阅读说明：本技术 可变容量泵控制装置、泵系统以及可变容量泵控制方法 (Variable displacement pump control device, pump system, and variable displacement pump control method ) 是由 赤见俊也 于 2020-11-10 设计创作，主要内容包括：本发明涉及一种可变容量泵控制装置、泵系统以及可变容量泵控制方法。本发明的一个方式是一种可变容量泵控制装置,该可变容量泵控制装置被用于根据斜板的倾斜角度来改变喷出容量的可变容量泵,该可变容量泵控制装置具备存储部和控制部,所述存储部存储外部空气的信息即外部空气信息,所述控制部基于所述外部空气信息来控制所述可变容量泵所具备的所述斜板的倾斜角度。(The present invention relates to a variable displacement pump control device, a pump system, and a variable displacement pump control method. One aspect of the present invention is a variable displacement pump control device used for a variable displacement pump that changes a discharge displacement in accordance with an inclination angle of a swash plate, the variable displacement pump control device including a storage unit that stores outside air information that is information on outside air, and a control unit that controls the inclination angle of the swash plate included in the variable displacement pump based on the outside air information.)

1. A variable displacement pump control device for a variable displacement pump for changing the discharge displacement in accordance with the inclination angle of a swash plate,

the variable displacement pump control device is provided with a storage unit and a control unit,

the storage unit stores outside air information that is information on outside air,

the control unit controls an inclination angle of the swash plate included in the variable capacity pump based on the outside air information.

2. The variable capacity pump control apparatus of claim 1,

the control unit includes an outside air information acquisition unit for acquiring the outside air information,

the storage unit stores relationship information that is information indicating a relationship between an inclination angle of the swash plate and the outside air information,

the control unit controls the inclination angle of the swash plate based on the outside air information with reference to the relationship information.

3. The variable capacity pump control apparatus of claim 2,

the control unit further includes a learning unit that learns the relationship information based on information indicating a history of the outside air information and information indicating a history of an inclination angle of the swash plate.

4. The variable capacity pump control apparatus of claim 1,

the control unit further includes a construction time estimation unit that estimates a construction time of the construction machine operated by the variable displacement pump based on a history of the outside air information, a history of an inclination angle of the swash plate, and information on the current outside air.

5. The variable capacity pump control apparatus of claim 2,

the control unit further includes a construction time estimation unit that estimates a construction time of the construction machine operated by the variable displacement pump based on a history of the outside air information, a history of an inclination angle of the swash plate, and information on the current outside air.

6. The variable capacity pump control apparatus of claim 3,

the control unit further includes a construction time estimation unit that estimates a construction time of the construction machine operated by the variable displacement pump based on a history of the outside air information, a history of an inclination angle of the swash plate, and information on the current outside air.

7. The variable capacity pump control apparatus according to any one of claims 1 to 3,

the control unit controls suction horsepower of the variable capacity pump based on the outside air information and information related to operation of a device provided in the construction machine operated by the variable capacity pump.

8. The variable capacity pump control apparatus according to any one of claims 4 to 6,

the control unit controls suction horsepower of the variable displacement pump based on information on operation of a device provided in the construction machine.

9. The variable capacity pump control apparatus of claim 8,

the device provided in the construction machine includes an air conditioner.

10. The variable capacity pump control apparatus according to any one of claims 1 to 6,

the information about the outside air includes any one of oxygen concentration, air pressure, and altitude.

11. The variable capacity pump control apparatus of claim 7,

the information about the outside air includes any one of oxygen concentration, air pressure, and altitude.

12. The variable capacity pump control apparatus of claim 8,

the information about the outside air includes any one of oxygen concentration, air pressure, and altitude.

13. The variable capacity pump control apparatus according to any one of claims 1 to 6,

the control unit further includes an outside air information acquisition unit that acquires information relating to the outside air based on position information indicating a position of a machine operated by the variable displacement pump and information indicating a relationship between an altitude and the position indicated by the position information.

14. The variable capacity pump control apparatus of claim 7,

the control unit further includes an outside air information acquisition unit that acquires information relating to the outside air based on position information indicating a position of a machine operated by the variable displacement pump and information indicating a relationship between an altitude and the position indicated by the position information.

15. The variable capacity pump control apparatus of claim 8,

the control unit further includes an outside air information acquisition unit that acquires information relating to the outside air based on position information indicating a position of a machine operated by the variable displacement pump and information indicating a relationship between an altitude and the position indicated by the position information.

16. The variable capacity pump control apparatus of claim 13,

the location information is information acquired by a global positioning system.

17. A pump system is provided with:

a variable capacity pump control apparatus according to any one of claims 1 to 16;

the variable displacement pump, the operation of which is controlled by the variable displacement pump control device; and

and a construction machine operated by the variable capacity pump.

18. A variable capacity pump control method used for a variable capacity pump that changes a discharge capacity in accordance with an angle of a swash plate, the variable capacity pump control method comprising:

a storage step of storing outside air information, which is information of outside air; and

and a control step of controlling an inclination angle of the swash plate included in the variable capacity pump based on the outside air information.

Technical Field

The present invention relates to a variable displacement pump control device, a pump system, and a variable displacement pump control method.

Background

Construction machines used in civil engineering sites are sometimes used in plateaus. In such a case, since the oxygen concentration of the plateau is lower than that of the plain, the power generated by the engine to operate the construction machine is lower in the plateau than in the plain. Therefore, there is a problem that the working efficiency of the construction machine is lower than that of the plain machine depending on the height. In order to solve such a problem, a structure has been proposed so far which restricts the discharge amount of the pump and utilizes the pump (see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2008-240518

Disclosure of Invention

Problems to be solved by the invention

However, in the proposed method, the discharge amount of the pump can be optimized only for two predetermined heights such as those in plains and plateaus. Therefore, the proposed method cannot solve the problem of the reduction in the work efficiency of the construction machine for a height other than the predetermined height.

In view of the above, an object of the present invention is to provide a variable displacement pump control device, a pump system, and a variable displacement pump control method that suppress a decrease in the work efficiency of a construction machine according to the height.

Means for solving the problems

One aspect of the present invention is a variable displacement pump control device used for a variable displacement pump that changes a discharge displacement in accordance with an inclination angle of a swash plate, the variable displacement pump control device including a storage unit that stores outside air information that is information on outside air, and a control unit that controls the inclination angle of the swash plate included in the variable displacement pump based on the outside air information.

Therefore, even if the height at which the construction machine operated by the variable capacity pump performs work is not a predetermined height, the pump control device can suppress a decrease in the work efficiency of the construction machine.

In the above-described variable displacement pump control device, the control unit may include an outside air information acquisition unit configured to acquire the outside air information, the storage unit may store relationship information that is information indicating a relationship between the inclination angle of the swash plate and the outside air information, and the control unit may control the inclination angle of the swash plate based on the outside air information with reference to the relationship information.

In the above-described variable displacement pump control device, the control unit may further include a learning unit that learns the relationship information based on information indicating a history of the outside air information and information indicating a history of an inclination angle of the swash plate.

In the above-described variable displacement pump control device, the control unit may further include a construction time estimation unit that estimates a construction time of the construction machine operated by the variable displacement pump based on a history of the outside air information, a history of an inclination angle of the swash plate, and information on the current outside air.

In the above-described variable displacement pump control device, the control unit may control suction horsepower of the variable displacement pump based on the outside air information and information on operation of a device provided in the construction machine operated by the variable displacement pump.

In the above-described variable displacement pump control device, the device provided in the construction machine may include an air conditioner.

In the above-described variable displacement pump control device, the information on the outside air may include any one of an oxygen concentration, an air pressure, and an altitude.

In the above-described variable displacement pump control device, the variable displacement pump control device may further include an outside air information acquisition unit that acquires information relating to the outside air based on position information indicating a position of a machine operated by the variable displacement pump and information indicating a relationship between an altitude and the position indicated by the position information.

In the above-described variable displacement pump control device, the position information may be information acquired by a Global Positioning System (GPS).

One aspect of the present invention is a pump system including: the variable displacement pump control device described above; the variable displacement pump, the operation of which is controlled by the variable displacement pump control device; and a construction machine that is operated by the variable capacity pump.

Therefore, according to the pump system, even if the height at which the construction machine performs work is not a predetermined height, it is possible to suppress a decrease in the work efficiency of the construction machine.

One aspect of the present invention is a variable displacement pump control method used for a variable displacement pump that changes a discharge displacement in accordance with an angle of a swash plate, the variable displacement pump control method including: a storage step of storing outside air information, which is information of outside air; and a control step of controlling an inclination angle of the swash plate included in the variable capacity pump based on the outside air information.

Therefore, according to the variable displacement pump control method, even if the height at which the construction machine operated by the variable displacement pump performs work is not a predetermined height, it is possible to suppress a decrease in the work efficiency of the construction machine.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a variable displacement pump control device, a pump system, and a variable displacement pump control method that suppress a decrease in the operating efficiency of a construction machine according to the height.

Drawings

Fig. 1 is a diagram illustrating an example of a functional configuration of a pump system according to an embodiment.

Fig. 2 is a diagram illustrating an example of a functional configuration of a control unit in the embodiment.

Fig. 3 is a flowchart showing an example of a process flow of controlling the operation of the hydraulic pump by the outside air sensor, the electromagnetic proportional valve, and the pump control device in the embodiment.

Fig. 4 is a diagram showing an example of a functional configuration of the control unit in the first modification.

Fig. 5 is a diagram showing an example of a functional configuration of a control unit in a second modification.

Fig. 6 is a diagram showing an example of the electromagnetic proportional valve 2, the outside air sensor, and the pump control device which are communicably connected via a network in the third modification.

Fig. 7 is a diagram showing an example of a functional configuration of a pump system in a fourth modification.

Fig. 8 is a diagram showing an example of a functional configuration of a control unit in a fourth modification.

Fig. 9 is a diagram showing an example of a functional configuration of a control unit in a fifth modification.

Description of the reference numerals

100. 100 a: a pump system; 1: a hydraulic pump; 2: an electromagnetic proportional valve; 3: an external air sensor; 4. 4a, 4 b: a pump control device; 11: a pump body; 12: a sloping plate; 13: a tilt actuator; 40. 40a, 40b, 40c, 40 d: a control unit; 41: a storage unit; 42: a communication unit; 43: an input section; 44: an output section; 401: an outside air information acquisition unit; 402. 402 a: an inclination angle determining part; 403: a valve control section; 404: a recording unit; 405: a construction machine control unit; 406. 406 a: a learning unit; 407: a construction time estimation unit; 408: an air conditioning information acquisition unit; 9: a network; 901. 901a, 901 b: a construction machine; 902: a personal computer; 903: an air conditioning device.

Detailed Description

(embodiment mode)

Fig. 1 is a diagram illustrating an example of a functional configuration of a pump system 100 according to an embodiment.

The pump system 100 includes a construction machine 901. The construction machine 901 includes a hydraulic pump 1, an electromagnetic proportional valve 2, an outside air sensor 3, and a pump control device 4.

The hydraulic pump 1 is a pump that converts power of an engine into hydraulic power. The hydraulic pump 1 includes a pump body 11, a swash plate 12 provided in the pump body 11, and a tilt actuator 13 that controls an inclination angle of the swash plate 12. The pump body 11 converts the power of the engine into hydraulic power. In the pump body 11, the magnitude of suction horsepower (discharge amount), which is horsepower of a portion of the power generated by the engine and absorbed by the hydraulic pump 1, is a magnitude corresponding to the inclination angle of the swash plate 12. The construction machine 901 operates so that the suction horsepower of the hydraulic pump 1 does not exceed the power generated by the engine.

The electromagnetic proportional valve 2 is controlled by the pump control device 4 to control the operation of the tilt actuator 13. Specifically, the electromagnetic proportional valve 2 controls the hydraulic pressure supplied to the tilt actuator 13 by the control of the pump control device 4. The electromagnetic proportional valve 2 controls the operation of the tilt actuator 13 by controlling the hydraulic pressure supplied to the tilt actuator 13.

The outside air sensor 3 acquires information of outside air (hereinafter referred to as "outside air information"). The outside air information includes, for example, any one of oxygen concentration, air pressure, and altitude.

The pump control device 4 includes a control Unit 40, and the control Unit 40 includes a processor 91 such as a CPU (Central Processing Unit) and a memory 92 connected by a bus. In the control unit 40, the processor 91 executes a program stored in the memory 92 in advance. The pump control device 4 functions as a device including the storage unit 41, the communication unit 42, the input unit 43, the output unit 44, and the control unit 40 by execution of a program.

The storage unit 41 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The storage unit 41 stores various information used for processing by the control unit 40. The various information is, for example, information stored in advance in the storage unit 41 and indicating a relationship between the inclination angle of the swash plate 12 and the outside air information. Hereinafter, information indicating the relationship between the inclination angle of the swash plate 12 and the outside air information is referred to as first relationship information. The first relationship information may be any information as long as it is information indicating the relationship between the outside air information and the inclination angle of the swash plate 12. For example, the first relationship information may be a numerical expression representing the relationship between the altitude and the inclination angle of the swash plate 12. For example, the first relationship information may be information indicating a relationship between the air pressure and the inclination angle of the swash plate 12. For example, the first relationship information may be information indicating a relationship between the oxygen concentration and the inclination angle of the swash plate 12. For example, the first relationship information may be information indicating a relationship between the altitude and the air pressure and the inclination angle of the swash plate 12. For example, the first relationship information may be information indicating the relationship between the altitude and the oxygen concentration and the inclination angle of the swash plate 12. For example, the first relationship information may be information indicating a relationship between the gas pressure and the oxygen concentration and the inclination angle of the swash plate 12. For example, the first relationship information may be information indicating a relationship between the altitude, the atmospheric pressure, and the oxygen concentration and the inclination angle of the swash plate 12.

The storage unit 41 stores, for example, outside air information. The storage unit 41 stores, for example, a history of the outside air information. The storage unit 41 stores, for example, a history of the inclination angle of the swash plate 12.

The communication unit 42 is configured to include a communication interface for connecting the present apparatus to an external apparatus. An example of the external device is the electromagnetic proportional valve 2. An example of the external device is an external air sensor 3. The communication unit 42 communicates with an external device by wire or wireless.

The input unit 43 includes an input device such as a keyboard or a touch panel. The input unit 43 may be configured as an interface for connecting these input devices to the present apparatus. The input unit 43 receives various commands and information input to the apparatus. The various commands are commands to start communication by the communication unit 42, for example. The various commands are, for example, commands for outputting predetermined information by the output unit 44. The various commands are commands for a predetermined action of the construction machine 901, for example. For example, in the case where the construction machine is a power shovel, the predetermined operation for the construction machine 901 may be an operation for moving an arm. For example, when the construction machine is a mobile body, the predetermined operation for the construction machine 901 may be an operation such as movement.

The output unit 44 is configured to include a display device such as a CRT (Cathode Ray Tube) display, a liquid crystal display, or an organic EL (Electro-Luminescence) display. The output unit 44 may be configured as an interface for connecting these display devices to the present apparatus. The output unit 44 outputs, for example, information indicating a history of control by the control unit 40. The output unit 44 outputs various information stored in the storage unit 41, for example.

The control unit 40 controls the operation of the electromagnetic proportional valve 2 based on the outside air information acquired by the outside air sensor 3. The control unit 40 controls not only the operation of the hydraulic pump 1 but also the operation of the construction machine 901 including the hydraulic pump 1.

Fig. 2 is a diagram illustrating an example of a functional configuration of the control unit 40 in the embodiment. The control unit 40 includes an outside air information acquisition unit 401, a tilt angle determination unit 402, a valve control unit 403, a recording unit 404, and a construction machine control unit 405.

The outside air information acquisition unit 401 acquires outside air information from the outside air sensor 3. The tilt angle determination unit 402 refers to the first relationship information to acquire the tilt angle corresponding to the outside air information acquired by the outside air information acquisition unit 401. The valve control unit 403 controls the operation of the electromagnetic proportional valve 2 so that the inclination angle of the swash plate 12 is the inclination angle of the swash plate 12 determined by the inclination angle determination unit 402.

The recording unit 404 records various information in the storage unit 41. For example, the recording unit 404 records the tilt angle determined by the tilt angle determining unit 402 in the storage unit 41. The recording unit 404 records, for example, the outside air information acquired by the outside air sensor 3 in the storage unit 41. The construction machine control unit 405 controls the operation of the construction machine 901.

Fig. 3 is a flowchart showing an example of a process flow of controlling the operation of the hydraulic pump 1 by the outside air sensor 3, the electromagnetic proportional valve 2, and the pump control device 4 in the embodiment.

The outside air sensor 3 acquires outside air information (step S101). The control unit 40 acquires the outside air information acquired in step S101 (step S102). The control unit 40 refers to the first relationship information stored in the storage unit 41 to acquire the inclination angle corresponding to the outside air information acquired in step S102 (step S103). The control unit 40 controls the inclination angle of the swash plate 12 to the inclination angle acquired in step S103 by controlling the operation of the electromagnetic proportional valve 2 (step S104).

This concludes the description of fig. 3.

The pump control device 4 configured as described above includes the control unit 40, and the control unit 40 controls suction horsepower of the hydraulic pump 1 based on the outside air information. As described above, since the pump control device 4 controls the suction horsepower of the hydraulic pump 1 based on the outside air information, it is possible to suppress a decrease in the work efficiency of the construction machine 901 even if the height at which the construction machine 901 performs work is not a predetermined height.

In addition, the hydraulic pump 1 is a swash plate type piston pump including a swash plate 12, and the control unit 40 controls the inclination angle of the swash plate 12. Therefore, even if the height at which the construction machine 901 performs work is not a predetermined height, the pump control device 4 can more efficiently suppress a decrease in the work efficiency of the construction machine 901.

In addition, the control unit 40 refers to relationship information that is predetermined information indicating a relationship between the inclination angle of the swash plate 12 and the outside air information, and controls the inclination angle of the swash plate 12 to the inclination angle of the swash plate 12 corresponding to the outside air information acquired by the outside air information acquisition unit 401. Therefore, even if the height at which the construction machine 901 performs work is not a predetermined height, the pump control device 4 can further effectively suppress a decrease in the work efficiency of the construction machine 901.

And, in addition to this, the outside air information is oxygen concentration, air pressure, or altitude. Therefore, even if the height at which the construction machine 901 performs work is not a predetermined height, the pump control device 4 can further effectively suppress a decrease in the work efficiency of the construction machine 901.

The pump system 100 configured as described above includes the control unit 40, and the control unit 40 controls suction horsepower of the hydraulic pump 1 based on the outside air information. In this way, the pump system 100 controls the suction horsepower of the hydraulic pump 1 based on the outside air information, and therefore, even if the height at which the construction machine 901 performs work is not a predetermined height, it is possible to suppress a decrease in the work efficiency of the construction machine 901.

(first modification)

The first relationship information may be a learning result learned by machine learning in advance. For example, the first relationship information may be a learning result learned by machine learning by the control unit 40. Hereinafter, the control unit 40 that learns the first relationship information by machine learning is referred to as a control unit 40 a. Further, machine learning also includes deep learning.

Fig. 4 is a diagram showing an example of the functional configuration of the control unit 40a in the first modification.

The pump control device 4 includes a control unit 40a instead of the control unit 40. The control unit 40a is different from the control unit 40 in that it includes a learning unit 406. In the following, functional units having the same functions as those of the respective functional units included in the control unit 40 are denoted by the same reference numerals as those in fig. 2, and the description thereof will be omitted.

The learning portion 406 learns the first relationship information based on the history of the outside air information and the history of the inclination angle of the swash plate 12. The first relationship information stored in the storage unit 41 is updated by the first relationship information learned by the learning unit 406.

This concludes the description of fig. 4.

The pump control device 4 of the first modification configured as described above includes the learning unit 406, and the learning unit 406 learns the relationship information based on the information indicating the history of the outside air information and the information indicating the history of the inclination angle of the swash plate 12. Therefore, even if the height at which the construction machine 901 performs work is not a predetermined height, the pump control device 4 can suppress a decrease in the work efficiency of the construction machine 901 more efficiently than the effect of the above-described embodiment.

(second modification)

The control unit 40 may estimate the construction time of the construction machine 901. Hereinafter, the control unit 40 that estimates the construction time of the construction machine is referred to as a control unit 40 b. The control unit 40b may further include a learning unit 406.

Fig. 5 is a diagram showing an example of a functional configuration of the control unit 40b in the second modification.

The pump control device 4 includes a control unit 40b instead of the control unit 40. The control unit 40b is different from the control unit 40 in that it includes the construction time estimation unit 407. In the following, functional units having the same functions as those of the respective functional units included in the control unit 40 are denoted by the same reference numerals as those in fig. 2, and the description thereof will be omitted.

The construction time estimation unit 407 estimates the construction time of the construction machine 901 equipped with the hydraulic pump 1 based on the history of the outside air information, the history of the inclination angle of the swash plate 12, and the current outside air-related information. The information on the current outside air is the outside air information closest to the time point at which the construction time estimation unit 407 starts estimating the construction time, among the outside air information acquired by the outside air sensor 3 before the construction time estimation unit 407 starts estimating the construction time.

This concludes the description of fig. 5.

The pump control device 4 of the second modification configured as described above includes the working time estimation unit 407, and the working time estimation unit 407 estimates the working time of the construction machine 901 based on the history of the outside air information, the history of the inclination angle of the swash plate 12, and the current outside air-related information. Therefore, the user of the pump control device 4 can make an efficient work plan.

(third modification)

The pump control device 4 may be mounted using a plurality of information processing devices. In this case, each functional unit included in the pump control device 4 may be mounted in a distributed manner on a plurality of information processing devices. For example, the outside air information acquisition unit 401, the tilt angle determination unit 402, the valve control unit 403, the recording unit 404, and the construction machine control unit 405 may be mounted on different information processing devices. The electromagnetic proportional valve 2, the outside air sensor 3, and the pump control device 4 may be communicably connected via a network.

Fig. 6 is a diagram showing an example of the electromagnetic proportional valve 2, the outside air sensor 3, and the pump control device 4 which are communicably connected via a network in the third modification.

In fig. 6, the construction machine 901a includes the electromagnetic proportional valve 2, the outside air sensor 3, the storage unit 41, the communication unit 42, the input unit 43, the output unit 44, and the construction machine control unit 405, and does not include the outside air information acquisition unit 401, the inclination angle determination unit 402, the valve control unit 403, and the recording unit 404. In fig. 6, the pump control device 4a is different from the pump control device 4 only in that it does not include the construction machine control unit 405. The construction machine 901 can communicate with the pump control device 4a via the network 9. The pump control device 4a acquires the outside air information acquired by the outside air sensor 3 via the network 9. The pump control device 4 controls the operation of the electromagnetic proportional valve 2 via the network 9. When the pump control device 4a includes the construction time estimation unit 407, the pump control device 4a can estimate the construction time based on the outside air information acquired via the network 9 and the history of the control of the electromagnetic proportional valve 2. The estimation result of the construction time estimated by the pump control device 4a is output to the personal computer 902 via the interfaces provided in the input unit 43 and the output unit 44.

Further, only the construction machine 901a is not necessarily provided with the outside air sensor 3. The outside air sensor 3 may be located at any position as long as it can communicate with the pump control device 4a via the network 9. The pump control device 4a may acquire outside air information from a plurality of outside air sensors 3 located at different positions. The pump control device 4a may include a learning unit 406 or a construction time estimation unit 407.

This concludes the description of fig. 6.

(fourth modification)

The construction machine 901 and the construction machine 901a may also include an air conditioner. Next, a case where the construction machine 901 is provided with an air conditioner will be described as an example. In such a case, the control unit 40 may control the inclination angle of the swash plate 12 based on not only the outside air information but also the outside air information and information on the operation of the air conditioner provided in the construction machine 901. Hereinafter, information related to the operation of the air conditioner provided in the construction machine is referred to as air conditioning information. The air conditioning information may indicate, for example, whether the air conditioner has started operating. The air conditioning information may indicate that the operation of the air conditioner is the energy saving mode, for example. The energy saving mode is an operation with less power than a predetermined power. The air conditioning information may indicate that the operation of the construction machine 901a is the operation in the energy saving mode, for example. The operation of the construction machine 901a in the energy saving mode is specifically an operation of performing a work with a relatively small load by suppressing the absorption of horsepower by the hydraulic pump. Hereinafter, the control unit 40 that controls the inclination angle of the swash plate 12 based on the outside air information and the air conditioning information is referred to as a control unit 40 c. Hereinafter, construction machine 901 provided with an air conditioner is referred to as construction machine 901 b.

Fig. 7 is a diagram showing an example of a functional configuration of a pump system 100a in a fourth modification. The pump system 100a includes a construction machine 901 b. The construction machine 901b differs from the construction machine 901 in that a pump control device 4b is provided instead of the pump control device 4, and an air conditioner 903 is provided. The air conditioner 903 can communicate with the pump control device 4b through the communication unit 42.

The pump control device 4b is different from the pump control device 4 in that a control unit 40c is provided instead of the control unit 40. The storage unit 41 included in the pump control device 4b stores the second relationship information in place of the first relationship information indicating the relationship between the outside air information and the inclination angle of the swash plate 12. The second relationship information is information indicating the relationship between the outside air information and the air conditioning information and the inclination angle of the swash plate 12.

Fig. 8 is a diagram showing an example of a functional configuration of the control unit 40c in the fourth modification.

The control unit 40c differs from the control unit 40 in that it includes an air conditioning information acquisition unit 408 and a tilt angle determination unit 402a instead of the tilt angle determination unit 402.

The air conditioning information acquisition unit 408 acquires air conditioning information. The air conditioning information acquisition unit 408 acquires air conditioning information by communicating with the air conditioner 903 via the communication unit 42. The inclination angle determining unit 402a determines the inclination angle of the swash plate 12 based on the second relationship information stored in the storage unit 41, the air conditioning information acquired by the air conditioning information acquiring unit 408, and the outside air information acquired by the outside air sensor 3.

This concludes the description of fig. 8.

The control unit 40c of the fourth modification configured as described above controls suction horsepower of the hydraulic pump 1 based on the outside air information and the air conditioning information. Therefore, the pump control device 4 can control the suction horsepower of the hydraulic pump 1 based on the load generated by the operation of the air conditioner, and can suppress the reduction in the work efficiency of the construction machine 901 more efficiently than the effect of the above-described embodiment.

The air conditioning apparatus according to the fourth modification is an example of an apparatus provided in a construction machine. The pump control device 4 does not necessarily control the suction horsepower of the hydraulic pump 1 based on the load generated by the operation of the air conditioner. The pump control device 4 may control suction horsepower of the hydraulic pump 1 based on a load generated by a device other than the air conditioner provided in the construction machine.

(fifth modification)

Fig. 9 is a diagram showing an example of a functional configuration of the control unit 40d in the fifth modification. The control unit 40d is different from the control unit 40c in that it includes the learning unit 406 a. The learning portion 406a learns the second relationship information based on the history of the outside air information, the history of the air conditioning information, and the history of the inclination angle of the swash plate 12. The second relationship information stored in the storage unit 41 is updated by the second relationship information learned by the learning unit 406 a. Hereinafter, the control unit 40c including the learning unit 406a is referred to as a control unit 40 d.

This concludes the description of fig. 9.

The operation of the hydraulic pump 1 is affected by the operation of the air conditioner 903. The pump system 100a having the control unit 40c or the control unit 40d controls the inclination angle of the swash plate 12 based on not only the outside air information but also air conditioning information which is information related to the operation of the air conditioner 903. Therefore, in the case where the construction machine includes an air conditioner, the pump systems 100a of the fourth modification and the fifth modification configured as described above can suppress a decrease in the work efficiency of the construction machine more than the pump system 100.

For example, the outside air information is not limited to the above information, and may include humidity.

The outside air information acquisition unit 401 may acquire outside air information based on position information acquired by, for example, a GPS (Global Positioning System). The position information indicates the position of a machine such as the construction machines 901, 901a, and 901b that is operated by the hydraulic pump 1. For example, in the case where the outside air information is the altitude, the outside air information acquisition unit 401 may acquire the altitude of the position where the construction machines 901, 901a, and 901b are located, based on information indicating the relationship between the altitude and the position indicated by the position information, which is stored in advance, and the position information acquired by the GPS. In this case, the construction machines 901, 901a, and 901b acquire the position information acquired by the GPS via the communication unit 42, for example. Information indicating the relationship between the altitude and the position indicated by the position information is stored in the storage unit 41 in advance, for example.

The control unit 40c and the control unit 40d may include a construction time estimation unit 407.

The hydraulic pump 1 may be any hydraulic pump as long as it is a variable displacement pump that generates power. The hydraulic pump 1 may be a variable displacement pump that includes a swash plate and changes a discharge capacity according to an angle of the swash plate. For example, the hydraulic pump 1 may be a swash plate type piston pump. The first relationship information is an example of relationship information. The pump control device 4, the pump control device 4a, and the pump control device 4b are examples of variable displacement pump control devices.

All or part of the functions of the pump control Device 4, the pump control Device 4a, and the pump control Device 4b may be implemented by hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The program may be recorded in a computer-readable recording medium. Examples of the computer-readable recording medium include a removable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk incorporated in a computer system. The program may also be transmitted via an electrical communication line.

While the embodiments of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to the embodiments, and the present invention may be designed without departing from the scope of the present invention.