Industrial vehicle

Abstract

To provide an industrial vehicle capable of suppressing application of an excessive load to a fork-side mechanism during a side shift operation.SOLUTION: An industrial vehicle 1 includes a side shift mechanism that horizontally side-shifts the position of a pair of forks 13, a distance sensor that is provided on at least one of the horizontal sides of the pair of forks 13 and detects the distance from the side to a detection target, and a control unit 23 that controls the side shift operation of the pair of forks 13 by the side shift mechanism based on the detection result of the distance sensor. The control unit 23 stores an initial value of the distance between the side of the fork 13 and an inner wall surface that defines the insertion hole when the side shift operation by the side shift mechanism is started, and stops the side shift operation by the side shift mechanism when the distance between the side of the fork 13 and the inner wall surface varies from an initial value ds during the side shift operation by the side shift mechanism.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to industrial vehicles. [Background technology]

[0002] For example, Patent Document 1 describes a forklift equipped with a side shift device. The side shift device described in Patent Document 1 includes a lift bracket that moves up and down along a mast, a backrest that is provided on the lift bracket and has a fork attached thereto, and a side shift mechanism that shifts the fork to the side in a horizontal direction (for example, the width direction of the vehicle body). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-143039 A Summary of the Invention [Problem to be solved by the invention]

[0004] When cargo is loaded onto the bed of a truck using the above-mentioned industrial vehicle, a method is adopted in which adjacent pallets are brought into contact with each other using a side shift mechanism, and the pallets are arranged so that no gaps are generated between them. By eliminating the gaps between the pallets, the space on the bed can be used more efficiently, and the shaking of cargo caused by vibration during transportation can be suppressed. On the other hand, when loading cargo, if the amount of side shift is excessive when the fork side shift operation is performed automatically, the pallet being loaded may hit another pallet that has already been loaded. In this case, the frictional force when the pallet slides on the fork and the reaction force against the force of the fork pushing the inner wall surface of the pallet after the pallet hits the other pallet are applied to the fork, and there is a risk of a load being applied to the fork mechanism (the fork itself, the hydraulic cylinder for side shift, etc.).

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an industrial vehicle that can prevent excessive load from being applied to the fork-side mechanism during side shifting operations. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, an industrial vehicle is provided with a loading device having a pair of forks, and performs loading and unloading by inserting the pair of forks into insertion holes of a pallet, the industrial vehicle including a side shift mechanism that side-shifts a position of the pair of forks in a horizontal direction, a distance sensor provided on a horizontal side surface of at least one of the pair of forks that detects a distance from the side surface to a detection target, and a control unit that controls a side shifting operation of the pair of forks by the side shift mechanism based on a detection result of the distance sensor. The control unit stores an initial value of a distance between a side surface of the fork and an inner wall surface that defines the insertion hole when a side shifting operation by the side shift mechanism is started, and stops the side shifting operation by the side shift mechanism when the distance between the side surface of the fork and the inner wall surface varies from the initial value during the side shifting operation by the side shift mechanism.

[0007] In this industrial vehicle, the stop of the side shift operation by the side shift mechanism is determined by the relationship between the distance between the side of the fork and the inner wall surface of the pallet and the initial value of the distance. During the side shift operation, both the fork and the pallet shift horizontally during the period from the start of the side shift operation until the pallet comes into contact with the loaded pallet or the like. Therefore, during the above period, the distance detected by the distance sensor does not vary from the initial value. On the other hand, after the pallet comes into contact with the loaded pallet or the like, only the fork starts to slide horizontally in the insertion hole, so the distance detected by the distance sensor varies from the initial value. Therefore, when performing the side shift operation, by stopping the side shift operation when the distance between the side of the fork and the inner wall surface of the pallet changes from the initial value, it is possible to quickly detect the start of sliding of the fork in the insertion hole. This makes it possible to prevent the fork from being subjected to the frictional force when the pallet slides on the fork or the reaction force against the force of the fork pushing the inner wall surface of the pallet after the pallet comes into contact with another pallet, and to suppress the application of excessive load to the fork side mechanism during the side shift operation.

[0008] The distance sensors may be provided on the respective sides of the pair of forks facing opposite directions, in which case the start of sliding of the forks in the insertion holes can be detected with high accuracy.

[0009] The control unit may stop the side shifting operation by the side shift mechanism when the distance detected by the distance sensor of one fork becomes larger than an initial value and the distance detected by the distance sensor of the other fork becomes smaller than the initial value. After the pallet being loaded comes into contact with a pallet or the like that has already been loaded, the pallet being loaded starts to slide horizontally in one direction in the insertion hole. At this time, as the pallet starts to slide, the distance between the side of one fork and the inner wall surface of the pallet increases, and the distance between the side of the other fork and the inner wall surface of the pallet decreases. Therefore, by providing distance sensors on the respective sides of the pair of forks facing oppositely to each other and stopping the side shifting operation as described above, it is possible to accurately detect the start of sliding of the forks in the insertion hole.

[0010] The distance sensor may be composed of a first distance sensor located at the base end of the fork and a second distance sensor located at the tip end of the fork, in which case it is possible to accurately detect the start of the fork slipping out of the insertion hole.

[0011] The control unit may stop the side shifting operation by the side shift mechanism when one of the distances detected by the first distance sensor and the second distance sensor varies from an initial value. In this case, by stopping the side shifting operation as described above, it is possible to more accurately detect the start of the fork slipping out of the insertion hole.

[0012] The control unit may stop the side shifting operation by the side shift mechanism when both the distances detected by the first distance sensor and the second distance sensor have changed from their initial values. When the forks are inserted into the insertion holes of the pallet, it is possible that the forks are inserted at an angle to the extension direction of the insertion holes. In this case, it is possible that a part of the pallet being loaded first abuts against the loaded pallet, and then another part abuts against the loaded pallet. Therefore, according to the above-mentioned control, when the forks are inserted at an angle to the extension direction of the insertion holes, the side shifting operation can be stopped at the point when the pallet being loaded abuts against the other loaded pallet. Therefore, it is possible to position the pallet being loaded against the loaded pallet without any gap, while suppressing excessive load from being applied to the fork-side mechanism during the side shifting operation.

[0013] The control unit may stop the side shifting operation by the side shift mechanism when a predetermined time has elapsed since one of the distances detected by the first distance sensor and the second distance sensor has changed from an initial value. According to this type of control, by setting the predetermined time in consideration of the speed of the side shifting operation, it is possible to position the pallet being loaded closely relative to the pallet that has already been loaded, while preventing excessive load from being applied to the fork-side mechanism during the side shifting operation.

[0014] The control unit may stop the side shifting operation by the side shift mechanism when the distance detected by the first distance sensor and the distance detected by the second distance sensor become equal after one of the distances detected by the first distance sensor and the second distance sensor has changed from the initial value. When the fork is inserted obliquely with respect to the extension direction of the insertion hole, as described above, a part of the pallet being loaded abuts against the pallet that has already been loaded. At this time, the distance detected by one distance sensor located closer to the part changes from the initial value. After that, the other part abuts against the pallet that has already been loaded, so that the distances detected by both distance sensors become equal. Therefore, according to the above-mentioned control, when the fork is inserted obliquely with respect to the extension direction of the insertion hole, the side shifting operation can be stopped at the point when the pallet being loaded abuts against another pallet that has already been loaded. Therefore, it is possible to arrange the pallet being loaded without any gap against the pallet that has already been loaded, while suppressing excessive load from being applied to the mechanism on the fork side during the side shifting operation.

[0015] The distance sensor may be provided on the side of the pair of forks facing the other fork. In this case, the distance sensor can be prevented from colliding with the inner wall surface of the pallet during side shifting, thereby preventing damage to the distance sensor.

[0016] The pair of forks may be provided with a bracket with a window. The bracket with a window may be provided on a side surface so that the distance sensor is exposed through the window. In this case, a configuration in which the distance sensor is provided on the side surface can be easily realized, and the distance sensor is protected by the bracket. Effect of the Invention

[0017] According to the present disclosure, it is possible to prevent excessive load from being applied to the fork-side mechanism during a side shift operation. [Brief description of the drawings]

[0018] [Figure 1]FIG. 1 is a side view showing an example of an industrial vehicle according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view that typically shows a state in which the industrial vehicle performs loading and unloading. [Diagram 3] FIG. 3 is a block diagram showing a functional configuration of the industrial vehicle shown in FIG. [Figure 4] FIG. 4 is a perspective view showing the configuration of the fork. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates a schematic configuration of the forks and the pallet. [Figure 6] FIG. 6 is a cross-sectional view that illustrates a schematic configuration of the fork and the pallet. [Figure 7] FIG. 7 is a flowchart showing an example of the operation of the industrial vehicle. [Figure 8] FIG. 8 is a flowchart showing an example of control of a side shift operation. [Figure 9] FIG. 9 is a cross-sectional view that illustrates a schematic configuration of a fork and a pallet. [Figure 10] FIG. 10 is a cross-sectional view that illustrates a schematic configuration of the fork and the pallet. [Figure 11] FIG. 11 is a flow chart showing another example of control of a side shift operation. [Figure 12] FIG. 12 is a flow chart showing yet another example of control of a side shift operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, a preferred embodiment of an industrial vehicle according to one aspect of the present disclosure will be described in detail with reference to the drawings.

[0020] First, the configuration of an industrial vehicle 1 according to the present disclosure will be described with reference to Fig. 1. Fig. 1 is a side view showing an example of an industrial vehicle 1. As shown in Fig. 1, the industrial vehicle 1 includes a traveling device 2 and a loading device 3 that is disposed in front of the traveling device 2 and has a pair of forks 13.

[0021] The traveling device 2 has a vehicle body 4, front wheels 5 which are a pair of drive wheels arranged at the front of the vehicle body 4, and rear wheels 6 which are a pair of steering wheels arranged at the rear of the vehicle body 4. The vehicle body 4 is provided with a cab 7 which is formed by a frame including a head guard. Inside the cab 7, a lift operation lever used to operate the lift cylinder 14, a tilt operation lever used to operate the tilt cylinder 15, a steering wheel for steering the industrial vehicle 1, and the like are arranged. In addition, the traveling device 2 has a traveling motor which rotates the front wheels 5, and a steering motor which steers the rear wheels 6 by rotating the handle shaft of the industrial vehicle 1. In the industrial vehicle 1, the traveling motor rotates the front wheels 5, and the steering motor steers the rear wheels 6, thereby realizing traveling by the traveling device 2.

[0022] The cargo handling device 3 has a mast 11 attached to the front of the vehicle body 4, a pair of forks 13 attached to the mast 11 via lift brackets 12 and holding cargo W, a lift cylinder 14 for raising and lowering the forks 13, a tilt cylinder 15 for tilting the mast 11, and a side shift cylinder 16 (see FIG. 2) for horizontally shifting the forks 13. In this embodiment, the side shift cylinder 16 functions as a side shift mechanism for horizontally shifting the position of the pair of forks 13.

[0023] The industrial vehicle 1 is a self-propelled vehicle that receives a pallet P at a loading position set at any position, for example, indoors or outdoors, and moves to a loading position where the pallet P should be loaded. The industrial vehicle 1 then loads the pallet P at the loading position. Figure 2 is a perspective view that shows a schematic view of the industrial vehicle 1 performing loading and unloading.

[0024] The pallet P is a loading platform for placing cargo W thereon, and is a loading target on which a loading operation is performed by the loading device 3. As shown in Fig. 2, for example, one or more cargoes W are placed on the pallet P. The pallet P is, for example, a flat pallet made of plastic or wood. The pallet P has a rectangular shape in a plan view.

[0025] The pallet P has a front surface Pa, a rear surface Pb, and a pair of side surfaces Pc. The front surface Pa is the surface that faces the industrial vehicle 1 when the pallet P is held by the forks 13. The rear surface Pb is the surface located opposite the front surface Pa. The pair of side surfaces Pc are the surfaces that come into contact with loaded pallets, etc. when the pallet P is loaded.

[0026] The pallet P is provided with insertion holes H into which the pair of forks 13 are inserted. In this embodiment, the pallet P is provided with a pair of insertion holes H corresponding to the pair of forks 13. The insertion holes H are through-holes with a rectangular cross section that penetrate the pallet P from the front surface Pa to the rear surface Pb. The insertion holes H are defined by the inner wall surface Pd of the pallet P.

[0027] In the following description, the pallet to be loaded by the industrial vehicle 1 will be referred to as "pallet P1," and the pallet on which the pallet has already been loaded will be referred to as "pallet P2." For convenience, the following description will be given assuming that the pallets P1 and P2 have the same configuration.

[0028] During loading and unloading, the industrial vehicle 1 holds the pallet P1 by inserting the pair of forks 13 into the insertion hole H. At this time, in the insertion hole H, the side surface 13a of the forks 13 and the inner wall surface Pd that defines the insertion hole H face each other horizontally. When loading the pallet P1, the side shift cylinder 16 automatically shifts the pair of forks 13 to the side, so that the pallet P1 and the loaded pallet P2 come into contact with each other, and loading is performed so that no gap is generated between them. At this time, if the amount of side shift of the pair of forks 13 becomes excessive, it is considered that the pallet P1 being loaded will hit the pallet P2. In this case, the frictional force when the pallet P1 slides on the forks 13 and the reaction force against the force that pushes the inner wall surface Pd of the pallet P1 that defines the insertion hole H after the pallet P1 hits the pallet P2 are applied to the forks 13, and there is a risk of a load being applied to the mechanism on the fork 13 side.

[0029] To address this issue, the industrial vehicle 1 quickly detects the start of sliding of the pallet P1 during side-shifting operation, thereby preventing the application of frictional force when the pallet P1 slides on the forks 13 and a reaction force against the force of the forks 13 pressing against the inner wall surface Pd of the pallet P1 after the pallet P1 hits the pallet P2 to the forks 13. To achieve this function, the industrial vehicle 1 is equipped with a control device 20.

[0030] The following describes in detail the functional configuration of the control device 20 for realizing the above functions. Fig. 3 is a block diagram showing an example of the functional configuration of an industrial vehicle. To realize the above functions, the control device 20 has a first distance sensor 21, a second distance sensor 22, and a control unit 23.

[0031] The first distance sensor 21 and the second distance sensor 22 are distance sensors that detect the distance from the sensor itself to a detection object located in front of the sensor. For example, the first distance sensor 21 and the second distance sensor 22 detect the distance between the sensor itself and the detection object by irradiating a laser light in front of the sensor itself and receiving the reflected light of the laser light from the detection object.

[0032] The first distance sensor 21 and the second distance sensor 22 are provided on the horizontal side surface 13a of each of the pair of forks 13. In this embodiment, as shown in Fig. 4, in each of the pair of forks 13, the first distance sensor 21 is provided on the base end side of the fork 13, and the second distance sensor 22 is provided on the tip end side of the fork. That is, in this embodiment, the first distance sensor 21 and the second distance sensor 22 are provided at different positions on the side surface 13a in the extension direction of the fork 13. On the side surface 13a, the first distance sensor 21 and the second distance sensor 22 may be provided so as to be embedded in the side surface 13a, or may be provided on the side surface 13a.

[0033] The first distance sensor 21 and the second distance sensor 22 are provided on the side surface 13a of the pair of forks 13 so as to face each other in opposite directions. The first distance sensor 21 and the second distance sensor 22 provided on one fork 13 and the first distance sensor and the second distance sensor 22 provided on the other fork face each other in the horizontal direction.

[0034] Furthermore, in this embodiment, as shown in Fig. 4, a bracket B with a window is provided on each side surface 13a of the pair of forks 13. Two windows Ba are provided in the bracket B. The windows Ba are, for example, openings provided in the bracket B. In the bracket B, the two windows Ba are provided at positions corresponding to the positions where the first distance sensor 21 and the second distance sensor 22 are provided. In other words, the bracket B with the window is provided on the side surface 13a of the fork 13 so that the first distance sensor 21 and the second distance sensor 22 are exposed from the corresponding windows Ba.

[0035] For example, when a pair of forks 13 are inserted into insertion holes H of a pallet P1, the side surfaces of the forks 13 face the inner wall surface Pd that defines the insertion holes H. Therefore, in this state, the detection object is the inner wall surface Pd of the pallet P1, and the first distance sensor 21 and the second distance sensor 22 detect the distance from the side surface 13a of the forks 13 to the inner wall surface Pd.

[0036] The control unit 23 is a part that controls the side shift operation by the side shift cylinder 16 (side shift mechanism). In this embodiment, in order to control the operation, the control unit 23 stores an initial value ds and starts and stops the side shift operation. The following describes in detail the processes performed by the control unit 23, that is, the storage of the initial value ds and the control of the start and stop of the side shift operation.

[0037] First, the storage of the initial value ds will be described. The initial value ds is the distance between the side surface 13a and the inner wall surface Pd when the side shift operation by the side shift cylinder 16 is started. In one example, the control unit 23 stores the distances d1 and d2 received when the side shift operation is started, among the distances d1 and d2 received from the first distance sensor 21 and the second distance sensor 22, as the initial value ds. In this case, the control unit 23 may store each of the distances received from the first distance sensor 21 and the second distance sensor 22 as the corresponding initial value ds when the side shift operation is started, or may store any one of the distances as the initial value ds. Alternatively, the control unit 23 may store a value input in advance by a user who uses the industrial vehicle 1 as the initial value ds.

[0038] Next, control of starting and stopping the side shift operation will be described. In this embodiment, the start of the side shift operation is controlled by transmitting a start command to the side shift cylinder 16, and the stop of the side shift operation is controlled by transmitting a stop command to the side shift cylinder 16. The start command is a command for starting the side shift operation, and the stop command is a command for stopping the side shift operation. In one example, the control unit 23 stops the side shift operation by the side shift cylinder 16 based on the relationship between the distances d1 and d2 during the side shift operation and the initial value ds.

[0039] In this embodiment, the control unit 23 controls the stopping of the side shift operation when, for example, the forks 13 are inserted along the extension direction of the insertion holes H. Before describing a more specific process for stopping the side shift operation, the configuration of the forks 13 and the pallet P1 during the side shift operation in the above case will be described in detail with reference to Figures 5 and 6.

[0040] 5 and 6 are cross-sectional views that show the configuration of the fork and the pallet. Specifically, FIG. 5 is a cross-sectional view that shows the configuration of the fork 13 and the pallet P1 when the side shift operation is started. FIG. 6 is a cross-sectional view that shows the configuration of the fork 13 and the pallet P1 when the pallet P1 abuts against the pallet P2. Note that in FIGS. 5 and 6, the configuration of the fork 13 is shown in a simplified manner, but in reality, it is the same configuration as that shown in FIG. 4.

[0041] First, the distance between the inner wall surface Pd and each position on the side surface 13a will be described. As described above, when the fork 13 is inserted along the extension direction of the insertion hole H, the distance between the inner wall surface Pd and each position on the side surface 13a is equal.

[0042] Next, a change in the distance between the side surface 13a and the inner wall surface Pd during the side shifting operation will be described. During the side shifting operation, both the fork 13 and the pallet P1 shift horizontally during the period from when the side shifting operation is started to when the pallets P1 and P2 held by the fork 13 come into contact with each other. As a result, during the above period, as shown in Fig. 5, the distance between the side surface 13a of the fork 13 and the inner wall surface Pd does not change from the distance at the start of the side shifting operation.

[0043] On the other hand, after the pallets P1 and P2 held by the forks 13 come into contact with each other, only the forks 13 start to slide horizontally within the insertion hole H. Specifically, as shown in Fig. 6, within the insertion hole H, the forks 13 start to slide toward the side surface Pc where the forks 13 come into contact with the pallet P2. As a result, the distance between the side surface 13a and the inner wall surface Pd of one of the forks 13 located on the side surface Pc side becomes larger, and the distance between the side surface 13a and the inner wall surface Pd of the other fork 13 becomes smaller.

[0044] From the above, when the fork 13 is inserted along the extension direction of the insertion hole H, the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13 are equal to each other.

[0045] Similarly, after pallets P1 and P2 abut, the distance d1 detected by the first distance sensor 21 and the distance d2 detected by the second distance sensor 22 on one of the forks 13 on the side abutting against pallet P2 become larger than the initial value ds, and the distances d1 and d2 on the other fork 13 become smaller than the initial values ​​ds.

[0046] In this embodiment, in consideration of the change in the distance between the side surface 13a of the fork 13 and the inner wall surface Pd during the above-mentioned side shift operation, the control unit 23 stops the side shift operation. That is, in this embodiment, the control unit 23 stops the side shift operation by the side shift cylinder 16 when the distances d1 and d2 in the fork 13 on the side surface Pc side of the pallet P1 in contact with the pallet P2 become larger than the initial values ​​ds and the distances d1 and d2 in the other fork 13 become smaller than the initial values ​​ds.

[0047] Alternatively, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when the distance d1 or the distance d2 of the fork 13 on the side Pc of the pallet P1 abutting against the pallet P2 becomes larger than the initial value ds, and the distance d1 or the distance d2 of the other fork 13 becomes smaller than the initial value ds.

[0048] As described above, the first distance sensor 21 and the second distance sensor 22 are provided on the side surface 13a of the fork 13, and the detection target is the inner wall surface Pd that defines the insertion hole H. Therefore, the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 are the distances between the side surface 13a of the fork 13 and the inner wall surface Pd. For this reason, the control unit 23 stops the side shift operation by the side shift cylinder 16 when the distance between the side surface 13a of one fork 13 and the inner wall surface Pd becomes larger than the initial value ds and the distance between the side surface 13a of the other fork 13 and the inner wall surface Pd becomes smaller than the initial value ds.

[0049] Next, an example of the operation of the industrial vehicle 1 will be described with reference to Fig. 7. Fig. 7 is a flow chart showing an example of the operation of the industrial vehicle 1.

[0050] In step S1, the forks 13 are inserted into the insertion holes H of the pallet P1. This causes the pallet P1 to be held by the forks 13. In step S2, the control unit 23 adjusts the fork positions in the insertion holes H. Here, the fork positions in the insertion holes H are adjusted based on the width of the forks 13 and the width of the insertion holes H so that the first distance sensor 21 and the second distance sensor 22 do not come into contact with the inner wall surface Pd of the pallet P1 during the side shift operation during stacking.

[0051] In step S3, the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13 detect the distance (initial value ds) between the side surface 13a of the fork 13 and the inner wall surface Pd when the side shift operation is initiated.

[0052] In step S4, the control unit 23 controls the side shift operation by the side shift cylinder 16. The control of the side shift operation by the control unit 23 in step S4 will be described in further detail with reference to Fig. 8. Fig. 8 is a flowchart showing an example of the control of the side shift operation.

[0053] In step S401, the control unit 23 starts a side shift operation by the side shift cylinder 16. Here, the control unit 23 starts the side shift operation by transmitting a start command to the side shift cylinder 16 to start the side shift operation.

[0054] In step S402, the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13 detect the distances d1, d2 between the side surface 13a of the fork 13 and the inner wall surface Pd.

[0055] In step S403, the control unit 23 determines whether the distances d1, d2 between the side surface 13a of the fork 13 and the inner wall surface Pd detected in step S402 have changed from the initial value ds. Here, the control unit 23 determines whether the distances d1 and d2 in one fork 13 have increased from the initial value ds, and whether the distances d1 and d2 in the other fork 13 have decreased from the initial value ds.

[0056] If the distances d1 and d2 at one fork 13 have increased from the initial value ds and the distances d1 and d2 at the other fork 13 have decreased from the initial value ds (YES in step S403), the process proceeds to step S404.

[0057] If the distances d1 and d2 at one fork 13 have not increased from the initial values ​​ds, or if the distances d1 and d2 at the other fork 13 have not decreased from the initial values ​​ds (NO in step S403), the process returns to step S402.

[0058] In step S404, the control unit 23 stops the side shift operation by the side shift cylinder 16. Here, the control unit 23 stops the side shift operation by transmitting a stop command to the side shift cylinder 16 to stop the side shift operation.

[0059] As described above, in the industrial vehicle 1, the stop of the side shift operation by the side shift cylinder 16 (side shift mechanism) is determined by the relationship between the distances d1, d2 between the side surface 13a of the fork 13 and the inner wall surface Pd of the pallet P1 and the initial value ds of the distances. During the side shift operation, both the fork 13 and the pallet P1 shift horizontally during the period from the start of the operation until the pallet P1 abuts against the loaded pallet P2. Therefore, during the above period, the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 do not vary from the initial value ds. On the other hand, after the pallet P1 abuts against the loaded pallet P2, only the fork 13 starts to slide horizontally within the insertion hole H, so the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 vary from the initial value ds. Therefore, when performing a side shift operation, by stopping the side shift operation if the distances d1, d2 between the side surface 13a of the fork 13 and the inner wall surface Pd of the pallet P1 vary from the initial value ds, it is possible to quickly detect the start of sliding of the fork 13 in the insertion hole H. This makes it possible to prevent the fork 13 from being subjected to a frictional force when the pallet P1 slides on the fork 13 or a reaction force against the force with which the fork 13 presses the inner wall surface Pd of the pallet P1 after the pallet P1 hits the pallet P2, and to suppress the application of an excessive load to the mechanism on the fork 13 side during the side shift operation.

[0060] In the industrial vehicle 1, the side shift amount is prevented from becoming excessive by stopping the side shift operation through the above-mentioned control. This makes it possible to reduce the time required for the side shift operation when loading one pallet P1 compared to conventional loading, and therefore the time required for loading and unloading operation by the industrial vehicle 1.

[0061] In the industrial vehicle 1, the first distance sensor 21 and the second distance sensor 22 are provided facing oppositely to each other on the respective side surfaces 13a of the pair of forks 13. In this case, the accuracy of detecting the start of sliding of the forks 13 in the insertion hole H can be improved.

[0062] In the industrial vehicle 1, the control unit 23 stops the side shift operation by the side shift cylinder 16 when the distances d1 and d2 in one fork 13 become larger than the initial values ​​ds and the distances d1 and d2 in the other fork 13 become smaller than the initial values ​​ds. After the pallet P1 being loaded comes into contact with the loaded pallet P2, the pallet P1 being loaded starts to slide in one horizontal direction in the insertion hole H. At this time, as the pallet P1 slides out, the distance between the side surface 13a of one fork 13 and the inner wall surface Pd of the pallet P increases, and the distance between the side surface 13a of the other fork 13 and the inner wall surface Pd of the pallet P decreases. Therefore, by providing the first distance sensor 21 and the second distance sensor 22 on the respective side surfaces 13a of the pair of forks 13 in the opposite directions and stopping the side shift operation as described above, the slide out of the fork 13 in the insertion hole H can be detected with high accuracy.

[0063] In the industrial vehicle 1, the control device 20 is provided with a first distance sensor 21 located on the base end side of the fork 13 and a second distance sensor 22 located on the tip end side of the fork. In this case, it is possible to accurately detect the start of the fork slipping inside the insertion hole.

[0064] In the industrial vehicle 1, the first distance sensor 21 and the second distance sensor 22 are provided on the side surface 13a of the pair of forks 13 facing the other fork 13. In this case, it is possible to prevent the first distance sensor 21 and the second distance sensor 22 from colliding with the inner wall surface Pd of the pallet P1 during the side shift operation. Therefore, it is possible to prevent damage to the first distance sensor 21 and the second distance sensor 22.

[0065] In the industrial vehicle 1, a bracket B with a window is provided on the pair of forks 13. The bracket B with the window is provided on the side surface 13a so that the first distance sensor 21 and the second distance sensor 22 are exposed from the window Ba. In this case, the first distance sensor 21 and the second distance sensor 22 can be easily provided on the side surface 13a, while the bracket B protects the first distance sensor 21 and the second distance sensor 22.

[0066] Next, a modified example of the control of the side shift operation by the control unit 23 will be described with reference to Figs. 9 and 10. Figs. 9 and 10 are cross-sectional views showing the configuration of the forks and pallets. Specifically, Fig. 9 is a cross-sectional view showing the configuration of the forks 13 and pallet P1 when the side shift operation is started. Fig. 10 is a cross-sectional view showing the configuration of the forks 13 and pallet P1 when the pallet P1 abuts against the pallet P2. Note that in Figs. 9 and 11, the configuration of the forks 13 is shown in a simplified manner, but in reality it is the same configuration as that shown in Fig. 4.

[0067] In this modified example, the control unit 23 controls the side shift operation when, for example, the fork 13 is inserted obliquely with respect to the extension direction of the insertion hole H. Prior to describing specific processing by the control unit 23 in this modified example, a detailed description will be given of the configuration of the fork 13 and the pallet P1 during the side shift operation when the fork 13 is inserted obliquely with respect to the extension direction of the insertion hole H.

[0068] First, the distance between the side surface 13a and the inner wall surface Pd at each position will be described. When the fork 13 is inserted obliquely with respect to the extending direction of the insertion hole H, the distance between the side surface 13a and the inner wall surface Pd is not uniform over the entire side surface 13a. That is, the distance between the side surface 13a and the inner wall surface Pd differs from one another at each position on the side surface 13a.

[0069] 9, for example, in one fork 13, the distance between the inner wall surface Pd decreases toward the base end, and in the other fork 13, the distance between the inner wall surface Pd increases toward the base end. In the following description, in order to distinguish between the pair of forks 13, the fork 13 in which the distance between the side surface 13a and the inner wall surface Pd decreases toward the base end will be referred to as "fork 13A," and the fork 13 in which the distance between the side surface 13a and the inner wall surface Pd increases toward the base end will be referred to as "fork 13B."

[0070] Next, the change in the distance between the side surface 13a and the inner wall surface Pd during the side shifting operation will be described. Even if the forks 13A and 13B are inserted obliquely with respect to the extension direction of the insertion hole H as shown in Fig. 9, both the forks 13A and 13B and the pallet P1 shift horizontally during the period from the start of the side shifting operation until the pallet P1 held by the forks 13A and 13B abuts against the loaded pallet P2. Therefore, during the above period, the distance between each side surface 13a of the forks 13A and 13B and the inner wall surface Pd does not change from the initial value ds, as in the case where the forks 13 are inserted along the extension direction of the insertion hole H.

[0071] On the other hand, when the pallet P1 and the pallet P2 come into contact with each other, a part of the pallet P1 comes into contact with the pallet P2 first. Specifically, a part of the side surface Pc of the pallet P1 comes into contact with the pallet P2. At this time, the distance between the part of the side surface Pc of each of the side surfaces 13a of the forks 13A and 13B near the part and the inner wall surface Pd varies from the distance when the side shift operation is started. Then, as shown in FIG. 10, the pallet P1 shifts so as to fill the gap between the remaining part of the side surface Pc of the pallet P1 and the pallet P2. Then, after the entire side surface Pc of the pallet P1 comes into contact with the pallet P2, the distance between the remaining part of the side surface 13a of each of the forks 13A and 13B and the inner wall surface Pd varies from the distance when the side shift operation is started, and the distance between the side surface 13a and the inner wall surface Pd becomes equal over the entire side surface 13a.

[0072] From the above, when the forks 13A, 13B are inserted obliquely with respect to the extending direction of the insertion hole H, the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 provided on the pair of forks 13A, 13B will be different from each other. Similarly, the initial values ​​ds will be different from each other depending on the positions of the distance sensors.

[0073] In the following description, in order to distinguish each distance d1, the distance d1 detected by the first distance sensor 21 provided on the fork 13A will be referred to as "distance d1A," and the distance d1 detected by the first distance sensor 21 provided on the fork 13B will be referred to as "distance d1B."

[0074] In order to distinguish each distance d2, the distance d2 detected by the second distance sensor 22 provided on the fork 13A is referred to as "distance d2A," and the distance d2 detected by the second distance sensor 22 provided on the fork 13B is referred to as "distance d2B."

[0075] In order to distinguish each initial value ds, the initial value ds at the positions where the first distance sensor 21 and the second distance sensor 22 are provided on fork 13A will be referred to as "initial value ds1" and "initial value ds2", respectively, and the initial value ds at the positions where the first distance sensor 21 and the second distance sensor 22 are provided on fork 13B will be referred to as "initial value ds3" and "initial value ds4", respectively.

[0076] Similarly, in the fork 13A, one of the distances d1A and d2A varies from the corresponding initial value ds1 or ds2 when a part of the pallet P1 comes into contact with the pallet P2, and then the other varies from the corresponding initial value ds1 or ds2 when the remaining part of the pallet P1 comes into contact with the pallet P2, until the distances d1A and d2A finally become equal. In the fork 13B, the distances d1B and d2B vary in the same manner as in the fork 13A.

[0077] In this modified example, the control unit 23 controls the side shift operation in consideration of the change in the distance between the side surface 13a of the forks 13A, 13B and the inner wall surface Pd when the forks 13A, 13B are inserted obliquely with respect to the extension direction of the insertion hole H described above.

[0078] Specifically, the control unit 23 stops the side shift operation by the side shift cylinder 16 when a predetermined time has elapsed after one of the distances d1A, d2A has changed from the corresponding initial value ds1, ds2 and one of the distances d1B, d1B has changed from the corresponding initial value ds3, ds4.

[0079] Alternatively, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when a predetermined time has elapsed since one of the distances d1A, d2A has changed from the corresponding initial value ds1, ds2, or when a predetermined time has elapsed since one of the distances d1B, d1B has changed from the corresponding initial value ds3, ds4.

[0080] The predetermined time is determined based on the speed of the fork 13 that is shifted according to the speed of the side shift operation. The predetermined time is set in consideration of the speed of the side shift operation, and the range is, for example, 0.5 seconds or more and 3.0 seconds or less. By setting the predetermined time to 0.5 seconds or more, the gap between the pallet P1 and the pallet P2 can be made as close to zero as possible. In addition, when the side shift amount in the side shift operation reaches a maximum during the side shift operation, the loading of the pallet P1 may start even if the pallet P1 and the pallet P2 are not in contact with each other. In such a case, by setting the predetermined time to 3.0 seconds or less, the side shift operation is stopped before the side shift amount reaches a maximum, and the loading of the pallet P1 can be prevented from being performed in a state in which the pallet P1 and the pallet P2 are not in contact with each other.

[0081] The speed of the side shifting operation includes, for example, the shifting speed of the fork 13 during the side shifting operation. Therefore, the predetermined time may be set taking into consideration the shifting speed of the fork 13 during the side shifting operation.

[0082] Next, the control of the side shift operation by the control unit 23 in step S4 in this modified example will be described with reference to Fig. 11. Fig. 11 is a flow chart showing another example of the control of the side shift operation.

[0083] In step S411, similarly to step S401, the control unit 23 starts a side shift operation by the side shift cylinder 16. In step S412, the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13A, 13B detect distances d1A, d1B, d2A, and d2B between the side surface 13a of the fork 13 and the inner wall surface Pd.

[0084] In step S413, the control unit 23 determines whether or not one of the distances d1A, d2A has changed from the corresponding initial value ds1, ds2, and whether or not one of the distances d1B, d2B has changed from the corresponding initial value ds3, ds4.

[0085] If one of the distances d1A, d2A has changed from the corresponding initial values ​​ds1, ds2, and one of the distances d1B, d2B has changed from the corresponding initial values ​​ds3, ds4 (YES in step S413), the process proceeds to step S414.

[0086] If one of the distances d1A, d2A has not changed from the corresponding initial value ds1, ds2, or if one of the distances d1B, d2B has not changed from the corresponding initial value ds3, ds4 (NO in step S413), the process returns to step S412.

[0087] In step S414, the control unit 23 determines whether a predetermined time has elapsed since one of the distances d1A, d2A has changed from the corresponding initial value ds1, ds2 and one of the distances d1B, d2B has changed from the corresponding initial value ds3, ds4.

[0088] If the predetermined time has elapsed (YES in step S414), the process proceeds to step S415. If the predetermined time has not elapsed (NO in step S414), the process returns to step S414. That is, in this modified example, control unit 23 does not proceed with the process until a predetermined time has elapsed since one of distances d1A, d2A has changed from the corresponding initial value ds1, ds2 and one of distances d1B, d2B has changed from the corresponding initial value ds3, ds4.

[0089] In step S415, similarly to step S404, the control unit 23 stops the side shift operation by the side shift cylinder 16.

[0090] In this modification, the control unit 23 stops the side shift operation by the side shift cylinder 16 when a predetermined time has elapsed since one of the distances d1A, d2A has changed from the corresponding initial value ds1, ds2 and one of the distances d1B, d2B has changed from the corresponding initial value ds3, ds4. According to this type of control, by setting the predetermined time in consideration of the speed of the side shift operation, it is possible to position the pallet P1 closely relative to the pallet P2 while preventing excessive load from being applied to the mechanism on the fork 13 side during the side shift operation.

[0091] Next, a description will be given of another modified example of the control of the side shift operation by the control unit 23. The control of the side shift operation by the control unit 23 in this modified example is also performed when the forks 13A, 13B are inserted obliquely with respect to the extension direction of the insertion hole H, for example.

[0092] In this case, as described above, in the fork 13A, one of the distances d1A and d2A varies from the corresponding initial value ds1 or ds2 when a part of the pallet P1 comes into contact with the pallet P2, and then the other varies from the corresponding initial value ds1 or ds2 when the remaining part of the pallet P1 comes into contact with the pallet P2, and finally the distances d1A and d2A become equal. The same is true for the fork 13B as for the fork 13A.

[0093] Therefore, in this modification, the control unit 23 stops the side shift operation by the side shift cylinder 16 when the distances d1A and d2A become equal to each other and the distances d1B and d2B become equal to each other after one of the distances d1A and d2A has changed from the corresponding initial value ds1 and ds2 and one of the distances d1B and d2B has changed from the corresponding initial value ds3 and ds4. Here, "equal" does not necessarily mean that the values ​​are the same. Even if the values ​​include a slight difference or measurement error within a preset range, they may be considered to be "equal."

[0094] Next, the control of the side shift operation by the control unit 23 in step S4 in this modified example will be described with reference to Fig. 12. Fig. 12 is a flow chart showing yet another example of the control of the side shift operation.

[0095] In step S421, similar to step S401, the control unit 23 starts a side shift operation by the side shift cylinder 16. In step S422, similar to step S412, the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13A, 13B detect the distances d1A, d1B, d2A, d2B between the side surface 13a of the fork 13 and the inner wall surface Pd.

[0096] In step S423, the control unit 23 determines whether or not one of the distances d1A, d2A has changed from the corresponding initial value ds1, ds2, and whether or not one of the distances d1B, d2B has changed from the corresponding initial value ds3, ds4.

[0097] If one of the distances d1A, d2A has changed from the corresponding initial values ​​ds1, ds2, and one of the distances d1B, d2B has changed from the corresponding initial values ​​ds3, ds4 (YES in step S423), the process proceeds to step S424.

[0098] If one of the distances d1A, d2A has not changed from the corresponding initial value ds1, ds2, or if one of the distances d1B, d2B has not changed from the corresponding initial value ds3, ds4 (NO in step S423), the process returns to step S422.

[0099] In step S424, similar to step S422 above, the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13A, 13B detect the distances d1A, d1B, d2A, d2B between the side surface 13a of the fork 13 and the inner wall surface Pd.

[0100] In step S425, the control unit 23 determines whether the distance d1A is equal to the distance d2A and whether the distance d1B is equal to the distance d2B. If the distance d1A is equal to the distance d2A and the distance d1B is equal to the distance d2B (YES in step S424), the process proceeds to step S426. If the distance d1A is not equal to the distance d2A or the distance d1B is not equal to the distance d2B (NO in step S424), the process returns to step S424.

[0101] In step S426, similarly to step S404, the control unit 23 stops the side shift operation by the side shift cylinder 16.

[0102] In this modification, the control unit 23 stops the side shift operation by the side shift cylinder 16 when the distances d1A and d2A are equal to each other and the distances d1B and d2B are equal to each other after one of the distances d1A and d2A has changed from the corresponding initial value ds1 and ds2 and one of the distances d1B and d2B has changed from the corresponding initial value ds3 and ds4. When the fork 13 is inserted obliquely with respect to the extending direction in the insertion hole H, as described above, a part of the pallet P1 being loaded abuts against the pallet P2 that has already been loaded. At this time, the distance detected by one of the distances d1A and d1B and the distances d2A and d2B, which is located closer to the part, changes from the corresponding initial value ds1 to ds4. After that, the other part of the pallet P1 abuts against the pallet P2, so that the distances d1A and d2A become equal to each other and the distances d1B and d2B become equal to each other. Therefore, according to the above-described control, the side shift operation can be stopped at the point when pallet P1 abuts against pallet P2 when the fork 13 is inserted at an angle to the extension direction of the insertion hole H. Therefore, it is possible to prevent excessive load from being applied to the fork-side mechanism during the side shift operation while positioning pallet P1 closely relative to pallet P2.

[0103] The above describes the embodiments and various modifications of the present disclosure, but the present disclosure is not necessarily limited to the above-described embodiments and various modifications, and various modifications are possible without departing from the gist of the present disclosure.

[0104] The control for stopping the side shift operation by the side shift cylinder 16 is not limited to the above-mentioned control. For example, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when one of the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13 varies from the initial value ds. In this case, by stopping the side shift operation as described above, the start of sliding of the fork 13 in the insertion hole H can be detected with even greater accuracy.

[0105] Alternatively, the side shift operation by the side shift cylinder 16 may be stopped when both of the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 provided on each of the pair of forks 13 have changed from the initial value ds. In this case, the pallet P1 being loaded can be positioned closely to the loaded pallet P2, while preventing excessive load from being applied to the mechanism on the fork 13 side during the side shift operation.

[0106] In the above-described embodiment and each modified example, the first distance sensor 21 and the second distance sensor 22 are provided on each of the pair of forks 13, but the first distance sensor 21 and the second distance sensor 22 may be provided on only one of the pair of forks 13. In this case, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when one of the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 provided on one of the forks 13 varies from the initial value ds. Alternatively, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when both of the distances d1, d2 detected by the first distance sensor 21 and the second distance sensor 22 provided on one of the forks 13 vary from the initial value ds.

[0107] In the above-described embodiment and each modified example, the first distance sensor 21 and the second distance sensor 22 are provided on each of the pair of forks 13, but only one distance sensor may be provided on each of the pair of forks 13. In this case, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when the distance detected by the one distance sensor provided on one fork 13 becomes larger than the initial value ds and the distance detected by the one distance sensor provided on the other fork 13 becomes smaller than the initial value ds.

[0108] Alternatively, one distance sensor may be provided on only one of the pair of forks 13. In this case, the control unit 23 may stop the side shift operation by the side shift cylinder 16 when the distance detected by the one distance sensor varies from the initial value ds.

[0109] The gist of this disclosure is as follows: [1] to [9] [1] An industrial vehicle equipped with a loading device having a pair of forks, which loads and unloads cargo by inserting the pair of forks into insertion holes of a pallet, the industrial vehicle comprising: a side shift mechanism that horizontally side-shifts a position of the pair of forks; a distance sensor that is provided on the horizontal side of at least one of the pair of forks and detects the distance from the side to an object to be detected; and a control unit that controls the side shifting operation of the pair of forks by the side shift mechanism based on the detection result of the distance sensor, wherein the control unit stores an initial value of the distance between the side of the fork and an inner wall surface that defines the insertion hole when the side shifting operation by the side shift mechanism is started, and stops the side shifting operation by the side shift mechanism if the distance between the side of the fork and the inner wall surface varies from the initial value during the side shifting operation by the side shift mechanism. [2] The industrial vehicle described in [1], wherein the distance sensors are provided on each side of the pair of forks facing opposite each other. [3] The control unit of the industrial vehicle of [2] stops the side shift operation by the side shift mechanism when the distance detected by the distance sensor of one fork becomes larger than the initial value and the distance detected by the distance sensor of the other fork becomes smaller than the initial value. [4] The industrial vehicle described in any of [1] to [3], wherein the distance sensor is composed of a first distance sensor located on the base end side of the fork and a second distance sensor located on the tip end side of the fork. [5] The control unit of the industrial vehicle described in [4] stops the side shift operation by the side shift mechanism when one of the distances detected by the first distance sensor and the second distance sensor varies from the initial value. [6] The control unit of the industrial vehicle described in [4] stops the side shift operation by the side shift mechanism when both the distances detected by the first distance sensor and the second distance sensor have changed from the initial values. [7] The control unit of the industrial vehicle described in [4] stops the side shift operation by the side shift mechanism when a predetermined time has elapsed since one of the distances detected by the first distance sensor and the second distance sensor has changed from the initial value. [8] The control unit of the industrial vehicle described in [4] stops the side shift operation by the side shift mechanism when the distance detected by the first distance sensor and the distance detected by the second distance sensor become equal after one of the distances detected by the first distance sensor and the second distance sensor fluctuate from the initial value. [9] The industrial vehicle according to any one of [1] to [8], wherein the distance sensor is provided on a side of the pair of forks facing the other fork.

[10] An industrial vehicle described in any of [1] to [9], wherein the pair of forks are provided with a bracket with a window, and the bracket with a window is provided on the side so that the distance sensor is exposed from the window. [Explanation of symbols]

[0110] 1...industrial vehicle, 3...loading device, 13...fork, 13a...side of fork, 16...side shift cylinder (side shift mechanism), 21...first distance sensor, 22...second distance sensor, 23...control unit, B...bracket, Ba...window, d1, d2...distance, ds...initial value, H...insertion hole, P...pallet, Pd...inner wall surface.

Claims

1. An industrial vehicle having a loading device having a pair of forks, which loads and unloads by inserting the pair of forks into insertion holes of a pallet, A side shift mechanism that shifts the position of the pair of forks in a horizontal direction; a distance sensor provided on at least one of the pair of forks in the horizontal direction to detect a distance from the side surface to a detection target; A control unit that controls a side shift operation of the pair of forks by the side shift mechanism based on a detection result of the distance sensor, The control unit is storing an initial value of the distance between a side surface of the fork and an inner wall surface that defines the insertion hole when the side shift operation by the side shift mechanism is started; an industrial vehicle in which the side shifting operation by the side shift mechanism is stopped if the distance between the side of the fork and the inner wall surface varies from the initial value while the side shifting operation is being performed by the side shift mechanism.

2. 2. The industrial vehicle according to claim 1, wherein the distance sensors are provided on respective sides of the pair of forks so as to face opposite each other.

3. 3. The industrial vehicle according to claim 2, wherein the control unit stops the side shift operation by the side shift mechanism when the distance detected by the distance sensor of one fork becomes larger than the initial value and the distance detected by the distance sensor of the other fork becomes smaller than the initial value.

4. 2. The industrial vehicle according to claim 1, wherein the distance sensor comprises a first distance sensor located on a base end side of the forks and a second distance sensor located on a tip end side of the forks.

5. 5. The industrial vehicle according to claim 4, wherein the control unit stops the side shift operation by the side shift mechanism when one of the distances detected by the first distance sensor and the second distance sensor varies from the initial value.

6. 5. The industrial vehicle according to claim 4, wherein the control unit stops the side shift operation by the side shift mechanism when both the distances detected by the first distance sensor and the second distance sensor have deviated from the initial values.

7. 5. The industrial vehicle according to claim 4, wherein the control unit stops the side shift operation by the side shift mechanism when a predetermined time has elapsed since one of the distances detected by the first distance sensor and the second distance sensor has changed from the initial value.

8. 5. The industrial vehicle according to claim 4, wherein the control unit stops the side shift operation by the side shift mechanism when the distance detected by the first distance sensor and the distance detected by the second distance sensor become equal after one of the distances detected by the first distance sensor and the second distance sensor has fluctuated from the initial value.

9. 9. The industrial vehicle according to claim 1, wherein the distance sensor is provided on a side of the pair of forks facing the other fork.

10. The pair of forks are provided with a bracket with a window, The industrial vehicle according to any one of claims 1 to 8, wherein the bracket with a window is provided on the side surface so that the distance sensor is exposed through the window.

Images