JP2021075384A - forklift - Google Patents

Abstract

To provide a forklift that can stably support a load loaded on a fork from a driver's seat side by means of a backrest when the load is loaded on the fork without deteriorating workability, and can easily secure a forward view of an operator from the driver's seat when the load is not loaded on the fork.SOLUTION: A forklift 10 includes a moving body 50 that operates according to the loading status of a load on a fork 17, and a backrest elevating device 30 that is driven in conjunction with the operation of the moving body 50. The backrest elevating device 30 is in a state where a backrest 26 is raised with respect to the fork 17 when the load is loaded on the fork 17, and enables the backrest 26 to be raised and lowered against the fork 17 so that the backrest 26 returns to its original position before being raised against the fork 17 when the load is loaded on the fork 17.SELECTED DRAWING: Figure 2

Description

The present invention relates to a forklift.

The forklift is a driver's seat provided on the vehicle body, a mast installed in front of the driver's seat on the vehicle body, a lift bracket supported by the mast so as to be able to move up and down, and a fork mounted on the lift bracket for driving. It has a backrest that is placed in front of the seat. Generally, the backrest is fixed to the lift bracket by fasteners such as bolts. The backrest can support the load loaded on the fork from the driver's seat side when the load is loaded on the fork, and has a function to prevent the load from collapsing toward the driver's seat side. I'm playing. The backrest has a crosspiece structure, and although the front view from the driver's seat through the backrest is sufficiently secured, there is a desire to further widen the front view.

Therefore, for example, the backrest of the forklift of Patent Document 1 is composed of a backrest main body provided on the upper part of the lift bracket (carriage) and a backrest sub-body provided so as to be able to move up and down with respect to the backrest main body. ing. The backrest sub-body is detachably attached to the backrest main body by fasteners such as bolts. When the fastener is loosened, the backrest subbody is released from being fixed to the backrest body, and can be raised and lowered with respect to the backrest body. When the fastener is tightened, the backrest subbody is backrested. It is fixed to the main body and cannot be raised or lowered with respect to the backrest main body.

Then, for example, when a load is loaded on the fork, the fastener is loosened to raise the backrest subbody with respect to the backrest main body, and the fastener is tightened to bring the backrest subbody to the backrest main body. And fix it in the raised position. This makes it possible to stably support the load loaded on the fork from the driver's seat side by the backrest, and prevent the load loaded on the fork from collapsing toward the driver's seat side by the backrest. Can be done.

On the other hand, for example, when the fork is not loaded with a load, the fastener is loosened to lower the backrest subbody to the original position before being raised with respect to the backrest body, and the fastener is tightened to back. Fix the rest accessory in its original position before raising it with respect to the backrest body. According to this, the backrest is less likely to enter the operator's field of view from the driver's seat when the fork is not loaded, as compared to the case where the backrest accessory remains raised with respect to the backrest body. As a result, the front view of the worker from the driver's seat is secured, and workability is improved.

Japanese Unexamined Patent Publication No. 2008-114994

As described above, in Patent Document 1, by raising and lowering the backrest sub-body with respect to the backrest main body, when a load is loaded on the fork, the load loaded on the fork is moved to the driver's seat side by the backrest. When the fork is not loaded with a load, the front view of the operator from the driver's seat is secured. However, in Patent Document 1, the workability is poor because the operator needs to manually raise and lower the backrest sub-body with respect to the backrest main body.

An object of the present invention is to enable the backrest to stably support the load loaded on the fork from the driver's seat side when the load is loaded on the fork without deteriorating workability. It is an object of the present invention to provide a forklift that can easily secure a front view of the operator from the driver's seat when the load is not loaded.

The forklift that solves the above problems includes a driver's seat provided on the vehicle body, a mast standing in front of the driver's seat on the vehicle body, a lift bracket that is supported by the mast so as to be able to move up and down, and the lift. A forklift equipped with a fork mounted on a bracket and a backrest arranged in front of the driver's seat, the actuating portion that operates according to the load status of the load on the fork, and the actuating portion of the actuating portion. It is driven in conjunction with the operation, and when the load is loaded on the fork, the backrest is in a raised state with respect to the fork, and when the load is not loaded on the fork, the backrest is raised. The backrest elevating device is provided so that the backrest can be raised and lowered with respect to the fork so that the backrest is returned to the original position before being raised with respect to the fork.

According to this, the backrest moves up and down with respect to the fork by driving the backrest elevating device in conjunction with the operation of the operating portion that operates according to the load status of the load on the fork. , There is no need for the operator to manually raise and lower the backrest. Then, the backrest lifting device is driven so that the backrest is in a raised state with respect to the fork when the fork is loaded, and when the fork is not loaded, the backrest is placed on the fork. On the other hand, it is driven so that it returns to the original position before rising. Therefore, when the load is loaded on the fork without deteriorating the workability, the load loaded on the fork can be stably supported from the driver's seat side by the backrest, and the load is loaded on the fork. When not, the front view of the worker from the driver's seat can be easily secured.

In the fork lift, the fork has a plate-shaped mounting portion that is attached to the lift bracket and extends in the vertical direction, and a plate-shaped loading portion that extends from the mounting portion to the front in the front-rear direction of the vehicle body and loads the load. The backrest elevating device is rotatable to a first rotating member rotatably supported on the side surface of the loading portion and an end portion on the side surface of the mounting portion opposite to the loading portion. The second rotating member supported by the above, the third rotating member rotatably supported by the end portion on the side surface of the mounting portion on the loading portion side, the first rotating member, the second rotating member, and the said. It has at least a hanging member that is mounted on the third rotating member and raises and lowers the backrest with respect to the mounting portion, and the operating portion is integrally provided on the hanging member and is loaded. It is a moving body that can slide and move with respect to the portion, and the first rotating member is pushed by the load loaded on the loading portion in a direction in which the moving body approaches the mounting portion with respect to the loading portion. , The hanging member is driven via the second rotating member and the third rotating member, and the backrest rises against the weight of the backrest with respect to the mounting portion, and the loading portion. When the load is unloaded, the hanging member is driven by the weight of the backrest via the first rotating member, the second rotating member, and the third rotating member, and the backrest is attached to the backrest. It descends to its original position before rising with respect to the portion, the moving body moves in a direction away from the mounting portion with respect to the loading portion, and is pushed in a direction approaching the mounting portion by the load. It is good to return to the previous original position.

According to this, the backrest can be raised and lowered by adopting a mechanical configuration using at least a moving body, a first rotating member, a second rotating member, a third rotating member, and a hanging member. Therefore, for example, a sensor that operates according to the load status of the load on the fork is used as the operating unit, and an electrical configuration is adopted in which the control device controls the drive of the backrest elevating device based on the operation of the sensor. It is not necessary to store a complicated control program in the control device in advance as in the case. Therefore, the backrest can be raised and lowered without complicating the configuration.

In the fork lift, the third rotating member has a first rotating body and a second rotating body, and the hanging member is provided integrally with the moving body, and the first rotating member and the first rotating body are provided. It is preferable to include the first hanging body mounted on the body, the second rotating member connected to the backrest, and the second hanging body mounted on the second rotating body.

According to this, for example, the third rotating member does not have the first rotating body and the second rotating body, and one hanging member is attached to the first rotating member, the second rotating member, and the third rotating member. Compared with the backrest elevating device having a mounted structure, the operation of the hooked member via the first rotating member, the second rotating member, and the third rotating member is likely to be stable. Therefore, it is possible to improve the reliability of the backrest raising / lowering operation in the backrest raising / lowering device.

In the forklift, the first rotating member is a first sprocket, the second rotating member is a second sprocket, and the third rotating member is a first gear as the first rotating body, and the said. A third sprocket having a second gear as a second rotating body, the first hook is a first chain mounted on the first sprocket and the first gear, and the second hook. The body may be a second chain mounted on the second sprocket and the second gear.

According to this, for example, in the third sprocket, the fork in the backrest is adjusted by adjusting the number of teeth of the first gear and the number of teeth of the second gear to adjust the gear ratio between the first gear and the second gear. The elevating stroke and the moving stroke of the moving body with respect to the loading portion can be freely adjusted.

In the forklift, the number of teeth of the first gear is preferably larger than the number of teeth of the second gear.
According to this, the movement stroke of the moving body with respect to the loading portion can be made shorter than the elevating stroke of the backrest with respect to the fork. Therefore, the moving body can be kept as far as possible from the end of the loading portion opposite to the mounting portion, that is, the tip of the fork, so that the moving body becomes an obstacle when scooping the load with the fork. Can be avoided and workability can be improved.

According to the present invention, when a load is loaded on the fork without deteriorating workability, the load loaded on the fork can be stably supported from the driver's seat side by the backrest, and the fork can be stably supported. When no load is loaded on the fork, the front view of the operator from the driver's seat can be easily secured.

The schematic side view which shows the forklift in an embodiment. A perspective view showing a part of a forklift. A perspective view showing a guide shaft, a guide portion, and its surroundings. A plan sectional view showing a part of a forklift. An exploded perspective view of a part of a forklift. The perspective view which shows the connection point of the moving body and the 1st chain in an enlarged manner. The perspective view which shows the connection part of the backrest and the 2nd chain in an enlarged manner. The schematic diagram which shows the state which the load is not loaded on the fork. The schematic diagram which shows the state which a moving body is moving by a load. The schematic diagram which shows the state which the load is loaded on the fork. A perspective view showing a state in which the backrest is raised with respect to the fork. The schematic diagram for demonstrating the backrest elevating device in another embodiment.

Hereinafter, an embodiment in which the forklift is embodied will be described with reference to FIGS. 1 to 11. In the following explanation, "front", "rear", "left", "right", "top", and "bottom" are based on the state in which the worker driving the forklift is facing the front of the vehicle. It shall indicate "front", "rear", "left", "right", "top", and "bottom" of.

As shown in FIG. 1, the forklift 10 includes a drive wheel 12 arranged at the front lower portion of the vehicle body 11 and a steering wheel 13 arranged at the rear lower portion of the vehicle body 11. The forklift 10 is provided with a cargo handling device 14 at the front portion of the vehicle body 11. The cargo handling device 14 includes a mast 15 erected at the front portion of the vehicle body 11, a lift bracket 16 fixed to the mast 15, and a pair of forks 17 mounted on the lift bracket 16. The load W1 is loaded on the fork 17.

The cargo handling device 14 includes a lift cylinder 18 that raises and lowers the lift bracket 16. Then, the fork 17 moves up and down together with the lift bracket 16 by the operation of the lift cylinder 18. The mast 15 supports the lift bracket 16 so as to be able to move up and down. Therefore, the lift bracket 16 is supported by the mast 15 so as to be able to move up and down. Further, the cargo handling device 14 includes a tilt cylinder 19 that tilts the mast 15. Then, the fork 17 tilts together with the mast 15 by driving the tilt cylinder 19. The lift cylinder 18 and the tilt cylinder 19 are hydraulic cylinders.

The vehicle body 11 is provided with a driver's cab 20. The driver's cab 20 is provided with a driver's seat 21 on which an operator sits. Therefore, the driver's seat 21 is provided on the vehicle body 11. The driver's seat 21 is located behind the mast 15. Therefore, the mast 15 is erected in front of the driver's seat 21 in the vehicle body 11. Further, the driver's cab 20 is instructed of a plurality of cargo handling levers 22 for performing various operations such as raising and lowering and tilting of the cargo handling device 14, a handle 23 for steering the forklift 10, and the traveling direction of the forklift 10. A direction lever 24 is provided. Further, an accelerator pedal 25 is provided on the floor surface of the driver's cab 20.

The forklift 10 includes a traveling motor M1 for driving the drive wheels 12 and a battery B1. Then, the forklift 10 travels at a vehicle speed corresponding to the accelerator opening degree of the accelerator pedal 25 by controlling the drive of the traveling motor M1 according to the accelerator opening degree of the accelerator pedal 25. Therefore, in the forklift 10 of the present embodiment, the traveling motor M1 is driven by supplying electric power from the battery B1 to the traveling motor M1, and the drive wheels 12 are rotationally driven by the driving of the traveling motor M1. It is a running battery type.

As shown in FIG. 2, the lift bracket 16 has a long square frame shape. The lift bracket 16 has an upper finger bar 16a and a lower finger bar 16b, and a pair of side bars 16c and 16d. The upper finger bar 16a and the lower finger bar 16b are elongated flat plates that are vertically opposed to each other and extend in the vehicle width direction of the vehicle body 11. The vehicle width direction of the vehicle body 11 coincides with the left-right direction. The upper finger bar 16a and the lower finger bar 16b extend parallel to each other. The length of the upper finger bar 16a in the extension direction and the length of the lower finger bar 16b in the extension direction are the same. The thickness direction of the upper finger bar 16a and the thickness direction of the lower finger bar 16b coincide with the front-rear direction of the vehicle body 11.

The pair of sidebars 16c and 16d are elongated square columns connecting both ends of the upper finger bar 16a in the extending direction and both ends of the lower finger bar 16b in the extending direction, respectively. The pair of sidebars 16c and 16d extend in the vertical direction, respectively. The pair of sidebars 16c and 16d extend parallel to each other. The lengths of the pair of sidebars 16c and 16d in the extending direction are the same. The length of each of the pair of sidebars 16c and 16d in the extending direction is shorter than the length of each of the upper finger bar 16a and the lower finger bar 16b in the extending direction. Therefore, in the lift bracket 16, the extension direction of the upper finger bar 16a and the lower finger bar 16b is the longitudinal direction, and the extension direction of the pair of side bars 16c and 16d is the lateral direction.

Each fork 17 has an elongated L-shaped plate shape. Each fork 17 has an elongated flat plate-shaped mounting portion 17a attached to the lift bracket 16 and an elongated flat plate-shaped loading portion 17b for loading the load W1. The mounting portion 17a and the loading portion 17b are continuous. The width of the mounting portion 17a and the width of the loading portion 17b are the same. The mounting portion 17a is attached to the lift bracket 16 so that one end surface 171a in the thickness direction of the mounting portion 17a faces forward and the other end surface 172a in the thickness direction of the mounting portion 17a faces rearward. Therefore, the extending direction of the mounting portion 17a coincides with the vertical direction. Therefore, the mounting portion 17a extends in the vertical direction. The mounting portion 17a is arranged in front of the lift bracket 16.

The loading portion 17b extends from the lower end edge of the end surface 171a of the mounting portion 17a in a direction orthogonal to the extending direction of the mounting portion 17a. Therefore, the loading portion 17b extends forward from the mounting portion 17a in the front-rear direction of the vehicle body 11. The loading portion 17b is arranged so that one end surface 171b in the thickness direction of the loading portion 17b faces upward and the other end surface 172b in the thickness direction of the loading portion 17b faces downward.

The mounting portion 17a of each fork 17 has a first side surface 173a which is a side surface of the vehicle body 11 facing each other in the vehicle width direction. Further, the mounting portion 17a of each fork 17 has a second side surface 174a which is a side surface located on the opposite side of the first side surface 173a in the vehicle width direction of the vehicle body 11.

The loading portion 17b of each fork 17 has a first side surface 173b which is a side surface facing each other in the vehicle width direction of the vehicle body 11. The first side surface 173a of each mounting portion 17a and the first side surface 173b of each loading portion 17b are continuous and located on the same surface. Further, the loading portion 17b of each fork 17 has a second side surface 174b which is a side surface located on the opposite side of the first side surface 173b in the vehicle width direction of the vehicle body 11. The second side surface 174a of each mounting portion 17a and the second side surface 174b of each loading portion 17b are continuous and located on the same surface.

A guide shaft 27 is attached to the second side surface 174a of each attachment portion 17a. Each guide shaft 27 has a cylindrical shape. Each guide shaft 27 is attached to the second side surface 174a of each attachment portion 17a so that the axial direction of each guide shaft 27 coincides with the extension direction of each attachment portion 17a. Therefore, each guide shaft 27 extends in the vertical direction. Each guide shaft 27 is joined to the second side surface 174a of each mounting portion 17a by welding, for example, between a part of the outer peripheral surface of each guide shaft 27 and the second side surface 174a of each mounting portion 17a. ..

The forklift 10 includes a backrest 26 arranged in front of the driver's seat 21. The backrest 26 has a long square frame shape. The backrest 26 has an upper support plate 26a and a lower support plate 26b, and a pair of side support plates 26c and 26d. The upper support plate 26a and the lower support plate 26b are elongated and thin flat plates that are arranged so as to face each other in the vertical direction and extend in the vehicle width direction of the vehicle body 11. The upper support plate 26a and the lower support plate 26b extend in parallel with each other. The length of the upper support plate 26a in the extension direction and the length of the lower support plate 26b in the extension direction are the same. The extending direction of the upper support plate 26a is the longitudinal direction of the upper support plate 26a. The extending direction of the lower support plate 26b is the longitudinal direction of the lower support plate 26b. The thickness direction of the upper support plate 26a coincides with the front-rear direction of the vehicle body 11. The thickness direction of the lower support plate 26b is a direction oblique with respect to the front-rear direction of the vehicle body 11. The lower support plate 26b is an inclined plate that is inclined so that the lateral direction of the lower support plate 26b is an upward direction from the front to the rear in the front-rear direction of the vehicle body 11.

The pair of side support plates 26c and 26d have an elongated thin plate shape that connects both ends of the upper support plate 26a in the extension direction and both ends of the lower support plate 26b in the extension direction, respectively. The pair of side support plates 26c and 26d have an L-shaped cross-sectional view. The pair of side support plates 26c and 26d extend in the vertical direction, respectively. The pair of side support plates 26c and 26d extend parallel to each other. The lengths of the pair of side support plates 26c and 26d in the extending direction are the same. The extension directions of the pair of side support plates 26c and 26d are the longitudinal directions of the pair of side support plates 26c and 26d, respectively.

The pair of side support plates 26c and 26d have mounting plates 261c and 261d and support plates 262c and 262d, respectively. The mounting plates 261c and 261d and the support plates 262c and 262d are elongated and thin flat plates. Both mounting plates 261c and 261d extend in parallel with each other in a state where the thickness directions of both mounting plates 261c and 261d are the same. The thickness directions of both mounting plates 261c and 261d coincide with the extending directions of the upper support plate 26a and the lower support plate 26b, respectively. The longitudinal directions of both mounting plates 261c and 261d coincide with the extending directions of the pair of side support plates 26c and 26d. Both mounting plates 261c and 261d have the same length in the longitudinal direction.

In both support plates 262c and 262d, the thickness directions of both support plates 262c and 262d coincide with the front-rear direction of the vehicle body 11. The support plates 262c and 262d are separated from each other in the extending direction of the upper support plate 26a and the lower support plate 26b from the long side edge located in front of the vehicle body 11 in the front-rear direction in the lateral direction of the mounting plates 261c and 261d. It extends in the direction of The surface of both support plates 262c and 262d located in front of the vehicle body 11 in the front-rear direction is located on the same surface as the surface of the upper support plate 26a located in front of the vehicle body 11 in the front-rear direction. Therefore, both ends of the upper support plate 26a in the extending direction are connected to the long side edges of the mounting plates 261c and 261d located in front of the vehicle body 11 in the front-rear direction in the lateral direction. Further, both ends of the lower support plate 26b in the extending direction are connected to the front and rear portions of the vehicle body 11 in the lateral direction in the mounting plates 261c and 261d.

The backrest 26 has a plurality of beam portions 26e connecting the upper support plate 26a and the lower support plate 26b. Each beam portion 26e has an elongated thin flat plate shape. The beam portions 26e are arranged at equal intervals between the pair of side support plates 26c and 26d in the extending direction of the upper support plate 26a and the lower support plate 26b. The thickness direction of each beam portion 26e coincides with the extending direction of the upper support plate 26a and the lower support plate 26b. The longitudinal direction of each beam portion 26e coincides with the longitudinal direction of the pair of side support plates 26c and 26d. Each beam portion 26e suppresses bending of the upper support plate 26a and the lower support plate 26b in the extending direction.

Of the plurality of beam portions 26e, each beam portion 26e located on both ends in the extending direction of the upper support plate 26a and the lower support plate 26b is provided with a guide portion 28 guided by each guide shaft 27. ing.

In FIGS. 3 and 4, one of the two guide portions 28 will be described in detail. Since the description of the other guide unit 28 of the two guide units 28 is the same as the description of one of the two guide units 28, the detailed description thereof will be omitted.

As shown in FIGS. 3 and 4, the guide portion 28 has an elongated flat plate-shaped base portion 28a and an elongated flat plate-shaped first side portion 28b and a second side portion 28c erected from both elongated side edges of the base portion 28a. And have. The longitudinal directions of the base portion 28a, the first side portion 28b, and the second side portion 28c are the same. The longitudinal directions of the base portion 28a, the first side portion 28b, and the second side portion 28c coincide with the longitudinal directions of the respective beam portions 26e. The first side portion 28b and the second side portion 28c extend parallel to each other. The guide portion 28 is arranged in a state where the side edges of the first side portion 28b and the second side portion 28c, which are opposite to the base portion 28a, are in contact with the second side surface 174a of the mounting portion 17a.

The shortest distance between the inner surface 281b, which is the surface of the first side portion 28b facing the second side portion 28c, and the inner surface 281c, which is the surface of the second side portion 28c facing the first side portion 28b, is the guide shaft 27. Slightly longer than the outer diameter. Further, the shortest distance between the inner surface 281a of the base portion 28a, which is the surface facing the second side surface 174a of the mounting portion 17a, and the second side surface 174a of the mounting portion 17a is slightly longer than the outer diameter of the guide shaft 27. Then, the guide shaft 27 passes through the space partitioned by the inner surface 281a of the base portion 28a, the inner surface 281b of the first side portion 28b, the inner surface 281c of the second side portion 28c, and the second side surface 174a of the mounting portion 17a. There is. The guide portion 28 can move in the vertical direction while the inner surface 281a of the base portion 28a, the inner surface 281b of the first side portion 28b, and the inner surface 281c of the second side portion 28c slide with respect to the outer peripheral surface of the guide shaft 27. ing.

The guide portion 28 is joined to the beam portion 26e by, for example, welding between the outer surface 282b of the first side portion 28b and the side edge of the beam portion 26e located at the rear portion in the front-rear direction of the vehicle body 11. Therefore, the guide portion 28 is attached to the backrest 26. The backrest 26 is arranged in front of each mounting portion 17a of the pair of forks 17. Therefore, the backrest 26 is arranged in front of the driver's seat 21.

As shown in FIG. 2, the forklift 10 includes a pair of backrest elevating devices 30. The pair of backrest elevating devices 30 allows the backrest 26 to be elevated and lowered with respect to the fork 17. Further, the forklift 10 includes a moving body 50 that can slide and move with respect to each loading portion 17b.

In FIG. 5, one backrest elevating device 30 of the pair of backrest elevating devices 30 will be described in detail. The description of the other backrest lifting device 30 of the pair of backrest lifting devices 30 is the same as the description of the backrest lifting device 30 of the pair of backrest lifting devices 30, so the details thereof. Explanation is omitted.

As shown in FIG. 5, the backrest elevating device 30 has a first sprocket 31, a second sprocket 32, a third sprocket 33, a first chain 34, and a second chain 35.

The first sprocket 31 is rotatably supported by the first side surface 173b of the loading portion 17b via the first support shaft 311. Therefore, the first side surface 173b of the loading unit 17b is the side surface of the loading unit 17b on which the first sprocket 31 as the first rotating member is rotatably supported, and is rotatable on the side surface of the loading unit 17b in the present embodiment. The first rotating member supported by the first sprocket 31 is a first sprocket 31. The first sprocket 31 is arranged at the center of the first side surface 173b of the loading portion 17b in the extending direction of the loading portion 17b.

The second sprocket 32 is rotatably supported by an end portion of the first side surface 173a of the mounting portion 17a on the first side surface 173a opposite to the loading portion 17b via the second support shaft 321. Therefore, the first side surface 173a of the mounting portion 17a is the side surface of the mounting portion 17a on which the second sprocket 32 as the second rotating member is rotatably supported, and in the present embodiment, the loading portion on the side surface of the mounting portion 17a. The second rotating member rotatably supported at the end opposite to 17b is the second sprocket 32.

The third sprocket 33 is rotatably supported by the end portion on the first side surface 173a of the mounting portion 17a on the loading portion 17b side via the third support shaft 331. Therefore, the first side surface 173a of the mounting portion 17a is the side surface of the mounting portion 17a on which the third sprocket 33 as the third rotating member is rotatably supported, and in the present embodiment, the loading portion on the side surface of the mounting portion 17a. The third rotating member rotatably supported at the end on the 17b side is the third sprocket 33.

The third sprocket 33 has a first gear 33a as a first rotating body and a second gear 33b as a second rotating body. The first gear 33a and the second gear 33b are connected by a connecting shaft 33c. The first gear 33a and the second gear 33b can rotate integrally via the connecting shaft 33c. Further, although specific illustration is omitted, in the present embodiment, the number of teeth of the first gear 33a and the number of teeth of the second gear 33b are the same. The number of teeth of the first sprocket 31 and the number of teeth of the second sprocket 32 are the same as the number of teeth of the first gear 33a and the number of teeth of the second gear 33b.

The first chain 34 is mounted on the first sprocket 31 and the first gear 33a. Although specific illustration is omitted, the first chain 34 is hooked on the first sprocket 31 and the first gear 33a in a state of being meshed with the teeth of the first sprocket 31 and the teeth of the first gear 33a. .. The second chain 35 is mounted on the second sprocket 32 and the second gear 33b. Although specific illustration is omitted, the second chain 35 is hooked on the second sprocket 32 and the second gear 33b in a state of being meshed with the teeth of the second sprocket 32 and the teeth of the second gear 33b. ..

As shown in FIG. 6, the first chain 34 is a known roller chain having a plurality of link plates 34a and a plurality of rollers 34b connecting the plurality of link plates 34a. The first chain 34 is connected to the moving body 50. Therefore, the first chain 34 is a first hanging body that is integrally provided with the moving body 50 and is hooked on the first sprocket 31 and the first gear 33a. Therefore, in the present embodiment, the first hooking body mounted on the first sprocket 31 and the first gear 33a is the first chain 34.

The moving body 50 has an elongated substantially square plate-shaped main body portion 50a. A pair of guide protrusions 50b are projected from one end surface 501 of both end faces located in the main body 50a in a direction orthogonal to the thickness direction of the main body 50a and orthogonal to the longitudinal direction of the main body 50a. There is. The pair of guide protrusions 50b are arranged at both ends of the main body 50a in the longitudinal direction on the end surface 501 of the main body 50a. The pair of guide protrusions 50b have guide surfaces 501b facing each other in the longitudinal direction of the main body 50a. Both guide surfaces 501b are flat and parallel to each other. The distance between the guide surfaces 501b in the longitudinal direction of the main body portion 50a is slightly longer than the width of the loading portion 17b of the fork 17.

The moving body 50 has a first connecting portion 39a and a second connecting portion 39b. The first connecting portion 39a and the second connecting portion 39b are provided on one of the pair of guide protrusions 50b. The first connecting portion 39a is a columnar shape protruding from the end face 502b located on one side of the guide protruding portion 50b in the thickness direction. The second connecting portion 39b is a columnar shape protruding from the end surface 503b located on the other side of the guide protruding portion 50b in the thickness direction. Then, the roller 34b located at one end of the first chain 34 penetrates the first connecting portion 39a in the direction orthogonal to the axial direction of the first connecting portion 39a, so that one end of the first chain 34 becomes the first. 1 It is connected to the connecting portion 39a. Further, the roller 34b located at the other end of the first chain 34 penetrates the second connecting portion 39b in the direction orthogonal to the axial direction of the second connecting portion 39b, so that the other end of the first chain 34 Is connected to the second connecting portion 39b. In this way, the first chain 34 is integrally provided with the moving body 50.

In the moving body 50 integrally provided with the first chain 34, the end surface 501 of the main body 50a is located on the end surface 171b of the loading portion 17b, and one of the guide surfaces 501b is the first side surface of the loading portion 17b. It is arranged with respect to the loading portion 17b so as to face the 173b and the other of the guide surfaces 501b to face the second side surface 174b of the loading portion 17b. The thickness direction of the moving body 50 coincides with the extending direction of the loading portion 17b. The end surface 501 of the main body 50a is slidable with respect to the end surface 171b of the loading portion 17b, and one of the guide surfaces 501b is slidable with respect to the first side surface 173b of the loading portion 17b. The other side of the surface 501b is slidable with respect to the second side surface 174b of the loading portion 17b. The first chain 34 is adjacent to the first side surface 173b of the loading portion 17b. Then, the moving body 50 can slide and move with respect to the loading portion 17b of the fork 17 as the first chain 34 is driven via the first sprocket 31 and the first gear 33a.

As shown in FIG. 7, the second chain 35 is a known roller chain having a plurality of link plates 35a and a plurality of rollers 35b connecting the plurality of link plates 35a. The second chain 35 is connected to the backrest 26. Therefore, the second chain 35 is a second hanging body connected to the backrest 26 and hooked on the second sprocket 32 and the second gear 33b. Therefore, in the present embodiment, the second hanging body mounted on the second sprocket 32 and the second gear 33b is the second chain 35.

The first chain 34 and the second chain 35 are hanging members to be hung on the first sprocket 31, the second sprocket 32, and the third sprocket 33. Therefore, the hanging member of the present embodiment includes the first chain 34 and the second chain 35.

The backrest 26 has a connecting portion 36 for connecting the second chain 35. The connecting portion 36 has an L-shaped plate shape that projects downward from the lower portion of the lower support plate 26b and then extends rearward in the front-rear direction of the vehicle body 11. The thickness direction of the tip portion of the connecting portion 36 coincides with the vertical direction.

The connecting portion 36 has a first connecting portion 37a and a second connecting portion 37b. The first connecting portion 37a is a columnar shape protruding from an end surface 36a located on one side in the thickness direction at the tip end portion of the connecting portion 36. The second connecting portion 37b is a columnar shape protruding from the end surface 36b located at the other end portion in the thickness direction of the tip portion of the connecting portion 36. Then, the roller 35b located at one end of the second chain 35 penetrates the first connecting portion 37a in the direction orthogonal to the axial direction of the first connecting portion 37a, so that one end of the second chain 35 becomes the first. 1 It is connected to the connecting portion 37a. Further, the roller 35b located at the other end of the second chain 35 penetrates the second connecting portion 37b in the direction orthogonal to the axial direction of the second connecting portion 37b, so that the other end of the second chain 35 is formed. Is connected to the second connecting portion 37b. In this way, the second chain 35 is connected to the backrest 26. Then, the backrest 26 is directed to the mounting portion 17a of the fork 17 while the guide portion 28 is guided by the guide shaft 27 as the second chain 35 is driven via the second sprocket 32 and the second gear 33b. It can be raised and lowered.

As shown in FIGS. 2 and 8, when the load W1 is not loaded on the loading portion 17b of each fork 17, the moving body 50 is located at the center of the loading portion 17b in the extending direction. The chain 34 is hooked on the first sprocket 31 and the first gear 33a. The moving body 50 is connected to a portion of the first chain 34 located on the upper side in the direction of gravity. Then, when the moving body 50 is located at the center of the loading portion 17b in the extending direction, the backrest 26 is in a state of being most lowered with respect to the mounting portion 17a of the fork 17 due to its own weight. The chain 35 is mounted on the second sprocket 32 and the second gear 33b. The backrest 26 is connected to a portion of the second chain 35 located on the front side of the vehicle body 11 in the front-rear direction.

Next, the operation of this embodiment will be described.
As shown in FIG. 9, when the load W1 is scooped up by the fork 17 and the moving body 50 is pushed in the direction approaching the mounting portion 17a with respect to the loading portion 17b by the load W1 loaded on the loading portion 17b, the first The first chain 34 is driven via the sprocket 31 and the first gear 33a. Specifically, in the first chain 34, the first sprocket 31 and the first gear 33a move so that the portion of the first chain 34 located on the upper side in the direction of gravity moves from the first sprocket 31 toward the first gear 33a. Driven through. Further, the first chain 34 passes through the first sprocket 31 and the first gear 33a so that the portion of the first chain 34 located on the lower side in the direction of gravity moves from the first gear 33a toward the first sprocket 31. Drive. The first sprocket 31 and the first gear 33a rotate as the first chain 34 is driven.

Then, the second gear 33b is integrally rotated with the first gear 33a due to the rotation of the first gear 33a, so that the second chain 35 is driven via the second sprocket 32 and the second gear 33b. .. Specifically, in the second chain 35, the second sprocket 32 and the second sprocket 32 so that the portion of the second chain 35 located on the front side of the vehicle body 11 in the front-rear direction moves from the second gear 33b toward the second sprocket 32. It is driven via the two gears 33b. Further, in the second chain 35, the second sprocket 32 and the second gear so that the portion of the second chain 35 located on the rear side of the vehicle body 11 in the front-rear direction moves from the second sprocket 32 toward the second gear 33b. It is driven via 33b. In this way, the second chain 35 is driven via the second sprocket 32 and the second gear 33b, and the backrest 26 is guided by the guide shaft 27 against the weight of the backrest 26. It rises with respect to the mounting portion 17a of the fork 17.

As shown in FIGS. 10 and 11, a state in which the moving body 50 is further pushed by the load W1 in the direction of approaching the mounting portion 17a with respect to the loading portion 17b, and the moving body 50 is closest to the mounting portion 17a. Then, the backrest 26 is in the most raised state with respect to the mounting portion 17a of the fork 17. As a result, the load W1 loaded on the loading portion 17b of the fork 17 can be stably supported from the driver's seat 21 side by the backrest 26.

On the other hand, when the load W1 is unloaded from the loading portion 17b of the fork 17, the weight of the backrest 26 drives the second chain 35 via the second sprocket 32 and the second gear 33b. Specifically, in the second chain 35, the second sprocket 32 and the second chain 35 are arranged so that the portion of the second chain 35 located on the front side of the vehicle body 11 in the front-rear direction moves from the second sprocket 32 toward the second gear 33b. It is driven via the two gears 33b. Further, in the second chain 35, the second sprocket 32 and the second gear so that the portion of the second chain 35 located on the rear side of the vehicle body 11 in the front-rear direction moves from the second gear 33b toward the second sprocket 32. It is driven via 33b. In this way, the second chain 35 is driven via the second sprocket 32 and the second gear 33b, and the backrest 26 is directed to the mounting portion 17a of the fork 17 while the guide portion 28 is guided by the guide shaft 27. Descend. The second sprocket 32 and the second gear 33b rotate as the second chain 35 is driven.

Then, the first gear 33a is rotated integrally with the second gear 33b as the second gear 33b rotates, so that the first chain 34 is driven via the first sprocket 31 and the first gear 33a. .. Specifically, in the first chain 34, the first sprocket 31 and the first gear 33a so that the portion of the first chain 34 located on the upper side in the direction of gravity moves from the first gear 33a toward the first sprocket 31. Driven through. Further, the first chain 34 passes through the first sprocket 31 and the first gear 33a so that the portion of the first chain 34 located on the lower side in the direction of gravity moves from the first sprocket 31 toward the first gear 33a. Drive. In this way, the first chain 34 is driven via the first sprocket 31 and the first gear 33a, and the moving body 50 moves in a direction away from the mounting portion 17a with respect to the loading portion 17b of the fork 17.

As shown in FIGS. 2 and 8, the backrest 26 is driven by the weight of the backrest 26 via the second sprocket 32 and the second gear 33b in the second chain 35 before the backrest 26 is raised with respect to the mounting portion 17a. Descend to its original position. As a result, the backrest 26 enters the operator's field of view from the driver's seat 21 when the load W1 is not loaded on the fork 17, as compared with the case where the backrest 26 remains raised with respect to the mounting portion 17a. It becomes difficult, and the front view of the worker from the driver's seat 21 is secured. Then, the backrest 26 descends to the original position before rising with respect to the mounting portion 17a, the moving body 50 moves in a direction away from the mounting portion 17a with respect to the loading portion 17b, and the mounting portion W1 causes the moving body 50 to move away from the mounting portion 17a. It returns to the original position before being pushed in the direction approaching 17a.

In this way, the moving body 50 moves according to the loading status of the load W1 on the fork 17. Therefore, the moving body 50 is an operating portion that operates according to the loading status of the load W1 on the fork 17. Then, the backrest elevating device 30 is driven in conjunction with the movement of the moving body 50, and the backrest 26 can be elevated and lowered with respect to the fork 17. Specifically, the backrest elevating device 30 drives the backrest 26 so as to be in a raised state with respect to the fork 17 when the load W1 is loaded on the fork 17. Further, when the load W1 is not loaded on the fork 17, the backrest elevating device 30 is driven so that the backrest 26 returns to the original position before being lifted with respect to the fork 17.

In the above embodiment, the following effects can be obtained.
(1) The forklift 10 is driven in conjunction with the operation of the moving body 50 and the moving body 50 that operate according to the loading status of the load W1 on the fork 17, and the backrest 26 can be raised and lowered with respect to the fork 17. A backrest elevating device 30 is provided. According to this, the backrest 26 moves up and down with respect to the fork 17 by driving the backrest elevating device 30 in conjunction with the operation of the moving body 50 that operates according to the loading status of the load W1 on the fork 17. It is not necessary for the operator to manually raise and lower the backrest 26 as in the prior art. Then, when the load W1 is loaded on the fork 17, the backrest elevating device 30 drives the backrest 26 so as to be in a raised state with respect to the fork 17, and the load W1 is not loaded on the fork 17. Occasionally, the backrest 26 is driven so that it returns to its original position before rising with respect to the fork 17. Therefore, when the load W1 is loaded on the fork 17, the load W1 loaded on the fork 17 can be stably supported by the backrest 26 from the driver's seat 21 side without deteriorating workability. Moreover, when the load W1 is not loaded on the fork 17, the front view of the operator from the driver's seat 21 can be easily secured.

(2) According to the present embodiment, a mechanical configuration using the moving body 50, the first sprocket 31, the second sprocket 32, the third sprocket 33, the first chain 34, and the second chain 35 is adopted. As a result, the backrest 26 can be raised and lowered. Therefore, for example, a sensor that operates according to whether or not the load W1 is loaded on the fork 17 is used as the operating unit, and the control device controls the drive of the backrest elevating device 30 based on the operation of the sensor. It is not necessary to store a complicated control program in the control device in advance as in the case of adopting an electrical configuration. Therefore, the backrest 26 can be raised and lowered without complicating the configuration.

(3) The third sprocket 33 has a first gear 33a and a second gear 33b. A first chain 34 integrally provided with the moving body 50 is mounted on the first sprocket 31 and the first gear, and the backrest 26 is mounted on the second sprocket 32 and the second gear 33b. A second chain 35 to be connected is hung. Here, for example, the third sprocket 33 does not have the first gear 33a and the second gear 33b, and one hooking member is hooked on the first sprocket 31, the second sprocket 32, and the third sprocket 33. Consider a backrest lift with a configured configuration. Compared with such a configuration, the operation of the first chain 34 and the second chain 35 via the first sprocket 31, the second sprocket 32, and the third sprocket 33 is likely to be stable. Therefore, the reliability of the lifting operation of the backrest 26 in the backrest lifting device 30 can be improved.

(4) For example, in the third sprocket 33, the number of teeth of the first gear 33a and the number of teeth of the second gear 33b are adjusted to adjust the gear ratio between the first gear 33a and the second gear 33b. The elevating stroke of the backrest 26 with respect to the fork 17 and the moving stroke of the moving body 50 with respect to the loading portion 17b can be freely adjusted.

The above embodiment can be modified and implemented as follows. The above embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

○ As shown in FIG. 12, the backrest elevating device 30A may have a configuration using a non-annular chain 60. The chain 60 is mounted on the first sprocket 31, the second sprocket 32, and the third sprocket 33. In the embodiment shown in FIG. 12, the third sprocket 33 does not have the first gear 33a and the second gear 33b, but has the same configuration as the first sprocket 31 and the second sprocket 32. A moving body 50 is fixed to one end of the chain 60, and a backrest 26 is connected to the other end of the chain 60. Then, the moving body 50 is pushed in the direction approaching the mounting portion 17a with respect to the loading portion 17b by the load W1 loaded on the loading portion 17b, so that the first sprocket 31, the second sprocket 32, and the third sprocket 33 are pushed. The chain 60 is driven via the chain 60. By driving the chain 60, the backrest 26 rises with respect to the mounting portion 17a against the weight of the backrest 26. Further, when the load W1 is unloaded from the loading portion 17b, the chain 60 is driven by the weight of the backrest 26 via the first sprocket 31, the second sprocket 32, and the third sprocket 33. Then, by driving the chain 60, the backrest 26 descends to the original position before rising with respect to the mounting portion 17a, and the moving body 50 moves in a direction away from the mounting portion 17a with respect to the loading portion 17b. , The load W1 returns to the original position before being pushed in the direction approaching the mounting portion 17a. Therefore, the chain 60 is a hanging member that is hooked on the first sprocket 31, the second sprocket 32, and the third sprocket 33 and raises and lowers the backrest 26 with respect to the mounting portion 17a. As a result, the number of parts used can be reduced.

○ In the embodiment, the backrest elevating device 30 is provided, for example, at the end of the mounting portion 17a on the first side surface 173a on the loading portion 17b side, in addition to the first sprocket 31, the second sprocket 32, and the third sprocket 33. It may be configured to further include a fourth sprocket that is rotatably supported. In this case, the chain mounted on the first sprocket 31 and the fourth sprocket, the chain mounted on the second sprocket 32 and the third sprocket 33, and the chain mounted on the third sprocket 33 and the fourth sprocket. Is used. In short, the backrest elevating device 30 is mounted on the first rotating member, the second rotating member, the third rotating member, the first rotating member, the second rotating member, and the third rotating member, and is backed up. The structure may have at least a hanging member for raising and lowering the rest 26 with respect to the mounting portion 17a.

○ In the embodiment, the number of teeth of the first gear 33a may be larger than the number of teeth of the second gear 33b. According to this, the movement stroke of the moving body 50 with respect to the loading portion 17b can be made shorter than the elevating stroke of the backrest 26 with respect to the fork 17. Therefore, the moving body 50 can be kept as far as possible from the end portion of the loading portion 17b opposite to the mounting portion 17a, that is, the tip end portion of the fork 17, and therefore, when scooping the load W1 with the fork 17, the moving body 50 Can be avoided from getting in the way, and workability can be improved.

○ In the embodiment, the number of teeth of the first gear 33a may be smaller than the number of teeth of the second gear 33b.
○ In the embodiment, the moving body 50 may be configured not to slide with respect to the end surface 171b of the loading portion 17b of the fork 17, for example, a configuration capable of sliding only on the first side surface 173b of the loading portion 17b. There may be. In short, the moving body 50 may be provided integrally with the hanging member and slidably movable with respect to the loading portion 17b.

○ In the embodiment, the forklift 10 is not limited to the battery type, and may be, for example, an engine type or a hybrid type in which an engine is further provided in addition to the battery B1.

○ In the embodiment, a chain such as a roller chain may not be used as a hanging member, and a belt may be used as a hanging member, for example. In this case, for example, a roller is used as the first rotating member, the second rotating member, and the third rotating member.

○ In the embodiment, for example, a sensor for detecting the load W1 loaded on the fork 17 is used, and an electrical configuration is provided such that the control device controls the drive of the backrest elevating device 30 based on the detection information of the sensor. It may be adopted. In this case, for example, the sensor operates so as to switch from off to on when the load W1 is loaded on the fork 17, and to switch from on to off when the load W1 is unloaded from the fork 17. Therefore, the sensor is an operating unit that operates according to the loading status of the load W1 on the fork 17. Then, the backrest elevating device 30 is driven in conjunction with the operation of the sensor.

○ In the embodiment, the forklift 10 may be configured to include only one fork 17, and the number of forks 17 is not particularly limited.

W1 ... Load, 10 ... Fork lift, 11 ... Body, 15 ... Mast, 16 ... Lift bracket, 17 ... Fork, 17a ... Mounting part, 17b ... Loading part, 21 ... Driver's seat, 26 ... Backrest, 30, 30A ... Back Rest elevating device, 31 ... 1st sprocket as the first rotating member, 32 ... 2nd sprocket as the 2nd rotating member, 33 ... 3rd sprocket as the 3rd rotating member, 33a ... 1st as the first rotating body Gears, 33b ... Second gear as second rotating body, 34 ... First chain as first hanging body, 35 ... Second chain as second hanging body, 50 ... Moving body as operating part, 60 ... Chain as a hanging member, 173a, 173b ... First side surface as a side surface.

Claims (5)

The driver's seat provided on the car body and
A mast erected in front of the driver's seat in the vehicle body,
A lift bracket that is supported by the mast so that it can be raised and lowered,
The fork mounted on the lift bracket and
A forklift equipped with a backrest arranged in front of the driver's seat.
An actuating part that operates according to the loading status of the load on the fork,
When the fork is loaded with the load, the backrest is raised with respect to the fork, and the fork is not loaded with the load. The backrest elevating device is provided so that the backrest can be raised and lowered with respect to the fork so that the backrest is returned to the original position before being raised with respect to the fork. Characterized forklift. The fork has a plate-shaped mounting portion that is attached to the lift bracket and extends in the vertical direction, and a plate-shaped loading portion that extends forward from the mounting portion in the front-rear direction of the vehicle body and loads the load. And
The backrest lifting device is
A first rotating member rotatably supported on the side surface of the loading portion,
A second rotating member rotatably supported at an end on the side surface of the mounting portion opposite to the loading portion,
A third rotating member rotatably supported at an end on the side surface of the mounting portion on the loading portion side,
It has at least a first rotating member, a second rotating member, and a hanging member that is mounted on the third rotating member and raises and lowers the backrest with respect to the mounting portion.
The operating portion is a moving body that is integrally provided with the hanging member and can be slidably moved with respect to the loading portion.
The first rotating member, the second rotating member, and the third rotating member are pushed by the load loaded on the loading portion in a direction approaching the mounting portion with respect to the loading portion. The hanging member is driven via the backrest, the backrest rises with respect to the mounting portion against the weight of the backrest, and the load is unloaded from the loading portion, so that the weight of the backrest is self-weight. Drives the hanging member via the first rotating member, the second rotating member, and the third rotating member, and lowers the backrest to its original position before rising with respect to the mounting portion. Then, the moving body moves in a direction away from the mounting portion with respect to the loading portion, and returns to the original position before being pushed in the direction approaching the mounting portion by the load. The forklift according to claim 1. The third rotating member has a first rotating body and a second rotating body.
The hanging member is provided integrally with the moving body, is connected to the first rotating member and the first hanging body mounted on the first rotating body, and is connected to the backrest, and is connected to the second rotating body. The forklift according to claim 2, wherein the forklift includes a rotating member and a second hanging body mounted on the second rotating body. The first rotating member is a first sprocket.
The second rotating member is a second sprocket.
The third rotating member is a third sprocket having a first gear as the first rotating body and a second gear as the second rotating body.
The first hanging body is a first chain hooked on the first sprocket and the first gear.
The forklift according to claim 3, wherein the second hanging body is a second chain mounted on the second sprocket and the second gear. The forklift according to claim 4, wherein the number of teeth of the first gear is larger than the number of teeth of the second gear.

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