JP2019206421A - Side forklift truck - Google Patents

Abstract

To provide a side forklift truck that can limit the moving speed of a cargo gear in the pulled-in state of the cargo gear even with a relatively simple structure irrespective of a model.SOLUTION: This side forklift truck comprises: a cargo gear 15 that can move back and forth in the car width direction of a car body orthogonal to the front-back direction of the car body; a reach cylinder 37 that can move the cargo gear 15 in the width direction; an oil amount adjustment device that adjusts the amount of hydraulic oil supplied to the reach cylinder 37; and a controller 47 that controls the oil amount adjustment device, and a reach angle formed between the longitudinal direction of the reach cylinder 37 and a reference direction set in an optional direction is changed according to the position of the cargo gear 15 in the width direction of the car body. The side forklift truck comprises a reach angle detector 42 that detects the reach angle, and the controller 47 controls the oil amount adjustment device so as to limit the amount of the hydraulic oil when the reach angle exceeds a preset threshold value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a side forklift.

  As a conventional technique of a side forklift, for example, an automatic mast reduction device for a side forklift disclosed in Patent Document 1 is known. In Patent Document 1, in a reach-type side forklift, a reduction valve formed by connecting a flow control valve and a check valve in parallel is interposed in a hydraulic line connecting the reach cylinder and the control valve. When the mast is pushed out, the spool of the flow control valve is moved as the reach cylinder tilts upward from a predetermined inclination angle, and the flow rate passing through the reduction valve gradually decreases. Hydraulic oil flows through the check valve when pulling back the mast. Therefore, when the mast approaches the stopper, it is automatically decelerated, and the impact caused by the contact between the mast and the stopper is minimized.

Microfilm of Japanese Utility Model No. 61-127182 (Japanese Utility Model Publication No. 63-35797)

  However, in the side forklift disclosed in Patent Document 1, in order to automatically decelerate the mast approaching the stopper, it is necessary to provide a deceleration valve and a hydraulic pipe for controlling the deceleration valve, thereby avoiding a complicated structure. There is a problem that you can not. Moreover, when providing a reduction valve, it is necessary to provide a different reduction valve for every model, and providing a different reduction valve for every model is complicated.

  As another means for automatically decelerating the mast, it is conceivable to limit the hydraulic oil supplied to the reach cylinder by a fixed throttle. However, there is a problem that pressure loss occurs due to the fixed throttle, resulting in energy loss. is there. In addition, when a fixed aperture is provided, it is necessary to provide a fixed aperture with different specifications for each model, and it is complicated to provide a different fixed aperture for each model.

  The present invention has been made in view of the above problems, and an object of the present invention is to have a relatively simple structure independent of the model, and to limit the moving speed of the cargo handling device in the retracted state of the cargo handling device. Is to provide a side forklift.

  In order to solve the above-described problems, the present invention provides a vehicle body, a cargo handling device that can advance and retreat in the width direction of the vehicle body perpendicular to the front-rear direction of the vehicle body, and the cargo handling device that can advance and retract in the width direction of the vehicle body. A reach cylinder, an oil amount adjusting device for adjusting the amount of hydraulic oil supplied to the reach cylinder, and a control device for controlling the oil amount adjusting device, wherein the reach cylinder is a cylinder supported by the vehicle body And a rod portion that can be moved forward and backward with respect to the cylinder portion and supported by the cargo handling device, and optionally in a longitudinal direction of the reach cylinder according to a separation distance from a retracted position of the cargo handling device. In a side forklift that changes a reach angle that is an angle formed by a reference direction set as a reference direction, a reach angle detector that detects the reach angle or a A separation distance detector for detecting a separation distance from the retracted position in the width direction of the vehicle body, wherein the reach angle in the retracted state of the cargo handling device is a preset threshold or the distance from the retracted position of the cargo handling device is When the preset threshold value is exceeded, the control device controls the oil amount adjusting device so as to limit the hydraulic oil amount.

  In the present invention, the cargo handling device reciprocates in the width direction of the vehicle body by the operation of the reach cylinder. The reach angle of the reach cylinder for advancing and retracting the cargo handling device varies when the cargo handling device moves between the maximum advanced position and the retracted position. When the reach angle detector detects a reach angle exceeding a threshold value, or when the separation distance from the retracting position of the cargo handling device exceeds a preset threshold value, the control device controls the oil amount adjusting device to reach the reach cylinder. The amount of hydraulic oil supplied to the engine is limited. By limiting the hydraulic oil supplied to the reach cylinder, the moving speed of the cargo handling device can be limited. Since the moving speed of the cargo handling device is limited, for example, even if the cargo handling device contacts a stopper provided on the vehicle body, the impact is reduced. Further, since the reach angle detector or the advance / retreat position detector is provided to limit the amount of hydraulic oil supplied to the reach cylinder, the structure can be made relatively simple regardless of the model.

Further, in the above-mentioned side forklift, the control device controls the oil amount adjusting device so as to change a hydraulic oil amount to be limited according to the reach angle or a separation distance from the retracting position of the cargo handling device. Also good.
In this case, since the limited amount of hydraulic oil is changed according to the reach angle or the separation distance from the retracted position of the cargo handling device, the cargo handling device can be smoothly decelerated.

In the above-mentioned side forklift, the reference direction is a vertical direction, and the control device uses the reach angle detector to determine the reach direction of the reach cylinder and the vertical direction according to the distance from the retracted position of the cargo handling device. A configuration may be adopted in which a reach angle that forms an acute angle with the direction is detected, and when the detected reach angle is less than a preset threshold value, the oil amount adjusting device is controlled so as to limit the amount of hydraulic oil.
In this case, when the reach angle is less than a preset threshold value, the amount of hydraulic oil supplied to the reach cylinder is limited, so that the moving speed of the cargo handling device can be limited.

In the above-mentioned side forklift, the cargo handling device includes a mast, a fork that can be raised and lowered with respect to the mast, and a load detector that detects a load applied to the fork, and the control device includes the load It is good also as a structure which changes the hydraulic oil amount restrict | limited according to the load detected by a detector.
In this case, since the amount of hydraulic oil to be limited is changed according to the load of the fork received by loading the load, the moving speed of the cargo handling device can be limited according to the weight of the load of the fork.

In the above-described side forklift, the control device may control the oil amount adjusting device so as to limit the amount of hydraulic oil when the cargo handling device advances.
In this case, when the cargo handling device starts to move, the moving speed of the cargo handling device is suppressed by limiting the amount of hydraulic oil. Since it becomes difficult for the cargo handling device to move rapidly, cargo collapse and spillage can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the side forklift which can restrict | limit the moving speed of a cargo handling apparatus in the retracted state of a cargo handling apparatus can be provided, although it is a comparatively simple structure irrespective of a model.

It is a perspective view which shows the side forklift which concerns on 1st Embodiment. It is a block diagram which shows schematic structure of the side forklift which concerns on 1st Embodiment. It is explanatory drawing which shows the principal part of the side forklift which concerns on 1st Embodiment. It is explanatory drawing of the reach angle detected by the reach angle detector. It is explanatory drawing which shows the principal part of the side forklift which concerns on 2nd Embodiment.

(First embodiment)
Hereinafter, the side forklift according to the first embodiment will be described with reference to the drawings. The side forklift is a forklift suitable for transporting a load of a long object (wood, pipe, etc.), and is an electric side forklift. Note that “front / rear”, “left / right”, and “up / down” that specify the direction are based on a state in which the operator of the side forklift is seated on the driving seat of the driver's seat and faces the forward side of the side forklift.

  As shown in FIG. 1, the vehicle body 11 of the side forklift 10 is provided with a pair of left and right front wheels 12 as steering wheels and a pair of left and right rear wheels 13 as drive wheels. The front wheel 12 and the rear wheel 13 correspond to wheels. A cabin-type driver's seat 14 is provided on the left side of the front portion of the vehicle body 11. A cargo handling device 15 is provided behind the driver's seat 14 and in the vicinity of the center of the vehicle body 11. On the right side of the vehicle body 11, loading platforms 16 and 17 are provided extending forward and backward with the cargo handling device 15 interposed therebetween. A battery cover 18 in which a battery (not shown) is accommodated is provided on the left side of the loading platform 17 at the rear of the vehicle body 11.

  The driver's seat 14 is provided with a driver's seat 19 and a steering wheel 20, and a directional lever (not shown) is provided in addition to the reach lever 21 and the lift lever 22 shown in FIG. The reach lever 21 and the lift lever 22 are levers for operating the cargo handling device 15. The direction lever is a lever for switching the forward / reverse movement of the side forklift 10. An accelerator pedal (not shown) and a brake pedal (not shown) are provided on the floor of the driver's seat 14. The accelerator pedal is a pedal that controls the vehicle speed according to the depression amount, and the brake pedal is a pedal that controls the braking force according to the depression amount.

  The cargo handling device 15 is provided so as to be able to advance and retreat in the left and right (in the width direction of the vehicle body 11) in a space 23 provided in the center of the vehicle body 11. In the vehicle body 11, a front reach rail 25 extends in the width direction on the front wall surface 24 facing the space portion 23, and a rear reach rail 27 extends in the width direction on the rear wall surface 26 facing the front wall surface 24. It is extended and provided. The cargo handling device 15 is guided by the front reach rail 25 and the rear reach rail 27 and is movable in the width direction orthogonal to the front-rear direction of the vehicle body 11. As shown in FIG. 3, the vehicle body 11 is provided with a stopper 28 that defines the retracting position of the cargo handling device 15. Further, the vehicle body 11 is provided with another stopper (not shown) that defines the advance position of the cargo handling device 15.

  The cargo handling device 15 includes a base 29 that can be guided by the front reach rail 25 and the rear reach rail 27, a pair of outer masts 30 fixed to the base 29, and a pair of inner masts that can move up and down with respect to the outer mast 30. 31. As shown in FIG. 3, the cargo handling device 15 includes a lift cylinder 32 that moves the inner mast 31 up and down. The lift cylinder 32 is a backward hydraulic cylinder. A fork bracket 33 is attached to the inner mast 31, and a pair of forks 34 is fixed to the fork bracket 33. As shown in FIG. 2, the lift cylinder 32 is provided with a load detector 35 that detects a load received by the fork 34. The cargo handling device 15 configured as described above enables the load to be transferred between the space on the right side of the vehicle body 11 and the loading platforms 16 and 17.

  A reach pillar 36 is erected between the driver's seat 14 and the battery cover 18 in the vehicle body 11. A reach cylinder 37 that connects the top of the reach pillar 36 and the cargo handling device 15 is provided. As shown in FIG. 3, the reach cylinder 37 includes a cylinder portion 38 whose base is supported by a support shaft 39 at the top of the reach pillar 36, and a rod portion 40 that can be advanced and retracted at the tip of the cylinder portion 38. The reach cylinder 37 is a backward hydraulic cylinder. The distal end portion of the rod portion 40 is connected to the base 29 via a connecting shaft 41. Therefore, the longitudinal direction of the reach cylinder 37 is a direction inclined from the upper side to the lower side in the width direction of the vehicle body 11. The cargo handling device 15 is moved by the operation of the reach cylinder 37. The cargo handling device 15 moves to the right of the vehicle body 11 when the rod portion 40 of the reach cylinder 37 advances, and moves to the left of the vehicle body 11 when the rod portion 40 moves backward.

  As shown in FIG. 4, the reach angle θ that is an angle at which the longitudinal direction of the reach cylinder 37 and the reference direction set as a reference in an arbitrary direction form an acute angle changes according to the operating state of the reach cylinder 37. In this embodiment, the reference direction is set to the vertical direction, and the reach angle θ is an acute angle formed by the longitudinal direction of the reach cylinder 37 and the vertical direction. That is, the reach angle θ increases as the cargo handling device 15 moves toward the advanced position, and the reach angle θ decreases as the cargo handling device 15 moves toward the retracted position.

  The reach pillar 36 is provided with a reach angle detector 42 for detecting the reach angle θ. The reach angle detector 42 includes a fixed portion (not shown) fixed to the reach pillar 36 and a rotating portion (not shown) that rotates together with the reach cylinder 37. The reach angle detector 42 outputs the relative movement of the rotating portion with respect to the fixed portion as an electric signal by the potentiometer, and detects the reach angle θ.

  The reach cylinder 37 operates upon receiving supply of hydraulic oil. As shown in FIG. 2, the side forklift 10 includes a hydraulic oil tank 43, a hydraulic pump 44, an electric motor 45 for cargo handling, a control valve 46, and a controller 47. The hydraulic oil tank 43 is a tank for storing hydraulic oil. The hydraulic pump 44 is a pump for pumping up the hydraulic oil stored in the hydraulic oil tank 43. The electric motor 45 for cargo handling is an electric motor 45 for driving the hydraulic pump 44 and includes a drive circuit 48. The electric motor 45 corresponds to an oil amount adjusting device that adjusts the amount of hydraulic oil.

  The control valve 46 is a control valve that supplies hydraulic oil pumped up by the hydraulic pump 44 to the hydraulic equipment to the cargo handling device 15 such as the reach cylinder 37. The control valve 46 supplies hydraulic oil to the reach cylinder 37 and the lift cylinder 32 according to the operation of the reach lever 21 and the lift lever 22. As shown in FIG. 2, a reach lever detector 49 for detecting the operation state of the reach lever 21 and a lift lever detector 50 for detecting the operation state of the lift lever 22 are provided. Hydraulic piping 51, 52, 53, 54, 55, 56 for connecting the hydraulic oil tank 43, the hydraulic pump 44, the control valve 46, the reach cylinder 37 and the lift cylinder 32 are provided.

  The controller 47 corresponds to a control device and controls each part of the side forklift 10. The controller 47 includes a calculation unit (not shown) that processes various programs and data, and a storage unit (not shown) that stores various programs and data. The controller 47 is electrically connected to the drive circuit 48 of the electric motor 45 and controls the electric motor 45 via the drive circuit 48. The drive circuit 48 transmits the rotation speed of the electric motor 45 to the controller 47, and the controller 47 transmits the command motor rotation speed to the drive circuit 48. The drive circuit 48 drives the electric motor 45 based on the command motor speed transmitted from the controller 47. The controller 47 is connected to the load detector 35, reach angle detector 42, reach lever detector 49, and lift lever detector 50. Therefore, the controller 47 receives the detection signal of each detector.

  When operating the reach cylinder 37, the controller 47 controls the electric motor 45 that drives the hydraulic pump 44 and supplies hydraulic oil to the reach cylinder 37 through the control valve 46. Reach cylinder 37 that has been supplied with hydraulic oil advances rod portion 40. As shown in FIG. 4, in the state in which the rod portion 40 is most advanced, the cargo handling device 15 is located at the rightward advance position of the vehicle body 11, and the reach angle θ is maximum (θ = θmax). In the state where the rod portion 40 is most retracted, the cargo handling device 15 is located at the retracted position, and the reach angle θ is minimized (θ = θmin).

  Incidentally, as shown in FIG. 4, a side A is defined from the center P of the support shaft 39 of the reach cylinder 37 to the center Q of the connecting shaft 41. The intersection R between the imaginary line M extending in the vertical direction from the center of the support shaft 39 of the reach cylinder 37 and the horizontal imaginary line N passing through the center Q of the connecting shaft 41 is defined as extending from the center Q of the support shaft 39 to the intersection R. A side B is defined as a side C between the center P of the support shaft 39 and the intersection R. Even when the reach cylinder 37 moves back and forth at a constant speed, the moving speed of the center Q of the connecting shaft 41 that moves along the side B increases as the moving distance approaches the minimum reach angle (θ = θmin). The closer to the advance position where the maximum reach angle (θ = θmax) is, the lower the moving speed is.

  Therefore, in the present embodiment, when the reach cylinder 37 is operated, when the reach angle θ is less than the threshold θt, the electric motor 45 that drives the hydraulic pump 44 is controlled so as to limit the amount of hydraulic oil supplied to the reach cylinder 37. To do. The threshold value θt of the reach angle θ is stored in the controller 47 in advance. When the reach angle θ is less than the threshold θt (θ <θt), the controller 47 limits the amount of hydraulic oil to be sufficiently smaller than the amount of hydraulic oil when the reach angle θ is equal to or greater than the threshold θt (θ ≧ θt). Thus, the electric motor 45 is controlled. Therefore, when the reach angle θ is less than the threshold value θt, the moving speed of the cargo handling device 15 is sufficiently suppressed compared to when the reach angle θ is equal to or greater than the threshold value θt. Note that the reach angle θ of the present embodiment is less than the threshold θt corresponds to the reach angle θ exceeding the threshold θt.

  When the reach angle θ when the cargo handling device 15 is located at the retracted position is about 20 ° and the reach angle θ when the cargo handling device 15 is located at the most advanced position is about 60 °, for example, the threshold θt is: It is about 30 °. The threshold value θt may be appropriately set according to various conditions of the side forklift 10.

  Further, the controller 47 limits the amount of hydraulic oil supplied to the reach cylinder 37 when the load detector 35 detects a load equal to or greater than a preset threshold value. The controller 47 performs control for releasing the restriction of the hydraulic oil amount itself when a load less than a threshold value indicating that there is no load on the fork 34 is detected.

  Next, the operation of the side forklift 10 will be described. When handling a long object such as wood or pipe (not shown), the operator places the long object on the right side of the vehicle body 11, and the longitudinal direction of the long object and the longitudinal direction of the vehicle body 11 are parallel to each other. The vehicle body 11 is moved so that it becomes. Next, the operator operates the reach lever 21 so that the cargo handling device 15 advances. When the reach lever 21 is tilted to the advance side, the controller 47 controls the electric motor 45 to be driven. Since there is no load on the fork 34, the hydraulic pump 44 is driven without limiting the amount of hydraulic oil. Accordingly, the hydraulic oil supplied to the reach cylinder 37 advances the rod portion 40 of the reach cylinder 37 at a constant speed. As the rod portion 40 advances, the cargo handling device 15 moves to the right toward the advance position.

  The operator operates the lift lever 22 in the process of the cargo handling device 15 moving to the advanced position to operate the lift cylinder 32 to mount a long object on the fork 34. The operator operates the lift lever 22 to raise the fork 34 loaded with a long object mounted on the fork 34, and further moves the cargo handling device 15 from the advanced position to the retracted position by operating the reach lever 21. . At this time, the fork 34 receives a load equal to or greater than a threshold value.

  When the reach angle θ is less than the threshold θt in the retracted state of the cargo handling device 15, the center Q of the connecting shaft 41 is closer to the retracted position than when the reach angle θ is the threshold θt. At this time, the controller 47 controls the electric motor 45 so as to limit the amount of hydraulic oil supplied to the reach cylinder 37. Specifically, a command motor rotational speed that is lower than the rotational speed when the reach angle θ is equal to or greater than the threshold θt is transmitted to the drive circuit 48. The electric motor 45 is driven at the number of rotations of the command motor, and as a result, the amount of hydraulic oil pumped up by the hydraulic pump 44 is reduced from the amount of hydraulic oil when the reach angle θ is equal to or greater than the threshold θt. Accordingly, when the amount of hydraulic oil supplied to the reach cylinder 37 is reduced, the reverse speed of the rod portion 40 of the reach cylinder 37 is reduced. The moving speed of the cargo handling device 15 becomes low because the rod portion 40 moves backward at a low speed.

  Even if the cargo handling device 15 moves to the retracted position and comes into contact with the stopper 28, the moving speed of the cargo handling device 15 is low, so that the impact due to contact is reduced. By reducing the impact caused by the contact with the stopper 28 of the cargo handling device 15, it is difficult for the long object mounted on the fork 34 to collapse or spill. When the cargo handling device 15 moves to the retracted position, the operator operates the lift lever 22 to lower the fork 34 to mount a long object on the loading platforms 16 and 17.

  Conversely, when unloading a long object from the loading platforms 16, 17, the operator moves the side forklift 10 to a position where the long object is unloaded. Then, the operator operates the lift lever 22 to raise the fork 34 and mount the long objects of the loading platforms 16 and 17 on the fork 34. At this time, the fork 34 receives a load equal to or greater than a threshold value. Next, the operator operates the reach lever 21 to move the cargo handling device 15 to the advanced position.

  Since the fork 34 receives a load greater than or equal to the threshold value, the controller 47 determines the amount of hydraulic oil supplied to the reach cylinder 37 when the reach angle θ is less than the threshold value θt in the process of moving the cargo handling device 15 toward the advanced position. The electric motor 45 is controlled so as to be limited. Specifically, a command motor rotational speed that is lower than the rotational speed when the reach angle θ is equal to or greater than the threshold θt is transmitted to the drive circuit 48. The electric motor 45 is driven at the number of rotations of the command motor, and as a result, the amount of hydraulic oil pumped up by the hydraulic pump 44 is reduced from the amount of hydraulic oil when the reach angle θ is equal to or greater than the threshold θt. Accordingly, when the amount of hydraulic oil supplied to the reach cylinder 37 decreases, the advance speed of the rod portion 40 of the reach cylinder 37 becomes low. Since the rod part 40 advances at a low speed, the moving speed of the cargo handling device 15 is low. Since the cargo handling device 15 that starts moving moves at a low speed, the long object mounted on the fork 34 is restrained from disturbing the posture.

  When the reach angle θ is equal to or greater than the threshold value, the controller 47 controls the electric motor 45 so as to release the restriction on the amount of hydraulic oil supplied to the reach cylinder 37. For this reason, the hydraulic pump 44 is driven without limiting the amount of hydraulic oil. Accordingly, the hydraulic oil supplied to the reach cylinder 37 has a higher advance speed of the rod portion 40 of the reach cylinder 37 than when the reach angle θ is less than the threshold θt.

  When the cargo handling device 15 moves to the advance position, the operator operates the lift lever 22 to lower the fork 34 to load and unload a long object to the position. After the long object is unloaded, the operator raises the fork 34 and, after the fork 34 is raised, operates the reach lever 21 to move the cargo handling device 15 to the retracted position. At this time, since there is no load on the fork 34, the hydraulic pump 44 is driven without limiting the amount of hydraulic oil. Accordingly, the hydraulic oil supplied to the reach cylinder 37 moves the rod portion 40 of the reach cylinder 37 backward at a constant speed. As the rod portion 40 moves backward, the cargo handling device 15 moves to the left toward the retracted position.

The side forklift 10 of this embodiment has the following effects.
(1) The cargo handling device 15 reciprocates in the width direction by the operation of the reach cylinder 37. The reach angle θ of the reach cylinder 37 for moving the cargo handling device 15 forward and backward fluctuates when the cargo handling device 15 moves between the maximum advanced position and the retracted position. When the reach angle detector 42 detects a reach angle θ less than the threshold value θt, the controller 47 controls the electric motor 45 that drives the hydraulic pump 44 to limit the amount of hydraulic oil supplied to the reach cylinder 37. By limiting the hydraulic oil supplied to the reach cylinder 37, the moving speed of the cargo handling device 15 can be limited. Since the moving speed of the cargo handling device 15 is limited, even if the cargo handling device 15 comes into contact with the stopper 28 provided on the vehicle body 11, the impact due to the contact is reduced. Further, since the reach angle detector 42 is provided to limit the amount of hydraulic oil supplied to the reach cylinder 37, the structure can be made relatively simple regardless of the model.

(2) The reach angle detector 42 is provided, and when the reach angle θ detected by the reach angle detector 42 is less than a preset threshold value θt, the controller 47 controls the electric motor 45 so as to limit the amount of hydraulic oil. To control. For this reason, when the reach angle θ is less than the preset threshold value θt, the amount of hydraulic oil is limited, so that the moving speed of the cargo handling device 15 can be limited. Further, since the threshold value θt is stored in the controller 47 in advance, the threshold value θt can be easily changed by rewriting the controller 47. Thereby, according to various conditions of the side forklift 10, it can set suitably.

(3) The cargo handling device 15 includes a mast, a fork 34 that can move up and down relative to the mast, and a load detector 35 that detects a load applied to the fork 34, and the controller 47 is detected by the load detector 35. The hydraulic oil amount is limited when the load to be applied is equal to or greater than a preset threshold value. For this reason, when a load is mounted on the fork 34 and the reach angle θ is less than the threshold value θt, the controller 47 can limit the amount of hydraulic oil supplied to the reach cylinder 37. Further, the controller 47 can release the restriction on the moving speed of the cargo handling device 15 when no load is loaded on the fork 34.

  In the present embodiment, when the reach angle θ is less than the threshold value θt, the controller 47 transmits a command motor rotational speed that is lower than the rotational speed when the reach angle θ is equal to or larger than the threshold value θt to the drive circuit 48. The command motor rotation speed may be changed according to the reach angle θ. That is, the controller 47 may control the electric motor 45 so as to change the amount of hydraulic oil to be limited according to the reach angle θ. As a result, when the reach angle θ is less than the threshold value θt, the amount of hydraulic oil to be restricted is changed according to the reach angle θ, and therefore the moving speed of the cargo handling device 15 can be smoothly reduced.

(Second Embodiment)
Next, a side forklift according to a second embodiment will be described. This embodiment is different from the first embodiment in that a reach angle detector is not provided, and a separation distance detector that detects a separation distance from the retracted position of the cargo handling device in the width direction of the vehicle body is provided. In the present embodiment, for the same configuration as the first embodiment, the description of the first embodiment is used, and common reference numerals are used.

  As shown in FIG. 5, the side forklift 60 of the present embodiment includes a separation distance detector 61 that detects a separation distance L from the retracted position of the cargo handling device 15 in the width direction of the vehicle body 11. The separation distance detection device is, for example, a wire reel winding type sensor, and outputs an electrical signal corresponding to the winding amount of the wire reel to detect the separation distance L from the retracted position of the cargo handling device 15. The separation distance detector 61 is connected to the controller 47. In the controller 47, a threshold value Lt of a separation distance L from the retracting position of the cargo handling device 15 is set in advance.

  When the separation distance L from the retracted position of the cargo handling device 15 in the retracted state of the cargo handling device 15 is less than a preset threshold value Lt, the controller 47 controls the electric motor 45 to limit the amount of hydraulic oil. The separation distance L being less than the threshold value Lt means that the cargo handling device 15 is present at a position closer to the retracted position than when the separation distance L is the threshold value Lt. The pull-in position is the minimum separation distance (L = Lmin) from the pull-in position, and the advance position is the maximum separation distance (L = Lmax) from the pull-in position.

  When the separation distance detector 61 detects a separation distance L that is less than the threshold value Lt, the controller 47 controls the electric motor 45 that drives the hydraulic pump 44 to limit the amount of hydraulic oil supplied to the reach cylinder 37. Specifically, the controller 47 transmits to the drive circuit 48 a command motor rotational speed that is lower than the rotational speed when the separation distance L is equal to or greater than the threshold value Lt. The electric motor 45 is driven at the number of revolutions of the command motor, and as a result, the amount of hydraulic oil pumped up by the hydraulic pump 44 is reduced from the amount of hydraulic oil when the separation distance L is greater than or equal to the threshold value Lt. Accordingly, when the amount of hydraulic oil supplied to the reach cylinder 37 is reduced, the reverse speed of the rod portion 40 of the reach cylinder 37 is reduced. The moving speed of the cargo handling device 15 becomes low because the rod portion 40 moves backward at a low speed.

  According to the present embodiment, the moving oil supplied to the reach cylinder 37 is restricted, so that the moving speed of the cargo handling device 15 can be restricted. Since the moving speed of the cargo handling device 15 is limited, even if the cargo handling device 15 comes into contact with the stopper 28 provided on the vehicle body 11, the impact due to the contact is reduced. In addition, since the separation distance detector 61 is provided to limit the amount of hydraulic oil supplied to the reach cylinder 37, the structure can be made relatively simple regardless of the model. Even when the reach angle detector cannot be provided, the moving speed of the cargo handling device 15 can be limited based on the separation distance L based on the threshold value Lt.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.

In the above embodiment, the amount of hydraulic oil supplied to the reach cylinder is limited when the fork load is equal to or greater than the threshold and the reach angle is less than the threshold or the distance from the retracting position of the cargo handling device is less than the threshold. But this is not the case. For example, the amount of hydraulic oil supplied to the reach cylinder may be limited when the reach angle is less than the threshold value or the separation distance from the retracting position of the cargo handling device is less than the threshold value, regardless of the fork load.
○ In the above embodiment, the amount of hydraulic oil supplied to the reach cylinder is limited when the cargo handling device moves from the retracted position to the advanced position and from the advanced position to the retracted position. Not as long. For example, the amount of hydraulic oil supplied to the reach cylinder may be limited only when moving from the advanced position to the retracted position.
In the above embodiment, the electric side forklift is exemplified as the electric industrial vehicle, but the present invention is not limited to this. The electric industrial vehicle may be, for example, a general battery-type forklift in which a fork other than the electric side forklift is provided in front of the vehicle body or a battery-type towing vehicle that pulls luggage. In addition to the battery, the power supply source may be a fuel cell.
In the above embodiment, the electric motor for cargo handling as the oil amount adjusting device is exemplified, but this is not restrictive. The oil amount adjusting device may be, for example, a control valve that can adjust the amount of hydraulic oil that passes through. Specifically, a control valve with a variable throttle may be used. In this case, even when the amount of hydraulic oil supplied from the hydraulic pump is constant, the control valve is operated to supply the reach cylinder with the control valve. The amount of oil can be limited. In this case, although a hydraulic oil pressure loss occurs, there is no need to prepare a different fixed throttle for each model. Further, by using the variable throttle, it is difficult to adjust the rotation speed of the hydraulic pump, and it can be easily applied to an engine side forklift.
In the above embodiment, the controller performs control to limit the amount of hydraulic oil supplied to the reach cylinder when the load detector detects a load exceeding the threshold, but this is not restrictive. For example, the controller may change the amount of hydraulic oil to be limited according to the load detected by the load detector. In this case, the heavier the load loaded on the fork, the greater the load received by the fork. The controller may perform control to increase the limit on the amount of hydraulic oil as the load received by the fork increases. The amount of hydraulic oil can be limited according to the load that the fork receives.
In the present embodiment, the vertical direction is shown as the reference direction, but the vertical direction is not limited as long as the reach angle formed by the longitudinal direction of the reach cylinder and the reference direction can be set. For example, any direction other than the vertical direction, such as the horizontal direction, may be used as the reference direction.
In the present embodiment, the reach angle is shown as an acute angle formed by the longitudinal direction of the reach cylinder and the vertical direction, but the reach angle may be an angle obtained by subtracting an acute angle from 360 ° (an angle of 270 ° or more). In this case, the threshold value is set appropriately. When the reach angle is larger than the threshold value, the controller controls the electric motor to limit the amount of hydraulic oil. That is, the oil amount adjusting device is controlled so as to limit the hydraulic oil amount when the reach angle exceeds the threshold value.
The separation distance detecting device only needs to be able to detect the separation distance L from the retracted position of the cargo handling device 15 in the width direction of the vehicle body 11, and is not limited to a wire reel take-up type sensor, but a distance measurement using laser light. It may be a sensor.

DESCRIPTION OF SYMBOLS 10, 60 Side forklift 11 Car body 15 Cargo handling device 16, 17 Loading platform 21 Reach lever 22 Lift lever 28 Stopper 30 Outer mast 31 Inner mast 34 Fork 35 Load detector 37 Reach cylinder 42 Reach angle detector 44 Hydraulic pump 45 Electric motor 46 Control valve 47 Controller 48 Drive circuit 49 Reach lever detector 50 Lift lever detector 61 Separation distance detector

Claims (5)

The car body,
A cargo handling device capable of advancing and retreating in the width direction of the vehicle body perpendicular to the longitudinal direction of the vehicle body;
A reach cylinder that enables the cargo handling device to advance and retreat in the width direction of the vehicle body;
An oil amount adjusting device for adjusting the amount of hydraulic oil supplied to the reach cylinder;
A control device for controlling the oil amount adjusting device,
The reach cylinder is
A cylinder portion supported by the vehicle body;
A rod part that can be advanced and retracted with respect to the cylinder part and supported by the cargo handling device;
In a side forklift in which a reach angle that is an angle formed by a longitudinal direction of the reach cylinder and a reference direction set as a reference in an arbitrary direction is changed according to a separation distance from a retracted position of the cargo handling device,
A reach angle detector for detecting the reach angle or a separation distance detector for detecting a separation distance from a retracted position of the cargo handling device in a width direction of the vehicle body;
When the reach angle in the retracted state of the cargo handling device exceeds a preset threshold value or a separation distance from the retracted position of the cargo handling device exceeds a preset threshold value, the control device limits the amount of hydraulic oil. A side forklift that controls the oil amount adjusting device.   The said control apparatus controls the said oil quantity adjustment apparatus so that the hydraulic oil quantity to restrict | limit according to the reach angle or the separation distance from the drawing-in position of the said cargo handling apparatus may be changed. Side forklift. The reference direction is a vertical direction,
The control device detects the reach angle by the reach angle detector, and controls the oil amount adjusting device to limit the hydraulic oil amount when the detected reach angle is less than a preset threshold value. The side forklift according to claim 1 or 2. The cargo handling device is:
With the mast,
A fork that can be raised and lowered relative to the mast;
A load detector for detecting a load applied to the fork,
The side forklift according to any one of claims 1 to 3, wherein the control device changes a hydraulic oil amount to be limited according to a load detected by the load detector.   The side forklift according to any one of claims 1 to 4, wherein when the cargo handling device advances, the control device controls the oil amount adjusting device so as to limit a hydraulic oil amount.

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