Work machine

A work machine in which an engine and a reserving unit configured to reserve lubricating oil to be supplied to the engine are connected by a lubricating oil channel, and the lubricating oil is circulated, wherein at least a part of the lubricating oil channel and at least a part of a working fluid channel for a working fluid to be supplied to a work unit of the work machine are arranged such that heat can be exchanged between the lubricating oil and the working fluid.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a work machine.

Description of the Related Art

PTL 1 discloses an engine oil circulation control apparatus. More specifically, there is disclosed a configuration in which, in an engine mounted in an automobile or the like, the other end of a hydraulic pipe3connected to an oil tank1is connected to a suction port5aof an oil pump5, and sucked lubricating oil is ejected from a discharge port5bto a piston, a crankshaft36, and the like via an oil supply passage.

Also disclosed is providing an oil cooler11configured to cool the lubricating oil to an appropriate temperature when it is heated by the piston and the like and becomes hot. More specifically, a switching valve is controlled to make an inlet10afor the lubricating oil communicate with an outlet10cto the oil cooler and also block the inlet10afrom the oil cooler and an outlet10bfor the lubricating oil.

CITATION LIST

Patent Literature

The technique described in PTL 1 shows using engine cooling water as the heat medium of the oil cooler11. However, to quickly cool the lubricating oil to an appropriate temperature using the cooling water of the engine that becomes hot, a large amount of cooling water needs to be ensured, and there is room for improvement.

The present invention provides a technique for efficiently cooling lubricating oil for an engine.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided a work machine in which an engine and a reserving unit configured to reserve lubricating oil to be supplied to the engine are connected by a lubricating oil channel, and the lubricating oil is circulated, wherein at least a part of the lubricating oil channel and at least a part of a working fluid channel for a working fluid to be supplied to a work unit of the work machine are arranged such that heat can be exchanged between the lubricating oil and the working fluid.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

Configuration of Work Machine 1

FIG. 1is a view for explaining the configuration of a work machine according to the first embodiment. Referring toFIG. 1, reference numeral10denotes a work machine. The work machine10according to this embodiment is, for example, a high pressure washing machine. The work machine10includes a control unit100, an engine101, an output shaft102, a high pressure pump103, working fluid channels104aand104b, a work unit105, a reserving unit106, a support unit107, lubricating oil channels108aand108b, and a solenoid valve109.

The control unit100is, for example, a CPU, and is connected to the engine101and the solenoid valve109. The control unit100reads out a computer program stored in a memory (not shown) and executes it, thereby controlling the operations of these constituent elements. The engine101is connected to the high pressure pump103via the output shaft102and supplies a driving force to the high pressure pump103.

The engine101is connected, via the lubricating oil channels108aand108b, to the reserving unit106that reserves engine oil (lubricating oil) to be supplied to the engine101, and the lubricating oil can be circulated between the engine101and the reserving unit106.

The reserving unit106can reserve engine oil (lubricating oil). The reserving unit106is supported by the support unit107. Note that the reserving unit106may be an oil cartridge attachable/detachable to/from the support unit107.

The lubricating oil flowing out of the engine101flows into the support unit107via the lubricating oil channel108a. As shown inFIG. 1, at least a part of the lubricating oil channel108ais arranged in the support unit107and connected to the reserving unit106via the support unit107. The lubricating oil reserved in the reserving unit106flows into the engine101via the lubricating oil channel108b. The solenoid valve109can control the flow in the lubricating oil channel108aunder the control of the control unit100, and this can control the circulation of the lubricating oil.

On the other hand, reference numeral120denotes a working fluid, which is water in this embodiment. Reference numeral130denotes a working fluid supply unit, which is, for example, a home water supply. The working fluid120supplied from the working fluid supply unit130flows into the high pressure pump103via the working fluid channel104a. As shown inFIG. 1, at least a part of the working fluid channel104ais arranged in the support unit107and connected to the high pressure pump103via the support unit107. The working fluid120then undergoes high pressure processing by the high pressure pump103and is guided to the work unit105via the working fluid channel104b. An operator operates the work unit105and blows the working fluid120against a target, thereby performing a work. Here, the work unit105is, for example, an operation unit configured to perform high pressure washing using the working fluid120.

As shown inFIG. 1, in the work machine10according to this embodiment, at least a part of the lubricating oil channel108aand at least a part of the working fluid channel104aare arranged to exchange heat between the lubricating oil and the working fluid120, and a heat exchange unit110is thus formed.

Hence, when a new working fluid (heat medium) is always supplied to the heat exchange unit110in the support unit107, the lubricating oil in the lubricating oil channel108acan efficiently be cooled. In addition, the apparatus configuration can be simplified by using the working fluid channel used for a work.

Configuration of Lower Portion of Support Unit

An example of the arrangement configuration of a part of the lubricating oil channel108aand a part of the working fluid channel104ain the support unit107will be described next with reference toFIGS. 2A and 2B.

FIG. 2Ashows an example of the lubricating oil channel108aand the working fluid channel104aarranged in the support unit107in a planar view of the reserving unit106and the support unit107shown inFIG. 1viewed vertically from above. On the other hand,FIG. 2Bshows an example of a part of the lubricating oil channel108aand a part of the working fluid channel104aarranged in the support unit107in a side view of the reserving unit106and the support unit107shown inFIG. 1.

As shown inFIGS. 2A and 2B, in the support unit107, a part of the lubricating oil channel108ais arranged planarly while folding back a plurality of times so that a first plane is formed. A part of the working fluid channel104ais also similarly arranged planarly while folding back a plurality of times so that a second plane is formed. Hence, the first plane and the second plane are arranged adjacently in parallel. According to this arrangement configuration, since the length in which the planarly arranged working fluid channel104aand the planarly arranged lubricating oil channel108aare arranged in parallel to be adjacent to each other can be increased, the heat exchange efficiency can further be improved. Also, since the internal space of the support unit107that supports the reserving unit106can be used, the lubricating oil (engine oil) can efficiently be cooled without making the work machine bulky.

Additionally, according to the arrangement example shown inFIGS. 2A and 2B, the second plane formed by the working fluid channel104ais arranged close to (vertically above) the reserving unit106, as compared to the first plane formed by the lubricating oil channel108a. Since this can shorten the distance between the working fluid channel104aand the reserving unit106, heat exchange between the lubricating oil reserved in the reserving unit106and the working fluid120in the working fluid channel104acan be more efficiently performed. It is therefore possible to further improve the cooling efficiency of the lubricating oil (engine oil).

As described above, in the work machine according to this embodiment, at least a part of the lubricating oil channel and at least a part of the working fluid channel are arranged to exchange heat between the lubricating oil and the working fluid. Hence, when a new working fluid (a heat medium such as water) is always supplied, the lubricating oil in the lubricating oil channel can efficiently be cooled.

Second Embodiment

Configuration of Work Machine

FIG. 3is a view for explaining the configuration of a work machine according to the second embodiment. Referring toFIG. 3, reference numeral30denotes a work machine. The work machine30according to this embodiment is, for example, a blower vacuum used to clean fallen leaves or a riding type lawn mower capable of blowing mowed pieces of grass into a grass bag and storing those.

The work machine30includes a control unit300, an engine301, an output shaft302, a blower unit303, a working fluid channel304, a solenoid valve305, a reserving unit306, a support unit307, a heat dissipation fin308, and lubricating oil channels309aand309b.

The control unit300is, for example, a CPU, and is connected to the engine301and the solenoid valve305. The control unit300reads out a computer program stored in a memory (not shown) and executes it, thereby controlling the operations of these constituent elements. The engine301is connected to the blower unit303via the output shaft302and supplies a driving force to the blower unit303.

A working fluid310(for example, air) blown by the blower unit303flows through the working fluid channel304.

The engine301is connected, via the lubricating oil channels309aand309b, to the reserving unit306that reserves engine oil (lubricating oil) to be supplied to the engine301, and the lubricating oil can be circulated between the engine301and the reserving unit306. The solenoid valve305can control the flow in the lubricating oil channel309aunder the control of the control unit300, and this can control the circulation of the lubricating oil.

The reserving unit306can reserve engine oil (lubricating oil). The reserving unit306is supported by the support unit307. Note that the reserving unit306may be an oil cartridge attachable/detachable to/from the support unit307. The support unit307includes the heat dissipation fin308, and the heat dissipation fin308are formed to project into the working fluid channel304. Via the heat dissipation fin308, heat can be exchanged between the lubricating oil flowing in the lubricating oil channel309aand the working fluid310flowing in the working fluid channel304. A heat exchange unit311is thus formed. Hence, when a new working fluid (heat medium) is always supplied to the heat exchange unit311, the lubricating oil in the lubricating oil channel309acan efficiently be cooled. In addition, the apparatus configuration can be simplified by using the working fluid channel used for a work.

Note that as in the example shown inFIGS. 2A and 2Bof the first embodiment, at least a part of the lubricating oil channel309amay be arranged planarly while folding back a plurality of times so that a plane is formed. Since this makes many parts of the lubricating oil channel309aclose to the working fluid channel304, the efficiency of heat exchange between the lubricating oil and the working fluid310can be further improved.

As described above, in the work machine according to this embodiment, at least a part of the lubricating oil channel and at least a part of the working fluid channel are arranged to exchange heat between the lubricating oil and the working fluid. Hence, when a new working fluid (a heat medium such as air) is always supplied, the lubricating oil in the lubricating oil channel can efficiently be cooled.

Third Embodiment

Configuration of Work Machine

FIG. 4is a view for explaining the configuration of a work machine according to the third embodiment. Referring toFIG. 4, reference numeral40denotes a work machine. The work machine40according to this embodiment is, for example, a high pressure washing machine. The same reference numerals as those of the above-described constituent elements denote the same constituent elements inFIG. 4, and a detailed description thereof will be omitted.

In this embodiment, a working fluid channel404ais provided in place of the working fluid channel104adescribed with reference toFIG. 1. In addition, a working fluid channel402is arranged in a part of the working fluid channel404a. A working fluid (for example, water) supplied from a working fluid supply unit130flows into a high pressure pump via the working fluid channel404a.

Also, in this embodiment, a lubricating oil channel408aand a lubricating oil channel408bare provided in place of the lubricating oil channel108adescribed with reference toFIG. 1, and a solenoid valve409aand a solenoid valve409bare provided in place of the solenoid valve109. Engine oil (lubricating oil) flows from an engine101to a reserving unit106via the lubricating oil channel408aor the lubricating oil channel408bin accordance with switching by the solenoid valve409aand the solenoid valve409b.

Opening/closing of the solenoid valve409aand the solenoid valve409bis controlled under the control of a control unit100. The control unit100controls the solenoid valve409aand the solenoid valve409bbased on the temperature of the lubricating oil detected by a temperature sensor401. For example, if the temperature detected by the temperature sensor401has a predetermined value or more, the lubricating oil needs to be cooled. Hence, the solenoid valve409aand the solenoid valve409bare controlled to make a change such that the lubricating oil passes through the lubricating oil channel408b. On the other hand, if the temperature is less than the predetermined value, the lubricating oil need not be cooled. Hence, the solenoid valve409aand the solenoid valve409bare controlled to make a change such that the lubricating oil passes through the lubricating oil channel408a.

In this embodiment, a part of the lubricating oil channel408bis covered to be included in the working fluid channel402. A double-tube structure is formed, as indicated by a section taken along a line A-A. When a heat exchange unit410is formed in this way, the cooling efficiency of the lubricating oil can be improved.

FIG. 5is a view for explaining the configuration of a work machine according to a modification of the third embodiment. Referring toFIG. 5, reference numeral50denotes a work machine. The work machine50according to this embodiment is, for example, a high pressure washing machine. The same reference numerals as those of the above-described constituent elements denote the same constituent elements inFIG. 5, and a detailed description thereof will be omitted.

The work machine50has almost the same configuration as the work machine40described with reference toFIG. 4. In this embodiment, a part of the lubricating oil channel408bis arranged to be adhered to the working fluid channel402. For example, these can be adhered by, for example, brazing. By the adhering, a contact structure is formed, as indicated by a section taken along a line B-B. When a heat exchange unit510is formed in this way, the cooling efficiency of the lubricating oil can be improved.

Fourth Embodiment

FIG. 6is a view for explaining the configuration of a work machine according to the fourth embodiment. Referring toFIG. 6, reference numeral60denotes a work machine. The work machine60according to this embodiment is, for example, a high pressure washing machine, but may be a blower vacuum or a riding type lawn mower described in the second embodiment with reference toFIG. 3. The same reference numerals as those of the above-described constituent elements denote the same constituent elements inFIG. 6, and a detailed description thereof will be omitted.

In the work machine60, engine oil (lubricating oil) flows from an engine101to a reserving unit106via a lubricating oil channel408aor a lubricating oil channel408bin accordance with switching by a solenoid valve409aand a solenoid valve409b, as in the configurations described with reference toFIGS. 4 and 5.

Here, since the lubricating oil channel408bincludes a heat dissipation fin608, heat can efficiently be exchanged between outside air and the lubricating oil in the lubricating oil channel408b. It is therefore possible to improve the cooling efficiency of the lubricating oil. Since the portion of the heat dissipation fin608can freely be located at a position where air flows, this configuration can readily be applied to work machines of various structures. Also, if the work machine according to this embodiment is a blower vacuum or a riding type lawn mower described in the second embodiment, the lubricating oil channel408band the heat dissipation fin608may be arranged to project into the channel where the working fluid (a heat medium such as air) flows. This allows the lubricating oil to exchange heat not only with outside air but also with the working fluid (air).

Note that even in the double-tube structure or the contact structure described in the third embodiment, when a heat dissipation fin is provided inside or outside the tube, or an uneven shape is formed, more efficient heat exchange can be implemented. This can further improve the cooling efficiency of the lubricating oil.

MODIFICATIONS

Note that in the above-described embodiments, several examples in which the lubricating oil channel and the working fluid channel are arranged such that heat can be exchanged between the lubricating oil and the working fluid have been described. However, the manner in which the arrangement configuration is implemented is not limited to the shown examples. What is only needed is to make at least parts of the channels close to each other, and it is not essential that the channels are parallel to each other.

Additionally, in the configurations of the work machines described in the above embodiments, not all the constituent elements are indispensable. Some constituent elements may not be included, and another constituent element may be added.

As examples of the work machine, a high pressure washing machine has been described as an example of water cooling, and a blower vacuum and a riding type lawn mower have been described as examples of air cooling. However, work machines to which the present invention is applicable are not limited to these examples, and the present invention can be applied to various other work machines as well.

Summary of Embodiments

A work machine (for example,10,30) according to the first aspect is

a work machine in which an engine (for example,101,301) and a reserving unit (for example,106,306) configured to reserve lubricating oil are connected by a lubricating oil channel (for example,108a,108b,309a,309b), and the lubricating oil to be supplied to the engine is circulated, wherein

at least a part of the lubricating oil channel and at least a part of a working fluid channel (104a,104b,304) for a working fluid (for example,120,310) to be supplied to a work unit (for example,105) of the work machine are arranged such that heat can be exchanged between the lubricating oil and the working fluid.

Accordingly, a fluid (heat medium) used in a work is always newly supplied, thereby increasing the cooling efficiency of the lubricating oil in the lubricating oil channel. Also, when the channel of the fluid used in a work is used, the apparatus can be simplified.

In the work machine according to the second aspect,

the work machine comprises a support unit (for example,107,307) configured to support the reserving unit,

wherein at least the part of the lubricating oil channel is arranged in the support unit.

Accordingly, heat can be exchanged between the lubricating oil and the working fluid without extending the lubricating oil channel connected to the reserving unit more than needed.

In the work machine according to the third aspect,

at least the part of the working fluid channel is arranged in the support unit, and

at least the part of the lubricating oil channel and at least the part of the working fluid channel are arranged close in the support unit such that heat can be exchanged between the lubricating oil and the working fluid.

When the working fluid channel is also provided in the support unit in which the lubricating oil channel is provided, the lubricating oil channel and the working fluid channel can be arranged close, and the heat exchange efficiency (cooling efficiency) can be improved.

In the work machine according to the fourth aspect,

at least the part of the lubricating oil channel and at least the part of the working fluid channel are arranged adjacently in parallel in the support unit.

Since this can ensure a portion where the lubricating oil channel and the working fluid channel are close, the heat exchange efficiency (cooling efficiency) can be improved.

In the work machine according to the fifth aspect,

at least the part of the lubricating oil channel is arranged planarly to form a first plane in the support unit (for example,FIG. 2A),

at least the part of the working fluid channel is arranged planarly to form a second plane in the support unit (for example,FIG. 2A), and

the first plane and the second plane are arranged adjacently in parallel.

Since this can ensure many portions where the lubricating oil channel and the working fluid channel are close, the heat exchange efficiency (cooling efficiency) can further be improved.

In the work machine according to the sixth aspect,

the second plane is arranged close to the reserving unit as compared to the first plane (for example,FIG. 2B).

When the second plane formed by the part of the working fluid channel is arranged close to the reserving unit, not only heat exchange between the working fluid in the working fluid channel and the lubricating oil in the lubricating oil channel but also heat exchange between the working fluid in the working fluid channel and the lubricating oil reserved in the reserving unit can be performed. It is therefore possible to further improve the heat exchange efficiency.

In the work machine according to the seventh aspect,

the support unit includes a heat dissipation fin (for example,308) formed to project into the working fluid channel, and

heat can be exchanged between the lubricating oil and the working fluid via the heat dissipation fin.

When the heat dissipation fin is formed to project into the working fluid channel, the heat exchange efficiency between the working fluid and (the lubricating oil in the lubricating oil channel via) the support unit can be improved.

In the work machine according to the eighth aspect,

the reserving unit is attachable/detachable to/from the support unit.

This facilitates exchange of the reserving unit.

In the work machine according to the ninth aspect,

at least the part of the lubricating oil channel and at least the part of the working fluid channel form a double-tube structure (for example, A-A section,408b,402) in which at least the part of the lubricating oil channel passes an inside of at least the part of the working fluid channel.

Since this can ensure a portion where the lubricating oil channel and the working fluid channel are close, the heat exchange efficiency (cooling efficiency) can be improved.

In the work machine according to the 10th aspect,

at least the part of the lubricating oil channel and at least the part of the working fluid channel form a contact structure (for example, B-B section,408b,404b) in which the parts are in contact with each other by adhering along a channel.

Since this can ensure a portion where the lubricating oil channel and the working fluid channel are close, the heat exchange efficiency (cooling efficiency) can be improved.

In the work machine according to the 11th aspect,

at least the part of the lubricating oil channel includes a heat dissipation fin (for example,608), and

heat can be exchanged between the lubricating oil and one of the working fluid and outside air via the heat dissipation fin.

This can improve the heat exchange efficiency (cooling efficiency) between the lubricating oil and the working fluid or outside air.

According to the present invention, it is possible to efficiently cool lubricating oil for an engine.

Other Embodiments

A program configured to implement one or more functions described in each embodiment is supplied to a system or an apparatus via a network or a storage medium, and one or more processors in the computer of the system or the apparatus can read out and execute the program. The present invention can be implemented by such an aspect as well.