JP3781584B2 - Control device for hybrid construction machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hybrid construction machine such as a hybrid excavator that performs various operations by combining an engine and a battery.
[0002]
[Prior art]
Construction machines such as excavators are generally configured to drive an actuator by an engine. In this configuration, it is necessary to perform work while greatly varying the engine output so as to cope with large load fluctuations during work. Therefore, there is a problem in terms of environmental efficiency such as noise and exhaust gas.
[0003]
Therefore, in recent years, an electric motor or a generator is connected to the engine, and part or all of the engine output is converted into electric power. There have been developed and proposed hybrid construction machines and their control devices that sometimes take out electric power from a battery and use it for heavy load work (Japanese Utility Model Laid-Open No. 5-48501). And if it is this structure, as shown, for example in FIG. 6, since the fluctuation | variation part of work load (work energy) can be smoothed by charging / discharging of a battery, work load (work energy) fluctuated significantly. Even in this case, fluctuations in the engine output can be suppressed to a minimum, and as a result, it is possible to achieve good fuel efficiency, low noise, and reduced exhaust gas.
[0004]
[Problems to be solved by the invention]
By the way, in the control device for a hybrid construction machine in which the engine and the battery are combined as in the conventional case, the engine is stopped when the battery is charged to a predetermined value or more in order to prevent deterioration due to overcharging of the battery. It is necessary to perform an operation to interrupt or reduce the charging of the battery by reducing the engine output or reducing the engine output. At this time, for example, in the case of an excavator, there are various types of work with greatly different loads such as excavation, horizontal leveling, earthing, and spreading (see FIG. 4). ). Therefore, when the engine output (the amount of power generated by the battery) is stopped or decreased, if work with a large workload is suddenly performed, the work is performed mainly using the electric power discharged from the battery. There is a problem of excessive discharge and early deterioration.
[0005]
Therefore, when working when the engine output (battery power generation amount) is stopped or decreasing, the work speed is limited until the engine output (battery power generation amount) returns to the predetermined value. Therefore, it is conceivable to take a method of reducing the work load and preventing excessive discharge of the battery. However, in this case, the work speed in all work modes is uniformly limited corresponding to the work with the maximum work load, so that there is a problem that work efficiency is greatly reduced.
[0006]
Therefore, according to the present invention, when the operation is performed when the engine output (the amount of power generated by the battery) is stopped or decreased, the deterioration of the work efficiency is minimized while preventing deterioration due to excessive discharge of the battery. The present invention provides a control device for a hybrid construction machine that can be used.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is capable of charging a battery with electric power of a generator driven by an engine, and operating the electric motor with electric power of at least one of the generator and the battery. In a control device for a workable hybrid construction machine, when the power of the generator is less than or equal to a predetermined value, the work speed is limited according to the work content so that the power consumption of the motor does not cause overdischarge of the battery. It is characterized by having working speed limiting means.
[0008]
According to the above configuration, when the electric power of the generator driven by the engine is equal to or lower than a predetermined value as in the case where the engine is stopped or idling, the engine is sufficiently rotated and the generator A predetermined delay time occurs until sufficient power is obtained. In the period of this delay time, the work of each work content is performed mainly using the electric power discharged from the battery. Therefore, when working with a large work load, if the work is performed at a normal work speed, the battery is excessively discharged and deteriorates. However, in the configuration of the present invention, the work speed limiting means is included in the work content. Accordingly, the battery is not deteriorated due to overdischarge because the battery is prevented from being overdischarged by limiting the work speed accordingly.
[0009]
Furthermore, since the work speed is limited according to the work content so that the electric power consumption of the motor does not cause overdischarge, the work speed of each work content should be set to the maximum value within the range that does not cause overdischarge. Can do. Therefore, in the case of work contents with a small work load, work can be performed at almost the same work speed as the normal work speed, and thus the work speed is uniformly limited for all work contents as in the past. It is possible to obtain higher work efficiency than the case, and as a result, it is possible to minimize a decrease in work efficiency due to limiting the work speed.
[0010]
Invention of Claim 2 is the control apparatus of the hybrid construction machine of Claim 1, Comprising: The said operation content is discriminate | determined based on the operation lever operated by the operator, and the operation signal from the said operation lever, and the said And a work discriminating section for outputting to the work speed limiting means.
According to the above configuration, since the work content can be determined and recognized based on the operation signal of the operation lever, it is possible to save labor for the operator to specify the work content.
[0011]
According to a third aspect of the present invention, there is provided the hybrid construction machine control device according to the first aspect, wherein a work content changeover switch capable of designating the work content by an operator and a work content designated by the work content changeover switch are detected. And a changeover switch detector for outputting to the working speed limiting means.
According to said structure, since the work content designated as the work content changeover switch can be recognized with high reliability, excessive discharge of the main battery due to erroneous recognition can be reliably prevented.
[0012]
A fourth aspect of the present invention is the hybrid construction machine control device according to any one of the first to third aspects, wherein the hybrid construction machine is a hybrid excavator.
According to said structure, it can apply suitably with respect to the hybrid shovel which implements the various work content which has the work load of a large fluctuation range.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 3, the control device according to the present embodiment is provided in a hybrid excavator that is a hybrid construction machine. In the following description, a hybrid excavator that employs a series hybrid system will be described, but the present invention can also be applied to a hybrid excavator that employs a parallel hybrid system. The hybrid excavator includes a lower traveling body 1, an upper revolving body 2 that is turnable at the center of the upper surface of the lower traveling body 1, and a excavation attachment 3 that is provided at the front of the upper revolving body 2. ing. The lower traveling body 1 is provided with a pair of crawler frames 4 arranged in parallel at both ends, a crawler 5 that is rotatably provided around each crawler frame 4 and that contacts the ground surface in a plane, and rotates the crawler 5. It has drive speed reducers 35 and 36 and electric motors 6 and 7. The undercarriage 1 configured as described above is configured so that each crawler 5 is individually rotated in the forward direction and the reverse direction by the electric motors 6 and 7 via the speed reducers 35 and 36, so that the entire excavator is placed on the ground. Move forward, backward, rotate, and turn.
[0014]
At the center of the upper surface of the lower traveling body 1, a turning shaft 8 a is provided orthogonal to the lower traveling body 1. A turning frame 8 constituting a part of the upper turning body 2 is rotatably provided on the upper part of the turning shaft 8a. The upper surface of the swivel frame 8 is provided with a cabin 9 serving as an operator's cockpit and a machine housing portion 41 covered with a protective cover 40, and the boom 17 and boom cylinder 18 of the excavation attachment 3 described above. One end of each of the two is pivotable in the vertical direction.
[0015]
In the machine housing portion 41, a turning electric motor 13 and a reduction gear 14 are provided, and a boom integrated actuator A1 provided with an integrated boom electric motor 15 and boom pump 16 is provided. The turning electric motor 13 drives the turning frame 8 through the speed reducer 14 with the turning shaft 8a as the turning center. The boom-integrated actuator A1 is connected to the boom cylinder 18 described above via a hydraulic pipe (not shown), and the boom rod 18 is moved forward and backward by hydraulic pressure to move the tip of the boom 17 (others). Move the end side up and down.
[0016]
An arm 19 is rotatably provided at the tip of the boom 17. A bucket 21 is rotatably provided at the tip of the arm 19. The boom 17 and the arm 19 are connected via an arm cylinder 20, and the arm 19 and the bucket 21 are connected via a bucket cylinder 22. These cylinders 20 and 22 are respectively provided with an arm-integrated actuator A2 and a bucket-integrated actuator A3. The actuators A2 and A3 are integrated with electric motors 23 and 25 and pumps 24 and 26, respectively. Configured. And each actuator A2 * A3 rotates the arm 19 and the bucket 21 to an up-down direction, respectively, by moving the cylinder rod of cylinder 20 * 22 forward / backward with oil_pressure | hydraulic.
[0017]
In addition to the turning electric motor 13 and the boom-integrated actuator A1, the generator 10 that generates AC power corresponding to the rotational speed (engine output) of the engine 10 and the engine 10 is included in the machine housing portion 41 described above. 11. A main battery 12 used during normal operation, an auxiliary battery 42 used in an emergency when the main battery 12 becomes unusable, and the like are provided. The batteries 12 and 42 are secondary batteries that can be repeatedly charged and discharged, such as lead acid batteries and nickel metal hydride batteries.
[0018]
The generator 11 is connected to a motor controller 37 of the control device as shown in FIG. The motor controller 37 is connected to the various electric motors 6, 7, 13, 15, 23, and 25 described above, and is connected to the main battery 12 and the auxiliary battery 42 via the changeover switch 43. The changeover switch 43 includes three systems of switch units 43a to 43c that can be switched in two directions, and the two systems of switch units 43a and 43b are used for charging the main battery 12 and switching its stop, The remaining one-system switch unit 43 c is used for switching between discharging from the main battery 12 and discharging from the auxiliary battery 42. The changeover switch 43 is set so that all the switch parts 43a to 43c connect the main battery 12 and the motor controller 37 during normal operation, and the switch parts 43a and 43b are connected to the main battery 12 in an emergency. The switch 43c is switched manually or automatically so that the auxiliary battery 42 and the motor controller 37 are connected.
[0019]
An operation signal system 44 is connected to the motor controller 37. The operation signal system 44 includes an operation lever 45 provided in the cabin 9 of FIG. 3, a work determination unit 46 that determines a work mode (work content) based on an operation signal from the operation lever 45, and a work speed limit unit. 47. The work speed limiting unit 47 is connected to the operation lever 45 and the work determination unit 46, and is also connected to a power detector 48 that detects the power consumption of the motors 6, 7, 13, 15, 23, and 25. . Then, the work speed limiting unit 47 executes the operation signal correction routine of FIG. 2, and based on the operation signal, the work mode signal, the power consumption signal, etc. input from each unit 46, 45, 48, In order to prevent overdischarge, the operation signal is output to the motor controller 37 while limiting the operation signal according to the work mode under a predetermined condition.
[0020]
The motor controller 37 converts AC power from the generator 11 into DC power, a power conversion function (inverter function) that converts DC power from the batteries 12 and 42 into AC power, and an operation signal system 44. For example, the motor operating function for outputting the AC power obtained by converting the power from the main battery 12 to each of the motors 6, 7, 13, 15, 23, and 25 based on the operation signal, and the power generated by the generator 11 as the main It has various functions such as a normal charging mechanism that charges the battery 12, and a regenerative charging function that charges the main battery 12 with regenerative power generated by the motors 6, 7, 13, 15, 23, and 25. It is arbitrarily executed based on the charge amount of the main battery 12, the power generation amount of the generator 11, the work mode, and the like.
[0021]
In the above configuration, the operation of the hybrid excavator control device will be described.
When the operator in the cabin 9 in FIG. 3 performs a starting operation such as rotating the operation key, when the motor controller 37 is powered on and the engine 10 is operated, the motor controller 37 is The amount of charge of the battery 12 is confirmed. If the amount of charge is insufficient, the main battery 12 is charged by converting the AC power generated by the generator 11 driven to rotate by the engine 10 into DC power. If the charge amount of the main battery 12 is extremely insufficient, the output of the engine 10 (rotational speed) is increased to increase the power generation amount of the generator 11, thereby quickly charging the main battery 12. Do. On the other hand, if the charge amount of the main battery 12 is sufficient, the output (rotation speed) of the engine 10 is set to the lowest idling state, or the engine 10 is stopped while preventing the main battery 12 from being excessively charged, Wait until an operation signal is input from the operation signal system 44.
[0022]
Next, when the operator operates the operation lever 45 so as to perform a predetermined work, an operation signal corresponding to the operation amount is output from the operation lever 45. The operation signal is input to the work determination unit 46 and the work speed limit unit 47, respectively. Then, the work determination unit 46 extracts the feature of the operation signal and determines the work. As the work discrimination method, for example, the one disclosed in Japanese Patent Laid-Open No. 9-217702 is used.
[0023]
The work mode recognized by the work determination unit 46 as described above is output to the work speed limiting unit 47. At this time, as shown in FIG. 3, the work speed limiting unit 47 executes an operation signal correction routine, and when an operation signal is input from the operation lever 45, this operation signal is output to the motor controller 37 as it is. To do. Then, by operating the motors 6, 7, 13, 15, 23, and 25 corresponding to the operation signal with the operation amount of the operation signal to the motor controller 37 in the standby state, for example, excavator traveling or excavation, Each work such as striking is performed (S1).
[0024]
Thereafter, whether or not the engine 10 is in a stopped state or an idling state is determined based on, for example, the amount of power generated by the generator 11 (S2). When the engine 10 is driving the generator 11 at a sufficient rotational speed (S2, NO), by using the large power from the generator 11 and the power from the main battery 12, Since the work can be performed without limiting the speed, S1 is re-executed and the operation signal is output to the motor controller 37 as it is to continue the work. On the other hand, when the engine 10 is in a stopped state or idling state (S2, YES), the electric power discharged from the main battery 12 is mainly used until the engine 10 reaches a predetermined rotational speed. Then, the operations after S3 are executed so as to prevent deterioration of the main battery 12 due to excessive discharge.
[0025]
That is, the power consumption of the motors 6, 7, 13, 15, 23, and 25 is acquired via the power detector 48 (S3), and the total value of power consumption is calculated (S4). Then, the set value set in advance so as to prevent excessive discharge of the main battery 12 is compared with the above total value, and it is determined whether or not the total value is equal to or greater than the set value (S5). If the total value is not greater than or equal to the set value (S5, NO), even if the operation is continued by operating the electric motors 6, 7, 13, 15, 23, 25 with the current operation signal, the main battery 12 is excessive. Since it can be determined that there is no damage due to a simple discharge, the operation is resumed from S1 and the operation is continued at the operation speed corresponding to the operation signal of the operation lever 45.
[0026]
On the other hand, when the total value of the power consumption is equal to or larger than the set value (S5, YES), the work mode (work content) input from the work determination unit 46 is taken in (S6), and this work mode is supported. Select the limit value. As shown in FIG. 4, the limit value corresponding to the work mode varies greatly depending on the work mode (work content) and the load level varies greatly. Therefore, the limit value corresponding to the work mode is based on the reference discharge amount that does not deteriorate the main battery 12. It is a value set individually according to the work mode. For example, in the case of a work mode with a large load fluctuation or load level such as traveling or excavation, the rotational speed (working speed) of the electric motors 6, 7, 13, 15, 23, and 25 is greatly reduced from that during normal operation. On the other hand, in the case of a small load fluctuation or load level work mode such as hanging work, the rotational speed (work speed) of the motors 6, 7, 13, 15, 23, 25 is set during normal operation. The limit value is set so as to decrease slightly (S7).
[0027]
When the limit value corresponding to the work mode is selected as described above, as shown in FIG. 1, the operation signal from the operation lever 45 is fetched (S8), and the operation amount with the limit value as the upper limit is obtained. After the correction, an operation signal is output to the motor controller 37 (S9). As a result, even if the operator operates the operation lever 45 to reach the maximum speed, the work is performed at the work speed (power consumption) of the limit value, so that the main battery 12 is not deteriorated due to excessive discharge. Absent. In addition, since the limit value of each work mode is set based on the reference discharge amount, in the work mode with a small load, the work can be performed at almost the same work speed as the normal work speed. Therefore, it is possible to minimize a decrease in efficiency as a whole work.
[0028]
Thereafter, it is determined whether or not to continue the restriction of the operation signal based on the rotation speed of the engine 10 and the power generation amount of the generator 11 (S10). When the engine 10 rotates at a sufficient rotation speed and the work can be performed without overdischarge of the main battery 12 even if the work speed is not limited by the power generation amount of the generator 11 and the discharge amount of the main battery 12, It is determined that the restriction of the operation signal is finished (S10, NO). Then, S1 is re-executed, and the operation signal is output to the motor controller 37 as it is to perform the operation at a normal operation speed. On the other hand, when the rotational speed of the engine 10 and the power generation amount of the main battery 12 are insufficient, it is determined that the restriction of the operation signal is continued (S10, YES), and deterioration due to excessive discharge of the main battery 12 is prevented. Therefore, it re-executes from S8. Then, by outputting to the motor controller 37 while restricting the operation amount, the operation is continued at the suppressed operation speed.
[0029]
As described above, the hybrid excavator control device of the present embodiment can charge the main battery 12 with the electric power of the generator 11 driven by the engine 10, and at least one of the generator 11 and the main battery 12. When the electric motor 6 or the like can be operated by electric power, and the electric power of the generator 11 is less than a predetermined value that may cause the main battery 12 to overdischarge, the main battery 12 is overdischarged. It is the structure which has the work speed restriction | limiting part 47 (work speed limit means) which restrict | limits a work speed according to work mode (work content) so that it may become the power consumption of the electric motor 6 etc. which does not produce.
[0030]
According to said structure, when the electric power of the generator 11 driven with the engine 10 is below a predetermined value like the case where the engine 10 is a stop state or an idling state, the engine 10 is fully A predetermined delay time occurs until sufficient power is obtained from the generator 11 by rotating. In the period of the delay time, the work is performed mainly using the electric power discharged from the main battery 12. Therefore, when working with a large work load, if the work is performed at a normal work speed, the main battery 12 is excessively discharged and deteriorates. However, in the above configuration, the work speed limiting means is used for the work. Accordingly, the main battery 12 is not deteriorated due to overdischarge because the main battery 12 is prevented from being overdischarged by limiting the work speed accordingly.
[0031]
Furthermore, since the work speed is limited according to the work so that the electric power consumption of the electric motor 6 and the like that does not cause overdischarge is limited, the work speed of each work should be set to the maximum value in a range that does not cause overdischarge. Can do. Therefore, in the case of work with a small work load, work can be performed at almost the same work speed as the normal work speed, so that the work speed is uniformly limited for all work as in the past. However, high work efficiency can be obtained, and as a result, a reduction in work efficiency due to limiting work speed can be minimized.
[0032]
In addition, the control device for the hybrid excavator of the present embodiment includes an operation lever 45 operated by an operator, and a work determination unit 46 that determines a work mode (work content) based on an operation signal from the operation lever 45. It has been configured. According to this configuration, since the work mode can be determined and recognized based on the operation signal of the operation lever 45, the labor for the operator to specify the work mode can be saved.
[0033]
In the control device of the present embodiment, the work determination unit 46 recognizes the work mode based on the operation signal of the operation lever 45, but is not limited to this. That is, as shown in FIG. 5, the control device detects the work mode switching switch 49 that allows the operator to specify the work mode and the work mode designated by the switch 49, thereby setting the work mode (work content). A changeover switch detection unit 50 that recognizes and outputs the motor speed correction unit 47 may be used. In this case, since the work mode can be recognized with high reliability, excessive discharge of the main battery 12 due to erroneous recognition can be reliably prevented.
[0034]
Further, the control device of the present embodiment can be suitably applied to a hybrid excavator that implements various work modes having a work load with a large fluctuation range, but is not limited to this, and a bulldozer It can be applied to all hybrid construction machines that can perform a plurality of work contents such as a crane and a crane.
[0035]
【The invention's effect】
The invention of claim 1 is capable of charging a battery with electric power of a generator driven by an engine and controlling a hybrid construction machine capable of working by operating an electric motor with electric power of at least one of the generator and the battery. In the apparatus, when the power of the generator is equal to or less than a predetermined value, the apparatus has a work speed limiting means for limiting the work speed according to the work content so that the power consumption of the electric motor does not cause overdischarge of the battery. is there.
[0036]
According to the above configuration, the work speed limiter prevents the battery from being overdischarged by limiting the work speed according to the work content, so that the battery does not deteriorate due to overdischarge. In addition, since the work speed of each work content can be set to the maximum value that does not cause overdischarge, the work speed is higher than when the work speed is uniformly limited for all work contents as in the past. Efficiency can be obtained, and as a result, the effect that the fall of work efficiency by restricting work speed can be suppressed to the minimum is produced.
[0037]
Invention of Claim 2 is the control apparatus of the hybrid construction machine of Claim 1, Comprising: The said operation content is discriminate | determined based on the operation lever operated by the operator, and the operation signal from the said operation lever, and the said And a work determination unit that outputs to the work speed limiting means.
According to the above configuration, since the work content can be determined and recognized based on the operation signal of the operation lever, it is possible to save labor for the operator to specify the work content.
[0038]
According to a third aspect of the present invention, there is provided the hybrid construction machine control device according to the first aspect, wherein a work content changeover switch capable of designating the work content by an operator and a work content designated by the work content changeover switch are detected. And a changeover switch detector for outputting to the working speed limiting means.
According to said structure, since the work content designated by the work content changeover switch can be recognized with high reliability, it is possible to reliably prevent excessive discharge of the main battery due to erroneous recognition. .
[0039]
A fourth aspect of the present invention is the hybrid construction machine control device according to any one of the first to third aspects, wherein the hybrid construction machine is a hybrid excavator.
According to said structure, there exists an effect that it can apply suitably with respect to the hybrid shovel which implements the various work content which has the work load of a large fluctuation range.
[Brief description of the drawings]
FIG. 1 is a block diagram of a control device of a hybrid excavator.
FIG. 2 is a flowchart of an operation signal correction routine.
FIG. 3 is an overall schematic side view of a hybrid excavator.
FIG. 4 is an explanatory diagram showing load characteristics in each work mode.
FIG. 5 is a block diagram of a drive control system of a hybrid excavator.
FIG. 6 is an explanatory diagram showing a state of charge / discharge of a battery when working in a hybrid system.
[Explanation of symbols]
1 Lower traveling body
2 Upper swing body
3 Excavation attachment
4 Crawler frame
5 Crawler
8 Swivel frame
9 cabin
10 engine
11 Generator
12 Main battery
13 Electric motor for turning
14 Reducer
15 Boom motor
16 Boom pump
17 Boom
18 Boom cylinder
19 Arm
20 Arm cylinder
21 bucket
22 Bucket cylinder
23 Electric motor for arm
24 Arm pump
41 Machine housing
42 Auxiliary battery
43 selector switch
44 Operation signal system
45 Control lever
46 Work discrimination part
47 Working speed limiter
48 Power detector
49 Work mode selector switch
50 selector switch detector

Claims (4)

In a control device for a hybrid construction machine that can charge a battery with electric power of a generator driven by an engine and can operate by operating an electric motor with electric power of at least one of the generator and the battery,
A working speed limiting means is provided for limiting the working speed according to the work content so that the electric power consumption of the electric motor does not cause overdischarge of the battery when the electric power of the generator is less than or equal to a predetermined value. Control device for hybrid construction machinery. An operating lever operated by an operator;
2. The control device for a hybrid construction machine according to claim 1, further comprising: a work determination unit that determines the work content based on an operation signal from the operation lever and outputs the work content to the work speed limiting means. A work content changeover switch that allows the operator to designate the work content;
2. The control device for a hybrid construction machine according to claim 1, further comprising a changeover switch detection unit that detects the work content designated by the work content changeover switch and outputs the work content to the work speed limiting means. The control apparatus for a hybrid construction machine according to any one of claims 1 to 3, wherein the hybrid construction machine is a hybrid excavator.

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