Work machine

Abstract

This work machine (1) comprises: a cab (5) which has motive-power equipment that can be started by a wireless key carried by a worker and in which the worker rides; a machinery chamber (6) in which the motive-power equipment is accommodated; and a reception device (8) that receives radio waves from the wireless key. The reception device (8) is disposed within the cab (5) and is positioned at least above the upper surface of the machinery chamber (6).

Description

Work machine

[0001] The present invention relates to a work machine.

[0002] For example, Patent Document 1 discloses a construction machine that employs a wireless key capable of starting a drive source without inserting a key into a keyhole.

[0003] In a work machine that employs a wireless key as described above, it is required that the engine can be started by operating the wireless key even when the operator is at a position away from the work machine (hereinafter referred to as the "remote engine start function").

[0004] When realizing this function, it is necessary to arrange a receiving device on the work machine that receives radio waves from the wireless key. On the other hand, a work machine includes larger structures compared to a passenger car, such as power equipment, hydraulic equipment, and heat exchangers. In addition to the above structures, the work machine includes many members that shield radio waves from the wireless key, such as counterweights. Therefore, depending on the location where the receiving device is arranged on the work machine, problems may occur, such as the distance at which the receiving device can receive radio waves being significantly reduced.

[0005] Japanese Patent Application Laid-Open No. 2023-171158

[0006] An object of the present invention is to provide a work machine that can stably receive radio waves from a wireless key and reliably exhibit a remote engine start function.

[0007] The present invention provides a work machine having a power device that can be started by a wireless key carried by an operator. The work machine includes a cab on which the operator rides, a machine room in which the power device is housed, and a receiving device that receives radio waves from the wireless key. The receiving device is arranged inside the cab and is located above the upper surface of the machine room.

[0008] Figure 1 is a side view of a work machine according to one embodiment of the present invention. Figure 2 is a top view of the work machine of Figure 1. Figure 3 is a perspective view showing an example of a receiving device. Figure 4 is an enlarged perspective view of the cab of Figure 1. Figure 5 is an enlarged side view of the machine room of Figure 1. Figure 6 is a front view of a receiving device arranged on the first support column. Figure 7 is a top view of the ceiling of the cab. Figure 8 is a side view of a work machine according to another embodiment of the present invention. Figure 9 is a perspective view of the first support column and the receiving device according to another embodiment of the present invention. Figure 10 is a schematic diagram of the receiving device of Figure 9 as viewed from the front. Figure 11 is a schematic diagram of the receiving device of Figure 9 as viewed from the left side.

[0009] Hereinafter, a working machine 1 according to one embodiment of the present invention will be described with reference to the drawings. The drawings are described in a manner that encompasses the features of the present invention, but may contain exaggerations or representations that differ from the actual dimensional ratios of the structure in order to aid in understanding the present invention. Furthermore, the same or common elements are denoted by the same reference numerals throughout each embodiment, and redundant explanations are omitted. In addition, well-known configurations may be appropriately adopted for configurations not described herein.

[0010] Figure 1 is a side view of the work machine 1 according to this embodiment, and Figure 2 is a top view of the work machine 1. In each figure of this specification, directions are indicated by arrows. As shown in Figure 1, arrow Up indicates the upward direction. Arrow Dw indicates the downward direction. Arrow Fw indicates the forward direction in the front-rear direction of the work machine 1. Arrow Rr indicates the rearward direction in the front-rear direction. As shown in Figure 2, arrow Rh indicates the rightward direction in the vehicle width direction of the work machine 1. Arrow Lf indicates the leftward direction in the vehicle width direction of the work machine 1.

[0011] As shown in Figures 1 and 2, the work machine 1 of this embodiment is, for example, a hydraulic excavator of the 7 to 13 ton class. Therefore, the work machine 1 of this embodiment includes a lower traveling body 2 that exerts driving force and an upper rotating body 3 that is rotatably mounted on the lower traveling body 2. The lower traveling body 2 of this embodiment is of the crawler type, but is not limited to this, and may, for example, exert driving force by multiple tires. Unless otherwise specified, the figures in this specification show the upper rotating body 3 and the lower traveling body 2 in an aligned state. The upper rotating body 3 also includes an arm 4a and a bucket 4b attached to the tip of the arm 4a. The work machine 1 of this embodiment can perform excavation work, etc. by operating the bucket 4b. However, the work machine 1 of the present invention is not limited to this form, and may be, for example, a bulldozer or a crawler crane.

[0012] The work machine 1 is equipped with a remote engine start function. Therefore, the work machine 1 has a power unit that can be started by a wireless key carried by the operator. The wireless key can transmit radio waves in response to the operator's operation. The work machine 1 also includes a cab 5 in which the operator sits, a machine room 6 housing the power unit, a receiving device 8 (shown by a dashed line in Figures 1 and 2) that receives radio waves from the wireless key, and a control unit that inputs a start command signal to the power unit in response to the receiving device 8 receiving radio waves. In this embodiment, all of these components are located on the upper rotating body 3. In this embodiment, one wireless key is used for one work machine 1. Therefore, the "operator" in this embodiment is assumed to be the operator who sits on and drives the work machine 1. However, the present invention is not limited to this embodiment, and for example, an embodiment in which two wireless keys are used for one work machine 1 is also included. In this case, for example, one wireless key is assumed to be held by the operator who is riding and driving the work machine 1, and the other wireless key is held by a person who is not riding the work machine 1 (for example, a person who monitors the operation of the work machine 1 from the outside). From the viewpoint that this embodiment is included, the workers who carry the wireless key may include not only the operator but also persons who are not riding the work machine 1.

[0013] In Figures 1 and 2, the area enclosed by the dashed line 5a corresponds to the cab 5. As shown in Figure 2, the cab 5 of this embodiment is located Lf to the left of the pivot center 3c of the upper rotating body 3 in a top view of the work machine 1. In the top view, the cab 5 of this embodiment overlaps with a virtual line (not shown) extending in the width direction of the work machine 1 through the pivot center 3c. The center position of the cab 5 in the front-rear direction is located in front of the pivot center 3c. The cab 5 is a box-shaped structure in which a driver's seat where an operator can sit is arranged. The cab 5 of this embodiment includes an internal space that is sealed to the extent that, for example, flying stones and the like do not enter. However, the cab 5 of the present invention is not limited to this configuration, and the interior may be open without being partitioned by glass or the like.

[0014] In Figure 2, the area enclosed by the dashed-dot line 6a corresponds to the machine room 6. As shown in Figure 2, in a top view of the work machine 1, the machine room 6 is positioned to surround the rear Rr and right Rh of the cab 5. The machine room 6 also includes a first part 11, which includes the part Rr behind the cab 5 and the pivot center 3c in the top view, and a second part 12, which includes the part Rh to the right of the pivot center 3c. In Figure 2, the boundary between the first part 11 and the second part 12 is shown by the dashed-dot line 6b. This boundary causes the first part 11 and the second part 12 to be rectangular in shape in the top view. The machine room 6 houses not only power equipment but also hydraulic equipment, heat exchangers, and the like. A counterweight 15 is also positioned at the rear Rr of the machine room 6 to improve the stability of the upper slewing body 3 during rotation.

[0015] Figure 3 is a perspective view showing an example of the receiving device 8. The receiving device 8 is configured as an RF antenna capable of receiving RF radio waves from a wireless key. RF radio waves are radio waves in a higher frequency band than LF radio waves (radio waves in a frequency band of approximately 30 to 300 kHz) transmitted from the work machine 1 toward the wireless key for authentication. The RF radio waves in this embodiment have a frequency band of approximately 300 to 500 MHz, which is common for use in remote engine start functions. The receiving device 8, configured as an RF antenna, is susceptible to interference from materials that block radio waves. Therefore, depending on the placement of the receiving device 8 on the work machine 1, problems may occur such as the distance between the receiving device 8 and the wireless key at which the receiving device 8 can receive radio waves (hereinafter referred to as the "receivable distance") becoming significantly smaller.

[0016] The receiving device 8 of this embodiment can transmit commands from a wireless key to the control unit (not shown) of a power equipment via cable 8a. Figure 3 also shows a connecting fitting 8b for attaching the receiving device 8 to another component. Without cable 8a and connecting fitting 8b, the receiving device 8 has, for example, a rectangular parallelepiped shape. Note that in diagrams schematically showing the position of the receiving device 8, such as Figures 1 and 2, the cable 8a and connecting fitting 8b shown in Figure 3 may be omitted. The receiving device 8 of this embodiment has, for example, a flattened rectangular parallelepiped shape with a width W1 smaller than the total length L1 and a thickness t1 smaller than the width W1. Generally, the manufacturer specifies a mounting orientation (hereinafter referred to as the "recommended mounting position") that allows the receiving device 8 to exhibit the best radio wave sensitivity. In this embodiment, the recommended mounting position for the receiving device 8 is when the reference axis direction (in this embodiment, the longitudinal direction constituting the total length L1) is parallel to the vertical direction.

[0017] Figure 4 is an enlarged perspective view of the cab 5 as seen from the left rear. As shown in Figure 4, the receiving device 8 is located inside the cab 5 and above the top surface of the machine room 6 (shown in Figure 1). In Figures 1, 2, and 4, the receiving device 8 is schematically shown by a dashed line. When the receiving device 8 is located in the above position, the radio waves are not shielded by the machine room 6, so the receiving device 8 can stably receive radio waves from the wireless key. Therefore, the work machine 1 of the present invention can reliably perform the remote engine start function.

[0018] The configuration of this embodiment will be described in more detail below. Note that each configuration described below represents a specific aspect of this embodiment. Therefore, it goes without saying that the present invention can achieve the above-described effects even without the configurations described below. Furthermore, even if any one of the configurations described below is applied individually to the work machine 1 of the present invention having the above-described features, an improvement in performance corresponding to each configuration can be expected. Moreover, if several of the configurations described below are applied in combination, a combined improvement in performance corresponding to each configuration can be expected.

[0019] As shown in Figures 1 and 2, the machine room 6 includes a cover 13 that can be opened during maintenance. A maintenance passage 14 is also provided around the cover 13, which can be used as a platform for workers during maintenance. In Figures 1 and 2, the outer surface of the cover 13 is marked with dots. In this embodiment, the area of ​​the outer surface of the machine room 6, excluding the outer surface of the cover 13, is configured as the maintenance passage 14, which can be used as a platform for workers.

[0020] Figure 5 shows an enlarged side view of the machine room 6 as observed from the right side Rh of the work machine 1. Note that in Figure 5, the lower traveling body 2 and the tip of the arm 4a, which are shown in Figures 1 and 2, are omitted. As shown in Figure 5, in the second part 12 of the machine room 6, the outer surface of the maintenance passage 14 includes a main body surface 14a at the same height as the outer surface of the first part 11, and a lower step surface 14b at a lower position than the main body surface 14a. The receiving device 8 (shown in Figure 4) of this embodiment is located above the outer surface (upper surface) of the maintenance passage 14. That is, the receiving device 8 is located above at least the lower step surface 14b of the maintenance passage 14, and preferably above the main body surface 14a of the maintenance passage 14. Even in this embodiment, the above-mentioned effects can be fully obtained. In a more desirable embodiment, the receiving device 8 is located above the upper surface of the lid 13 of the machine room 6. This prevents radio waves from being blocked by the machine room 6, making it possible to increase the receiving range of the receiving device 8.

[0021] As shown in Figure 4, the actual cab 5 has a frame 20 (partially shown by a dashed line) and an interior panel 35 (omitted in Figure 4, but shown in Figure 6, which will be described later) that covers this frame 20. It is desirable that the receiving device 8 be concealed by this interior panel. This improves the appearance inside the cab 5. In addition, since the receiving device 8 is not exposed, problems such as workers coming into contact with the receiving device 8 can be prevented.

[0022] The cab 5 includes a floor 21, a ceiling 22, and a plurality of support columns 23 (shown by dashed lines) connected to the floor 21 and ceiling 22. The receiving device 8 is preferably located on one of the plurality of support columns 23. This allows the support columns 23 to act as protective members for the receiving device 8. For example, even if a large impact is transmitted to the cab 5, the support columns 23 can absorb the impact and prevent damage to the receiving device 8. The specific support column 23 on which the receiving device 8 is located will be described later.

[0023] As described above, the cab 5 is constructed as a box-shaped structure. Therefore, as shown in Figure 2, the cab 5 includes a first side wall 26, a second side wall 27, a front wall 28, and a rear wall 29, and a driver's seat (not shown) surrounded by these. As shown in Figure 4, the first side wall 26 includes a door through which workers can enter and exit, and in this embodiment is located on the left side Lf of the driver's seat. As shown in Figure 2, the second side wall 27 is located on the opposite side of the first side wall 26, and in this embodiment is located on the right side Rh of the driver's seat. The front wall 28 is the wall Fw in front of the driver's seat, and the rear wall 29 is the wall Rr in rear of the driver's seat.

[0024] If the receiving device 8 is far from the pivot center 3c of the upper rotating body 3, the distance between the receiving device 8 and the wireless key will change significantly depending on the pivot position of the upper rotating body 3, which may cause the following problems. For example, if the distance from the wireless key to the pivot center 3c is 10m and the distance from the receiving device 8 to the pivot center 3c is Xm, then depending on the pivot position of the upper rotating body 3, the shortest distance from the wireless key to the receiving device 8 will be (10-X)m and the longest distance will be (10+X)m.

[0025] When the aforementioned distance X is large, the difference between the shortest distance and the longest distance described above becomes large. For this reason, even if the distance from the wireless key to the pivot center 3c is the same, depending on the pivot position of the upper pivot body 3, the remote engine start function may be activated at the shortest distance, but at the longest distance, the radio waves may not reach and the function may not be activated (engine cannot be started). To prevent such problems, it is desirable that the remote engine start function be activated stably regardless of the pivot position of the upper pivot body 3 as much as possible, provided that the distance from the wireless key to the pivot center 3c is the same. Therefore, it is desirable that the receiving device 8 be as close to the pivot center 3c as possible.

[0026] From this perspective, the receiving device 8 of this embodiment is located on the second side wall 27 side (towards the pivot center 3c) of the cab 5's widthwise center, and more preferably, it is located in the region closest to the second side wall 27 within the three equal parts obtained by dividing the cab 5 in the widthwise direction. This mitigates the aforementioned problems.

[0027] In the cab 5, it is desirable to ensure a large forward field of view for the operator. On the other hand, even if the receiving device 8 is concealed by the interior panel of the cab 5, the surrounding interior panel may need to be enlarged to accommodate the receiving device 8. For this reason, it is desirable to position the receiving device 8 in a location that does not obstruct the operator's forward field of view as much as possible. From this viewpoint, it is desirable that the receiving device 8 be positioned behind the center of the cab 5 in the front-to-rear direction. In a more desirable configuration, the receiving device 8 is positioned in the area closest to the rear wall 29 of the region obtained by dividing the cab 5 into three equal parts in the front-to-rear direction. In an even more desirable configuration, the receiving device 8 is positioned behind the driver's seat headrest (not shown).

[0028] As shown in Figure 4, the multiple support columns 23 include a first support column 31 connected to the second side wall 27 and the rear wall 29. That is, the first support column 31 is arranged to extend vertically inside the corner between the second side wall 27 and the rear wall 29. In this embodiment, the first support column 31 corresponds to the support column 23 located to the right rear of the driver's seat. From the viewpoint of satisfying the above-mentioned arrangement requirements for the receiving device 8, the receiving device 8 in this embodiment is located on the first support column 31. The first support column 31 has the smallest distance from the pivot center 3c of the upper slewing body 3 among the multiple support columns 23. As a result, the work machine 1 of this embodiment can reliably perform the remote engine start function even when the pivot position of the upper slewing body 3 changes, and a wide forward field of view can be secured in the driver's seat.

[0029] Figure 6 shows a front view of the receiving device 8 located on the first support column 31. Figure 6 is a front view of the first support column 31 and the receiving device 8 when viewed from the driver's seat side towards the rear Rr. In Figure 6, a portion of the interior panel 35 is omitted, and the receiving device 8 located on the first support column 31 is shown. The outline of the omitted portion is indicated by a dashed line 35a. As shown in Figure 6, a beam member 33 extending from the first side wall 26 (shown in Figure 4) is connected to the first support column 31, and a gusset plate 37 is provided between the first support column 31 and the beam member 33 (inside the corner) to reinforce them. The gusset plate 37 is, for example, a right-angled triangular steel plate, with one of the two sides forming the right angle welded to the side surface of the first support column 31 and the other welded to the lower surface of the beam member 33.

[0030] The receiving device 8 is provided on the side of the first support column 31. In this embodiment, it is provided on the left side Lf of the side of the first support column 31, which is easily accessible from inside the cab 5 (in other words, the side facing the inside of the cab 5 among the sides facing the vehicle width direction). This improves the workability when installing and maintaining the receiving device 8. However, it is not limited to this configuration, and the receiving device 8 may be provided on any of the front side Fw, rear side Rr, or right side Rh of the first support column 31. In this embodiment, a cable fixing device 36 is provided on the side, and the cable 8a and connecting fitting 8b of the receiving device 8 are attached to it. It is preferable that the receiving device 8 be positioned directly below the gusset plate 37, for example, and although the receiving device 8 and the gusset plate 37 are not in contact, the shortest distance between the receiving device 8 and the gusset plate 37 is 50 mm or less.

[0031] It is desirable that the receiving device 8 be mounted on the first support column 31 in a position as close as possible to the recommended mounting position (shown in Figure 3). However, depending on the positional relationship with the gusset plate 37, the receiving device 8 may be mounted at a certain degree of inclination relative to the recommended mounting position. In this case, it is desirable that the receiving device 8 be mounted such that the reference axis direction of the mounted receiving device 8 (in this embodiment, the longitudinal direction of the receiving device 8) is at an angle of, for example, 15° or less with respect to the reference axis direction of the receiving device 8 in the recommended mounting position. This prevents the receiving distance of the receiving device 8 from becoming excessively small.

[0032] The above-described embodiment is particularly effective when, in the recommended mounting position, it is necessary to bring the longitudinal direction of the receiving device 8 closer to the vertical direction. On the other hand, depending on the type of receiving device 8, it may be required that, in the recommended mounting position, the longitudinal direction of the receiving device 8 be brought closer to the horizontal direction. In this case, it is desirable that the receiving device 8 be placed, for example, inside the ceiling portion 22 of the cab 5, particularly inside the ceiling portion 22. This allows the receiving device 8 to be placed without difficulty.

[0033] Figure 7 shows an enlarged top view of the ceiling portion 22 of the cab 5. In Figure 7, the position of the receiving device 8 on the ceiling portion 22 is conceptually shown by a dashed line. As shown in Figure 7, when the receiving device 8 is located on the ceiling portion 22, it is desirable that the receiving device 8 be located behind the center position 22a in the front-rear direction of the ceiling portion 22. Furthermore, it is desirable that the receiving device 8 be located closer to the second side wall 27 than the center position 22b in the width direction of the ceiling portion 22. This brings the receiving device 8 closer to the pivot center of the upper rotating body 3, allowing the remote engine start function to be performed stably.

[0034] Figure 8 shows a side view of a work machine 1 according to another embodiment of the present invention. As shown in Figure 8, the work machine 1 of the present invention may be a rearward-swinging model with a relatively small swing range of the upper swinging body 3, or a so-called mini excavator weighing 6 tons or less.

[0035] Figures 9 to 11 show yet another embodiment in which the receiving device 8 is arranged on the first support column 31. Figure 9 is a perspective view of the first support column 31 and the receiving device 8 in this embodiment. Note that in Figure 9, the interior panel 35 (exemplified in Figure 6) that covers the first support column 31 and the receiving device 8 is omitted. Figure 10 is a schematic diagram of the receiving device 8 in this embodiment as viewed from its front side Fw. Figure 11 is a schematic diagram of the receiving device 8 in this embodiment as viewed from its left side Lf.

[0036] As shown in Figures 9 and 11, in this embodiment, the receiving device 8 is mounted on the left side Lf of the first support column 31 at a position away from the inner surface of the rear window 40 of the cab 5. This prevents damage to the receiving device 8 in the event of damage to the rear window 40, while still allowing for sufficient remote engine starting functionality. The shortest distance from the receiving device 8 to the inner surface of the rear window 40 is, for example, 20 to 50 mm. However, the shortest distance in this embodiment is not limited to this range.

[0037] A partial covering member 41 is provided on the inner surface of the rear window 40 to conceal the first support column 31 and the receiving device 8. In this embodiment, the receiving device 8 is surrounded on all four sides by the covering member 41, the interior cover (not shown), and the first support column 31. As a result, the receiving device 8 is not visible from inside or outside the cab 5, improving the aesthetics.

[0038] In this embodiment, a tubular cable fastener 36 extending vertically is provided on the left side Lf of the first support column 31. The cable 8a of the receiving device 8 can be passed through the inside of this cable fastener 36. The receiving device 8 is attached to the upper end of the cable fastener 36 via a metal bracket 45 (support member).

[0039] The bracket 45 is a component manufactured, for example, by bending a single metal plate, and includes a front portion 46, a main body portion 47, and a rear portion 48. The front portion 46 is bolted to the front Fw surface of the upper end of the cable fastener 36 and is planar, extending in the same direction as the rear window 40. The main body portion 47 is connected to the left side Lf of the front portion 46 and extends at a slight inclination relative to the left side Lf of the first support portion 31. The receiving device 8 is bolted to the main body portion 47. The rear portion 48 is connected to the rear side Rr of the main body portion 47 and extends along the rear window 40. The rear portion 48 also extends to the opposite side (left side) from the front portion 46 relative to the main body portion 47. As a result, the bracket 45 is bent at right angles between the main body portion 47 and the front portion 46, and between the main body portion 47 and the rear portion 48.

[0040] As shown in Figure 10, when the receiving device 8 is observed from the front Fw, it is desirable that the entire receiving device 8 overlaps with the rear portion 48 of the bracket 45. In other words, as shown in Figure 9, when the bracket 45 is observed from the rear Rr, the receiving device 8 is completely hidden by the rear portion 48. This ensures that even if the rear window 40 is damaged, the receiving device 8 can be protected by the rear portion 48 of the bracket 45.

[0041] As shown in Figure 4, the cab 5 is equipped with a transmitter 9. This transmitter 9 is used to detect whether or not a wireless key is present inside the cab 5 (in other words, whether or not a worker is inside the cab). The transmitter 9 is configured as an LF antenna that transmits LF radio waves. When the wireless key is present inside the cab 5 and receives the LF radio waves, the wireless key transmits a response radio wave. Through this transmission and reception, it is determined whether or not the wireless key is present inside the cab 5.

[0042] On the other hand, depending on the arrangement of the transmission device 9, there may be a case where the above-described radio wave transmission and reception are established even though the wireless key is outside the cab 5. From the viewpoint of preventing such a problem, it is desirable that the transmission device 9 is located below the upper surface of the machine room 6 (shown in FIG. 2). More specifically, the transmission device 9 is located below the upper surface when the lid 13 in the first part 11 of the machine room 6 is excluded. Thereby, it is possible to prevent the LF radio wave transmitted by the transmission device 9 from being transmitted unnecessarily far. For this reason, even when an operator holds a wireless key and is on the maintenance passage 14 (shown in FIG. 5), and the wireless key is at a position higher than the upper surface of the machine room 6 and is in a situation where misrecognition is likely to occur, it is possible to accurately determine that the wireless key is not in the cab 5.

[0043] In the embodiment shown in FIG. 4, the transmission device 9 is arranged on the first support part 31. Thereby, since the transmission device 9 is arranged closer to the machine room 6, the above-described effect is further exerted. However, the transmission device 9 is not limited to such an arrangement, and for example, it may be arranged inside the second side wall 27. Even in this case, the second part 12 of the machine room 6 can prevent the LF radio wave from being transmitted unnecessarily far.

[0044] As described above, the particularly preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the illustrated embodiments and can be implemented in various forms.

[0045] As described above, the present invention is useful as a working machine.

[0046] The working machine according to the first aspect of the present invention includes a power device that can be started by a wireless key carried by an operator, a cab on which the operator rides, a machine room that houses the power device, and a receiving device that receives radio waves from the wireless key. The receiving device is arranged inside the cab and is located above the upper surface of the machine room.

[0047] The work machine according to the second aspect of the present invention is the work machine according to the first aspect, wherein the upper surface of the machine room includes a maintenance passage that can be used as a scaffold for the operator during maintenance, and the receiving device is preferably located above the outer surface of the maintenance passage.

[0048] The work machine according to the third aspect of the present invention is the work machine according to the first or second aspect, wherein the receiving device is preferably hidden by an interior panel in the cab.

[0049] The work machine according to the fourth aspect of the present invention is the work machine according to any one of the first to third aspects, wherein the receiving device is preferably arranged on the ceiling portion of the cab.

[0050] The work machine according to the fifth aspect of the present invention is the work machine according to the fourth aspect, wherein the receiving device is preferably arranged behind the center position in the front-rear direction of the ceiling portion.

[0051] The work machine according to the sixth aspect of the present invention is the work machine according to any one of the first to fifth aspects, wherein the cab includes a first side wall including a door through which the operator can enter and exit, and a second side wall located on the opposite side of the first side wall, and the receiving device is preferably located on the second side wall side of the center position in the width direction of the cab.

[0052] The work machine according to the seventh aspect of the present invention is the work machine according to any one of the first to third aspects, wherein the cab includes a floor portion, a ceiling portion, and a plurality of support portions connecting the floor portion and the ceiling portion, and the receiving device is preferably arranged on any one of the plurality of support portions.

[0053] The work machine according to the eighth aspect of the present invention is the work machine according to the seventh aspect, wherein the cab includes a first side wall including a door through which the operator can enter and exit, a second side wall located on the opposite side of the first side wall, a driver's seat on which the operator can sit, and a rear wall behind the driver's seat, the plurality of support portions include a first support portion connecting the second side wall and the rear wall, and the receiving device is preferably arranged on the first support portion.

[0054] A working machine according to the ninth aspect of the present invention includes, in the working machine according to the eighth aspect, a lower traveling body and an upper rotating body that is rotatably mounted on the lower traveling body, wherein the upper rotating body includes the cab and the machine room, and in a top view of the working machine, the machine room is arranged to surround the rear and right sides of the cab, and it is desirable that the first support column has the smallest distance from the rotation center of the upper rotating body among the plurality of support columns.

[0055] A work machine according to the tenth aspect of the present invention is a work machine according to any one of the first to third, comprising a lower traveling body and an upper rotating body that is rotatably mounted on the lower traveling body, wherein the upper rotating body comprises a cab and a machine room, the cab comprises a plurality of support columns extending in the vertical direction, and preferably the receiving device is positioned on the support column closest to the pivot center of the upper rotating body among the plurality of support columns.

[0056] By adopting the above-mentioned features, the work machine of the present invention can stably receive radio waves from a wireless key and reliably perform the remote engine start function.

[0057] In the eleventh aspect of the present invention, in the first to third aspect of the work machine, the cab is provided with a transmitting device that transmits radio waves for determining whether or not the wireless key is present inside the cab, and it is preferable that the transmitting device is located below the upper surface of the machine room.

[0058] By adopting the above-mentioned features, the work machine of the present invention can accurately determine whether the wireless key is not inside the cab.

Claims

1. A work machine comprising: a power unit that can be started by a wireless key carried by an operator; a cab in which the operator sits; a machine room in which the power unit is housed; and a receiving device that receives radio waves from the wireless key, wherein the receiving device is located inside the cab and above the top surface of the machine room.

2. The machine according to claim 1, wherein the upper surface of the machine room includes a maintenance passage that can be used as a platform for the worker during maintenance, and the receiving device is located above the outer surface of the maintenance passage.

3. The work machine according to claim 1 or 2, wherein the receiving device is covered by an interior panel inside the cab.

4. The working machine according to any one of claims 1 to 3, wherein the receiving device is located on the ceiling of the cab.

5. The work machine according to claim 4, wherein the receiving device is positioned behind the center position of the ceiling in the front-to-back direction.

6. The work machine according to any one of claims 1 to 5, wherein the cab includes a first side wall with a door through which the worker can enter and exit, and a second side wall located on the opposite side of the first side wall, and the receiving device is located on the side of the second side wall that is closer to the center of the cab in the width direction.

7. The work machine according to any one of claims 1 to 3, wherein the cab includes a floor, a ceiling, and a plurality of support columns connected to the floor and the ceiling, and the receiving device is located on one of the plurality of support columns.

8. The work machine according to claim 7, wherein the cab includes a first side wall with a door through which the worker can enter and exit, a second side wall located on the opposite side of the first side wall, a driver's seat in which the worker can sit, and a rear wall located behind the driver's seat, the plurality of support columns include a first support column connected to the second side wall and the rear wall, and the receiving device is located on the first support column.

9. The work machine according to claim 8, comprising a lower traveling body and an upper rotating body rotatably mounted on the lower traveling body, wherein the upper rotating body includes the cab and the machine room, and in a top view of the work machine, the machine room is arranged to surround the rear and right sides of the cab, and the first support column is the one with the smallest distance from the pivot center of the upper rotating body among the plurality of support columns.

10. A working machine according to any one of claims 1 to 3, comprising a lower traveling body and an upper rotating body rotatably mounted on the lower traveling body, wherein the upper rotating body includes a cab and a machine room, the cab includes a plurality of support columns extending in the vertical direction, and the receiving device is positioned on the support column among the plurality of support columns closest to the pivot center of the upper rotating body.

11. The cab is provided with a transmitting device that transmits radio waves for determining whether or not the wireless key is present inside the cab, and the transmitting device is located below the upper surface of the machine room, the work machine according to any one of claims 1 to 3.

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