Mobile crane

Abstract

This mobile crane comprises a boom and a traveling vehicle body for supporting the boom, and travels in a state where the boom is brought down forward. The crane has: a distance detection device which has an ultrasonic sensor disposed on the front side of the traveling vehicle body and which detects a distance between the ultrasonic sensor and a detection object; and a shielding member which is disposed between the ultrasonic sensor and the boom in a traveling state and which shields ultrasonic waves emitted from the ultrasonic sensor.

Description

Technical Field

[0001] The present invention relates to a mobile crane.

Background Art

[0002] In recent years, in traveling vehicles such as automobiles, detection means are often provided to prevent collisions and the like. Patent Document 1 discloses a technique for stopping a mobile crane at a desired position based on the detection result of distance detection means provided on the front side of the vehicle body of the mobile crane.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the case of a mobile crane as well as an ordinary automobile, it is preferable that the detection means for detecting obstacles such as vehicles and people in front during traveling is provided in front of the vehicle.

[0005] Further, in the case of a mobile crane having a boom beside the driver's cab as in Patent Document 1, the boom may limit the driver's forward view. Therefore, it is preferable that the detection means is provided at least in front of the vehicle in the direction where the boom is located as viewed from the driver's cab.

[0006] In the mobile crane disclosed in Patent Document 1, since the position of the boom during traveling is high and the amount of protrusion of the boom forward is relatively small, the boom does not obstruct the detection means. However, in a mobile crane that lowers the boom to a low position in front of the vehicle during traveling or a mobile crane with a large amount of protrusion of the boom forward, there is a risk that the detection means may misdetect the boom.

[0007] An object of the present invention is to provide a mobile crane provided with detection means that does not erroneously detect a boom during travel.

Means for Solving the Problems

[0008] One aspect of the mobile crane according to the present invention is a mobile crane that includes a boom and a traveling vehicle body that supports the boom, and travels with the boom folded forward, having an ultrasonic sensor provided on the front side of the traveling vehicle body, a distance detection device that detects the distance between the ultrasonic sensor and the detection target, and a shielding member that is provided between the boom and the ultrasonic sensor in the traveling state and blocks the ultrasonic waves transmitted by the ultrasonic sensor. Mobile crane.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a mobile crane provided with detection means that does not erroneously detect a boom during travel.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

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Figure 8

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Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

MODE FOR CARRYING OUT THE INVENTION

[0011] [Embodiment 1] FIGS. 1 and 2 show the mobile crane 1 in a traveling mode in which the boom 122 is lowered and can travel. The mobile crane 1 has a slewing body 12 on which a driver's cab 121 and a boom 122 are mounted on the vehicle body 11.

[0012] The vehicle body 11 corresponds to an example of a traveling vehicle body and has a bumper 13 at the front. The vehicle body 11 has outriggers 14. The outriggers 14 include a front outrigger 14 disposed on the front side of the vehicle body 11 and a rear outrigger 14 disposed on the rear side of the vehicle body 11. The front outrigger 14 is provided behind the bumper 13.

[0013] Before the operation, the outriggers 14 project laterally from the vehicle body 11 and lower the tips thereof toward the ground. As a result, the outriggers 14 lift the vehicle body 11 to stabilize the posture of the mobile crane 1.

[0014] The outrigger 14 is stored in the front and rear of the vehicle body 11 in the traveling mode. In the traveling mode, the mobile crane 1 generally travels with the boom 122 lowered forward as shown in FIGS. 1 and 2. Therefore, the tip of the boom 122 is located in front of the front surface of the vehicle body 11. In such a mobile crane 1, if an ultrasonic sensor is provided in front of the vehicle body 11, there is a risk that the ultrasonic sensor will detect the boom 122.

[0015] Therefore, in the present embodiment, the ultrasonic device 2 having the shielding member 22 shown in FIGS. 3 and 4 is used. FIG. 3 is a front view of the ultrasonic device 2. FIG. 4 is a side view of the ultrasonic device 2 shown in FIG. 3 as viewed from the direction indicated by the arrow A1 in FIG. 3.

[0016] In the orthogonal coordinate system (X, Y, Z) shown in FIGS. 3 and 4, the Z direction corresponds to the front-rear direction of the mobile crane 1. The + side in the Z direction coincides with the front side (in other words, the forward direction of the mobile crane 1). The - side in the Z direction coincides with the rear side (in other words, the backward direction of the mobile crane 1).

[0017] Further, the Y direction corresponds to the vertical direction of the mobile crane 1. The + side in the Y direction coincides with the upper side. The - side in the Y direction coincides with the lower side.

[0018] The X direction corresponds to the left-right direction of the mobile crane 1. The + side in the X direction coincides with the left side when viewed from the front of the mobile crane 1. The - side in the X direction coincides with the right side when viewed from the front of the mobile crane 1. Note that the orthogonal coordinate system (X, Y, Z) shown in each figure other than FIGS. 3 and 4 corresponds to the orthogonal coordinate system (X, Y, Z) shown in FIGS. 3 and 4.

[0019] The - side (right side) in the X direction as viewed from the shielding member 22 is also the direction in which the boom 122 is present. The shielding plate 232 protrudes forward (Z direction + side) from the back plate 231. The back plate 231 is substantially parallel to the XY plane, and the shielding plate 232 is provided substantially perpendicular to the XY plane. The shielding plate 232 can also be regarded as an example of the shielding member.

[0020] Figures 3 and 4 show the ultrasonic device 2 of this embodiment using the ultrasonic sensor 21 and the shielding member 22. The ultrasonic sensor 21 is thin and used for both transmission and reception, and is provided on the front surface of the back panel 231 of the shielding member 22.

[0021] Also, as shown in FIG. 3, the shielding plate 232 protruding from the front surface of the back panel 231 curves upward from the side of the ultrasonic sensor 21 to shield ultrasonic waves.

[0022] As shown in FIG. 4, the wiring 211 of the ultrasonic sensor 21 extends to the back side (rear side) through a small hole provided in the back panel 231. The shielding plate 232 is a shielding wall that limits the ultrasonic wave reach area by the ultrasonic sensor 21.

[0023] FIG. 5 is a diagram showing an example in which the ultrasonic device 2 is attached to the front surface of the bumper 13 of the mobile crane 1. FIG. 5 corresponds to an enlarged view of the dotted circle portion on the front surface of the mobile crane 1 shown in FIG. 2.

[0024] FIG. 5 is an enlarged view of the left half portion of the front surface of the mobile crane 1.

[0025] The ultrasonic device 2 corresponds to an example of a distance detection device and is also provided on the right half portion of the front surface of the mobile crane 1. The ultrasonic device 2 has an ultrasonic sensor 21 provided on the front side of the vehicle body 11. The ultrasonic device 2 detects the distance between the ultrasonic sensor 21 and the detection target OB (see FIG. 7) existing in front of the vehicle body 11.

[0026] In the case of this embodiment, the mobile crane 1 has the ultrasonic device 2 on each of the right front side and the left front side of the vehicle body 11. That is, the mobile crane 1 has a pair of left and right ultrasonic devices 2.

[0027] The ultrasonic device 2 provided on the left half portion of the front surface of the mobile crane 1 and the ultrasonic device 2 provided on the right half portion of the front surface of the mobile crane 1 are symmetrical. These points are the same in FIGS. 6, 10, and 12 described later.

[0028] The wiring 211 of the ultrasonic sensor 21 is connected to a detection device (not shown) through the inside of the bumper 13. The detection device causes the ultrasonic sensor 21 to transmit an ultrasonic pulse (send it).

[0029] The ultrasonic pulse transmitted by the ultrasonic sensor 21 (hereinafter also referred to as the transmitted pulse) is reflected by the detection target OB and returns to the ultrasonic sensor 21. The ultrasonic sensor 21 receives the returned ultrasonic pulse (hereinafter also referred to as the received pulse).

[0030] The detection device measures the distance to the detection target OB based on the time difference (in other words, the phase difference) between the transmitted pulse and the received pulse.

[0031] When the distance between the mobile crane 1 and the detection target OB becomes smaller than a predetermined value, a warning is given in the operator's cab 121 or the brake of the moving mobile crane 1 is actuated.

[0032] The boom 122 is located diagonally above the right of the ultrasonic device 2, but the ultrasonic wave heading towards the boom 122 (that is, diagonally upwards to the right) is shielded by the shielding plate 232 and does not reach the boom 122. That is, the ultrasonic device 2 does not misdetect the boom 122.

[0033] In the present embodiment, the ultrasonic device 2 is provided on the front surface of the bumper 13 as shown in FIG. 5. However, the ultrasonic device 2 may be provided below the bumper 13 as shown in FIG. 6.

[0034] In the case of a configuration where the ultrasonic device 2 is provided below the bumper 13, the shielding plate 232 can be prevented from protruding further forward than the bumper 13. Further, the ultrasonic device 2 may be embedded in the bumper 13. According to the configuration in which the ultrasonic device 2 is embedded in the bumper 13, it is possible to prevent the body of the operator from hitting the shielding plate 232 during crane preparation or the like. The shielding plate 232 may have a conical shape with the left side, which is on the side opposite to the boom 122, open.

[0035] [Embodiment 2] Next, the ultrasonic device 3 (see FIG. 8) mounted on the mobile crane according to Embodiment 2 of the present invention will be described. The ultrasonic device 3 according to the present embodiment is an ultrasonic device using a so-called passing detection method. The ultrasonic device 3 includes a first ultrasonic sensor 31 and a second ultrasonic sensor 32.

[0036] First, the passing detection method will be described with reference to FIG. 7. In this method, a plurality of ultrasonic sensors are used. The first ultrasonic sensor 31 and the second ultrasonic sensor 32 shown in FIG. 7 have a function of transmitting ultrasonic waves (hereinafter also referred to as the ultrasonic wave transmission function) and a function of receiving ultrasonic waves (hereinafter also referred to as the ultrasonic wave reception function).

[0037] The control of ultrasonic wave transmission and the calculation and control using the received information are executed by the detection device 9. The detection device 9 may be realized by a computer.

[0038] As shown in FIG. 7, the first ultrasonic sensor 31 transmits an ultrasonic wave S. Also, the first ultrasonic sensor 31 receives a reflected wave R1. The reflected wave R1 is an ultrasonic wave obtained by reflecting the ultrasonic wave S from the detection target OB. Also, the second ultrasonic sensor 32 receives a reflected wave R2. The reflected wave R2 is an ultrasonic wave obtained by reflecting the ultrasonic wave S from the detection target OB. In this way, the detection method in which the first ultrasonic sensor 31 transmits the ultrasonic wave S, the first ultrasonic sensor 31 receives the reflected wave R1, and the second ultrasonic sensor 32 receives the reflected wave R2 is referred to as the first detection.

[0039] Although not shown, the detection method in which the second ultrasonic sensor 32 transmits the ultrasonic wave S, the first ultrasonic sensor 31 receives the reflected wave R1 of the ultrasonic wave S, and the second ultrasonic sensor 32 receives the reflected wave R2 of the ultrasonic wave S is referred to as the second detection. The detection device 9 repeatedly executes the first detection and the second detection.

[0040] FIG. 7 shows the state of the first detection. The detection device 9 issues an instruction to the first ultrasonic sensor 31, and the ultrasonic wave S is transmitted from the first ultrasonic sensor 31. The ultrasonic wave S transmitted by the first ultrasonic sensor 31 is reflected by the detection target OB to become the reflected wave R1 and the reflected wave R2.

[0041] Then, the first ultrasonic sensor 31 receives the reflected wave R1. Also, the second ultrasonic sensor 32 receives the reflected wave R2.

[0042] The detection device 9 receives information regarding the reflected wave R1 from the first ultrasonic sensor 31 and receives information regarding the reflected wave R2 from the second ultrasonic sensor 32. Then, based on the time difference between the time when the first ultrasonic sensor 31 transmits the ultrasonic wave S and the time when the first ultrasonic sensor 31 receives the reflected wave R1, the detection device 9 calculates the distance D1 from the first ultrasonic sensor 31 to the detection target OB.

[0043] In other words, the detection device 9 calculates the distance D1 from the first ultrasonic sensor 31 to the detection target OB based on the time taken from when the first ultrasonic sensor 31 transmits the ultrasonic wave S until the first ultrasonic sensor 31 receives the reflected wave R1.

[0044] Furthermore, the detection device 9 calculates the distance D2 from the second ultrasonic sensor 32 to the detection target OB based on the time difference between the time when the first ultrasonic sensor 31 transmits the ultrasonic wave S and the time when the second ultrasonic sensor 32 receives the reflected wave R2, and the distance D1.

[0045] In other words, the detection device 9 calculates the distance D2 from the second ultrasonic sensor 32 to the detection target OB based on the time taken from when the first ultrasonic sensor 31 transmits the ultrasonic wave S until the second ultrasonic sensor 32 receives the reflected wave R2, and the distance D1.

[0046] Then, the detection device 9 calculates the position of the detection target OB based on the distances D1 and D2, and the positions of the first ultrasonic sensor 31 and the second ultrasonic sensor 32.

[0047] When the position of the detection target OB is detected within the dangerous area, the detection device 9 sends an alarm signal to an alarm device (not shown), and an alarm sound rings inside the operation cabin 121.

[0048] Furthermore, by sending a braking signal from the detection device 9 to a brake detection device (not shown), the mobile crane 1 during travel is braked by an automatic brake.

[0049] In the second detection, the second ultrasonic sensor 32 emits ultrasonic waves S, the first ultrasonic sensor 31 receives the reflected wave R1, and the second ultrasonic sensor 32 receives the reflected wave R2.

[0050] In the present embodiment, the detection device 9 detects the position of the detection target OB while alternately repeating the first detection and the second detection.

[0051] As described above, in the first detection and the second detection, the reflected waves R1 and R2 from the detection target OB are used. By the way, in the case of such a detection method, as shown by the curved arrow in FIG. 7, when the direct wave N of the ultrasonic wave S transmitted by the first ultrasonic sensor 31 is received by the second ultrasonic sensor 32, it may become noise for the position detection of the detection target OB.

[0052] Therefore, in the case of the present embodiment, as shown in FIGS. 8 and 9, a shielding member 33 is provided between the first ultrasonic sensor 31 and the second ultrasonic sensor 32.

[0053] FIG. 8 is a front view of the ultrasonic device 3 according to the present embodiment. FIG. 9 is a side view of the ultrasonic device 3 shown in FIG. 8 as viewed from the direction indicated by the arrow A2 in FIG. 8. The boom 122 (see FIG. 2) is provided on the right side (X-direction side) of the shielding member 33.

[0054] The shielding member 33 includes a first back plate 331, a second back plate 332, a front plate 335, a first shielding plate 333, and a second shielding plate 334.

[0055] The first back plate 331 and the second back plate 332 are arranged at positions that are aligned in the front-rear direction. The front plate 335 is arranged in front of the first back plate 331 and the second back plate 332. The front plate 335 is a plate-like member that extends in the left-right direction and is parallel to the XY plane.

[0056] The first shielding plate 333 corresponds to an example of a shielding member and a first shielding member, and connects the front panel 335 and the first back panel 331 in the front-rear direction. The second shielding plate 334 connects the front panel 335 and the second back panel 332 in the front-rear direction. The first shielding plate 333 and the second shielding plate 334 are substantially perpendicular to the XY plane.

[0057] The first shielding plate 333 is provided between the boom 122 (see FIG. 2) and the first ultrasonic sensor 31 in the traveling state. The first shielding plate 333 is the portion indicated in bold with the reference numeral 333 in FIG. 8. The shape of the first shielding plate 333 is substantially the same as the shape of the shielding member 22 shown in FIGS. 3 and 4.

[0058] The first shielding plate 333 blocks the ultrasonic waves transmitted by the first ultrasonic sensor 31. Specifically, the first shielding plate 333 blocks the ultrasonic waves traveling toward the boom 122 among the ultrasonic waves emitted from the first ultrasonic sensor 31.

[0059] The second shielding plate 334 corresponds to an example of a second shielding member, and is provided between the boom 122 (see FIG. 2) and the second ultrasonic sensor 32 in the traveling state. The second shielding plate 334 is the portion indicated in bold with the reference numeral 334 in FIG. 8. The shape of the second shielding plate 334 is substantially the same as the shape of the shielding member 22 shown in FIGS. 3 and 4.

[0060] The second shielding plate 334 blocks the ultrasonic waves transmitted by the second ultrasonic sensor 32. Specifically, the second shielding plate 334 blocks the ultrasonic waves traveling toward the boom 122 among the ultrasonic waves emitted from the second ultrasonic sensor 32.

[0061] A first sensor hole 331h is provided in the first back panel 331. The first ultrasonic sensor 31 is attached to the first sensor hole 331h.

[0062] In addition, a second sensor hole 332h is provided in the second back panel 332. The second ultrasonic sensor 32 is attached to the second sensor hole 332h.

[0063] The first ultrasonic sensor 31 is provided closer to the boom 122 than the second ultrasonic sensor 32. In other words, the second ultrasonic sensor 32 is provided farther from the boom 122 than the first ultrasonic sensor 31.

[0064] As shown in FIG. 9, the wiring 311 of the first ultrasonic sensor 31 extends rearward from the first ultrasonic sensor 31. The wiring 321 of the second ultrasonic sensor 32 extends rearward from the second ultrasonic sensor 32.

[0065] The first shielding plate 333 is provided so as to curve from the right side to the upper side of the first sensor hole 331h. Also, the second shielding plate 334 is provided so as to curve from the right side to the upper side of the second sensor hole 332h.

[0066] The first shielding plate 333 and the second shielding plate 334 are connected in the left - right direction by the upper surface 333a of the shielding plate. The upper surface 333a of the shielding plate is a plate - like member extending in the left - right direction and parallel to the XZ plane. The first shielding plate 333 is provided below the second shielding plate 334. The upper surface 333a of the shielding plate corresponds to an example of the third shielding member.

[0067] The first shielding plate 333 is a shielding wall that restricts the reach area of the ultrasonic wave transmitted by the first ultrasonic sensor 31. The second shielding plate 334 is a shielding wall that restricts the reach area of the ultrasonic wave transmitted by the second ultrasonic sensor 32.

[0068] The ultrasonic wave transmitted by the first ultrasonic sensor 31 is blocked by the first shielding plate 333 and does not reach the boom 122. Also, the ultrasonic wave transmitted by the second ultrasonic sensor 32 is blocked by the second shielding plate 334 and does not reach the boom 122.

[0069] The first sensor hole 331h is provided below the second sensor hole 332h. Between the first sensor hole 331h and the second sensor hole 332h, a shielding plate upper surface 333a and a second shielding plate 334 are provided. Therefore, the direct wave N (see FIG. 7) of the ultrasonic wave transmitted by the first ultrasonic sensor 31 is shielded by the shielding plate upper surface 333a and the second shielding plate 334 and does not reach the second ultrasonic sensor 32.

[0070] The ultrasonic device 3 according to the present embodiment having the above-described configuration is attached to the mobile crane 1 in the state shown in FIG. 10. Specifically, the ultrasonic device 3 is provided below the bumper 13 of the vehicle body 11.

[0071] As shown in FIG. 10, a part of the shielding member 33 is hidden behind the bumper 13. In other words, the bumper 13 covers a part of the shielding member 33 from the front.

[0072] In FIG. 10, the boom 122 is located diagonally above the right of the ultrasonic device 3. The ultrasonic wave S transmitted from the first ultrasonic sensor 31 is blocked by the shielding member 33 (specifically, the first shielding plate 333) and does not reach the boom 122.

[0073] Also, the ultrasonic wave S transmitted from the second ultrasonic sensor 32 is blocked by the shielding member 33 (specifically, the second shielding plate 334) and does not reach the boom 122.

[0074] Further, the direct wave N (see FIG. 7) of the ultrasonic wave transmitted by the first ultrasonic sensor 31 is shielded by the shielding member 33 (specifically, the shielding plate upper surface 333a and the second shielding plate 334) and does not reach the second ultrasonic sensor 32. The shielding plate upper surface 333a and the second shielding plate 334 can also be regarded as an example of a third shielding member.

[0075] On the other hand, among the ultrasonic waves S transmitted from the first ultrasonic sensor 31, the ultrasonic waves directed toward the detection target OB (see FIG. 7) located in front of the mobile crane 1 are not shielded by the shielding member 33 and thus reach the detection target OB.

[0076] Then, the ultrasonic wave S is reflected by the detection target OB to become reflected waves R1 and R2 (see FIG. 7). Since the reflected wave R1 is not shielded by the shielding member 33, it is received by the first ultrasonic sensor 31. Since the reflected wave R2 is not shielded by the shielding member 33, it is received by the second ultrasonic sensor 32.

[0077] In addition, the above description is about the ultrasonic device 3 provided in the left half of the front surface of the mobile crane 1 (hereinafter, also referred to as the left ultrasonic device 3).

[0078] The mobile crane 1 according to the present embodiment is also provided with an ultrasonic device 3 (right ultrasonic device 3) having the same configuration as the left ultrasonic device 3 on the right half of the front surface. The left ultrasonic device 3 and the right ultrasonic device 3 are in a left-right symmetric relationship. Such a configuration is also provided in the mobile crane according to the embodiment described later.

[0079] <Modification 1> FIG. 11 is a side view of the ultrasonic device 4 according to Modification 1 of Embodiment 2. The front view of the ultrasonic device 4 according to Modification 1 is substantially the same as FIG. 8, which is the front view of the ultrasonic device 3 according to Embodiment 2.

[0080] The shielding member 43 of Modification 1 has a configuration in which the shielding member 33 according to Embodiment 2 is inclined. Specifically, the shielding member 43 is inclined such that the front end portion is located above the rear end portion.

[0081] More specifically, the first ultrasonic sensor 41, the second ultrasonic sensor 42, the first back plate 431, the second back plate 432, the first shielding plate 433, the upper surface 433a of the shielding plate, and the second shielding plate 434 are inclined such that the front end portion is higher than the rear end portion.

[0082] Note that the front plate 435 is not inclined. By forming it in this way, even if the ultrasonic device 4 is installed below the bumper 13, a detection target OB at a slightly higher position can also be detected.

[0083] <Modification 2> FIG. 12 is a front view of the ultrasonic device 5 according to Modification 2 of Embodiment 2. In the ultrasonic device 5 of Modification 2, a shielding bumper 53 that forms a shielding wall with a bumper is used.

[0084] The shielding bumper 53 is made of metal or resin. The shielding bumper 53 has a first sensor hole (not shown) for supporting the first ultrasonic sensor 51 and a second sensor hole (not shown) for supporting the second ultrasonic sensor 52.

[0085] In the traveling state, the boom 122 (see FIG. 2) is located obliquely above and to the right of the first ultrasonic sensor 51 and the second ultrasonic sensor 52.

[0086] The shielding bumper 53 has a first back plate 531 and a second back plate 532. The first back plate 531 and the second back plate 532 are provided at positions aligned in the front-rear direction.

[0087] Further, the shielding bumper 53 has a first shielding plate 533 and a second shielding plate 534. The first shielding plate 533 and the second shielding plate 534 correspond to an example of a shielding member.

[0088] The first shielding plate 533 is substantially perpendicular to the XY plane. The first shielding plate 533 connects the front plate 535 and the first back plate 531 of the shielding bumper 53 in the front-rear direction. The first shielding plate 533 is provided between the boom 122 (see FIG. 2) and the first ultrasonic sensor 51 in the traveling state. The first shielding plate 533 is the portion indicated in bold with the reference numeral 533 in FIG. 12. The shape of the first shielding plate 533 is substantially the same as the shape of the shielding member 22 shown in FIGS. 3 and 4.

[0089] The first shielding plate 533 blocks the ultrasonic waves transmitted by the first ultrasonic sensor 51. Specifically, the first shielding plate 533 blocks the ultrasonic waves traveling toward the boom 122 among the ultrasonic waves emitted from the first ultrasonic sensor 51.

[0090] The second shielding plate 534 is substantially perpendicular to the XY plane. The second shielding plate 534 connects the front panel 535 of the shielding bumper 53 and the second back panel 532 in the front-rear direction. The second shielding plate 534 is provided between the boom 122 (see FIG. 2) and the second ultrasonic sensor 52 in the traveling state. The second shielding plate 534 is the portion indicated in bold with the symbol 534 in FIG. 12. The shape of the second shielding plate 534 is substantially the same as the shape of the shielding member 22 shown in FIGS. 3 and 4.

[0091] The second shielding plate 534 blocks the ultrasonic waves transmitted by the second ultrasonic sensor 52. Specifically, the second shielding plate 534 blocks the ultrasonic waves heading toward the boom 122 among the ultrasonic waves emitted from the second ultrasonic sensor 52.

[0092] A first sensor hole is provided in the first back panel 531. The first ultrasonic sensor 51 is attached to the first sensor hole. Also, a second sensor hole is provided in the second back panel 532. The second ultrasonic sensor 52 is attached to the second sensor hole.

[0093] The first ultrasonic sensor 51 is provided closer to the boom 122 than the second ultrasonic sensor 52. In other words, the second ultrasonic sensor 52 is provided farther from the boom 122 than the first ultrasonic sensor 51.

[0094] The wiring (not shown) of the first ultrasonic sensor 51 extends rearward from the first ultrasonic sensor 51. The wiring (not shown) of the second ultrasonic sensor 52 extends rearward from the second ultrasonic sensor 52.

[0095] The first shielding plate 533 and the second shielding plate 534 are connected in the left-right direction by the upper shielding plate surface 533a. The upper shielding plate surface 333a is a plate-like member extending in the left-right direction and parallel to the XZ plane. The first shielding plate 333 is provided below the second shielding plate 334. The upper shielding plate surface 533a corresponds to an example of the third shielding member.

[0096] The first shielding plate 533 is a shielding wall that restricts the reach area of the ultrasonic waves transmitted by the first ultrasonic sensor 51. The second shielding plate 534 is a shielding wall that restricts the reach area of the ultrasonic waves transmitted by the second ultrasonic sensor 52.

[0097] The ultrasonic waves transmitted by the first ultrasonic sensor 51 are blocked by the first shielding plate 533 and do not reach the boom 122. Also, the ultrasonic waves transmitted by the second ultrasonic sensor 52 are blocked by the second shielding plate 534 and do not reach the boom 122.

[0098] The first ultrasonic sensor 51 is provided below the second ultrasonic sensor 52. And between the first ultrasonic sensor 51 and the second ultrasonic sensor 52, the upper surface 333a of the shielding plate and the second shielding plate 334 are provided. For this reason, the direct wave N (see Fig. 7) of the ultrasonic waves transmitted by the first ultrasonic sensor 51 is blocked by the upper surface 533a of the shielding plate and the second shielding plate 534 and does not reach the second ultrasonic sensor 32. The upper surface 333a of the shielding plate and the second shielding plate 334 can also be regarded as an example of a third shielding member.

[0099] <Modification Example 3> Fig. 13 is a front view of the ultrasonic device 6 according to Modification Example 3 of Embodiment 2. Fig. 14 is a bottom view of the ultrasonic device 6 as seen from the direction of arrow A3 shown in Fig. 13.

[0100] In the case of this example, as shown in Fig. 13, the first ultrasonic sensor 61 and the second ultrasonic sensor 62 are provided at the same height. Also, the first sensor hole 631h and the second sensor hole 632h are provided at the same height.

[0101] In the traveling state, the boom 122 (see Fig. 2) is located on the right side of the first ultrasonic sensor 51 and the second ultrasonic sensor 52. The first back plate 631 and the second back plate 632 are provided at positions that are aligned in the front-rear direction.

[0102] The first back panel 631 and the second shielding plate 634 are connected in the left - right direction by an inclined plate 631a. The inclined plate 631a is inclined so as to be positioned forward as it approaches the second shielding plate 634 (in other words, as it moves away from the boom 122). The inclined plate 631a corresponds to an example of a third shielding member. The first shielding plate 633 and the second shielding plate 634 are substantially perpendicular to the XY plane.

[0103] A first sensor hole 631h is provided in the first back panel 631. A first ultrasonic sensor 61 is attached to the first sensor hole 631h. Also, a second sensor hole 632h is provided in the second back panel 632. A second ultrasonic sensor 62 is attached to the second sensor hole 632h.

[0104] The first ultrasonic sensor 61 is provided closer to the boom 122 than the second ultrasonic sensor 62. In other words, the second ultrasonic sensor 62 is provided farther from the boom 122 than the first ultrasonic sensor 61.

[0105] As shown in FIG. 14, the wiring 611 of the first ultrasonic sensor 61 extends rearward from the first ultrasonic sensor 61. The wiring 621 of the second ultrasonic sensor 62 extends rearward from the second ultrasonic sensor 62.

[0106] The first shielding plate 633 is provided so as to curve from the right side to the upper side of the first sensor hole 631h. Also, the second shielding plate 634 is provided so as to curve from the right side to the upper side of the second sensor hole 632h.

[0107] The first shielding plate 633, the second shielding plate 634, and the inclined plate 631a are shielding walls that limit the reach areas of the ultrasonic waves transmitted by the first ultrasonic sensor 61 and the second ultrasonic sensor 62.

[0108] In this case, an inclined plate 631a and a second shielding plate 634 are provided between the first ultrasonic sensor 61 and the second ultrasonic sensor 62. Therefore, the direct wave N (see FIG. 7) of the ultrasonic wave transmitted by the first ultrasonic sensor 61 is shielded by the inclined plate 631a and the second shielding plate 634 and does not reach the second ultrasonic sensor 62. Note that the ultrasonic device 6 in this example may be inclined like the ultrasonic device 5 (see FIG. 12) according to the above-described Modification 2.

[0109] <Modification 4> FIG. 15 is a bottom view of an ultrasonic device 7 according to Modification 4 of Embodiment 2. In the ultrasonic device 7 of this example, a first ultrasonic sensor 71 and a second ultrasonic sensor 72 are provided at positions shifted from each other in the front-rear direction.

[0110] In this case, the first sensor hole 731h and the second sensor hole 732h are provided at the same height. Therefore, the first ultrasonic sensor 71 and the second ultrasonic sensor 72 are also provided at the same height.

[0111] In the traveling state, the boom 122 (see FIG. 2) is located on the right side of the first ultrasonic sensor 71 and the second ultrasonic sensor 72. The first back plate 731 is provided on the front side of the second back plate 732. The first back plate 731 is parallel to the XY plane and is in the shape of a plate extending in the left-right direction.

[0112] The first back plate 731 is in the shape of a flat plate. The left end portion of the first back plate 731 (in other words, the end portion far from the boom 122) is connected to the second shielding plate 734. The first shielding plate 733 and the second shielding plate 734 are substantially perpendicular to the XY plane.

[0113] A first sensor hole 731h is provided in the first back plate 731. The first ultrasonic sensor 71 is attached to the first sensor hole 731h. Further, a second sensor hole 732h is provided in the second back plate 732. The second ultrasonic sensor 72 is attached to the second sensor hole 732h.

[0114] The wiring 711 of the first ultrasonic sensor 71 extends rearward from the first ultrasonic sensor 71. The wiring 721 of the second ultrasonic sensor 72 extends rearward from the second ultrasonic sensor 72.

[0115] The first shielding plate 733 is provided so as to curve from the right side to the upper side of the first ultrasonic sensor 71. The first shielding plate 733 shields the ultrasonic wave that travels from the first ultrasonic sensor 71 toward the boom 122 among the ultrasonic waves transmitted by the first ultrasonic sensor 71. Incidentally, the basic shape of the first shielding plate 733 is substantially the same as the shape of the shielding member 22 shown in FIGS. 3 and 4.

[0116] Also, the second shielding plate 734 is provided so as to curve from the right side to the upper side of the second ultrasonic sensor 72. The second shielding plate 734 shields the ultrasonic wave that travels from the second ultrasonic sensor 72 toward the boom 122 among the ultrasonic waves transmitted by the second ultrasonic sensor 72. Incidentally, the shape of the second shielding plate 734 is substantially the same as the shape of the shielding member 22 shown in FIGS. 3 and 4.

[0117] In the case of this example, a first back plate 731 and a second shielding plate 734 are provided between the first ultrasonic sensor 71 and the second ultrasonic sensor 72. The first back plate 731 and the second shielding plate 734 can also be regarded as an example of a third shielding member. Therefore, the direct wave N (see FIG. 7) of the ultrasonic wave transmitted by the first ultrasonic sensor 71 is shielded by the first back plate 731 and the second shielding plate 734 and does not reach the second ultrasonic sensor 32.

[0118] Incidentally, the ultrasonic device 7 of this example may be inclined like the ultrasonic device 5 (see FIG. 12) according to the above-described Modification 2.

[0119] <Supplementary Note>

[0120] The configuration of the ultrasonic device 2 according to the above-described Embodiment 1 and the configurations of the ultrasonic devices 3 to 7 according to the above-described Embodiments 2 and Modifications 1 to 4 may be appropriately combined.

[0121] Furthermore, the shape of the shielding member is not limited to the shapes of the shielding members in the above-described Embodiments 1 and 2 and Modification Examples 1 to 4. The shape of the shielding member may be various shapes provided between the boom and the ultrasonic sensor in the traveling state and capable of blocking the ultrasonic waves traveling toward the boom among the ultrasonic waves transmitted by the ultrasonic sensor.

[0122] For example, the shielding member may be composed of a plurality of plate-like members fixed by fixing means such as welding. For example, the shielding plate 232 shown in FIG. 2 may have a configuration in which a side plate that is a plate-like member parallel to the ZY plane and an upper plate that is a plate-like member parallel to the XY plane are connected. In this case, the side plate is disposed on the right side of the ultrasonic sensor 21 and covers the ultrasonic sensor 21 from the right side. Further, the upper plate is disposed above the ultrasonic sensor 21 and covers the ultrasonic sensor 21 from the upper side.

[0123] Furthermore, the routing mode of the wiring connecting the ultrasonic sensor and the detection device is not limited to the above-described case. The wiring of the ultrasonic sensor may extend in the left-right direction or the up-down direction from the ultrasonic sensor.

[0124] In the case of the above-described mobile crane, the ultrasonic device on the left side and the ultrasonic device on the right side are arranged symmetrically left and right. However, the ultrasonic device on the left side and the ultrasonic device on the right side may be arranged asymmetrically left and right.

[0125] Furthermore, the mobile crane may be provided with at least one of the ultrasonic devices on the left side and the ultrasonic devices on the right side. When the mobile crane is provided with only one ultrasonic device, it is preferable that the ultrasonic device is provided in front of the vehicle in the direction in which the boom is located when viewed from the operator's cab.

[0126] Also, in the case of the ultrasonic device 3 (see FIG. 8) according to the above-described Embodiment 2, the first back plate 331 and the second back plate 332 are provided at the same position in the front-rear direction. However, the first back plate 331 and the second back plate 332 may be provided at positions shifted in the front-rear direction. Further, the first shielding plate 333 and the second shielding plate 334 are not limited to being substantially perpendicular to the XY plane and may be inclined with respect to the XY plane. The shielding plate 232 in Embodiment 1 may also be inclined with respect to the XY plane.

[0127] As the detection means such as an ultrasonic sensor, various ones can be used, such as those with a thin thickness to those with a thick thickness. Also, the two detection means may be wired so as to be connected from the detection device to one detection means and from one detection means to the other detection means. In the examples and modified examples, an example of applying the present invention to a rough terrain crane was shown. However, the present invention can be applied to a crane capable of traveling.

[0128] In addition, the specific configuration is not limited to the embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. Further, each of the above-described embodiments can be combined by diverting each other's technologies as long as there are no particular contradictions or problems in their purposes and configurations.

[0129] The disclosure contents of the specification, drawings, and abstract included in the Japanese application of Japanese Patent Application No. 2022-30996 filed on March 1, 2022 are all incorporated herein by reference.

Industrial Applicability

[0130] The present invention is applicable to various mobile cranes.

Explanation of Reference Numerals

[0131] 1 Mobile crane 11 Vehicle body 12 Slewing body 121 Operator's cab 122 Boom 13 Bumper 14 Outrigger 2 Ultrasonic device 21 Ultrasonic sensor 211 Wiring 22 Shielding member 231 Back panel 232 Shielding plate 3 Ultrasonic device 31 First ultrasonic sensor 311 Wiring 32 Second ultrasonic sensor 321 Wiring 33 Shielding member 331 First back panel 331h First sensor hole 332 Second back panel 332h Second sensor hole 333 First shielding plate 333a Upper surface of the shielding plate 334 Second shielding plate 335 Front panel 4 Ultrasonic device 41 First ultrasonic sensor 42 Second ultrasonic sensor 43 Shielding member 431 First back panel 432 Second back panel 433 First shielding plate 433a Upper surface of the shielding plate 434 Second shielding plate 435 Front panel 5 Ultrasonic device 51 First ultrasonic sensor 52 Second ultrasonic sensor 53 Shielding bumper 531 First back panel 532 Second back panel 533 First shielding plate 533a Upper surface of the shielding plate 534 Second shielding plate 535 Front panel 6 Ultrasonic device 61 First ultrasonic sensor 611 Wiring 62 Second ultrasonic sensor 621 Wiring 63 Shielding member 631 First back panel 631a Inclined plate 631h First sensor hole 632 Second back panel 632h Second sensor hole 633 First shielding plate 634 Second shielding plate 7 Ultrasonic device 71 First ultrasonic sensor 711 Wiring 72 Second ultrasonic sensor 721 Wiring 73 Shielding member 731 First back panel 731h First sensor hole 732 Second back panel 732h Second sensor hole 733 First shielding plate 734 Second shielding plate 9 Detection device OB Detection target S Ultrasonic wave R1 Reflected wave R2 Reflected wave N Direct wave

Claims

1. A mobile crane comprising a boom and a traveling vehicle body that supports the boom, the mobile crane traveling with the boom in a forwardly collapsed state, having an ultrasonic sensor provided on the front side of the traveling vehicle body, and a distance detection device that detects the distance between the ultrasonic sensor and a detection target, and comprising a shielding member provided between the boom and the ultrasonic sensor in a traveling state, the shielding member blocking ultrasonic waves transmitted by the ultrasonic sensor. Mobile crane.

2. The shielding member covers the ultrasonic sensor from the boom side. The mobile crane according to Claim 1.

3. The ultrasonic sensor has a first ultrasonic sensor, and a second ultrasonic sensor, The shielding member is provided between the boom and the first ultrasonic sensor in the traveling state, and has a first shielding member that blocks ultrasonic waves traveling toward the boom among the ultrasonic waves transmitted by the first ultrasonic sensor, is provided between the boom and the second ultrasonic sensor in the traveling state, and has a second shielding member that blocks ultrasonic waves traveling toward the boom among the ultrasonic waves transmitted by the second ultrasonic sensor, and the distance detection device detects the distance by means of the first ultrasonic sensor and the second ultrasonic sensor. The mobile crane according to Claim 1.

4. The shielding member has a third shielding member provided between the first ultrasonic sensor and the second ultrasonic sensor. The mobile crane according to Claim 3.

5. The third shielding member connects the first shielding member and the second shielding member in the left-right direction. The mobile crane according to Claim 4.

6. The second ultrasonic sensor is provided at a position higher than the first ultrasonic sensor. The mobile crane according to Claim 3.

7. The first ultrasonic sensor and the second ultrasonic sensor are provided at the same height. The mobile crane according to Claim 3.

8. The ultrasonic sensor is provided below the bumper of the traveling vehicle body. The mobile crane according to Claim 1.

9. The shielding member is constituted by a part of the bumper of the traveling vehicle body. The mobile crane according to Claim 1.

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