JP4578857B2 - Tilt structure of lifting carriage - Google Patents

Description

  The present invention relates to a tilt structure of a lifting carriage mounted on a three-way stacking track.

  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). A tilt structure that supports the rear end of the fork on the lifting carriage and pivots the fork in a direction in which the front end moves up and down is disclosed in the following patent document, and the fork is tilted by a hydraulic cylinder. Has been adopted.

Japanese Utility Model Publication No. 55-172297

  In the configuration in which the fork is tilted by the hydraulic cylinder, it is difficult to reduce the size of the hydraulic cylinder itself because it is necessary to secure a sufficient stroke of the hydraulic cylinder, and the downsizing of the entire lifting carriage is hindered.

  Although it is conceivable that the fork is tilted by an electric motor instead of the hydraulic cylinder, the lifting carriage is unnecessarily enlarged in order to secure such a storage space for the electric motor. In particular, in a three-way stacking truck, a drive for performing an operation of rotating (forking) a fork around a support shaft provided upright on the lifting carriage and an operation of moving (shifting) the lifting carriage itself in the vehicle width direction. Since the source has to be stored, the above problem becomes even more pronounced.

  Accordingly, an object of the present invention is to provide a tilt structure that can achieve downsizing of the lifting carriage.

  The present invention comprises a fork having a rear end raised to form an upright piece having an upper end, the tip extending horizontally, an upper end and a lower end, and a rotating upright shaft rotated by a drive source, and the upright A tilting horizontal shaft that is connected to a shaft and protrudes from both ends of the upright shaft in the horizontal direction and rotatably supports an upper end portion of the upright piece of the fork, and is spaced downward from the horizontal shaft. A tilt structure of an elevating carriage that is coupled to the upright shaft at a position and includes tilt drive means for rotating the fork in a direction in which the tip moves up and down with the horizontal shaft as a fulcrum. An output shaft projecting from the lower end of the upright shaft, and an input shaft penetrating the output shaft and projecting downward from the output shaft, and decelerating rotation of the input shaft to rotate the output shaft And the input shaft A rotating machine for inputting a rotational force, bonded via an eccentric pin on said output shaft, characterized in that it comprises a transmission means for the follower of the upright of the fork.

Furthermore, tilt structure of the lifting carriage according to the present invention comprises a tilt bar close to the upright of the hanging passed the fork between the pair of bearing portions rotatably respectively supported at both ends of the horizontal axis Rutotomoni The transmission means is an eccentric pin positioned so as to be eccentric with respect to the output shaft of the speed reducer, and a connecting rod having one end joined to the output shaft via the eccentric pin and the other end joined to the tilt bar. The rotation of the output shaft is converted into the reciprocating motion of the connecting rod by the eccentric pin, and the reciprocating motion of the connecting rod is transmitted to the tilt bar as a motion of moving forward and backward toward the upright piece of the fork. The tilt bar moves forward and backward , and the upright piece of the fork is driven by the tilt bar that moves forward and backward together with the connecting rod.

  Furthermore, the tilt structure of the lifting carriage according to the present invention is characterized in that the rotating machine is disposed near the lower end of the upright shaft.

  Furthermore, the tilt structure of the lifting carriage according to the present invention is characterized in that the upright shaft and the input shaft rotate around the same axis.

  According to the tilt structure of the lifting carriage according to the present invention, when the rotational force of the rotating machine is input to the input shaft from the lower end of the upright shaft, the rotation of the input shaft (hereinafter referred to as “high-speed rotation”) decelerates. It is decelerated by the machine, 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.

  The transmission means includes an eccentric pin positioned so as to be eccentric with respect to the output shaft of the speed reducer, and a connecting rod having one end joined to the output shaft via the eccentric pin and the other end joined to the tilt bar. In the transmission means, one end of the connecting rod is joined to the output shaft via the eccentric pin, and the other end of the connecting rod is joined to the tilt bar. Therefore, the rotation of the output shaft is reciprocated, that is, toward the upright piece of the fork. As a result, it can be transmitted to the tilt bar while converting the movement of the connecting rod back and forth. Therefore, compared to the case where the rotational force of the output shaft is transmitted to the fork using a transmission mechanism such as a chain or gear, the periphery of the lower end of the upright shaft and the entire lifting carriage can be reduced in size. Instead of the connecting rod, a cam follower may be attached to the eccentric pin, and the tilt bar may be pressed by the cam follower.

In addition, the tilt bar is placed between a pair of bearings that are rotatably supported at both ends of the horizontal shaft and is close to the upright piece of the fork. Therefore, the tilt bar is moved forward and backward together with the connecting rod. Thus, the fork can be driven by the tilt bar. Therefore, as long as the upper end of the fork is located anywhere between the ends of the horizontal shaft, in other words, the fork is reliably moved no matter where the fork is moved between the ends of the horizontal shaft. It can be rotated (tilted).

  Furthermore, according to the tilt structure of the lift carriage according to the present invention, since the rotating machine is disposed near the lower end of the upright shaft, the height dimension of the lift carriage can be suppressed. Also, since the upright shaft and the input shaft rotate around the same axis, even if the upright shaft rotates (rotates), the rotation center of the input shaft of the speed reducer does not move, and There is an advantage that the interval can be kept constant and the rotational force of the rotating machine can be stably transmitted to the input shaft.

  A tilt structure of a lifting carriage according to an embodiment of the present invention will be described with reference to the drawings. The elevating carriage exemplified below is mounted exclusively on the three-way stacking track v shown in FIGS. 1 and 2.

  As shown in FIGS. 3 to 5, the tilt structure 20 includes a rotating upright shaft 1 having an upper end 11 and a lower end 12, a tilt horizontal shaft 2 supported in a horizontal posture on the upright shaft 1, and the horizontal shaft. 2, a fork 3 having a rear end 31 rotatably supported and a tip 32 extending substantially horizontally, and a fork 3 coupled to an upright shaft 1 at a position spaced downward from the horizontal shaft 2 and having the horizontal shaft 2 as a fulcrum. 3 is generally composed of a tilt driving means 4 that rotates (tilts) the tip 3 in the direction in which the tip 32 moves up and down. Details are as follows.

  That is, the entire lifting carriage 10 to which the tilt structure 20 is applied is shown in FIG. The elevating carriage 10 has a base portion that is movable up and down in the vertical direction on the mast m raised on the chassis of the three-way stacking truck v illustrated in FIGS. 1 and 2 via a plurality of rollers 101 and 102 shown in FIG. 103 is engaged. 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. The upright shaft 1 has an upper end 11 and a lower end 12 supported by the head portion 107.

  As shown in FIGS. 4 to 6, the fork 3 has an upright piece 34 having a rear end 31 raised and an upper end portion (bearing hole) 33. The horizontal shaft 2 is connected to the upright shaft 1 via a support 30, and both end portions 21 thereof protrude from the upright shaft 1, and the upright piece 34 of the fork 3 is located between the both end portions 21. 11 is supported rotatably. A flat portion 35 is provided at a portion directed to the fork 3 on the peripheral surface of the upright shaft 1. The support 30 is provided on each end of the main body 37 fixed to the flat surface 35 by a plurality of bolts 36, a horizontal extension 38 extending to both sides of the main body 37, and the horizontal extension 38, respectively. And a pair of fixing portions 39 for fixing both end portions 21 of the horizontal shaft 2.

  The tilt drive means 4 has an input shaft 5 to which a rotational force is input from a drive source (rotating machine) M housed in the lower part of the lifting carriage 10 and an output shaft 7 that decelerates and outputs the high-speed rotation of the input shaft 5. A speed reducer 8 and transmission means 9 described later for rotating the tilt of the fork 3 by transmitting the rotational force of the output shaft 7 to the fork 3 are provided. 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 a rotating machine that transmits the rotational force generated in the pulley 51 provided on the output shaft to the pulley 53 provided on the input shaft 5 via the endless belt 52.

  The speed reducer 8 illustrated in FIG. 5 is mainly a known cyclo speed reducer (registered trademark). In addition, a planetary gear or a reduction gear mainly composed of a differential 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 may be applied. . The upright shaft 1 and the input shaft 5 are positioned so as to be able to rotate about the same axis with their axes aligned. This prevents the distance from the rotation center of the input shaft 5 of the speed reducer 8 to the drive source M from changing even when the upright shaft 1 rotates (rotates), and the tension of the endless belt 52 can be kept constant. Because.

  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. The tilt bar 16 has a pair of bearing portions (holes) 161 that are rotatably supported by both end portions 21 of the horizontal shaft 2, and the main body spanned between the pair of bearing portions 161 has its own weight. In the state where it hangs down from the horizontal shaft 2, it approaches the upright piece 34 of the fork 3.

  According to the tilt structure 20 described above, when the rotational force of the driving source M is input to the input shaft 5 and the input shaft 5 rotates, this high speed rotation is converted into a low speed rotation by the speed reducer 8 and the output shaft 7. Is output from. 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. This is because even if the shaft 5 is rotated, the rotation of the upright shaft 1 hardly affects the tilting operation of the fork 3 if the rotation ratio is set as described above.

  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 retracts toward the upright piece 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. When the rotational force is input to the speed reducer 8 and the eccentric pin 17 continues to rotate together with the output shaft 7, the connecting rod 19 only repeats forward and backward movement, so that the tip 32 of the fork 3 repeatedly moves up and down between the upper limit and the lower limit. Will do. Therefore, even if a safety device such as a torque limiter is not provided between the speed reducer and the fork, there is no fear that an overload is applied to a drive source for inputting rotational force to the speed reducer.

  Moreover, the height dimension of a raising / lowering carriage can be suppressed with the above structure. That is, when the drive source M is accommodated in the upper part of the lift carriage 10, a pulley or the like that transmits a rotational force from the drive source M to the input shaft 5 must be accommodated in the upper part of the lift carriage 10. On the other hand, since the tilt structure 10 has the speed reducer 8 disposed at the lower end 12 of the upright shaft 1, the drive source M for inputting rotational force to the input shaft 5 of the speed reducer 8 is used as the lower end 12 of the upright shaft 1. It is possible to dispose the pulley near the lower end 12 of the upright shaft 1. Further, a pulley or the like that transmits the rotational force from the drive source M to the input shaft 5 can be disposed near the lower end 12 of the upright shaft 1.

  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 the above description, the tilt bar 16 and the connecting rod 19 are simply brought into contact, but these contacts may be pin-bonded or the like. Moreover, the relationship between a mere cam follower and a board may be sufficient. Thereby, the fork 3 can be forcedly rotated.

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. 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. Sectional drawing of the reduction gear applied to the raising / lowering carriage which concerns on embodiment of this invention. The front view of the tilt bar 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 16: Tilt bar 17: Eccentric pin 19: Connecting rod 20: Tilt structure 21: End portion 31: Rear end 32: Front end 34: Upright piece 161: Bearing portion M: Driving source (rotating machine)

Claims (4)

A fork that raises the rear end to form an upright piece having an upper end, and horizontally extends the tip;
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 connected to the upright shaft and projecting at both ends in the horizontal direction from the upright shaft, and rotatably supporting an upper end portion of the upright piece of the fork between the both ends;
A tilt structure of an elevating carriage, which is coupled to the upright shaft at a position spaced downward from the horizontal shaft and includes a tilt driving means for rotating the fork in a direction in which the tip moves up and down with the horizontal shaft as a fulcrum. There,
The tilt drive means has an output shaft projecting from the lower end of the upright shaft, and an input shaft that penetrates the output shaft and projects downward from the output shaft, and reduces the rotation of the input shaft and outputs the output shaft. A speed reducer that rotates the shaft;
A rotating machine that inputs rotational force to the input shaft;
A transmission means joined to the output shaft via an eccentric pin, and the upright piece of the fork is driven;
A tilt structure of an elevating carriage characterized by comprising: Rutotomoni comprises a tilt bar close to the upright of the hanging passed the fork between the pair of bearing portions rotatably respectively supported at both ends of the horizontal shaft,
The transmission means includes an eccentric pin positioned to be eccentric with respect to the output shaft of the speed reducer, and a connecting rod having one end joined to the output shaft via the eccentric pin and the other end joined to the tilt bar. Prepared,
The rotation of the output shaft is converted into the reciprocating motion of the connecting rod by the eccentric pin, and the reciprocating motion of the connecting rod is transmitted to the tilt bar as a motion of moving back and forth toward the upright piece of the fork. 2. The tilt structure of the elevating carriage according to claim 1, wherein the upright piece of the fork is driven by the tilt bar that moves forward and backward with the connecting rod.   The tilt structure of the elevating carriage according to claim 1 or 2, wherein the rotating machine is disposed near a lower end of the upright shaft.   4. The tilt structure of an elevating carriage according to claim 1, wherein the upright shaft and the input shaft rotate about the same axis.

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