance, it is necessary to replace the expensive control unit 17, 18 or 19 every time, which is uneconomical.

(4) The control units 17, 18 and 19 are provided with θmax1, θmax2, θmax2, and θmax used in the calculation as shown in FIGS. 30 and 35 according to the type of the hydraulic circuit used.
Nmin2 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.

(5) Because there are many types of control units for each model for the reason (4), the control unit 1
There is a possibility that the combination of 7, 18, and 19 is incorrect.

(6) The control unit 17 or 1 at the time of failure
A similar error can occur when exchanging 8, or 19.

A first object of the present invention is to provide an electronic control unit for a hydraulic circuit, in which the number of signal lines between control units is reduced, wiring failures are small, and repairs are easy even in the case of a failure. That is.

A second object of the present invention is to provide an electronic control unit for a hydraulic circuit, which can replace a control unit for improving performance at low cost.

A third object of the present invention is to provide an electronic control unit for a hydraulic circuit that avoids the need to produce many types of control units solely due to differences in basic data, and reduces the time required for assembly and repair. It is an object of the present invention to provide an electronic control device that does not cause a wrong combination of control units and that does not easily cause a mismatch in control states.

[0033]

In order to achieve the first object, the present invention provides first and second control units for controlling a hydraulic circuit.
In the electronic control device having the control unit, a third control unit is provided separately from the first and second control units, and the first control unit sends an operation state signal to the third control unit. It has a first communication means for transmitting, the third control unit has means for storing basic data used for control calculation in the second control unit, and an operation state signal from the first control unit. And second communication means for receiving and transmitting the basic data to the second control unit based on the operation state signal.
The control unit has third communication means for receiving the basic data from the third control unit, and means for inputting the received basic data and using the input basic data for control calculations.

Preferably, in the electronic control unit for a hydraulic circuit, a plurality of the second control units are provided.

In order to achieve the first to third objects, the present invention relates to an electronic control device having first and second control units for controlling a hydraulic circuit. A third control unit is provided separately from the third control unit, the first control unit includes first communication means for transmitting an operation state signal to the third control unit, and the third control unit Means for storing first basic data used for a control operation in a first control unit and second basic data used for a control operation in a second control unit; and storing the first basic data in the first A second communication for transmitting to the first control unit, receiving an operation state signal from the first control unit, and transmitting the second basic data to the second control unit based on the operation state signal. Means The first communication unit of the first control unit has a function of receiving first basic data from the third control unit, and the first control unit inputs the received first basic data. Means for use in control calculations, the second control unit comprising: third communication means for receiving second basic data from the third control unit; and Means for inputting and used for control calculation.

Preferably, in the electronic control unit for a hydraulic circuit, a plurality of the second control units are provided.

[0037]

According to the present invention constructed as described above, the second
Even if the number of control units increases or the control becomes complicated, signals between the control units are exchanged via one communication line via the third control unit, so that wiring is simplified and failures At the same time as the probability is reduced, it is easy to find when a failure occurs.

Also, in the present invention, only the third control unit stores basic data corresponding to the model and the state of control, and the first and second control units do not need to store the basic data. It suffices to prepare something common to all models. Therefore, the first and second control units can be mass-produced and can be manufactured at low cost.

Further, since the third control unit does not include expensive input / output devices and a power supply attached thereto,
It 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 third control unit, and the replacement of the control unit can be reduced.

The basic data corresponding to the model and the state of the control are stored only in the third control unit, and the first and second control units do not need to store the basic data. It is enough to prepare Therefore, the production management of the control unit is facilitated.

Further, the first control unit and the second control unit are common to all the models with respect to the third control unit storing the basic data, so that an erroneous combination can be prevented.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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. The electronic control unit includes an engine 13, a hydraulic pump 1 driven by the engine 13, a hydraulic actuator 2 driven by pressure oil discharged from the hydraulic pump 1, and a connection between the hydraulic pump 1 and the hydraulic actuator 2. A control valve 3 for controlling the flow rate of pressurized oil supplied to the hydraulic actuator 2 and a control unit 7;
The control unit includes a control unit 10, a control unit 11, and a control unit 12.

The control unit 11 is a control unit for storing basic data, and performs data communication with the other control units 7, 10, and 12.

The speed of the engine 13 is controlled by a governor 13a. The setting of the rotation speed at this time is governor 1
This is performed by changing the angle of the governor lever 13b built in 3a. The governor lever 13b is provided with a governor lever angle detector 15 for detecting the angle of the governor lever 13b. The signal monitored by the governor lever angle detector 15 and the signal of the throttle lever 16 are transmitted to the control unit 12, and the control unit 12 drives the motor 14 based on those signals to control the angle of the governor lever 13b. 13 is controlled.

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 opening of the control valve 3 is controlled to control the direction and flow rate of the pressure oil to the actuator 2 or the tank 9. .

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.
And a random access memory (RAM) 23a for temporarily storing numerical values during the operation, and 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 serial interface (SI) for communicating data in accordance with commands from the control unit 11 and the CPU.
/ O) 27a.

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 is connected to the other control unit 11 and the CP.
Data communication is performed according to the command of U.

FIG. 4 shows the structure of the control unit 12. In the figure, the same parts as those of the control unit 7 are indicated by the same numbers as those in FIG. The throttle signal NL of the throttle lever 16 and the governor lever angle signal Ng of the governor lever angle detector 15 are A
It is converted into a digital signal by the / D converter 20c. Signals to the motor 14 are output interface (I / O)
24c and output via the motor driver 31. The serial interface (SI / O) 27c performs data communication with another control unit 11 according to a command from the CPU.

FIG. 5 shows the configuration of the control unit 11. In the figure, the same parts as those of the control unit 7 are indicated by the same numbers as those in FIG. The serial interface (SI / O) 27d communicates data with other control units 7, 10, and 12 according to instructions from the CPU.

Serial interface (SI / O) 2
FIG. 6 shows an example of a communication method using 7d. The figure shows communication from the control unit 11 to the control unit 7. The serial interface (S
I / O) 27d converts the one parallel data sent from the CPU 21d into time-series data for each bit, and converts the data into a serial interface (S) of the control unit 7 of the communication destination.
I / O) 27a. The serial interface (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. CPU 21 of control unit 7
a monitors the state of the serial interface (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 serial interfaces (SI / O) can be easily obtained as commercially available LSIs.

The control procedure stored in the ROMs 22a to 22d of each control unit will be described with reference to FIGS. FIG. 7 shows a control procedure of the control unit 11. First, step 30
At 0, the basic data Tr is communicated to the control unit 7 via the SI / O 27c. Next, in step 310, the basic data Ky and Xo are communicated to the control unit 10 via the SI / O 27c. At this time, the basic data Tr, Ky,
Xo is a set and corresponds to one specific model.

FIG. 8 shows the details of the procedure 300 shown in FIG. First, in step 320, the SI of the control unit 11
The initial setting of / O 27c, that is, the number of bits of one data in serial communication, the communication speed, and the like are set. Next, the procedure moves to step 301.

In step 301, Tr data is communicated to the control unit 7 via the SI / O 27c. On this occasion,
As shown in FIG. 9A, a start code which is the beginning of data, a destination address (in this case, the number of the control unit 7) for identifying that the control unit which has received the data is a transmission to itself, Tr Data and an end code indicating the end of the data are transmitted as a set of data. That is, the CPU 21d, the SI / O 27d and the CP shown in FIG.
The communication procedure by the U21a and the SI / O 27a is performed four times of the start code, the destination address, the Tr data, and the end code, and transmitted.

Next, the procedure proceeds to step 302, where it is determined 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. 9B, the response data includes a start code, a source address indicating from which control unit the response is sent,
It is a set of data of a response code and an end code. At this time, the communication procedure shown in FIG. 6 is reversed four times to receive one set of data. If there is no data reception from the control unit 7, the procedure goes to step 303.

In step 303, it is determined whether or not a predetermined time has elapsed in consideration of a response delay from the control unit 7. If the time has not elapsed, the process returns to step 302 again to determine the response from the control unit 7. If it is determined that the time has passed, step 30
Returning to step 1, the data is transmitted to the control unit 7 again. This is because the case where the control unit 7 was not ready for communication, could not receive data from the control unit 11, and could not return a response was considered.

On the other hand, in step 302, the control unit 7
When it is confirmed that a response has been received from the control unit 10, the process proceeds to step 310 where data Ky and Xo are communicated to the control unit 10. This procedure is similar to that shown in procedure 300. However, the data transmitted from the control unit 11 to the control unit 7 is as shown in FIG. 9C, and the destination address is the control unit 10 and two data, 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. 9 except that the source address is changed to the control unit 10 as shown in FIG.
This is the same configuration as (a).

Next, in step 400, the control unit 1
Then, an Lv signal request command is transmitted to the device 0 via the serial interface (SI / O) 27b. This command negotiates that when a specific code is communicated between the two control units, the command is recognized as a transmission request of Lv, and that code is used. FIG. 10 shows the configuration of communication data at that time. At this time, as shown in FIG. 10A, a start code which is the start of data and a destination address (in this case, control unit 1) for identifying that the control unit that has received the data is transmitting to itself.
0 number), an Lv transmission request, and an end code indicating the end of data are transmitted as a set. That is, the CPU 21a and the serial interface (SI
/ O) 27a and a serial interface (SI /
O) The communication procedure between the 27d and the CPU 27a is performed four times: the start code, the destination address, the Lv transmission request, and the end code, and transmitted.

Next, the procedure proceeds to step 410, where it is determined whether or not the operation state signal Lv has been received from the control unit 10. When the control unit 10 receives the Lv transmission request from the control unit 11 as described later, it responds to the operation state signal Lv.
Should be returned. This response data is shown in FIG.
As shown in (1), it is a set of data including a start code, a source address indicating from which control unit the response is sent, Lv data, and an end code. At this time, FIG.
The communication procedure shown in (1) is reversed four times to receive one set of data.

Next, the Lv received earlier in step 420
Is changed from the previous state. If not, the procedure returns to step 400. If it has changed, step 43
Move to 0. In step 430, the state of Lv is determined.

If Lv is 'ON', the procedure moves to step 440. In step 440, the maximum value θmax1 during operation of the actuator is set as the maximum pump tilt angle θmax, and θmax data is transmitted to the control unit 7 via the serial interface (SI / O) 27a. The details of the procedure 440 are shown in FIG.

First, in step 440a, the maximum value θmax1 during operation of the actuator is set to the maximum value θmax of the pump tilt angle.
Set. The value of θmax1 is a unique value depending on the specification of the vehicle body in which the pump is used. θmax1 will be described later.

Next, in step 440b, θmax data is transmitted to the control unit 7. At this time, as shown in FIG. 10C, the start code, the destination address, the θmax data, and the end code are transmitted as one set of data.

Next, it is determined in step 440c whether a response from the control unit 7 has been received. As will be described later, when the control unit 7 receives the θmax data from the control unit 11, the control unit 7 returns a response shown in FIG. 10D so that the transmission and reception can be confirmed reliably. If a response is received, the procedure moves to step 450.

In step 450, similarly, the governor lever angle set value Nmin1 at the time of operating the actuator is set for the governor lever angle set value Nmin, and Nmin is transmitted to the control unit 12 via the serial interface (SI / O) 27c.
Send data. The details of the procedure 450 are shown in FIG.

First, in step 450a, the governor lever angle set value Nmin1 at the time of operating the actuator is set as the governor lever angle set value Nmin. The value of Nmin1 is a value specific to the specification of the vehicle body in which the engine is used.
Nmin1 will be described later.

Next, in step 450b, Nmin data is transmitted to the control unit 12. At this time, the start code, the destination address, the Nmin data, and the end code are transmitted as a set of data as shown in FIG.

Next, it is determined in step 450c whether a response from the control unit 12 has been received. As will be described later, when the control unit 12 receives the Nmin data from the control unit 11, the control unit 12 returns a response shown in FIG. 10F so that transmission and reception can be confirmed reliably. If a response is received, the procedure returns to step 400.

On the other hand, if it is determined in step 430 that Lv is “OFF”, the flow proceeds to step 460. In step 460, the maximum value θmax2 when the actuator is not operated is set as the pump tilt angle maximum value θmax, and transmitted to the control unit 7 in the same manner as in step 440. Here, θmax2 is a value specific to the specification of the vehicle body in which the pump is used. θmax2 will also be described later.

Next, in step 470, the minimum value Nmin2 when the actuator is not operated is set for the governor lever angle set value Nmin, and transmitted to the control unit 12 in the same manner as in step 450. This Nmin2 is a unique value depending on the specifications of the vehicle body in which this engine is used. Nmin2 will also be described later. When the procedure 470 ends, the procedure returns to the procedure 400. As described above, the control unit 11 performs steps 400 to
Step 470 is always repeated.

FIG. 13 shows a control procedure of the control unit 7. Here, the difference from the control procedure of the control unit 18 shown in FIG. 29 is that the procedures 101 and 102 are eliminated and the procedures 130A, 130 and 140 are added first.

In step 130A, the target absorption torque Tr of the hydraulic pump, which is basic data used for control calculation, is read from the control unit 11 via the serial interface (SI / O) 27a and stored in the RAM 23a. FIG.
FIG. 4 shows details of the procedure 130A.

First, in step 131, the control unit 7
Initialization of the serial interface (SI / O) 27a is performed. Next, in step 132, the reception of the data shown in FIG. 9A from the control unit 11 is determined.
If not received, proceed to step 132 until data is received.
repeat. If data has been received, go to step 133
Move to

In step 133, it is determined whether the destination address of the data shown in FIG. 9A is itself, that is, the control unit 7. If it is determined that the address is not its own address, the process returns to step 132 and waits for communication from the control unit 11 again. If it is determined that the address is its own address, the process proceeds to step 134.

In step 134, Tr data shown in FIG. 9A is stored in the RAM 23a. Next, the procedure proceeds to step 135, where the response shown in FIG. 9B is transmitted to the control unit 11, and the procedure proceeds to the normal control procedure after step 130.

In a normal control procedure, first, 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 communication has occurred, step 14
Move to 0.

In step 140, the control unit 11 reads the maximum hydraulic pump displacement angle θmax, which is basic data used for control calculations, via the serial interface (SI / O) 27a and stores it in the RAM 23a. The details of this procedure 140 are shown in FIG.

In step 141, the destination address of the data shown in FIG.
Is determined. If it is determined that the address is not the address itself, the process proceeds to step 100 and waits for communication from the control unit 11 again. If it is determined that the address is itself, the process proceeds to step 142.

In step 142, θmax shown in FIG.
The data is stored in the RAM 23a. Next, the procedure proceeds to step 143, where the response shown in FIG. 10D is transmitted to the control unit 11, and the procedure proceeds to step 100 to start normal control.

Next, in step 110, the target tilt angle θr is calculated using θmax stored in the RAM 23a. The details are shown in FIG.

First, in step 110a, the pressure signal Pd
From the value of the hydraulic pump target absorption torque Tr and the target tilt angle θr
Calculate 1. θr1 = C · Tr / Pd Next, in step 110b, the target tilt angle θr1 is compared with the pump tilt angle maximum value θmax. Procedure 1 when θr1 ≧ θmax
At 10c, the final target tilt angle θr is set to θr = θmax. If θr1 <θmax, in step 110d, θr =
θr1.

Here, regarding the procedures 110c and 110d, the aforementioned θmax1 and θmax2 stored as θmax
Will be described with reference to FIG. In FIG. 17, θma
x1 is a soft upper limit value of the tilt angle set at a position slightly lower than the mechanical upper limit of the pump. θmax2 is
This is the standby flow rate set to the minimum flow rate necessary for lubrication and the like when the actuator is not operated. Θr1 is a hyperbola as shown.

If Lv is “ON”, the procedure 440 in FIG.
As a result, θmax1 is transmitted from the control unit 11 as θmax. In this case, in step 110, when θmax1 ≦ θr1, θr = θmax1 is set, but when θmax1> θr1, θr = θr1 is set, so that θr does not exceed θmax1.

If Lv is 'OFF', the procedure 46 in FIG.
Due to 0, θmax2 is transmitted from the control unit 11 as θmax. In this case, since θmax2 is always smaller than θr1, θr = θmax2 is set in step 110c, and the hydraulic pump is kept at the standby flow rate. As described above,
The values of θmax1 and θmax2 are unique values depending on the specifications of the vehicle body in which the pump is used.

Finally, in step 120, the target tilt angle θr
The drive signal is output to the swash plate control device 8 so that the swash plate position signal θ coincides with the swash plate control signal.

FIG. 18 shows a control procedure of the control unit 10. Here, the difference from the control procedure of the control unit 13 shown in FIG.
230 and 240 are added.

In step 200A, the arithmetic unit Ky and the value Xo of the dead zone are read from the control unit 11 via the SI / O 27b as basic data to be used in the control arithmetic.
3b. This procedure is the same as that shown in FIG. 14; the received data is as shown in FIG. 9C, the stored data is Ky and Xo, and the response to the control unit 11 is as shown in FIG. The only difference is that of d).

Next, the procedure proceeds to a normal procedure after the procedure 200, and the A / D converter 2 is executed in the procedure 200 as in FIG.
0b, the operation signal X is read in.
In step, the operation signal X is determined, and the operation state signal Lv is set.

Next, in step 230, the control unit 1 is controlled via the serial interface (SI / O) 27b.
It is determined whether there has been an Lv transmission request communication from 1.
If there is no communication, the process moves to step 210 and normal control is continued.

FIG. 19 shows the details of the procedure 210. First, in step 210a, the sign of the operation signal X is determined. If X is positive (X ≧ 0), the procedure goes to step 210b to calculate the valve operation amounts Y1, Y2. The arithmetic expression is as follows. Y1 = Ky. (X-Xo) Y2 = 0 If X is determined to be negative (X <0) in step 210a, the flow goes to step 210c to calculate the valve operation amounts Y1 and Y2. The arithmetic expression is as follows. Y1 = 0 Y2 = Ky · (| X | −Xo) Here, FIG. 20 shows the relationship between the operation signal X obtained by the calculation in steps 210b and 210c and the valve operation amounts Y1 and Y2. In the figure, X
In the region of ≧ 0, Y1 has a value and Y2 is 0.
At this time, Y1 moves in parallel as indicated by the dashed line due to the value of Xo. Further, the slope changes depending on the value of Ky, as shown by the two-dot chain line. In the region where X <0, Y1 is 0.
And Y2 has a value. The change of Y2 due to Xo and Ky is the same as the change of Y1. Step 210b or 210
When c is completed, the procedure moves to the next step 220.

On the other hand, if it is determined in step 230 that there has been communication, the process proceeds to step 240. In step 240, Lv data is transmitted to the control unit 11 via the serial interface (SI / O) 27b. The transmission data at this time is as shown in FIG.

The control procedure of the control unit 12 is shown in FIG. Here, the difference from the control procedure of the control unit 19 shown in FIG. 34 is that the procedure 310 is eliminated, the same procedures 340 and 350 as the control unit 7 are performed, and the procedure 360 is provided instead of the procedure 320. That is.

First, in step 340, the control unit 11 sends a command to the N through the serial interface (SI / O) 27c.
It is determined whether there has been a communication of min. If there is no communication, the process moves to step 300 and normal control is continued.

If it is determined in step 340 that there has been communication, the process proceeds to step 350. In step 350, the governor lever angle set value Nmin, which is basic data used for control calculation, is read via the serial interface (SI / O) 27c and stored in the RAM 23c.

In step 360, the target governor lever angle Nr is set. The details are shown in FIG. First, step 360
a, the throttle lever signal NL and the control unit 1
Compare the governor lever angle set value Nmin received from No. 1. If NL ≧ Nmin, proceed to step 360, where Nr is Nmin.
Set the value of. If NL <Nmin, the flow shifts to step 360c, where NL is set to Nr.

Here, regarding the procedure 360, the above-mentioned Nmin1 and Nmin2 stored as Nmin will be described with reference to FIG. In FIG. 23, Nmin1 is a virtual value set at a position slightly higher than the set value of the maximum engine speed. Nmin2 is a standby speed set to a low value in order to save energy, and set to a value slightly higher than the idle position so as not to feel a delay in the rise of the engine speed when Lv becomes "ON". Is done.

As described above, when Lv is ON ', FIG.
Nmin1 is transmitted as Nmin from the control unit 11 by the procedure 450 of (1). In this case, the throttle lever 16
Is always smaller than Nmin1, NL is always set as Nr in step 360c.

On the other hand, when Lv is 'OFF', the control unit 11 sets Nmin2 to Nmin2 by the procedure 470 in FIG.
Is sent. At this time, if the set value NL set by the throttle lever 16 is in the region (B) larger than Nmin2, that is, if NL≥Nmin2, Nmi is set to Nr in step 360b.
n2 is set and the engine is kept at standby speed. On the other hand, the set value NL by the throttle lever 16 is Nm
In the area (A) smaller than in2, that is, when NL <Nmin2, NL is set to Nr in step 360c.

FIG. 24 is a schematic diagram showing the transmission and reception of signals between the control units 7, 10, and 12 centered on the control unit 11 described above. As described above, the basic data Tr is communicated to the control unit 7 in the procedure 300 of FIG. 7, and the basic data Ky and Xo are communicated to the control unit 10 in the procedure 310. Thereafter, in step 410, the reception of the operation state signal Lv from the control unit 10 is determined.

When it is determined that the operation state signal Lv has been received,
In step 440, the maximum value θmax1 during the operation is set to the pump tilt angle maximum value θmax, or in step 460, the maximum value θmax2 when the actuator is not operated is set to θmax, and the θmax data is transmitted to the control unit 7. Then, in step 450, the governor lever angle set value Nmin1 at the time of operation is applied to the governor lever angle set value Nmin, or in step 470, the standby speed N
min2 is set and transmitted to the control unit 12.

In this embodiment, the control unit 11 sends the pump tilt angle maximum value θmax to the control unit 7 and the governor lever angle set value Nmin to the control unit 12 in response to the operation state signal Lv of the control unit 10. However, a configuration is also conceivable in which the control unit 7 or 12 issues an operation state signal Lv, and thereby the data is transmitted from the control unit 11 to another control unit.

In the above, the control units 7, 10, 1
2 does not require different data for each model, so that the same data can be used for all models. Therefore, the control units 7, 10, and 12 can be mass-produced,
It can be manufactured at low cost. Also, the control unit 11
Can be manufactured at low cost because it does not include expensive input / output devices and devices attached thereto.

Therefore, according to the present embodiment, since signals between the control units 10, 7, and 12 are exchanged via the control unit 11 through one communication line, the wiring is simple, the number of failures is small, and the number of failures is small. Even if it occurs, it becomes easier to detect.

The control units 7, 10, 11, 12
The overall cost can be reduced. In replacing the control unit for improving the performance, it is sufficient to replace only the inexpensive control unit 11, and it is not necessary to replace the control units 7, 10, and 12 having expensive input / output mechanisms. Can be replaced at low cost.

Further, only the control unit 11 stores the basic data corresponding to the model and the control state, and it is sufficient that the control units 7, 10, and 12 do not need to store the basic data and prepare a common data for all models. Therefore, 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.

In the production and assembly of a certain model,
Control unit 11 that stores basic data specific to the model
On the other hand, since the control units 7, 10, and 12 are common to all models, it is possible to prevent an error in which a control unit 7, 10, and 12 of another model is combined with the specific model.

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 units for the hydraulic pump, the engine, and the control valve are shown. However, the present invention can be applied to other control units that can be considered as construction machines, for example, for controlling the operation of a monitor display front member.

[0108]

According to the present invention, the number of signal lines can be reduced and the number of wiring failures can be reduced, and repair can be easily performed even when a failure occurs.

Further, according to the present invention, the first and second control units can be mass-produced, and the third control unit does not require an input / output device, so that the cost of the entire control unit can be reduced. . Further, replacement of the control unit for improving performance can be performed at low cost. Also, the first
Since the second control unit and the second control unit need only be common to all models, production control of the control unit can be easily performed. In addition, an error in the combination of the control units hardly occurs at the time of assembling or repair, and the reliability can be improved.

[0110]

[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 configuration diagram of a control unit.

FIG. 6 is a diagram illustrating an example of a communication method using a serial interface.

FIG. 7 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 8 is a flowchart showing details of a control procedure.

FIG. 9 is a diagram showing a configuration of communication data in a communication method.

FIG. 10 is a diagram showing a configuration of communication data in a communication method.

FIG. 11 is a flowchart showing details of a control procedure.

FIG. 12 is a flowchart showing details of a control procedure.

FIG. 13 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 14 is a flowchart showing details of a control procedure.

FIG. 15 is a flowchart showing details of a control procedure.

FIG. 16 is a flowchart showing details of a control procedure.

FIG. 17 is a diagram showing details of setting of a pump target tilt angle maximum value.

FIG. 18 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 19 is a flowchart showing details of a control procedure.

FIG. 20 is a diagram showing a relationship between an operation signal and a valve operation amount.

FIG. 21 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 22 is a flowchart showing details of a control procedure.

FIG. 23 is a diagram showing details of setting a target governor lever angle.

FIG. 24 is a schematic diagram of transmission and reception of basic data.

FIG. 25 is an overall configuration diagram of an electronic control device for a hydraulic circuit according to a conventional technique.

FIG. 26 is a configuration diagram of a control unit.

FIG. 27 is a configuration diagram of a control unit.

FIG. 28 is a configuration diagram of a control unit.

FIG. 29 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 30 is a flowchart showing details of a control procedure.

FIG. 31 is a flowchart showing details of a control procedure.

FIG. 32 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 33 is a flowchart showing details of a control procedure.

FIG. 34 is a flowchart showing a control procedure stored in a ROM of the control unit.

FIG. 35 is a flowchart showing details of a control procedure.

[Explanation of symbols]

 7 control unit 10 control unit 11 control unit 12 control unit 21a-d central processing unit (CPU) 22a-d read-only memory (ROM) 23a-d random access memory (RAM) 27a-d serial interface (SI / O)

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FIF15B 11/00 BE (56) References JP-A-5-280501 (JP, A) JP-A-61-28639 (JP, A JP-A-63-195403 (JP, A) JP-A-1-279101 (JP, A) JP-A-2-209601 (JP, A) JP-A-2-93103 (JP, A) JP-A-3- 66901 (JP, A) JP-A-3-134304 (JP, A) JP-A-4-17740 (JP, A) JP-A-5-248414 (JP, A) JP-A-6-506287 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) F15B 11/00-11/22 E02F 9/22 F15B 21/08 G05B 11/36 501

Claims (4)

(57) [Claims] 1. An electronic control device comprising first and second control units for controlling a hydraulic circuit, wherein a third control unit is provided separately from the first and second control units, The control unit has first communication means for transmitting an operation state signal to the third control unit, and the third control unit stores basic data used for control calculation in the second control unit. Means,
Second communication means for receiving an operation state signal from the first control unit and transmitting the basic data to the second control unit based on the operation state signal, wherein the second control unit An electronic control device for a hydraulic circuit, comprising: third communication means for receiving basic data from the third control unit; and means for inputting the received basic data and using the data for control calculation. 2. The electronic control unit for a hydraulic circuit according to claim 1, wherein there are a plurality of said second control units. 3. An electronic control device comprising first and second control units for controlling a hydraulic circuit, wherein a third control unit is provided separately from the first and second control units, The control unit has first communication means for transmitting an operation state signal to the third control unit, and the third control unit includes first basic data used for control calculation in the first control unit. Means for storing second basic data used for control calculations in the second control unit, and transmitting the first basic data to the first control unit, and operating the first control unit. Second communication means for receiving a state signal and transmitting the second basic data to the second control unit based on the operation state signal, the first communication means of the first control unit Is the third The first from the control unit 1
The first control unit has a function of receiving the first basic data and using the received first basic data for control calculation, and the second control unit has a function of receiving the third basic data. An electronic control device for a hydraulic circuit, comprising: third communication means for receiving second basic data from a control unit; and means for receiving the second basic data and using the second basic data for control calculation. 4. The electronic control unit for a hydraulic circuit according to claim 3, wherein a plurality of said second control units are provided.