JP7239892B2 - forklift - Google Patents

Description

The present invention relates to forklifts.

A forklift includes a driver's seat provided in a vehicle body, a mast erected in front of the driver's seat in the vehicle body, a lift bracket supported so as to be able to move up and down by the mast, a fork mounted on the lift bracket, and an operator. and a backrest arranged forward of the seat. Typically, the backrest is secured to the lift bracket by fasteners such as bolts. When the forks are loaded with cargo, the backrest can support the cargo loaded on the forks from the driver's seat side, preventing the cargo from collapsing toward the driver's seat. play. The backrest has a crosspiece structure, which ensures a sufficient front view through the backrest from the driver's seat, but there is a demand for a wider front view.

Therefore, for example, the backrest of a forklift in Patent Document 1 is composed of a backrest main body provided on the upper part of a 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 secondary body is detachably attached to the backrest main body with fasteners such as bolts. When the fasteners are loosened, the backrest sub-body is released from the fixing of the backrest sub-body to the backrest main body, and can be raised and lowered relative to the backrest main body. It is fixed to the main body and cannot be raised or lowered with respect to the backrest main body.

Then, for example, when the forks are loaded, the fasteners are loosened to raise the backrest sub-body relative to the backrest main body, and the fasteners are tightened to move the backrest sub-body to the backrest main body. and lock it in the raised position. As a result, the load loaded on the forks can be stably supported from the driver's seat side by the backrest, and the backrest prevents the load loaded on the forks from collapsing toward the driver's seat. can be done.

On the other hand, for example, when the forks are unloaded, the fasteners are loosened to lower the backrest sub-body to its original position before being raised relative to the backrest body, and the fasteners are tightened to move the backrest. Securing the rest sub-body in its original position prior to raising it relative to the backrest body. According to this, when the fork is not loaded with a load, the backrest is less likely to enter the field of view of the operator from the driver's seat, compared to the case where the backrest sub-body remains raised with respect to the backrest main body. As a result, the front view of the operator from the driver's seat is secured, and workability is improved.

JP 2008-114994 A

As described above, in Patent Document 1, when a load is loaded on the forks, the load loaded on the forks is lifted by the backrest by moving the backrest secondary body up and down with respect to the backrest main body. The front view of the operator from the driver's seat is ensured when the load is not loaded on the forks. However, in Patent Literature 1, it is necessary for an operator to manually raise and lower the backrest sub-body with respect to the backrest main body, resulting in poor workability.

An object of the present invention is to enable the load loaded on the forks to be stably supported from the driver's seat side by the backrest when the load is loaded on the forks without deteriorating workability, and To provide a forklift capable of easily securing a front view of a worker from the driver's seat when a load is not loaded on the forklift.

A forklift that solves the above problems includes a driver's seat provided in a vehicle body, a mast erected in front of the driver's seat in the vehicle body, a lift bracket supported by the mast so that it can be raised and lowered, and the lift A forklift provided with a fork mounted on a bracket and a backrest arranged in front of the driver's seat, comprising: an operating portion that operates according to a loading condition of a load on the fork; When the load is loaded on the forks, the backrest is raised relative to the forks, and when the load is not loaded on the forks, the backrest is moved. a backrest lifting device that enables the backrest to move up and down with respect to the fork so that the backrest returns to the original position before the fork rises.

According to this, the backrest elevating device is driven in conjunction with the operation of the actuating part that operates according to the loading condition of the fork, so that the backrest moves up and down with respect to the fork. , the operator does not need to manually raise and lower the backrest. When the forks are loaded with a load, the backrest lifting device is driven so that the backrest is raised relative to the forks. On the other hand, it is driven so that it returns to the original position before it ascends. Therefore, when the load is loaded on the forks, the load loaded on the forks can be stably supported from the driver's seat side by the backrest without deterioration of workability, and the load is loaded on the forks. A front view of the operator from the driver's seat can be easily secured when the driver's seat is not installed.

In the forklift, the fork includes a plate-shaped mounting portion that is mounted on the lift bracket and extends in the vertical direction, and a plate-shaped loading portion that extends forward in the front-rear direction of the vehicle body from the mounting portion and loads the load. and the backrest lifting device includes a first rotating member rotatably supported on the side surface of the loading section, and a rotatable end portion of the side surface of the mounting section opposite to the loading section. a third rotating member rotatably supported at an end portion of a side surface of the mounting portion on the side of the loading portion; the first rotating member; the second rotating member; a hanging member that is hung on a third rotating member and lifts and lowers the backrest with respect to the mounting portion; The moving body is slidably movable with respect to the loading section, and when the moving body is pushed toward the mounting section with respect to the loading section by the load loaded on the loading section, the first rotating member , the second rotating member, and the third rotating member, the hanging member is driven, the backrest rises against the mounting portion against the weight of the backrest, and the loading portion When the load is unloaded from the backrest, 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 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. Return to the previous original position.

According to this, the backrest can be raised and lowered by adopting a mechanical configuration using at least the moving body, the first rotating member, the second rotating member, the third rotating member, and the hanging member. Therefore, for example, an electrical configuration is adopted in which a sensor that operates according to the loading condition of the fork is used as the operating unit, and the control device controls the driving of the backrest lifting device based on the operation of the sensor. Unlike the case, there is no need to pre-store a complicated control program in the control device. Therefore, the backrest can be raised and lowered without complicating the configuration.

In the above forklift, 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 rotates the first rotating member and the first rotating member. It is preferable to include a first hanging body that is hung on the body, and a second hanging body that is connected to the backrest and is hung on the second rotating member and the second rotating body.

According to this, for example, the third rotating member does not have the first rotating member and the second rotating member, and one hanging member is provided for the first rotating member, the second rotating member, and the third rotating member. Compared with the backrest lifting device having a suspended configuration, the operation of the hanging member via the first rotating member, the second rotating member, and the third rotating member tends to be stable. Therefore, the reliability of the lifting operation of the backrest in the backrest lifting device can be improved.

In the above forklift, the first rotating member is a first sprocket, the second rotating member is a second sprocket, the third rotating member is a first gear as the first rotating body, and the A third sprocket having a second gear as a second rotating body, wherein the first hanging body is a first chain hung on the first sprocket and the first gear, and the second hanging body The body may be a second chain entrained on the second sprocket and the second gear.

According to this, for example, in the third sprocket, 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 fork in the backrest and the movement stroke of the moving body with respect to the loading section can be freely adjusted.

In the forklift described above, the number of teeth of the first gear may be 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 section 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 away as possible from the end of the loading part opposite to the attachment part, i.e., the tip of the fork, so that the moving body does not get in the way when scooping up 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, the load loaded on the fork can be stably supported from the driver's seat side by the backrest without degrading workability, and the fork When the load is not loaded, the front view of the worker can be easily secured from the driver's seat.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic side view which shows the forklift in embodiment. The perspective view which shows a part of forklift. The perspective view which shows a guide shaft, a guide part, and its periphery. FIG. 2 is a cross-sectional plan view showing a portion of the forklift; 1 is an exploded perspective view of a portion of a forklift; FIG. FIG. 4 is an enlarged perspective view showing a connecting portion between a moving body and a first chain; The perspective view which expands and shows the connection part of a backrest and a 2nd chain. The schematic diagram which shows the state with which the load is not loaded on the fork. The schematic diagram which shows the state which the mobile body is moving with the load. The schematic diagram which shows the state with which the load was loaded on the fork. The perspective view which shows the state which the backrest raised with respect to the fork. The schematic diagram for demonstrating the backrest raising/lowering apparatus in another embodiment.

An embodiment embodying a forklift will be described below with reference to FIGS. 1 to 11. FIG. In the following explanation, "front", "rear", "left", "right", "up", and "down" are based on the state where the worker driving the forklift is facing the front of the vehicle. "Front", "Rear", "Left", "Right", "Upper" and "Lower".

As shown in FIG. 1 , the forklift 10 includes driving wheels 12 arranged at the front lower portion of the vehicle body 11 and steering wheels 13 arranged at the rear lower portion of the vehicle body 11 . The forklift 10 has a cargo handling device 14 on the front part of the vehicle body 11 . The cargo handling device 14 includes a mast 15 erected on 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 forks 17 are loaded with a load W1.

The cargo handling device 14 includes a lift cylinder 18 that moves the lift bracket 16 up and down. By the operation of the lift cylinder 18 , the fork 17 moves up and down together with the lift bracket 16 . The mast 15 supports the lift bracket 16 so that it can be raised and lowered. Therefore, the lift bracket 16 is supported by the mast 15 so that it can be raised and lowered. The cargo handling device 14 also includes a tilt cylinder 19 that tilts the mast 15 . Driving the tilt cylinder 19 tilts the fork 17 together with the mast 15 . The lift cylinder 18 and tilt cylinder 19 are hydraulic cylinders.

A driver's cab 20 is provided in the vehicle body 11 . 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 . A 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 . In addition, in the operator's cab 20, there are a plurality of cargo handling levers 22 for performing various operations such as lifting and tilting operations of the cargo handling device 14, a handle 23 for steering the forklift 10, and a direction of travel of the forklift 10. A direction lever 24 is provided. Further, an accelerator pedal 25 is provided on the floor of the driver's cab 20 .

The forklift 10 includes a travel motor M1 that drives the drive wheels 12, and a battery B1. Then, the forklift 10 runs at a vehicle speed corresponding to the accelerator opening of the accelerator pedal 25 by controlling the drive of the driving motor M1 according to the accelerator opening of the accelerator pedal 25 . Therefore, in the forklift 10 of the present embodiment, electric power is supplied from the battery B1 to the traveling motor M1 to drive the traveling motor M1. It is a running battery type.

As shown in FIG. 2, the lift bracket 16 has a rectangular frame shape. The lift bracket 16 has an upper finger bar 16a, a lower finger bar 16b, and a pair of side bars 16c, 16d. The upper finger bar 16 a and the lower finger bar 16 b are elongated flat plates that are arranged to face each other in the vertical direction 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 extending direction is the same as the length of the lower finger bar 16b in the extending direction. The thickness direction of the upper finger bars 16 a and the thickness direction of the lower finger bars 16 b coincide with the longitudinal direction of the vehicle body 11 .

The pair of side bars 16c and 16d are in the shape of an elongated quadrangular prism that connects 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. The pair of side bars 16c and 16d extend vertically. A pair of side bars 16c and 16d extend parallel to each other. The pair of side bars 16c and 16d have the same length in the extending direction. The length in the extending direction of each of the pair of side bars 16c and 16d is shorter than the length in the extending direction of each of the upper finger bar 16a and the lower finger bar 16b. Therefore, the lift bracket 16 has a longitudinal direction in which the upper finger bar 16a and the lower finger bar 16b extend, and a lateral direction in which the pair of side bars 16c and 16d extend.

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

The stacking portion 17b extends from the lower 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 in the longitudinal direction of the vehicle body 11 from the mounting portion 17a. The stacking portion 17b is arranged such that one end face 171b in the thickness direction of the stacking portion 17b faces upward and the other end face 172b in the thickness direction of the stacking portion 17b faces downward.

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

The loading portion 17b of each fork 17 has a first side surface 173b that 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 plane. Moreover, the loading portion 17b of each fork 17 has a second side surface 174b, which is a side surface located on the side opposite to the first side surface 173b in the vehicle width direction of the vehicle body 11. As shown in FIG. 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 plane.

A guide shaft 27 is attached to the second side surface 174a of each attachment portion 17a. Each guide shaft 27 is cylindrical. 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 extending direction of each attachment portion 17a. Therefore, each guide shaft 27 extends vertically. Each guide shaft 27 is joined to the second side surface 174a of each mounting portion 17a by, for example, welding between a portion of the outer peripheral surface of each guide shaft 27 and the second side surface 174a of each mounting portion 17a. .

The forklift 10 has a backrest 26 arranged forward of the driver's seat 21 . The backrest 26 has a rectangular frame shape. The backrest 26 has an upper support plate 26a, 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 plate-like members arranged to face each other in the vertical direction and extend in the vehicle width direction of the vehicle body 11, respectively. The upper support plate 26a and the lower support plate 26b extend parallel to each other. The length of the upper support plate 26a in the extending direction is the same as the length of the lower support plate 26b in the extending direction. 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 26 a coincides with the longitudinal direction of the vehicle body 11 . The thickness direction of the lower support plate 26b is a direction oblique to the longitudinal direction of the vehicle body 11 . The lower support plate 26b is an inclined plate that is inclined such that the lateral direction of the lower support plate 26b is directed upward from the front to the rear in the longitudinal direction of the vehicle body 11 .

The pair of side support plates 26c and 26d are elongate thin plates that connect both ends of the upper support plate 26a in the extending direction and both ends of the lower support plate 26b in the extending direction. The pair of side support plates 26c and 26d are L-shaped in cross section. The pair of side support plates 26c and 26d extend vertically. The pair of side support plates 26c and 26d extend parallel to each other. The pair of side support plates 26c and 26d have the same length in the extending direction. The extending direction of each of the pair of side support plates 26c and 26d is the longitudinal direction of the pair of side support plates 26c and 26d.

The pair of side support plates 26c, 26d have mounting plates 261c, 261d and support plates 262c, 262d, respectively. Each of the mounting plates 261c, 261d and each of the supporting plates 262c, 262d is an elongated thin flat plate. Both mounting plates 261c and 261d extend parallel to each other with their respective thickness directions aligned. The thickness direction of each of the mounting plates 261c and 261d coincides with the extending direction of each of the upper support plate 26a and the lower support plate 26b. The longitudinal directions of both mounting plates 261c and 261d are aligned with the extending directions of the pair of side support plates 26c and 26d. Both mounting plates 261c and 261d have the same longitudinal length.

The thickness directions of the support plates 262c and 262d are aligned with the longitudinal direction of the vehicle body 11. As shown in FIG. The support plates 262c and 262d are separated from each other in the extension directions of the upper support plate 26a and the lower support plate 26b from the long side edges of the mounting plates 261c and 261d that are located forward in the longitudinal direction of the vehicle body 11 in the short direction. extending in the direction of The surfaces of both support plates 262c and 262d positioned forward in the front-rear direction of the vehicle body 11 are positioned on the same plane as the surface of the upper support plate 26a positioned forward in the front-rear direction of the vehicle body 11. As shown in FIG. 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 forward in the longitudinal direction of the vehicle body 11 in the lateral direction. Both ends of the lower support plate 26b in the extending direction are connected to portions near the front in the longitudinal direction of the vehicle body 11 in the lateral direction of the mounting plates 261c and 261d.

The backrest 26 has a plurality of beams 26e connecting the upper support plate 26a and the lower support plate 26b. Each beam 26e has an elongated thin plate shape. Each beam portion 26e is arranged at regular intervals between a 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 extension 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 26e suppresses bending in the extension direction of the upper support plate 26a and the lower support plate 26b.

Of the plurality of beams 26e, each beam 26e positioned at 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.

3 and 4, one guide portion 28 of the two guide portions 28 will be described in detail. The description of the other guide portion 28 out of the two guide portions 28 is the same as the description of the one guide portion 28 out of the two guide portions 28, so detailed description thereof will be omitted.

As shown in FIGS. 3 and 4, the guide portion 28 includes an elongated plate-like base portion 28a, and elongated plate-like first side portions 28b and second side portions 28c erected from both long 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 aligned. The longitudinal direction of each of the base portion 28a, the first side portion 28b, and the second side portion 28c coincides with the longitudinal direction of each beam portion 26e. The first side portion 28b and the second side portion 28c extend parallel to each other. The guide portion 28 is arranged such that the side edges of the first side portion 28b and the second side portion 28c on the side 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 of the first side portion 28b facing the second side portion 28c and the inner surface 281c of the second side portion 28c facing the first side portion 28b is Slightly longer than outer diameter. The shortest distance between the inner surface 281 a of the base portion 28 a facing the second side surface 174 a of the mounting portion 17 a and the second side surface 174 a of the mounting portion 17 a is slightly longer than the outer diameter of the guide shaft 27 . The guide shaft 27 passes through the space defined 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 vertically 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 against 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 of the vehicle body 11 in the longitudinal direction. The guide 28 is therefore attached to the backrest 26 . The backrest 26 is arranged forward of the mounting portions 17 a of the pair of forks 17 . Therefore, the backrest 26 is arranged forward of the driver's seat 21 .

As shown in FIG. 2 , the forklift 10 has a pair of backrest lifting devices 30 . A pair of backrest elevating devices 30 enables the backrest 26 to be raised and lowered with respect to the fork 17 . The forklift 10 also includes a moving body 50 that can slide relative to each loading portion 17b.

5, one backrest lifting device 30 of the pair of backrest lifting devices 30 will be described in detail. The description of the other backrest lifting device 30 out of the pair of backrest lifting devices 30 is the same as the description of the one backrest lifting device 30 out of the pair of backrest lifting devices 30. detailed description is omitted.

As shown in FIG. 5 , the backrest lifting 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 section 17b via the first support shaft 311. As shown in FIG. Therefore, the first side surface 173b of the loading section 17b is the side surface of the loading section 17b on which the first sprocket 31 as the first rotating member is rotatably supported. The first rotating member supported by is the first sprocket 31 . The first sprocket 31 is arranged on the first side surface 173b of the loading portion 17b at the center in the extending direction of the loading portion 17b.

The second sprocket 32 is rotatably supported via a second support shaft 321 at the end of the first side surface 173a of the mounting portion 17a opposite to the loading portion 17b. 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. A second rotating member rotatably supported at the end opposite to 17b is a second sprocket 32 .

The third sprocket 33 is rotatably supported via a third support shaft 331 at the end of the first side surface 173a of the mounting portion 17a on the side of the loading portion 17b. 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. 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 rotor and a second gear 33b as a second rotor. 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 are integrally rotatable via a connecting shaft 33c. Also, although not specifically illustrated, 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 second gear 33b.

The first chain 34 is hung on the first sprocket 31 and the first gear 33a. Although not specifically illustrated, the first chain 34 is hooked on the first sprocket 31 and the first gear 33a while being meshed with the teeth of the first sprocket 31 and the teeth of the first gear 33a. . The second chain 35 is hung on the second sprocket 32 and the second gear 33b. Although not specifically illustrated, the second chain 35 is hooked on the second sprocket 32 and the second gear 33b while being meshed with the teeth of the second sprocket 32 and 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 provided integrally with the moving body 50 and is hung on the first sprocket 31 and the first gear 33a. Therefore, in this embodiment, the first chain 34 is the first hanging body that is hung on the first sprocket 31 and the first gear 33a.

The moving body 50 has a main body portion 50a in the shape of an elongated substantially rectangular plate. In the body portion 50a, a pair of guide protrusions 50b are protruded from one end face 501 of both end faces positioned in a direction perpendicular to the thickness direction of the body portion 50a and perpendicular to the longitudinal direction of the body portion 50a. there is The pair of guide protrusions 50b are arranged at both longitudinal ends of the body portion 50a on the end face 501 of the body portion 50a. The pair of guide protrusions 50b has 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 body portion 50a is slightly longer than the width of the loading portion 17b of the fork 17. As shown in FIG.

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 has a columnar shape protruding from an end surface 502b positioned on one side in the thickness direction of the guide protrusion 50b. The second connecting portion 39b has a columnar shape protruding from the end face 503b positioned on the other side in the thickness direction of the guide protrusion 50b. Then, the roller 34b positioned at one end of the first chain 34 penetrates the first connecting portion 39a in a direction orthogonal to the axial direction of the first connecting portion 39a, thereby moving the one end of the first chain 34 to the first chain. 1 connecting portion 39a. In addition, the roller 34b positioned at the other end of the first chain 34 penetrates the second connecting portion 39b in a 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 manner, the first chain 34 is provided integrally with the moving body 50 .

In the mobile body 50 integrally provided with the first chain 34, the end surface 501 of the body portion 50a is positioned on the end surface 171b of the loading portion 17b, and one of the two guide surfaces 501b is located on the first side surface of the loading portion 17b. 173b, and the other of the guide surfaces 501b faces the second side surface 174b of the stacking portion 17b. The thickness direction of the moving body 50 coincides with the extending direction of the stacking portion 17b. The end surface 501 of the body portion 50a is slidable against the end surface 171b of the loading portion 17b, and one of the guide surfaces 501b is slidable against the first side surface 173b of the loading portion 17b. The other of the surfaces 501b is slidable against the second side surface 174b of the stacking portion 17b. The first chain 34 is adjacent to the first side surface 173b of the loading section 17b. The moving body 50 is slidable 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. A second chain 35 is connected to the backrest 26 . Therefore, the second chain 35 is a second hanging body that is connected to the backrest 26 and is hung on the second sprocket 32 and the second gear 33b. Therefore, in this embodiment, the second chain 35 is the second hanging body that is hung on the second sprocket 32 and the second gear 33b.

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

The backrest 26 has a connecting portion 36 for connecting a second chain 35 . The connection portion 36 has an L-shaped plate shape that protrudes downward from the lower portion of the lower support plate 26 b 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 has a columnar shape protruding from an end face 36a located on one side in the thickness direction of the distal end portion of the connecting portion 36 . The second connecting portion 37b has a columnar shape protruding from the end face 36b located on the other side 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 a direction orthogonal to the axial direction of the first connecting portion 37a, thereby moving the one end of the second chain 35 to the second chain. 1 connecting portion 37a. In addition, the roller 35b located at the other end of the second chain 35 penetrates the second connecting portion 37b in a direction orthogonal to the axial direction of the second connecting portion 37b, so that the other end of the second chain 35 is connected to the second connecting portion 37b. The second chain 35 is thus connected to the backrest 26 . As the second chain 35 is driven through the second sprocket 32 and the second gear 33b, the backrest 26 is mounted on the mounting portion 17a of the fork 17 while the guide portion 28 is guided by the guide shaft 27. It is possible to go up and down.

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 positioned at the central portion in the extending direction of the loading portion 17b. A chain 34 is hung on the first sprocket 31 and the first gear 33a. The moving body 50 is connected to a portion of the first chain 34 positioned above in the gravitational direction. Then, when the movable body 50 is positioned at the central portion in the extending direction of the loading portion 17b, the second position is set such that the backrest 26 is in the most lowered state with respect to the mounting portion 17a of the fork 17 due to its own weight. A chain 35 is hung 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 picked up by the fork 17 and the load W1 loaded on the loading portion 17b pushes the moving body 50 toward the mounting portion 17a with respect to the loading portion 17b, the first A first chain 34 is driven via the sprocket 31 and the first gear 33a. Specifically, the first chain 34 includes the first sprocket 31 and the first gear 33a such that the upper portion of the first chain 34 in the gravitational direction moves from the first sprocket 31 toward the first gear 33a. to drive through. In addition, the first chain 34 moves 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 gravitational direction moves from the first gear 33a toward the first sprocket 31. to drive. The first sprocket 31 and the first gear 33a rotate as the first chain 34 is driven.

As the first gear 33a rotates, the second gear 33b rotates integrally with the first gear 33a, thereby driving the second chain 35 via the second sprocket 32 and the second gear 33b. . Specifically, the second chain 35 is configured such that the portion of the second chain 35 located on the front side in the front-rear direction of the vehicle body 11 moves toward the second sprocket 32 from the second gear 33b. It drives via the 2 gear 33b. Further, the second chain 35 is configured such that the portion of the second chain 35 located on the rear side in the front-rear direction of the vehicle body 11 moves from the second sprocket 32 toward the second gear 33b. 33b. In this way, the second chain 35 is driven via the second sprocket 32 and the second gear 33b, and the backrest 26 resists the weight of the backrest 26 and the guide portion 28 is guided by the guide shaft 27. It rises with respect to the mounting portion 17 a of the fork 17 .

As shown in FIGS. 10 and 11, the load W1 further pushes the moving body 50 toward the mounting portion 17a with respect to the loading portion 17b, so that the moving body 50 is closest to the mounting portion 17a. At this point, the backrest 26 is in a state of being raised to the maximum 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 by the backrest 26 from the driver's seat 21 side.

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, the second chain 35 is configured such that the portion of the second chain 35 located on the front side in the longitudinal direction of the vehicle body 11 moves from the second sprocket 32 toward the second gear 33b. It drives via the 2 gear 33b. Further, the second chain 35 is configured such that the portion of the second chain 35 located on the rear side in the front-rear direction of the vehicle body 11 moves toward the second sprocket 32 from the second gear 33b. 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 moved against 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.

As the second gear 33b rotates, the first gear 33a rotates integrally with the second gear 33b, thereby driving the first chain 34 via the first sprocket 31 and the first gear 33a. . Specifically, the first chain 34 is configured so that the upper portion of the first chain 34 in the gravitational direction moves from the first gear 33a toward the first sprocket 31. to drive through. In addition, the first chain 34 moves through the first sprocket 31 and the first gear 33a such that the lower portion of the first chain 34 in the gravitational direction moves from the first sprocket 31 toward the first gear 33a. to 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 with respect to the loading portion 17b of the fork 17 in the direction away from the mounting portion 17a.

As shown in FIGS. 2 and 8, the weight of the backrest 26 drives the second chain 35 through the second sprocket 32 and the second gear 33b, so that the backrest 26 rises with respect to the mounting portion 17a. down to its original position. As a result, when the load W1 is not loaded on the forks 17, the backrest 26 enters the field of view of the operator from the driver's seat 21, compared to the case where the backrest 26 remains raised with respect to the mounting portion 17a. It becomes difficult, and the front view of the operator from the driver's seat 21 is ensured. Then, the backrest 26 is lowered to the original position before being raised with respect to the mounting portion 17a, and the moving body 50 is moved with respect to the loading portion 17b in the direction away from the mounting portion 17a, and the mounting portion is lifted by the load W1. It returns to the original position before being pushed in the direction approaching 17a.

In this manner, the moving body 50 moves according to the loading condition of the load W1 on the forks 17. As shown in FIG. Therefore, the moving body 50 is an operating portion that operates according to the loading condition of the load W1 on the forks 17. As shown in FIG. The backrest lifting device 30 is driven in conjunction with the movement of the moving body 50 and enables the backrest 26 to be lifted and lowered with respect to the fork 17 . Specifically, the backrest lifting device 30 drives so that the backrest 26 is lifted relative to the forks 17 when the load W1 is loaded on the forks 17 . When the load W1 is not loaded on the fork 17, the backrest lifting device 30 is driven so that the backrest 26 returns to the original position before being lifted with respect to the fork 17. - 特許庁

In the above embodiment, the following effects can be obtained.
(1) The forklift 10 includes a moving body 50 that operates according to the loading condition of the load W1 on the forks 17, and a backrest 26 that can be raised and lowered with respect to the forks 17 while being driven in conjunction with the operation of the moving body 50. and a backrest lifting device 30. According to this, the backrest 26 moves up and down with respect to the fork 17 by driving the backrest lifting device 30 in conjunction with the operation of the moving body 50 that operates according to the loading condition of the load W1 on the fork 17. , there is no need for the operator to manually raise and lower the backrest 26 as in the prior art. When the load W1 is loaded on the forks 17, the backrest lifting device 30 is driven so that the backrest 26 is raised relative to the forks 17, and the load W1 is not loaded on the forks 17. At times, the backrest 26 is driven back to its original position before being lifted relative to the fork 17 . Therefore, when the load W1 is loaded on the forks 17, the load W1 loaded on the forks 17 can be stably supported from the driver's seat 21 side by the backrest 26 without deterioration of workability. In addition, when the load W1 is not loaded on the forks 17, the front view of the operator from the driver's seat 21 can be easily ensured.

(2) According to this 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. , the backrest 26 can be raised and lowered. Therefore, for example, a sensor that operates depending on whether or not the load W1 is loaded on the fork 17 is used as the operating unit, and the control device controls the driving of the backrest lifting device 30 based on the operation of the sensor. There is no need to pre-store a complicated control program in the control device 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 provided integrally with the moving body 50 is attached to the first sprocket 31 and the first gear, and the second sprocket 32 and the second gear 33b are attached to the backrest 26. 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 hanging member is hung on the first sprocket 31, the second sprocket 32, and the third sprocket 33. Consider a backrest lift device with the following configuration. Compared to such a configuration, the operations of the first chain 34 and the second chain 35 via the first sprocket 31, the second sprocket 32, and the third sprocket 33 tend 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, by adjusting the number of teeth of the first gear 33a and the number of teeth of the second gear 33b to adjust the gear ratio between the first gear 33a and the second gear 33b, The lifting stroke of the backrest 26 with respect to the fork 17 and the movement stroke of the moving body 50 with respect to the loading portion 17b can be freely adjusted.

It should be noted that the above embodiment can be implemented with the following modifications. The above embodiments and the following modifications can be combined with each other within a technically consistent range.

O As shown in FIG. 12 , the backrest lifting device 30A may be configured using a non-circular chain 60 . The chain 60 is hung on the first sprocket 31 , the second sprocket 32 and the third sprocket 33 . In addition, in the embodiment shown in FIG. 12, the third sprocket 33 has the same configuration as the first sprocket 31 and the second sprocket 32, instead of the configuration having the first gear 33a and the second gear 33b. The moving body 50 is fixed to one end of the chain 60 , and the backrest 26 is connected to the other end of the chain 60 . Then, the load W1 loaded on the loading portion 17b pushes the moving body 50 toward the mounting portion 17a with respect to the loading portion 17b, thereby moving the first sprocket 31, the second sprocket 32, and the third sprocket 33. Chain 60 drives through. By driving the chain 60, the backrest 26 rises with respect to the mounting portion 17a against the weight of the backrest 26 itself. When the load W1 is unloaded from the loading portion 17b, the weight of the backrest 26 drives the chain 60 through the first sprocket 31, the second sprocket 32, and the third sprocket 33. Then, by driving the chain 60, the backrest 26 is lowered to the original position before being raised with respect to the mounting portion 17a, and the movable body 50 is moved with respect to the loading portion 17b in the direction away from the mounting portion 17a. , it returns to the original position before it was pushed by the load W1 toward the mounting portion 17a. Therefore, the chain 60 is a hanging member that is hung 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. This makes it possible to reduce the number of parts used.

○ In the embodiment, in addition to the first sprocket 31, the second sprocket 32, and the third sprocket 33, the backrest lifting device 30, for example, has The configuration may further include a fourth sprocket that is rotatably supported. In this case, the chain is attached to the first sprocket 31 and the fourth sprocket, the chain is attached to the second sprocket 32 and the third sprocket 33, and the chain is attached to the third sprocket 33 and the fourth sprocket. Use In short, the backrest lifting device 30 is hung 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 the backrest lifting device 30 is mounted on the back. and a hanging member for moving the rest 26 up and down with respect to the mounting portion 17a.

O 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 17 b can be made shorter than the lifting stroke of the backrest 26 with respect to the forks 17 . Therefore, the movable body 50 can be kept as far away as possible from the end of the loading portion 17b opposite to the mounting portion 17a, that is, the tip of the fork 17. can be avoided from becoming an obstacle, and workability can be improved.

O 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 against the end face 171b of the loading portion 17b of the fork 17. There may be. In short, it is sufficient that the moving body 50 is provided integrally with the hanging member and is slidable with respect to the loading portion 17b.

O 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 having an engine in addition to the battery B1.

(circle) in embodiment, you may use a belt as a hanging member instead of using a chain like a roller chain as a hanging member. In this case, for example, rollers are used as the first rotating member, the second rotating member, and the third rotating member.

○ In the embodiment, for example, a sensor is used to detect the load W1 loaded on the fork 17, and an electrical configuration is adopted in which the control device controls the driving of the backrest lifting device 30 based on the detection information of the sensor. may be adopted. In this case, for example, the sensor operates to switch from OFF to ON when the load W1 is loaded on the forks 17 and to switch from ON to OFF when the load W1 is unloaded from the forks 17 . Therefore, the sensor is an operating part that operates according to the loading condition of the load W1 on the forks 17. As shown in FIG. The backrest lifting device 30 is driven in conjunction with the operation of the sensor.

(circle) in embodiment, the forklift 10 may be the structure provided with the one fork 17, and the number of the forks 17 is not specifically limited.

W1... load, 10... forklift, 11... vehicle body, 15... mast, 16... lift bracket, 17... fork, 17a... mounting part, 17b... loading part, 21... driver's seat, 26... backrest, 30, 30A... back Rest lifting device 31... First sprocket as first rotating member 32... Second sprocket as second rotating member 33... Third sprocket as third rotating member 33a... First sprocket as first rotating member Gears 33b...Second gear as a second rotating body 34...First chain as a first hanging body 35...Second chain as a second hanging body 50...Moving body as an operating part 60 . . chains as hanging members, 173a, 173b . . . first side faces as side faces.

Claims (5)

A driver's seat provided in the vehicle body,
a mast erected in front of the driver's seat in the vehicle body;
a lift bracket that is liftably supported by the mast;
a fork mounted on the lift bracket;
A forklift comprising a backrest arranged in front of the driver's seat,
an operating portion that operates according to the loading condition of the load on the fork;
When the load is loaded on the fork, the backrest is raised relative to the fork, and when the load is not loaded on the fork. and a backrest lifting device that enables the backrest to move up and down with respect to the fork so that the backrest returns to its original position before being lifted with respect to the fork. Characteristic forklift. The fork has a plate-like mounting portion that is attached to the lift bracket and extends in the vertical direction, and a plate-like loading portion that extends forward in the front-rear direction of the vehicle body from the mounting portion and on which the load is loaded. death,
The backrest lifting device is
a first rotating member rotatably supported on a side surface of the loading unit;
a second rotating member rotatably supported at the end of the side surface of the mounting portion opposite to the loading portion;
a third rotating member rotatably supported by an end portion of the side surface of the mounting portion on the side of the loading portion;
at least a hanging member that is hung on the first rotating member, the second rotating member, and the third rotating member and raises and lowers the backrest with respect to the mounting portion,
the operating portion is a moving body integrally provided with the hanging member and slidable with respect to the loading portion;
The first rotating member, the second rotating member, and the third rotating member are driven by the load loaded on the loading portion, which pushes the movable body toward 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. By driving the hanging member via the first rotating member, the second rotating member, and the third rotating member, the backrest is lowered to the original position before being raised with respect to the mounting portion. and the movable body moves away from the mounting portion with respect to the loading portion, and returns to the original position before being pushed by the load in the direction of approaching the mounting portion. A forklift according to claim 1. The third rotating member has a first rotating body and a second rotating body,
The hanging member includes a first hanging body provided integrally with the moving body and hung on the first rotary member and the first rotary body, and a first hanging body connected to the backrest and the second hanging body. 3. A forklift according to claim 2, further comprising a rotating member and a second mounting body that is mounted on said 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 that is hung on the first sprocket and the first gear,
4. A forklift truck according to claim 3, wherein said second hook is a second chain hooked on said second sprocket and said second gear. 5. A forklift truck according to claim 4, wherein the number of teeth of said first gear is greater than the number of teeth of said second gear.

Images