JP2013147893A - Work machine and arrangement structure for selector valve thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work machine having a selector valve, for allowing easy access to the selector valve, and for surely preventing the introduction of hot air from a selector valve arrangement part into a utility chamber and a radiator chamber when the work machine has a medium or small capacity.SOLUTION: A work machine 1 includes a revolving superstructure 3 having an engine 9, a front 4 mounted on the revolving superstructure, and an undercarriage 2 located below the revolving superstructure. A cab 6 is provided on the front part of the revolving superstructure, and a utility chamber 15 is formed behind the cab. A selector valve 10 is laid in an oil path connecting pilot valve units 97, 99 to which operation commands from the work machine are input to a hydraulic control valve 30 which operates in response to the operation commands, and the selector valve is arranged in the utility chamber. A heat shielding cover 52 storing at least part of the selector valve shields heat from the engine.

Description

  The present invention relates to a work machine such as a hydraulic excavator and a disposition structure of a switching valve provided in the work machine, and more particularly to a medium / small capacity work machine and a disposition structure of a change-over valve provided therein.

  In a work machine such as a hydraulic excavator, a pilot valve is operated by operating a plurality of operation levers provided in the cab, and a hydraulic control valve connected to the pilot valve is operated to operate various operation parts such as a boom and a bucket. Operate. Here, the correspondence between the operation direction of the operation lever and the operation of the actuators such as booms and buckets may differ depending on the manufacturer of the work machine. If different work machines are used, the operation direction of the operation lever is the same. However, there is a possibility that the actuators that operate are different, resulting in confusion for the operator. In order to eliminate such problems, a switching valve is arranged between the pilot valve and the hydraulic control valve. By switching this switching valve before work, the actuator is operated in the operating direction of the operating lever familiar to the operator. It is possible to correspond.

  A conventional example of this switching valve is described in Patent Document 1. In the construction machine described in Patent Document 1, effective arrangement of space and an optimum layout are realized by devising an arrangement structure of a switching valve that changes a connection relationship between a hydraulic control valve and a pilot valve. For this reason, a switching valve capable of switching the connection relationship between each pilot port of the hydraulic control valve and a plurality of pilot valves operated by the operation lever is provided between the pair of frame members of the tail frame and the hydraulic control valve is provided on the frame member. It is arranged on the upper flange on the side close to the operation lever.

  By the way, a utility machine may be formed in the work machine, and in that case, the utility room is often formed behind the cab. An example of effectively using this utility room is described in Patent Document 2. In the construction machine described in this publication, an engine controller is provided in the utility room to protect the engine controller from temperature changes and vibrations in the vicinity of the engine and improve maintainability.

JP 2001-262616 A JP 2007-170129 A Japanese Utility Model Publication No. 5-49858 (CD-ROM of Japanese Utility Model Application No. 3-108200)

  When there is a possibility of using different construction machines, using a construction machine having a switching valve and switching the switching valve before work is from the viewpoint of ease of work of the worker and improvement of safety. It is also important. For this reason, it is necessary for the worker to easily access the switching valve that is switched before the work.

  In the construction machine described in the above-mentioned Patent Document 1, because the switching valve is arranged near the hydraulic control valve, the space can be effectively utilized, but the engine is located in the substantially central part of the construction machine. It is difficult for an operator to work while standing on the ground near a construction machine. For this reason, the worker is forced to climb the construction machine.

  Moreover, even if it is attempted to switch the switching valve while standing by the construction machine for the reason of a small construction machine, from the viewpoint of safety, for example, as described in Patent Document 3, a malfunction at the time of switching the switching valve is prevented. Therefore, it is set not to be easily switched. In addition, it is necessary to be able to visually recognize the switching position. Therefore, it is essential to perform the switching operation close to the switching valve.

  Therefore, if the switching valve is disposed in the utility chamber formed behind the cab of the work machine, the switching valve can be switched while the operator is standing on the ground. That is, if the utility room is effectively used as described in Patent Document 2, it is possible to eliminate the difficulty of the switching operation of the switching valve and to confirm the switching contents.

  Since the construction machine described in Patent Document 2 is a relatively large construction machine, a utility room and a room in which a radiator and an oil cooler are arranged are partitioned by a partition wall. For this reason, hot air generated in a machine room or the like in which the engine is disposed is prevented from flowing into the utility room, and the temperature of the utility room is prevented from rising. However, in a small construction machine, it is difficult to secure a room partitioned as a utility room, and a room in which a radiator and an oil cooler are arranged must be integrated with a room. In that case, since the switching valve is disposed in a small space formed in the utility chamber portion, it is difficult to take measures for preventing heat intrusion.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to facilitate access to the switching valve in a work machine having a switching valve, and to use a switching valve even in a small work machine. The object is to reliably prevent hot air from being introduced from the placement section into the utility room (part) and the radiator room. Another object of the present invention is to easily recognize the switching operation of the switching valve in addition to the above-mentioned object.

  A feature of the present invention that achieves the above object is to provide an upper swing body in a work machine including an upper swing body having an engine, a front attached to the upper swing body, and a lower traveling body positioned below the upper swing body. A utility chamber is formed in the rear of the cab provided at the front of the machine, and the switching is interposed in the oil passage connecting the pilot valve unit to which the operation command of this work machine is input and the control valve unit that operates according to the operation command. A valve is disposed in the utility chamber, and heat from the engine is shielded by a heat shield cover that houses at least a part of the switching valve.

  In this feature, the heat insulating cover is provided with a hole for exposing the upper surface portion of the switching valve, and a heat insulating member is provided on the inner surface of the heat insulating cover to heat the gap exposed from the hole. May be. The heat shield cover has a lower cover and an upper cover, and the upper cover is removable from the lower cover. When the switching valve is switched, the upper cover is removed and switched. Also good.

  Another feature of the present invention that achieves the above-described object is an upper swing body having a cab on which an operator is boarded and on which an engine is mounted, a front mounted on the upper swing body, and a position below the upper swing body. In a switching valve arrangement structure used in a work machine having a lower traveling body, a switching valve is connected to a pilot valve unit provided in a cab and to which an operation command is input and a control valve unit that operates in accordance with the operation command. A switching valve is arranged in a utility chamber located in the oil passage and located behind the cab, and heat from the engine is shielded by a heat shielding cover that houses at least a part of the switching valve.

  According to the present invention, in a work machine having a switching valve, the switching valve is arranged in the utility chamber (part) behind the cab, and the switching valve body is covered with an easily removable cover or the switching valve is thermally partitioned by a heat insulating material. As a result, access to the switching valve is easy, and hot air is reliably prevented from being introduced into the utility room (part) and radiator room from the position of the switching valve, even for small and medium capacity work machines. it can. Moreover, since the switching valve is arranged in the utility room (part), the switching operation of the switching valve can be easily visually confirmed.

The side view of one Example of the working machine which concerns on this invention. FIG. 1B is a top view of the work machine shown in FIG. 1A. The perspective view of the working machine shown to FIG. 1A, and its A arrow directional view. The perspective view explaining arrangement | positioning of the switching valve and control valve in the working machine shown to FIG. 1A. FIG. 1B is a perspective view and a partial sectional front view of an embodiment of a switching valve provided in the work machine shown in FIG. 1A. It is a figure of other Examples of a switching valve, Comprising: The partial cross section front view.

  Hereinafter, an embodiment of a work machine according to the present invention will be described with reference to the drawings. In the following description, a small hydraulic excavator is taken up as a work machine, but the work machine is not limited to a hydraulic excavator, and the present invention is applied to various hydraulically driven work machines such as a wheel loader and various road machines. Applicable.

  FIG. 1A shows a side view of the excavator 1 according to the present invention, and FIG. 1B shows a top view of the excavator 1. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2, and is mounted on the lower traveling body 2 so as to be able to turn, and together with the lower traveling body 2, an upper revolving body 3 constituting a vehicle body of the hydraulic excavator 1, A front 4 is provided on the front side of the upper swing body 3 so as to be movable up and down. The excavator 1 is used for excavation work of earth and sand.

  The upper swing body 3 includes a swing frame 5 serving as a center of swing, a cab 6 mounted on the upper side of the swing frame 5 and on the front side, and a counter mounted on the rear side of the upper side of the swing frame 5. It has a weight 8 and an engine 9 located between the cab 6 and the counterweight 8. A heat exchanger 12 is disposed on the outside air intake side of the engine 9, and a hydraulic pump unit 19 is disposed on the exhaust side. A portion where the engine 9 and the like are arranged constitutes a machine room, and a part of the machine room is covered with a machine room cover 17. On the other hand, the side portion of the excavator 1 on the rear side of the cab 6 is covered with a building cover 11. The building cover 11 is a single-open type, and can be opened and closed with the end portion on the cab 6 side as the center of rotation.

  A turning motor 3A is disposed on the right side of the cab 6 and immediately behind the mounting portion of the front 4, and a hydraulic control valve 30 is disposed on the rear portion of the turning motor 3A. As will be described in detail later, the hydraulic control valve 30 is connected to a switching valve 10 disposed behind the cab 6 by piping.

  FIG. 2A is a perspective view of the excavator 1 shown in FIG. This is a state in which the single-opening type building cover 11 is opened. FIG. 2B shows a state behind the cab 6 with the building cover 11 opened. This FIG.2 (b) is A arrow view of Fig.2 (a). Behind the cab 6, a partition wall 14 forms a space partitioned from the cab 6.

  By the way, this space has been conventionally partitioned by a wall surface member into a utility room on the front side and a radiator chamber on the rear side. In this embodiment, since this is a small hydraulic excavator, this space is an integrated space without walls. Hereinafter, this space is referred to as a utility section or utility room 15.

  In the utility chamber 15, heat exchangers 12 such as an oil cooler, a radiator, and an intercooler are arranged in parallel on the rear side, and on the back side of these heat exchangers 12, that is, on the back side in FIG. Is provided with an engine 9. A switching valve 10 is arranged on the front side of the utility chamber 15, and an air cleaner 13 is arranged on the upper part of the front part. The outside air sucked from the air cleaner 13 is supplied to the engine 9.

  Here, the hydraulic piping system and the like of the switching valve 10 are shown in a perspective view in FIG. FIG. 3 is a diagram showing the structure of the frame 20. The frame 20 is erected on the floor steel plate 21 with a gap, and is provided at the center frame 25 composed of two vertical plates each provided with a mounting hole for the front 4 at the upper end portion, and at the rear portion of the center frame 25. The tail frame 23 provided with the flanges 22 on the upper and lower sides, the side frame 24 provided on the outermost side in the left-right direction, the center frame 25 and the tail frame 23, respectively, are provided in parallel with the center frame 25 and the tail frame 23. And a plurality of reinforcing beams connecting the side frames 24. A rectangular cab portion 6A that constitutes the floor surface of the cab 6 is formed at the forefront portion at a position formed between the left side frame 24 and the center frame 25 and the tail frame 23 in FIG. A utility chamber portion 15A is formed behind the portion 6A. Further, operation levers 96 and 98 for instructing each operation of the front 4 and the upper swing body 3 of the excavator 1 are arranged in parallel on the left and right at the foremost part of the cab 6A. Pilot valve units 97 and 99 are disposed at the bases of the operation levers 96 and 98, respectively. Note that beams 31 and 32 (see FIG. 4B and FIG. 5), which will be described later, are provided as reinforcing beams under the utility chamber 15A.

  A utility room 15 is defined between the cab 6A and the utility chamber 15A by a partition wall 14 indicated by a one-dot chain line provided in a reinforcing beam connecting the left side frame 24 and the center frame 25. ing. In the utility chamber portion 15A, the switching valve 10 is arranged as described above, and is connected by piping through the pilot valve units 97 and 99 and the hydraulic hose 26.

  An arrangement position of the engine 9 and the hydraulic control valve 30 is defined between the center frame 25 and the tail frame 23. The hydraulic control valve 30 is connected by piping with the switching valve 10 and the hydraulic hose 27 disposed in the utility chamber 15 </ b> A. The hydraulic hose 27 is piped so as to straddle the upper flange 23 of the tail frame 23.

  The center frame 25 also serves as a heat shield. The center frame 25, the tail frame 23, and each reinforcing beam are provided with brackets (not shown), and members such as the heat exchanger 12, the engine 9, and the hydraulic pump unit 19 are fixed to the frame 20 by the brackets. In addition, holes are formed in the floor steel plate 21, the center frame 25, the tail frame 23, and the reinforcing beam as necessary for the piping and wiring.

  As shown in FIG. 3, in this embodiment, the switching valve 10 is arranged in the middle of the piping system that connects the pilot valve units 97 and 99 and the hydraulic control valve 30. This is because when there are a plurality of work machines, the operation directions of the operation levers 96 and 98 are unified for all machines, or the operation levers 96 and 98 for the operator who operates the work machine 1 are easy to operate. This is because the driving direction is set as follows. That is, in order to improve workability by matching the operation direction familiar to the operator in the present situation where the moving direction of the operation levers 96 and 98 differs from the operation direction and operation direction of the front for each company.

  Therefore, the switching valve 10 is interposed between the pilot valve units 97 and 99 and the hydraulic control valve 30, and the switching valve is switched before the start of work or when the work machine 1 is introduced. Since the switching of the switching valve 10 determines the operation direction and start / stop of the front 4 and the turn, it is necessary to be able to execute the switching operation with certainty and to visually recognize the switching state. For this reason, in this embodiment, the utility room (part) 15 located behind the cab 6 is disposed near the floor.

  When the switching valve 10 is arranged in the utility chamber (part) 15, it is necessary to make a hole in the floor part for handling the hydraulic hose piping. In that case, the heat exchanger 12 is arranged in the utility chamber (part) 15. There is a possibility that hot air enters the heat exchanger 12 because it is not partitioned from the portion that is present. Moreover, although the air cleaner 13 is provided in the upper part of the utility chamber, there exists a possibility that the intake air temperature of this air cleaner 13 may rise.

  Therefore, in this embodiment, high temperature air from the floor steel plate 21 is blocked by the case of the switching valve 10 to prevent high temperature air from entering the air cleaner 13 and the heat exchanger 12.

  The structure of the switching valve 10 with a cover that prevents high-temperature air generated in the machine room from entering the air cleaner 13 and the heat exchanger 12 will be described with reference to FIGS. FIG. 4 is a perspective view (an example perspective view (FIG. 4A)) and a partial cross-sectional front view (FIG. 4B) of an embodiment of a switching valve according to the present invention.

  In the switching valve 10, the main shaft 44 passes through the central portion of the polygonal cylindrical switching valve main body 10 </ b> A, and the lever 42 extends in a direction perpendicular to the main shaft 44. The size of the switching valve 10 is, for example, a diameter φ of about φ = 100 to 150 mm and a height h of about h = 300 to 500 mm. The length of the lever is about 100 mm. A large number of connector portions 10B to which the hydraulic hoses 26 led from the pilot valve units 97 and 99 are connected are provided on the side surface portion of the switching valve main body 10A. Similarly, a connector portion 10B to which a hydraulic hose 27 leading to the hydraulic control valve 30 is connected is also provided on the side surface portion of the switching valve main body 10A.

  On the upper surface of the switching valve main body 10A, a notch 45 indicating the position where the main shaft 44 is rotated by the lever 42, and a mark 46 formed by engraving or casting the contents indicated by the notch 45 are provided. By the marking 46, the operator can visually recognize the switching position. A through hole 43 penetrating in the vertical direction is formed in an intermediate portion of the lever 42. By inserting a pin (not shown) into the hole 43, the pin is engaged with the notch 45 to hold the switching position. be able to. In this embodiment, the switching position is locked by the pin and the notch 45, but the locking method is not limited to this, and any locking method that is normally used can be applied.

  Next, the structure of the case 52 that shields heat by the switching valve body 10A configured as described above will be described. The heat shielding case 52 has a box shape, and a surface corresponding to the front side of the excavator 1 is attached to the partition plate 14 with the cabin 6 with bolts 33. A flange is formed at the lowermost part on the rear side of the heat shielding case 52, and this flange portion is attached to the beam 32 with a bolt 53 (34). A floor plate 21a is attached by bolts 35 and 36 between the beams 31 and 32 running in parallel, and the bottom of the switching valve main body 10A is fixed to the floor plate 21a by a bolt 47.

  Here, a hole 52 a that is slightly larger than the switching valve body 10 </ b> A is formed in the center of the ceiling of the box-shaped heat shielding case 52, and the upper part of the switching valve body 10 </ b> A may penetrate the box-shaped heat shielding case 52. It is possible. Inside the ceiling surface of the box-type heat shield case 52, a glass wool or urethane heat insulating member 51 is attached in close contact with the plate member of the heat shield case 52, and the switching valve body 10A is placed in the heat shield case. When accommodated, it is fitted to the side surface of the switching valve main body 10A without any gap.

  In the switching valve 10 configured as above, hot air to which the heat generated in the engine 9 is transferred is transferred into the heat shielding case 52 from the holes formed in the floor plate 21a for the routing of the hydraulic hoses 26 and 27. Even if it enters, heat transfer is blocked by the heat insulating member 51, and a high temperature rise in the utility chamber 15 can be prevented. Moreover, since the upper part of the switching valve 10 is exposed to the utility chamber 15, the operator can easily perform the switching operation and can visually recognize the switching content. Furthermore, when performing inspection and maintenance of the hydraulic hoses 26 and 27, it is possible to easily remove the heat shield cover simply by removing the bolts 33 and 34 (53).

  FIG. 5 is a partial front sectional view showing another embodiment of the heat shield case attached to the switching valve main body 10A and a modification thereof. FIG. 5A is a diagram of another embodiment of the heat shield case 52b. In this case, a bottomed floor member 21b having an upper plate 21b1 and a bottom plate 38 and having a space formed therein is provided between the beam 31 and the beam 32. The bottom surface portion of the plate member 21 b is fixed to the bottom plate 38 formed at a position lower than the upper plate 21 b 1 with bolts 47. One end of the floor member 21 b is fixed to the beam 31 with bolts 36 and 37, and the other end is fixed to the beam 32 with bolts 35.

  The heat shielding case 52b is formed in a box shape without a bottom surface portion, and a flange portion is formed at the bottom end. This flange portion is fixed to the upper plate 21b1 with bolts 33 and 34. Therefore, when switching the switching valve 10, the bolts 33 and 34 are removed, and the entire box-shaped heat shield case 52b is removed. Since the hole 21A for exposing the switching valve 10 is formed in the floor member 21b, the operator can perform the switching operation while looking at the upper surface portion of the switching valve 10, so that the switching can be easily performed. At the same time, the contents of switching can be confirmed visually. Although there is inconvenience that the heat shield cover 52b must be removed every time the switching valve 10 is switched, the switching frequency of the switch valve 10 is several times a year, and the flange portion of the floor member 21b and the heat shield cover 52b is used. It is only necessary to pay attention to the adhesiveness, and packing and the like can be used supplementarily for these adhesiveness and heat insulation, so that the heat shielding performance is further improved.

  FIG. 5B to FIG. 5D show a modification of this embodiment. These drawings are partial cross-sectional front views of the switching valve 10 as shown in FIG. 5 (a). 5 (b) is different from the embodiment shown in FIG. 5 (a) in that the heat shielding case 52c is of an openable / closable type. In order to be openable, the heat shield cover is divided into two parts, one heat shield cover 52d is fixed and not removed, and the other heat shield cover 52c is rotatable about the rotation shaft 54. That is, in the figure, the rear heat shield case 52c is rotatable about a rotation shaft 54 provided on the bottom flange portion.

  When switching the switching valve 10, the bolt 53 for fastening the two heat shield covers 52c, 52d is removed, and only the heat shield cover 52c is rotated to expose the upper surface of the switch valve 10. As a result, the operator can easily perform the switching operation and can visually confirm the switching content. Moreover, it can be easily used as a heat shield means after the operation. Also in this modified example, if an auxiliary seal such as packing or a heat insulating material is used for the overlapping portion of the heat shield covers 52c and 52d or the close contact portion of the floor member 21b and the heat shield covers 52c and 52d, the heat shield effect is further increased. .

  FIG. 5C shows another modified example of the heat shield cover, which is different from the above embodiment and the modified example in that the heat shield cover is divided into a cylindrical lower cover 62 and a lid-shaped upper cover 61. In this structure, the upper cover 61 is locked to the lower cover 62 by locking portions 61A and 62A provided at respective end portions. At least one of the upper cover 61 and the lower cover 62 is elastically deformed to be in close contact and locked, and the plate thickness on the elastically deformed side is limited. Therefore, in order to further ensure the heat shielding property, it is desirable to attach a heat insulating material to the inner surface of one or both of the heat shielding covers 61 and 62.

  FIG. 5D shows still another modified example of the heat shield cover, in which a screw structure is used instead of the locking portion that is elastically deformed in the modified example of FIG. Because of the screw structure, the entire heat shield cover has a cylindrical shape. Screws 73a and 73b are cut at respective end portions of the upper cover 71 and the lower cover 72, and the upper cover 71 can be easily detached from the lower cover 72 by loosening the screws 73a and 73b. According to this modification, there is no restriction | limiting in the plate | board thickness of the heat insulation covers 71 and 72, and heat insulation can be ensured reliably. In addition, the switching operation is easy, and the switching state is easily recognized.

  In each of the above embodiments and modifications, a box-type heat shield cover is used except for FIG. 5D, but the shape of the heat shield cover is not limited to a box shape, and may be a cylindrical shape or the like. Further, if a heat insulating material is provided on the inner surface side of the heat shield cover, the heat shield effect is further increased. Furthermore, the height of the upper surface of the heat shield cover is desirably a height that can be visually recognized from above while the operator is standing on the ground, and is desirably such a height or the height of the bottom plate can be adjusted.

  In each of the above embodiments, the utility chamber and the radiator chamber are not partitioned. However, even if the utility chamber and the radiator chamber are partitioned, there is a possibility that high-temperature air may flow into the radiator chamber or the air cleaner by providing a switching valve in the utility chamber. In some cases, the present invention is effective.

DESCRIPTION OF SYMBOLS 1 ... Work machine (hydraulic excavator), 2 ... Lower traveling body, 3 ... Upper turning body, 3A ... Turning motor, 4 ... Front, 5 ... Turning frame, 6 ... Cab, 6A ... Cab part, 8 ... Counter weight, DESCRIPTION OF SYMBOLS 9 ... Engine, 10 ... Switching valve, 10A ... Switching valve main body, 10B ... Connector part, 11 ... Building cover, 12 ... Heat exchanger, 13 ... Air cleaner, 14 ... Partition wall, 15 ... Utility room (part), 15A ... Utility chamber, 17 ... machine room cover, 19 ... hydraulic pump unit, 20 ... frame, 21a ... floor plate, 21b ... floor member, 21b1 ... upper plate, 22 ... lower flange, 23 ... upper flange, 24 ... side frame, 25 ... Center frame, 26, 27 ... Hydraulic hose (oil passage), 30 ... Hydraulic control valve, 31, 32 ... (Reinforcement) beam, 33-37 ... Bolt, 38 ... Bottom plate, 41 ... , 42 ... lever, 43 ... hole, 44 ... main shaft, 45 ... notch, 46 ... engraving, 47 ... bolt, 51 ... heat insulation member, 52 ... heat insulation case, 52a ... hole, 52b, 52c ... heat insulation case, 53 ... Bolt 54 ... Rotating shaft 61 ... Upper cover 61A ... Locking part 62 ... Lower cover 62A ... Locking part 71 ... Upper cover 72 ... Lower cover 73a, 73b ... Screw part 96 ... Operation lever, 97 ... pilot valve unit, 98 ... operation lever, 99 ... pilot valve unit.

Claims (4)

In a working machine comprising an upper swing body having an engine, a front attached to the upper swing body, and a lower traveling body positioned below the upper swing body,
An oil passage that forms a utility chamber behind a cab provided at the front of the upper swing body, and connects a pilot valve unit to which an operation command of the work machine is input and a control valve unit that operates in accordance with the operation command A working machine characterized in that a switching valve interposed in the utility chamber is disposed in the utility chamber, and heat from the engine is shielded by a heat shielding cover that houses at least a part of the switching valve.   The heat shield cover has a hole for exposing the upper surface portion of the switching valve, and the switching valve is provided with a heat insulating member on the inner surface of the heat shield cover to shield the gap exposed from the hole. The work machine according to claim 1, wherein   The heat insulating cover has a lower cover and an upper cover, the upper cover is detachable from the lower cover, and when the switching valve is switched, the upper cover is removed and switched. The work machine according to claim 1 or 2. Used in a work machine having an upper swing body on which an engine is mounted and an engine is mounted, a front mounted on the upper swing body, and a lower traveling body positioned below the upper swing body. In the arrangement structure of the switching valve,
The switching valve is interposed in an oil passage that connects a pilot valve unit provided in the cab to which an operation command is input and a control valve unit that operates in accordance with the operation command, and is installed in a utility chamber located behind the cab. An arrangement structure of a switching valve provided in a work machine, wherein the switching valve is arranged, and heat from the engine is shielded by a heat shielding cover that houses at least a part of the switching valve.

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