JP2005255401A - Lifting carriage tilting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilting structure, achieving a smaller size of lifting carriage while reducing the working labor of an operator by detecting the tilting condition of a fork. <P>SOLUTION: The tilting structure 20 comprises a tilting horizontal shaft 2 supported by a rotating upright shaft 1, a fork 3 having a rear end 31 rotatably supported on the horizontal shaft 2 and a front end 32 horizontally extending, a tilt driving means 4 for tilting the fork 3 in the vertical direction of its front end 32 with the horizontal shaft 2 as a supporting point, a circular plate 132 protruded to the outside of the upright shaft 1 and adapted to be lifted up and down together with a lifting nut 13, and a pair of detecting means 14, 15 for detecting the height of the circular plate 132. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tilt structure that is mounted on a lifting carriage of a three-way stacking track and detects a state in which a fork is tilted.

  2. Description of the Related Art Conventionally, forklifts that can load a fork with the fork directed in the traveling direction of the vehicle and both sides thereof, a so-called three-way stacking truck is known. According to the three-way stacking track, the elevating carriage is provided so as to be movable up and down with respect to the mast standing on the vehicle body, and the elevating carriage is provided with a fork that can be turned (rotated). The tilting structure in which the rear end of the fork is supported on the lifting carriage and the fork is rotated (tilted) in the direction in which the front end moves up and down is disclosed in the following patent document.

Japanese Utility Model Publication No. 55-172297

  Conventionally, it is desirable to detect the state of the fork with a sensor or the like in order to avoid the complication that the operator visually recognizes that the tip of the fork has reached the upper limit or the lower limit in the process of tilting the fork as described above. ing.

  However, when the tilt structure described above is applied to a three-way stacking track, the fork turns (rotates) around a support shaft provided upright on the lifting carriage, so that a detection signal from a sensor or the like is sent to the operator side. For this reason, there is a possibility that the electric wire for twisting may be twisted with the turning of the fork and disconnected. It is also difficult to secure a space for passing such an electric wire in the lift carriage.

  Furthermore, in the configuration in which the fork is tilted using the hydraulic cylinder as a prime mover, it is difficult to reduce the size of the hydraulic cylinder itself because of the need to ensure a sufficient stroke of the hydraulic cylinder, and the size of the entire lifting carriage is hindered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a tilt structure that can reduce the burden on the operator's work by detecting the tilt state of the fork and that can achieve downsizing of the lifting carriage.

  The present invention includes an upright shaft for rotation that has an upper end and a lower end, and is rotated by a drive source, a tilt horizontal shaft that is connected to the upright shaft and protrudes at both ends in a horizontal direction from the upright shaft, and a rear end on the horizontal shaft And a fork having a tip extending horizontally, and a direction in which the tip of the fork moves up and down with the horizontal shaft as a fulcrum that is coupled to the upright shaft at a position spaced downward from the horizontal shaft. The tilt drive means includes a tilt drive means for rotating the lift carriage, and the tilt drive means includes an input shaft to which a rotational force is input, and an upright shaft that is housed in the upright shaft and rotates together with the input shaft. A screw rod coupled to the upright shaft, a speed reducer coupled to the upright shaft to decelerate rotation of the input shaft and output to the output shaft protruding from the lower end of the upright shaft, and an output of the output shaft of the speed reducer transmitted to the fork To do A transmission means for rotating the fork with the horizontal shaft as a fulcrum, a lifting nut screwed to the screw rod and displaced in the vertical direction in accordance with the rotation of the screw rod, and the vertical shaft It comprises a detected piece that is provided outside and moves up and down together with the elevating nut, and a detecting means that detects the height of the detected piece.

  Further, in the tilt structure of the lifting carriage, the detection means is provided in a pair in the vicinity of the upright shaft so as to be vertically separated, and one of the pair of detection means is in a state where the tip of the fork reaches the lower limit. The detected piece is detected, and the other of the pair of detecting means detects the detected piece in a state where the tip of the fork reaches the upper limit.

  Further, in the tilt structure of the lifting carriage, a long hole extending in the vertical direction is provided between the upper end and the lower end of the upright shaft, and the detected piece is connected to the lifting nut through the long hole. And

  Furthermore, the tilt structure of the lifting carriage is characterized in that the detected piece includes an arc-shaped plate curved along the circumferential direction of the upright shaft.

  According to the tilt structure of the lift carriage according to the present invention, the tilt horizontal shaft is connected to the upright shaft for rotation rotated by the drive source, and the tilt drive means rotates the fork with the horizontal shaft as a fulcrum. In the configuration, for example, when a rotational force is input to the input shaft from the lower end of the upright shaft via a pulley or the like, the screw rod rotates inside the upright shaft together with the input shaft (hereinafter referred to as “high speed rotation”). To do. This high speed rotation is decelerated by the speed reducer, converted to low speed rotation, and output from the output shaft. Then, when the rotational force of the output shaft is transmitted to the fork via the transmission means, the fork rotates (tilts) about the horizontal shaft so that the tip of the fork moves up and down.

  On the other hand, since the elevating nut is screwed to the screw rod that rotates together with the input shaft, the fork rotates (tilt) in the process of rotating so that the tip moves up and down as described above. The lifting nut and the detected piece are displaced upward or downward along the screw rod in accordance with the angle to be).

  Therefore, if the position of the detected piece is detected by detection means provided outside the upright shaft, and this is displayed to the operator using a monitor display or the like as information suggesting the state of the fork, for example, It is possible to efficiently carry out the cargo handling work by omitting the misoperation of the operator visually recognizing the state of the fork on the way.

  Moreover, since the detection means can detect the detected piece that is displaced upward or downward together with the elevating nut as described above from the outside of the upright shaft, the detection means, for example, an electric signal based on the detection of the detected piece. When the proximity sensor to send out is applied, it is not necessary to wire an electric wire for transmitting an electric signal on the upright shaft. Further, even if the upright shaft rotates by rotating the fork, it is not necessary to rotate the detection means together with the upright shaft. That is, since the detection means can be fixed to the lifting carriage, the electric wire is not twisted and the electric wire is not broken.

  Furthermore, according to the tilt structure of the lifting carriage according to the present invention, it is possible to detect that the tip of the fork is located at the upper limit or the lower limit simply by arranging the detection means in pairs near the upright shaft. . Accordingly, the manufacturing cost can be greatly reduced as compared with the case where the angle at which the fork rotates (tilt) is monitored using, for example, a rotary encoder. Further, if it is possible to detect that the tip of the fork is located at the upper limit or the lower limit, the operator can easily predict the state without visually checking the fork, and thus the above-described effect of efficiently performing the cargo handling work is achieved. You can also.

  Further, according to the tilt structure of the lifting carriage according to the present invention, the detection piece is connected to the lifting nut through a long hole provided between the upper end and the lower end of the upright shaft, so that the detection means is connected to the vertical shaft. It can arrange | position close to the middle of a longitudinal direction. Therefore, it is not necessary to secure a space for disposing the detection means near the upper end or the lower end of the upright shaft, and the height dimension of the lifting carriage can be reduced accordingly.

  Furthermore, when the detected piece includes an arc-shaped plate curved along the circumferential direction of the upright shaft, the upright shaft rotates to rotate the fork relative to the detection means fixed to the lifting carriage. Even so, the arcuate plate is always positioned between a pair of detection means that are vertically separated from each other. Therefore, when the arc-shaped plate reaches a predetermined height as the lifting nut is displaced as described above, either one of the pair of detecting means reliably detects such an arc-shaped plate, and the above effect is obtained. Can be achieved.

  A tilt structure 20 of the lifting carriage 10 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 9. FIG. 1 is a side view of a forklift v on which a lifting carriage 10 according to an embodiment of the present invention is mounted, and FIG. 2 is a plan view thereof. The forklift v is provided with an elevating carriage 10 that can be raised and lowered with respect to a mast erected on a vehicle body, and the elevating carriage 10 is provided with a fork that can be turned (rotated). The lift carriage is provided with a tilt structure 20 that supports the rear end of the fork 3 and rotates (tilts) the fork 3 in a direction in which the front end thereof moves up and down. First, the outline of the tilt structure 20 will be described with reference to FIG.

  The tilt structure 20 includes a rotating upright shaft 1 having an upper end 11 and a lower end 12, a tilting horizontal shaft 2 connected to the upright shaft 1 in a horizontal posture via a support described later, and a rear end of the horizontal shaft 2. A fork 3 that is rotatably supported at an end 31 and that extends horizontally at a tip 32 and a fork 3 that is coupled to an upright shaft 1 at a position spaced downward from the horizontal shaft 2 with the horizontal shaft 2 as a fulcrum. It is generally composed of tilt drive means 4 for rotating (tilting) 32 in the up and down direction.

  The tilt drive means 4 includes an input shaft 5 to which a rotational force is input from a drive source M disposed near the lower end 12 of the upright shaft 1, a screw rod 6 that is built in the upright shaft 1 and rotates integrally with the input shaft 5, By reducing the high speed rotation of the input shaft 5 and outputting it to the output shaft 7 protruding from the lower end 12 of the upright shaft 1 and transmitting the rotational force of the output shaft 7 to the fork 3, the fork 3 can be And transmission means 9 for rotating the device. The input shaft 5 passes through the output shaft 7, and the output shaft 7 can freely rotate around the input shaft 5. The drive source M is mainly composed of an electric motor having a speed reducer G and a friction brake B, and the rotational force generated in the pulley 51 provided on the output shaft is supplied to the pulley provided on the input shaft 5 via the endless belt 52. 53.

  Further, the tilt structure 20 detects the height of the elevating nut 13 screwed to the screw rod 6, the arcuate plate 132 that can be moved up and down together with the elevating nut 13 arranged outside the upright shaft 1, and the height of the arcuate plate 132. And a pair of detection means 14 and 15. As the detection means 14 and 15, a proximity sensor arranged on the outside of the upright shaft 1 with being vertically separated from each other may be applied. Details are as follows.

  FIG. 4 shows the entire lifting carriage 10 to which the tilt structure 20 is applied. The elevating carriage 10 engages the base 103 with a mast m raised on the chassis of the forklift v illustrated in FIGS. 1 and 2 through a plurality of rollers 101 and 102 shown in FIG. Match. The base portion 103 fixes a pair of horizontal rails 104 extending in the vehicle width direction, and further fixes two rack gears 105 extending in the vehicle width direction to the pair of horizontal rails 104, respectively.

  On the other hand, a groove 106 is formed in each of the pair of horizontal rails 104, and a roller (same reference numeral) is engaged in the groove 106, and the head portion 107 is movable in the vehicle width direction via the roller. Installed on. The head unit 107 includes a main shaft 109 provided with a pair of pinions 108 that mesh with the two rack gears 105, a motor 110 with a shift gear in which an output pinion 119 is engaged with one of the pair of pinions 108, and the upright shaft 1. A rotation motor 112 for applying a rotational force via the gear train 111.

  As shown in FIGS. 3 to 7, the fork 3 raises the rear end 31 to form an upright piece 34 having an upper end portion (bearing hole) 33, and the tip 32 is inclined horizontally or slightly with respect to the horizontal. It extends like so. The horizontal shaft 2 is connected to the upright shaft 1 via a support 30 and protrudes both end portions 21 from the upright shaft 1 in the horizontal direction, and between the both end portions 21, the upright piece 34 of the fork 3. The upper end 33 is rotatably supported.

  The upright shaft 1 has an upper end 11 and a lower end 12 that are respectively supported by the head portion 107, forming an insertion hole 115 that reaches the middle in the longitudinal direction (between the upper end 11 and the lower end 12), and near the upper end of the insertion hole 115. A long hole 116 extending in the vertical direction is opened. The insertion hole 115 is a space for installing the screw rod 6 and the lifting nut 13 on the upright shaft 1.

  As shown in FIGS. 8A to 8C, the arc-shaped plate 132 mainly includes an arc-shaped plate 131 that is curved along the circumferential direction of the upright shaft 1. The elevating nut 13 is connected through a support piece 133 that passes through the long hole 116. Reference numeral 134 denotes two bolts that integrally join the arc-shaped plate 131, the support piece 133, and the elevating nut 13.

  FIG. 9 shows an example in which the speed reducer 8 is attached to the lower end 12 of the upright shaft 1. A flat portion 35 in which four screw holes are formed is provided at a portion directed to the fork 3 on the peripheral surface of the upright shaft 1. The support 30 includes a main body portion 37 fixed to the flat portion 35 of the upright shaft 1 by bolts 36 respectively screwed into the four screw holes, a horizontal extending portion 38 having a shape extending to both sides thereof, A pair of fixing portions 39 are provided at both ends of the horizontal extension portion 38 and respectively fix both end portions 21 of the horizontal shaft 2.

  The tilt drive means 4 includes a speed reducer 8, a transmission means 9, and a tilt bar 16 having a pair of bearing portions (holes) 161 that are rotatably supported by both end portions 21 of the horizontal shaft 2. The tilt bar 16 approaches the upright piece 34 of the fork 3 in a state where it is hung from the horizontal shaft 2 by its own weight.

  The speed reducer 8 illustrated in FIG. 9 is mainly a known cyclo speed reducer (registered trademark). In addition, a planetary gear mechanism that rotates the planetary gear around the sun gear rotated by the input shaft 5 and transmits the rotational force of the planetary gear to the output shaft or a reduction gear mainly composed of a differential gear mechanism is applied. Also good. The transmission means 9 includes an eccentric pin 17 mainly composed of a spherical plain bearing that is positioned so as to be eccentric with respect to the output shaft 7 of the speed reducer 8, and a pin 18 mainly composed of a spherical plain bearing attached to the lower part of the tilt bar 16. And a connecting rod 19 having one end joined to the output shaft 7 via an eccentric pin 17 and the other end joined to a tilt bar 16 via a pin 18.

  According to the tilt structure 20 described above, when the rotational force of the driving source M is input to the input shaft 5, the screw rod 6 rotates at a high speed together with the input shaft 5. This high speed rotation is converted into a low speed rotation by the speed reducer 8 and output from the output shaft 7. The rotation ratio between the input shaft 5 and the output shaft 7 is preferably around 90: 1. In addition to being able to increase the rotational force of the drive source M satisfactorily, the upright shaft 1 rotates (rotates) within a range of, for example, about 180 °, and the input of the speed reducer 8 to the drive source M correspondingly. Even if the shaft 5 is rotated, if the rotation ratio is set as described above, the rotation of the upright shaft 1 hardly affects the tilting operation of the fork 3 and the displacement of the elevating nut 13. .

  Further, the rotation of the output shaft 7 is converted into the reciprocating motion of the connecting rod 19 by the eccentric pin 17. Such a reciprocating motion is transmitted to the tilt bar 16 as a movement in which the connecting rod 19 advances and retreats toward the upright piece 34 of the fork 3. At the same time, the tilt bar 16 moves forward and backward together with the connecting rod 19. The upright piece 34 of the fork 3 is driven by the tilt bar 16, and the fork 3 rotates (tilt) about the horizontal shaft 2 so that the tip 32 thereof moves up and down (up or down). To do.

  Further, the tilt bar 16 is close to the upright piece 34 of the fork 3, as is apparent from FIG. 6, no matter where the upper end 33 of the fork 3 is positioned between both ends 21 of the horizontal shaft 2. . For this reason, even if the operator adjusts the position of the fork 3 according to the size of the load, the fork 3 can be reliably rotated as described above.

  Since the screw rod 6 rotates at a high speed in the process of rotating the fork 3 as described above, the elevating nut 13 that is screwed to the screw rod 6 is displaced according to the angle at which the fork 3 rotates as described above. Along with this, the arcuate plate 132 is also displaced. For example, in a state where the tip 32 of the fork 3 has reached the lower limit, one of the pair of detection means 14, 15 detects the arcuate plate 132, and in a state where the tip 32 of the fork 3 has reached the upper limit, A pair of detection means 14 and 15 may be arranged so that the other of 14 and 15 detects the arcuate plate 132.

  Here, the distinction from “one” or “the other” is the process in which the tip 32 of the fork 3 moves up and down, and the lifting nut 13 is similarly displaced up and down, or the direction in which the tip 32 of the fork 3 moves. This is because whether the elevating nut 13 is displaced in the opposite direction depends on the specifications of the speed reducer 8 applied to the present embodiment.

  As described above, the position of the arcuate plate 132 is detected by the detection means 14 and 15, and for example, the tip 32 of the fork 3 reaches the upper limit or the lower limit, that is, the tilt amount (rotatable angle) of the fork 3. If the information is displayed to the operator using a monitor display or the like as information suggesting that the maximum has occurred, the operator can visually check the state of the fork 3 in the middle of the cargo handling work, and the cargo handling work can be efficiently performed. Can be done.

  Further, as described above, the arc-shaped plate 132 is configured to protrude to the outside of the upright shaft 1 through the long hole 116 formed in the middle of the upright shaft 1 in the longitudinal direction. Therefore, it is not necessary to secure a space for disposing the detection means 14 and 15 near the lower end 12 or the lower end 12, and the height dimension of the lifting carriage 10 can be reduced accordingly.

  Further, as illustrated in FIG. 8, it is desirable that the space between the one side edge 135 and the other side edge 136 of the arcuate plate 132 is curved by 180 ° or more. This is due to the following reason. That is, even if the upright shaft 1 is rotated within a range of 180 ° or less in order to rotate the fork 3, the one side edge 135 and the other side edge 136 are between the detection means 14 and 15 aligned vertically. Somewhere in between will be located. Therefore, when the arcuate plate 131 reaches a predetermined height as the elevating nut 13 is displaced as described above, one of the pair of detection means 14 and 15 reliably detects the arcuate plate 131, and the above-described effect. Can be achieved.

  It should be noted that the present invention can be implemented in a mode in which various improvements, modifications, or variations are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention. For example, in addition to detecting the upper and lower limits of the tip 32 of the fork 3 by the detection means 14 and 15, a rotary encoder is connected to the drive source M or the screw rod 6 to tilt the fork 3 between the upper and lower limits. You may comprise so that quantity can be detected. In the above description, the tilt bar 16 and the connecting rod 19 are pin-joined, but this joining may be a simple contact between the tilt bar 16 and the eccentric pin 17. Thereby, the number of components can be reduced.

  The present invention is an optimum configuration for a three-way stacking truck, and in addition to this, the present invention may be adopted in a state in which a lifting carriage is attached to a driver's cab of an order picking truck in which a driver's cab on which an operator enters is lifted, The present invention may be applied to a carriage that moves up and down in a stacker crane of an automatic warehouse.

The side view of the forklift carrying the raising / lowering carriage which concerns on embodiment of this invention. The top view of the forklift carrying the raising / lowering carriage which concerns on embodiment of this invention. Schematic which shows the tilt structure of the raising / lowering carriage which concerns on embodiment of this invention. The side view of the raising / lowering carriage which concerns on embodiment of this invention. (A) is a side view of the principal part of the raising / lowering carriage which concerns on embodiment of this invention, (b) is sectional drawing which shows the connection structure. The front view of the tilt bar applied to the raising / lowering carriage which concerns on embodiment of this invention. (A) is a front view of the upright shaft for rotation applied to the raising / lowering carriage which concerns on embodiment of this invention, (b) is the sectional drawing. (A) is a top view of the to-be-detected piece applied to the raising / lowering carriage which concerns on embodiment of this invention, (b) is the front view, (c) is the side view. Sectional drawing of the reduction gear applied to the raising / lowering carriage which concerns on embodiment of this invention.

Explanation of symbols

1: Upright shaft 2: Horizontal shaft 3: Fork 4: Tilt drive means 5: Input shaft 6: Screw rod 7: Output shaft 8: Reducer 9: Transmission means 10: Lifting carriage 11: Upper end 12: Lower end 13: Lifting nut 14, 15: Detection means 20: Tilt structure 21: End portion 31: Rear end 32: Front end 33: Upper end portion 34: Upright piece 32: Front end 116: Long hole 131: Detected piece 132: Arc-shaped plate 133: Support piece

Claims (4)

Rotating upright shaft having an upper end and a lower end, rotated by a drive source, a tilting horizontal shaft connected to the upright shaft and projecting from the upright shaft at both ends in the horizontal direction, and a rear end pivotable to the horizontal shaft And a fork that is horizontally extended at the tip, and is coupled to the upright shaft at a position spaced downward from the horizontal shaft, and the fork is rotated in the direction in which the tip moves up and down with the horizontal shaft as a fulcrum. A tilt structure of a lifting carriage comprising a tilt drive means,
The tilt driving means includes an input shaft to which a rotational force is input, a screw rod that is housed in the upright shaft and rotates together with the input shaft, and is coupled to the upright shaft to decelerate rotation of the input shaft to reduce the upright shaft. A speed reducer that outputs to the output shaft protruding from the lower end of the shaft, a transmission means for rotating the fork about the horizontal axis by transmitting the output of the output shaft of the speed reducer to the fork, and the screw rod A lifting nut that is displaced in the vertical direction inside the upright shaft according to the rotation of the screw rod, a detected piece that is provided outside the upright shaft and moves up and down with the lifting nut, and a height of the detected piece And a tilting structure of the lift carriage, characterized by comprising a detecting means for detecting the height.   The detection means is provided as a pair in the vicinity of the upright shaft so as to be vertically separated, and with the tip of the fork reaching the lower limit, one of the pair of detection means detects the detected piece, 2. The tilt structure of the lifting carriage according to claim 1, wherein the other of the pair of detection means detects the detected piece in a state in which the tip of the fork reaches the upper limit.   The elevating / lowering according to claim 2, wherein a long hole extending in the vertical direction is provided between an upper end and a lower end of the upright shaft, and the detected piece is connected to the elevating nut via the long hole. Carriage tilt structure. The tilt structure of the lifting carriage according to claim 3, wherein the detected piece includes an arc-shaped plate curved along a circumferential direction of the upright shaft.

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