JPH0820498A - Control device for solenoid valve in industrial machine - Google Patents

Abstract

PURPOSE:To form a DC transformer compact for facilitating securing mounting space, and reduce cost. CONSTITUTION:In a forklift in which three proportional solenoid valves 2a, 2b, 2c are actuated by operating three levers 1a, 1b, 1c, a capacity of a DC transformer 3 is set as a required one for actuation of the two valves. For the levers 1a, 1b, 1c, priorities are set in the order of the lever 1a, 1b, 1c. and in the case where the three levers la, lb, 1c are operated simultaneously, operation to the two levers 1a, 1b of the higher priorities is set effective to actuate the valves 2a, 2b, while operation to the lever 1c of the lowest priority is set ineffective to keep the valve 2c non-actuated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cargo handling vehicle, a construction machine,
The present invention relates to a control device for an electromagnetic valve driven by lever operation in an industrial machine such as an agricultural machine.

[0002]

2. Description of the Related Art In hydraulic equipment, a valve is operated by a lever to operate a valve directly by mechanical means or indirectly by electrical means to adjust the flow rate of hydraulic oil.
Forklifts are equipped with operating levers for lift, tilt, reach, etc., and construction machines are equipped with operating levers for each stage of a multi-stage arm. These levers are operated individually or simultaneously to perform work. Be done. A dedicated DC transformer is indispensable for the electromagnetic valve power supply that operates by electrical means, and therefore a DC transformer having a capacity corresponding to the number of electromagnetic valves must be mounted.

Taking the case of a forklift truck as an example,
As shown in FIG. 7, when electromagnetic valves (proportional solenoid valves) are used for all the valves driven by operating the lift, tilt, and reach levers 1, 1, 1, when the controller A operates the valve 2 , 2, 2 at the same time 3
DC transformer 3 with guaranteed power capacity required for continuous operation
Is connected to a 48V battery power source 4, and 48V is supplied to 14.V.
The electric power for driving each electromagnetic valve is secured by stepping down to 5V, and the electric power for driving the CPU is supplied to the CPU 7 through the small capacity DC transformer 6 that further steps down 14.5V to 5V. And to the CPU 7 via a bus
The OM 11 and the RAM 12 are connected. The operation angle information of each lever 1, 1, 1 is sent to the CPU 7 via the A / D converter 8, and the CPU 7 is in charge of the ROM 1
1 and RAM 12 to calculate data corresponding to the operation angle, and drive drivers 5, 5, via D / A converters 9, 9, 9, constant current amplifiers 10, 10, 10.
5, the solenoid of each valve 2, 2, 2 is operated. In this way, a forklift with three valves is equipped with a DC transformer with a power capacity of three stations, so that even if the three levers are operated simultaneously, the capacity of the DC transformer will not be exceeded. Was taken into consideration.

[0004]

As the number of valves increases, the capacity of the DC transformer must be increased with the increase in the number of valves. However, the DC transformer becomes large in size, and there is a problem in terms of storage space and price. Occurs. If the capacity of the DC transformer is not increased even if the number of valves is increased, when the capacity of the DC transformer is insufficient and the levers are simultaneously operated, an overload state occurs, causing a failure.

[0005]

SUMMARY OF THE INVENTION The present invention aims at downsizing of a DC transformer, and when the levers are simultaneously operated and the power supply capacity required for driving the valve exceeds the power supply capacity of the DC transformer, To prevent overloading of vessels,
The configuration is such that the capacity of the DC transformer is small with respect to the power supply capacity required to fully open all the valves at the same time, priority is set for each valve operating lever, and multiple levers are operated simultaneously. In this case, among the operated levers, only the operation of the lever selected in accordance with the priority order is effective and the operation of the other levers is ineffective. The simultaneously actuable levers are selected either by a number counted according to priority or on the basis of the sum of the volumes required for valve operation according to priority. Further, when a lever having a higher priority than the lever is operated while the valve is being operated by the lever operation determined to be valid, the operated higher lever operation can be prioritized. Furthermore, when the capacity of the DC transformer is small with respect to the power supply capacity required to fully open all the valves at the same time, and when a plurality of levers are operated simultaneously, each lever is operated for all the operated levers. The power supply capacity required for each valve operation is determined by the above D
It is also possible to adopt a configuration provided with a distribution means for allocating within the capacity of the C transformer.

[0006]

According to the first to third aspects of the present invention, since the lever operations other than the selected lever are invalidated, the total capacity of the power source required to drive the valve operated by the selected lever operation is It is within the range of the power supply capacity of the DC transformer. According to the invention of claim 4, the operability is improved by adding the function of interrupting the upper lever. Further, according to the invention of claim 5, when all the valves for the operated levers are driven and the capacity of the DC transformer is exceeded, the valves are driven in a relationship corresponding to the operating angle of each lever. It drops at a uniform rate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the electromagnetic valve control device according to the present invention is implemented in a forklift having a triple lever for cargo handling work will be described with reference to the drawings. The control apparatus shown in FIG. 1 employs solenoid valves (proportional solenoid valves) for all of the valves 2a, 2b, 2c driven by operating the lift, tilt, and reach levers 1a, 1b, 1c. , The controller A connects the DC transformer 3 to the 48V battery power source 4 and steps down 48V to 14.5V to supply power for driving each electromagnetic valve to each valve 2a, 2b, 2c as in the conventional example. A voltage of 14.5V output from the DC transformer 3 by connecting a small capacity DC transformer 6 to the DC transformer 3 which can be supplied to the driving drivers 5a, 5b, 5c to be driven. Is stepped down to 5V and the CPU 7 is supplied with power for driving the CPU. Information on the operating angle of each lever 1a, 1b, 1c is sent to the CP via the A / D converter 8 respectively.
U7 is sent to each D / A converter 9 from the CPU 7.
a, 9b, 9c, constant current amplifiers 10a, 10b, 10c
A command is sent to the drive drivers 5a, 5b, 5c via the solenoid, and the solenoids of the valves 2a, 2b, 2c are operated. The DC transformer 3 has sufficient capacity to operate the valves for two stations, but cannot satisfy the capacity required to operate the valves for three stations.

A ROM 11 and a RAM 12 are connected to the CPU 7 via a bus.
Necessary data can be read or stored from M11 and RAM12. The ROM 11 stores a map of the digital output (FIG. 2a) for each operation lever angle, a map of the current value output from the D / A converter corresponding to the digital output (FIG. 2b), and the current thereof. Map of flow rate controlled according to value (Fig. 2
c) can be determined on the drive driver and the hardware of the valve, respectively, and the opening degree of the valve is controlled according to the lever operation angle.

The controller A having the CPU as a core is provided with input means for inputting the priority order of the levers 1a, 1b and 1c, and the three levers 1a, 1b and 1c are simultaneously operated. In this case, a program is installed as a selection means that sends a digital signal to the D / A converter corresponding to the upper two levers and does not output the driving command corresponding to the remaining lower lever.

An example of control by the control device thus constructed will be described with reference to a flow chart. First, start by turning on the key switch, and in step S1, the CPU
The initial value of is set, and in the subsequent step S2, the priority order of the lever is set. The priority of this lever is R in advance.
This is executed by reading data registered in the OM and automatically setting it, selecting a desired pattern from the read data, or newly inputting it. Here, the priority of the lever is 1a (lift),
It is assumed that the order is 1b (tilt) and 1c (reach). When any one of the levers 1a, 1b, 1c is operated, the operation angle data is A / D in step S3.
It is input to the CPU 7 via the converter 8 and step S
In 4, the lever operation is determined to be valid regardless of the priority of the operated lever, and in step S5, a digital signal corresponding to the lever is transmitted to the D / A converter, and the valve is opened. Even when two levers are operated simultaneously, the valve corresponding to each lever is opened regardless of the priority order of the operated levers, as described above. When the three levers are operated simultaneously, it is determined in step S4 that only the upper two levers are effective, and in step S5, the valves 2a and 2b corresponding to those levers 1a and 1b are opened and the remaining remaining levers are operated. The operation of the lower lever 1c is invalidated, and the opening operation output of the valve 2c corresponding to the lever 1c is not output. When it is confirmed that the valve 2a or 2b has been closed by the upper lever operation, the opening operation output of the valve 2c corresponding to the lowest lever 1c is issued. As described above, the power supply capacity required for valve operation does not always exceed the power supply capacity for two stations, and even a DC transformer that does not have a power supply capacity for three stations will not be overloaded. The valve 2
The fact that a or 2b has been closed means that the lever is returned to its original position and the operating angle data is sent to the CPU 7 via the A / D converter.
It can be confirmed by a detection signal for automatically stopping by detecting that the cylinder piston rod has reached the stroke end.

If it is determined that two lever operations are effective, and one of the levers has the lowest priority, and the remaining one lever is operated, the lever operated thereafter is prioritized. It is programmed to issue an interrupt command and immediately stop and interrupt the valve corresponding to the lever with the lowest priority.
On the contrary, it is possible to prioritize the lever operated first and take a measure to prohibit interruption.

In the above embodiment, the DC transformer has a capacity for two stations for three levers, but as shown in FIG. 4, the lever 1d, the valve 2d and the drive driver 5 are used for side shift.
d, a D / A converter 9d, and a constant current amplifier 10d are added, and control is performed so that valves of two or more stations do not operate simultaneously even if the capacity of the DC transformer 3 is two stations for four levers. Or, the capacity of the DC transformer is 3 for four levers.
If the capacity of the DC transformer is less than the number of levers for three or more levers, such as when using multiple stations, the number of levers and DC
The capacity of the transformer can be set freely. It is also applied to construction machinery and agricultural machinery other than forklifts.

The selection of the lever by the selecting means is not limited to the number of levers, but if the selection is made based on the capacity, the workability can be expected to be improved. . That is, the valve driving power supply capacity according to the lever operation angle is added in order from the operated lever to the higher order, and the added capacity is controlled within a range not exceeding the capacity of the transformer. As shown in FIG. 4, an example in which the DC transformer has a capacity for two stations with respect to four levers will be described. When four levers are simultaneously operated, the priority order is 1 when the number of levers is selected. It is determined that only the lever operations of 2 and 2 are valid, and the lever operations of the priorities 3 and 4 are invalid. However, based on the power supply capacity required for the valve according to the angle of each lever operation according to the priority order, the valve opening degrees operated by the levers of the priority order 1 and 2 are 5 respectively.
If 0% and the required power capacity is 50%, there is a margin of power capacity corresponding to one station. Therefore, the levers of priority 3 can be operated simultaneously, and four consecutive operations can be performed depending on the operation angle of the levers.

A specific example will be described with reference to the flow chart shown in FIG. 5. When it is confirmed in step S3 that all four levers have been operated, the valve operation is performed in accordance with the lever operation angle in step S6. The required power supply capacity is calculated from the map, and the power supply capacity necessary for the valve operation corresponding to the lever operation up to the third highest priority is added. In step S8, the added value is larger than the power supply capacity of the DC transformer. Smallness is judged. If the added value exceeds the capacity of the DC transformer, the process proceeds to step S9, and the upper two lever operations are considered to be valid. On the contrary, if the added value is less than the capacity of the DC transformer, the process proceeds to step S10 to add the power source capacity necessary to operate all valves, and in step S11, the added value is the capacity of the DC transformer. Judgment is made. If the power supply capacity required for valve operation is equal to or greater than the capacity of the DC transformer, the process proceeds to step S12, and only the upper three lever operations are enabled. If the added value is less than the capacity of the DC transformer, the process proceeds to step S13. To operate all valves. It should be noted that each lever operation angle is constantly monitored, and if there is a change, the control can be repeated by repeating the control each time.
The capacity of the transformer can be fully utilized.

In the above description, the priority order is set for each lever, and the lever operations other than the valid upper order are invalidated. Therefore, the valve does not operate even if the lever is operated. Therefore, it may be mistaken for a failure. Therefore, all the lever operations are enabled for the controller A, and the power distribution capacity required for each valve operation is allocated within the range of the capacity of the DC transformer at a ratio according to the operation angle of each lever. Incorporate the program as. A specific embodiment will be described with reference to the flowchart shown in FIG. 6 in the case of the apparatus shown in FIG. For example, the opening degree of the lever 1a (the opening degree of the valve with respect to the operation angle of the lever) is 80%, the opening degree of the lever 1b is 50%,
If the lever 1c is operated at the opening of 50% at the same time,
In S3, the operation angles of the respective levers are input, and in S6, the power supply capacity required for valve operation according to the operation angles of the levers operated simultaneously is calculated. The result is 80% +
50% + 50% = 180%, so it is 2 in S8
It is determined that the capacity of the continuous DC transformer is within the capacity, and in S14, the data corresponding to the opening degree of the valve with respect to the operation angle of each lever is output to each valve 2a, 2b, 2c. Here, it is assumed that the lever 1d is operated on the lever and the opening of the lever 1d is 70%. In this case, S6
The calculation result in 80% + 50% + 50% + 70% = 2
Since it will be 50%, if all the valves are operated according to the operating angle of the lever, the capacity of the DC transformer for two stations will be exceeded. Therefore, in S15, 2 stations (2
(00%) power supply capacity for each lever 1a, 1b, 1c, 1d
According to the operating angle of the lever,
a is 64%, lever 1b is 40%, lever 1c is also 40%
%, The lever 1d becomes 56%, and the data corresponding to the power source capacity thus allocated in S16 is output. If all valves are operated simultaneously at such a ratio, the required power supply capacity will be 200% for two stations, and the operating capacity of each valve will decrease, but all the valves corresponding to the operated lever will operate. At least, it will not be perceived as a failure, and the DC transformer will be used 100% effectively.
The present invention comprises a mode controlled by the priority setting and selection means in the inventions described in claims 1 to 4 and a mode controlled by the distribution means in the invention described in claim 4, Either one can be selected according to the preference of the operator.

[0016]

According to the present invention, in an industrial machine having a plurality of levers, it is possible to reduce the capacity of the DC transformer, downsize the controller, and reduce the cost. Further, the lever operation is based on the priority order, and the workability is not sacrificed by giving priority to the lever having a high degree of importance. Further, by allocating the power source capacity according to the opening degree of each operation lever, it becomes possible to drive the valves corresponding to all the lever operations.

[Brief description of drawings]

FIG. 1 is an explanatory diagram in which a control device of the present invention is implemented in a forklift.

2A is a map of a digital output for each operation lever angle, b is a map of a current value output from the D / A converter corresponding to the digital output, and c is a flow rate controlled according to the current value. It is an explanatory view showing each map

FIG. 3 is a flowchart of a control example.

FIG. 4 is an explanatory diagram of a modified example.

FIG. 5 is a flowchart of a modified example.

FIG. 6 is a flowchart of a modification example.

FIG. 7 is an explanatory diagram of a conventional example.

[Explanation of symbols]

A ... Controller, 1, 1a, 1b, 1c, 1d ...
Lever, 2, 2a, 2b, 2c, 2d ... Valve, 3 ...
・ DC transformer, 4 ・ ・ Battery power supply, 5 ・ ・ Drive driver, 6 ・ ・ DC transformer, 7 ・ ・ CPU, 8 ・ ・ A / D converter, 9,9a, 9b, 9c, 9d ・ ・ D / A converter, 10, 10a, 10b, 10c, 10d ... Constant current amplifier, 11 ... ROM, 12 ... RAM, S1
S16 ... Step.

Claims (5)

[Claims] 1. The capacity of a DC transformer is set small relative to the power supply capacity required to fully open all valves at the same time, priority is set for each valve operating lever, and a plurality of levers are operated simultaneously. Of the operated levers,
A control device for an electromagnetic valve in an industrial machine, comprising a sorting means for enabling only the operation of the lever selected according to the priority and invalidating the operation of the other levers. 2. The capacity of the DC transformer is set small relative to the power supply capacity required to fully open all the valves at the same time, and the lever priority for operating each valve and the capacity of the DC transformer operate simultaneously. When the number of levers that can be operated is set and multiple levers are operated simultaneously, only the operation of the levers that can be operated simultaneously from the highest priority of each operated lever is valid, and the other levers are operated. A control device for an electromagnetic valve in an industrial machine, which is provided with a sorting means to be invalidated. 3. The capacity of the DC transformer is made small with respect to the power supply capacity required to fully open all the valves at the same time, the priority of each valve operating lever is set, and a plurality of levers are operated simultaneously. In this case, the power supply capacity required for valve operation corresponding to the operated angle of each operated lever is added according to the priority order, and only the lever operation within the range where the added value does not exceed the capacity of the DC transformer is effective. The control device for an electromagnetic valve in an industrial machine, which is equipped with a selecting means that determines that the lever operation is invalid. 4. When a lever higher in priority than the lever is operated while the valve is operating by the operation of the lever judged to be effective, the selecting means gives priority to the operation of the higher lever operated. A control device for an electromagnetic valve in an industrial machine according to any one of claims 1 to 3. 5. When the capacity of the DC transformer is small with respect to the power supply capacity required to fully open all the valves at the same time and a plurality of levers are operated at the same time, all the operated levers are to be operated. A control device for an electromagnetic valve in an industrial machine, comprising a distribution means for allocating a power supply capacity required for each valve operation within a capacity range of the DC transformer at a ratio according to an operation angle of each lever.