JP2017039456A - Industrial vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrial vehicle which achieves explosion protection performance without causing enlargement even when having a device for an electric power steering.SOLUTION: A forklift includes a steering wheel, an electric motor which steers the steering wheel on the basis of steering of the steering wheel, instruments 22, and a key switch 26. The forklift includes one pressure-resistant explosion-proof case 21. The instruments 22, the key switch 26, a steering operation detection mechanism, a controller 24, and a motor driver 25 are arranged in the pressure-resistant explosion-proof case 21.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an industrial vehicle.

  In the industrial vehicle disclosed in Patent Document 1, instruments, a direction switch, a blinker switch, and a key switch are incorporated in a flameproof case. Moreover, it has an escape portion to avoid interference with the steering shaft.

Japanese Patent Laid-Open No. 10-120386

  By the way, in an explosion-proof specification vehicle having an electric power steering, the mechanism for detecting the steering operation also needs to have explosion-proof performance. Therefore, the steering operation is detected in addition to the explosion-proof case described in Patent Document 1. An explosion-proof structure for the mechanism is required, and the explosion-proof structure is divided into a plurality of parts, which may be disadvantageous in terms of space.

  An object of the present invention is to provide an industrial vehicle capable of explosion-proofing without causing an increase in size even when an apparatus for electric power steering is provided.

  In the first aspect of the present invention, a steering wheel disposed in a driver's seat, an electric motor that steers a steering wheel based on steering of the steering wheel, instruments disposed in the driver's seat, and the driving An industrial vehicle including a switch disposed in a seat, and includes an explosion-proof case, and steering for detecting steering of the instrument, the switches, and the steering wheel in the explosion-proof case The gist is that an operation detection mechanism, a controller for controlling the electric motor, and a motor driver for driving the electric motor are arranged.

  According to the first aspect of the present invention, instruments, switches, a steering operation detection mechanism, a controller, and a motor driver are arranged in the explosion-proof case, so that a compact explosion-proof structure is obtained. As a result, the industrial vehicle can be explosion-proof without causing an increase in size even when it has a device for electric power steering.

  As described in claim 2, in the industrial vehicle according to claim 1, in the explosion-proof case, the instrument, the switches, the steering operation detection mechanism, the controller, and the motor driver are at least one It is good to be connected and arranged by connection means without explosion-proof performance.

  According to a third aspect of the present invention, in the industrial vehicle according to the first or second aspect, the steering operation detection mechanism includes a rotation axis direction changing unit and a torque detector, and the rotation of the steering wheel is transmitted. A steering shaft may be connected to the torque detector via the rotating shaft direction changing means.

As described in claim 4, in the industrial vehicle according to claim 3, the rotating shaft direction changing means may be a universal joint.
As described in claim 5, in the industrial vehicle according to claim 3 or 4, the explosion-proof case has a first bearing holder on an upper surface and a second bearing holder on a lower surface, and the torque detector is It is good to be provided near the second bearing holder from the first bearing holder.

  As described in claim 6, in the industrial vehicle according to claim 3, the torque detector includes an upper bracket that rotates by rotation of the steering shaft, and a lower bracket that rotates by the steering angle of the steering wheel. A potentiometer having a rotating rod supported rotatably, and is fixed to the rotating rod of the potentiometer, and rotates when the upper bracket rotates against the spring force of the spring while the lower bracket is stationary. And a lever, and it may be configured to have no explosion-proof performance.

  According to the present invention, even when a device for electric power steering is provided, explosion prevention can be achieved without causing an increase in size.

The side view of a reach type forklift. The top view of a reach type forklift. The perspective view of a flameproof case. The perspective view which shows a steering operation detection mechanism. (A) is a front view of a steering operation detection mechanism, (b) is a partial front view of the steering operation detection mechanism, and (c) is a partial front view of the steering operation detection mechanism. (A) is a top view of a steering operation detection mechanism, (b) is a perspective view of a steering operation detection mechanism, (c) is a perspective view of a steering operation detection mechanism. (A) is a top view of a steering operation detection mechanism, (b) is a perspective view of a steering operation detection mechanism, (c) is a perspective view of a steering operation detection mechanism. (A) is a top view of a steering operation detection mechanism, (b) is a perspective view of a steering operation detection mechanism, (c) is a perspective view of a steering operation detection mechanism.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
In the drawings, the horizontal plane is defined by the orthogonal X and Y directions, and the vertical direction is defined by the Z direction.

  As shown in FIGS. 1 and 2, a reach-type forklift 10 (hereinafter referred to as a forklift) as an industrial vehicle has a front wheel and a rear wheel. A pair of left and right reach legs 12 extend forward at the front of the vehicle body 11. A standing type driver's seat (driver's cab) 13 is provided at the right rear portion of the vehicle body 11. In the driver's seat 13, an operation lever 14 for cargo handling operation and the like is provided on the front instrument panel 11 a. A steering wheel (handle) 15 is provided on the upper surface of the storage box 11 b that is erected on the left side of the driver's seat 13.

  A mast device 16 is mounted on the vehicle body 11 so as to be movable in the front-rear direction along a pair of left and right reach legs 12. The mast device 16 is connected to a piston rod 17a of a reach cylinder (hydraulic cylinder) 17 as a reach driving device disposed in the center of the bottom of the vehicle body 11 in the vehicle width direction. By operating the reach lever of the operation lever 14, hydraulic oil is supplied from the oil pump to the reach cylinder 17 via the oil control valve by driving an electric motor for cargo handling (not shown), and the piston rod 17a is driven to extend and contract. Thus, the mast device 16 moves back and forth within a predetermined stroke range.

  The left and right front wheels 18 are driven wheels and are attached to the front ends of the left and right reach legs 12, respectively. One rear wheel is a driving steering wheel 19 that serves as both a steering wheel and a driving wheel. The driving steering wheel 19 is offset to the left in the vehicle width direction, and is adjacent to the right side of the driving steering wheel 19 at a predetermined distance. A caster 20 is provided as a driven wheel that is paired with the left and right. Therefore, the forklift 10 of the present embodiment travels with the drive steering wheel 19 rotating by driving of a traveling electric motor (not shown).

  The forklift 10 is a vehicle having an electric power steering, and the drive steering wheel 19 is steered based on the steering of the steering wheel 15 by driving an electric motor (power steering motor) 27. That is, the electric power steering detects the difference in the direction of the drive steering wheel 19 with respect to the operation position of the steering wheel 15, and is electrically driven by the difference so that the direction of the drive steering wheel 19 becomes the operation position of the steering wheel 15. The motor 27 assists. The forklift 10 is an explosion-proof forklift.

  One explosion-proof case 21 is disposed under the steering wheel 15, and the explosion-proof case 21 has a fully closed structure. The explosion-proof case 21 has a substantially square box shape, and is fixed to the vehicle body (base) 11 in a state where the side faces are in the vertical direction.

  As shown in FIG. 3, an instrument (display) 22, a steering operation detection mechanism 23 (see FIG. 4), a controller 24, a motor driver (inverter) 25, and a key switch 26 as a switch are included in the explosion-proof case 21. Has been placed. The instrument group 22 is arranged in the driver's seat 13. The key switch 26 is disposed in the driver seat 13. The steering operation detection mechanism 23 is for detecting the steering of the steering wheel 15. The controller 24 is for controlling in-vehicle devices (including a traveling motor, a cargo handling motor, and an electric motor 27). The motor driver 25 is for driving the traveling motor, the cargo handling motor, and the electric motor 27.

  That is, in addition to the instruments 22 and the key switches 26 as switches, the steering operation detection mechanism 23, the controller 24, and the motor driver 25 are arranged in a single explosion-proof case 21 in a modular state. The equipment in the explosion-proof case 21 is wired (connected) in the explosion-proof case 21, and the wiring material does not require an explosion-proof structure and is connected by at least one connection means (such as a lead wire) that does not have explosion-proof performance. ing. As a result, a space-saving and low-cost explosion-proof control module structure is provided.

  The schematic configuration of the steering mechanism will be described. As shown in FIGS. 5A, 5B, and 5C, when the movable portion is roughly divided, a portion A1 connected to the steering wheel 15 and a drive steering wheel (tire) ) It is divided into a part A2 connected to 19. As shown in FIG. 5 (a), the upper side is a portion A1 mechanically connected to the steering wheel 15, and the lower side shown in FIG. 5 (b) is mechanically connected to a drive steering wheel (tire) 19. This is the portion A2. As shown in FIG. 5C, the lower spiral cable case 43 is a portion A3 that is fixed to the explosion-proof case 21 and does not move.

As shown in FIGS. 4 and 5, a steering shaft 44 is fixed to the steering wheel 15, and the rotation of the steering wheel 15 is transmitted to the steering shaft 44.
The steering operation detection mechanism 23 includes a universal joint 28 as a rotation axis direction changing unit and a torque detector 29. The steering shaft 44 is connected to the torque detector 29 via the universal joint 28. The torque detector 29 includes a detection shaft 45 (see FIG. 5) for detecting torque. The detection shaft 45 extends in the vertical direction, and the steering shaft 44 extends obliquely by a predetermined angle θ1 with respect to the vertical direction. The rotation of the steering wheel 15 changes the rotation axis direction by the universal joint 28 and transmits the rotation of the steering shaft 44 to the detection shaft 45.

  The universal joint 28 is configured by combining two sets of universal shaft joints, and universal shaft joints (links) 28b and 28c are provided at both ends of the intermediate shaft 28a in the middle. The steering shaft 44 is connected to the upper universal joint 28b, and the detection shaft 45 is connected to the lower universal joint 28c.

  As shown in FIG. 5, the steering wheel 15 is disposed obliquely with respect to the horizontal plane by a predetermined angle θ2. As described above, when the steering wheel 15 is disposed obliquely with respect to the horizontal plane, the steering wheel 15 can be mounted in a space-saving manner in the explosion-proof explosion-proof case 21, and is also applicable to a machine base in which the mounting angle is disposed obliquely with respect to the detection unit. Cheap. That is, it is adapted to an explosion-proof forklift, and the instrument 22, the key switch 26 as a switch, the steering operation detection mechanism 23, the controller 24, and the motor driver 25 are integrated in one explosion-proof explosion-proof case 21.

  As shown in FIGS. 4 and 5, an explosion-proof first bearing holder 30 is disposed on the upper surface of the explosion-proof case 21 below the steering wheel 15, and the steering shaft 44 penetrates the upper surface of the explosion-proof case 21 and A bearing in one bearing holder 30 is rotatably supported.

  As shown in FIG. 5, the torque detector 29 includes an upper bracket 31, a lower bracket 32, a spring 33, a potentiometer 34, and a lever 35 connected to the detection shaft 45, and has no explosion-proof performance. It is a configuration. The flat upper bracket 31 and the flat lower bracket 32 are arranged vertically so as to face each other horizontally. The upper bracket 31 is connected to the detection shaft 45. Therefore, the upper bracket 31 is rotated by the steering of the steering wheel 15. On the other hand, the lower bracket 32 is connected to the shaft 41. An explosion-proof second bearing holder 42 is disposed on the lower surface of the explosion-proof case 21 under the steering operation detection mechanism 23 (torque detector 29), and the shaft 41 penetrates the lower surface of the explosion-proof case 21 and the second bearing. A bearing in the holder 42 is rotatably supported. The shaft 41 is mechanically connected to the drive steering wheel 19. Therefore, the lower bracket 32 is rotated by the steering angle of the drive steering wheel 19.

  Thus, the explosion-proof case 21 has the first bearing holder 30 on the upper surface and the second bearing holder 42 on the lower surface, and the torque detector 29 is closer to the second bearing holder 42 than the first bearing holder 30. Is provided.

  The spring 33 is a cylindrical coil spring, and is arranged in a state of being erected between the center portion of the upper bracket 31 and the center portion of the lower bracket 32. As shown in FIGS. 5 and 6, a pin 36 extending downward is fixed to the outer peripheral portion of the upper bracket 31. On the other hand, a pin 37 extending upward is fixed to the outer peripheral portion of the lower bracket 32. As shown in FIG. 6, one end of the spring 33 engages with the pin 36 and the other end of the spring 33 engages with the pin 37. The upper bracket 31 mechanically connected to the steering wheel 15 is rotated with the steering of the steering wheel 15 with respect to the lower bracket 32 mechanically connected to the drive steering wheel 19. The upper bracket 31 and the lower bracket 32 can increase the relative angle against the spring force of the spring 33.

  As shown in FIG. 4, a bracket 38 is erected on the outer peripheral portion of the upper surface of the lower bracket 32. The bracket 38 is configured by bending a belt plate into a U shape, and both ends are fixed to the upper surface of the lower bracket 32. A potentiometer 34 is attached to the upper surface of the bracket 38. As shown in FIG. 4, the potentiometer 34 has a rotating rod 39 that is rotatably supported. The rotating rod 39 extends downward through the bracket 38. A lever 35 (see FIG. 6) is fixed to the rotating rod 39. The lever 35 extends in the horizontal direction, and a U-shaped notch 35a is formed at the tip. On the other hand, a pin 40 extending downward is fixed to the outer peripheral portion of the upper bracket 31. As shown in FIG. 6A, the pin 40 is inserted into the notch 35 a of the lever 35. When the upper bracket 31 rotates against the spring force of the spring 33 while the lower bracket 32 is stationary, the pin 40 also rotates and the lever 35 rotates, and this rotation is converted into an electrical signal by the potentiometer 34. Is done. The potentiometer 34 is connected to a spiral cable in a spiral cable case 43 fixed to the explosion-proof case 21.

  Then, when the steering wheel 15 is steered, the steering shaft 44 is rotated, and the rotation is changed in the direction of the rotation axis via the universal joint 28 and the upper bracket 31 is rotated. On the other hand, when the drive steering wheel 19 is steered by the electric motor 27, the lower bracket 32 also rotates. The potentiometer 34 detects the relative position between the upper bracket 31 and the lower bracket 32, and the controller 24 feeds back the electric motor 27 in order to match the relative position between the upper bracket 31 and the lower bracket 32 based on the detection result. Control. Specifically, the controller 24 sends a command signal to the motor driver 25, and the electric motor 27 is driven by the motor driver 25.

Next, the operation will be described.
6A, 6B, and 6C show the neutral time (neutral position). That is, the steering wheel 15 and the drive steering wheel (tire) 19 are in the same position.

As shown in FIG. 6B, the upper bracket 31 and the lower bracket 32 are not moving at the neutral position. As shown in FIG. 6C, the lever 35 is also in the neutral position.
FIGS. 7A, 7B, and 7C show a state in which the steering wheel 15 is rotated 10 degrees to the left, for example. That is, FIG. 4 shows a state in which the steering wheel 15 is rotated by an angle θ20 from the position indicated by P1 to the position indicated by P2.

  As shown in FIG. 7B, only the upper bracket 31 rotates and the upper bracket 31 and the lower bracket 32 open 10 degrees. At this time, both ends of the spring 33 are opened by turning the steering wheel 15 against the spring force of the spring 33. That is, a force is required to turn the steering wheel 15. As shown in FIG. 7C, the lower bracket 32 does not move because it is connected to the drive steering wheel (tire) 19. That is, the position of the potentiometer 34 remains unchanged. On the other hand, since the upper bracket 31 rotates to the left together with the steering wheel 15, the lever 35 rotates to the right. As a result, the output (voltage) of the potentiometer 34 changes.

  Then, the controller 24 detects a change in the output (voltage) of the potentiometer 34, and the electric motor 27 operates so that the drive steering wheel (tire) 19 rotates so that the output of the potentiometer 34 becomes neutral.

FIGS. 8A, 8B, and 8C show a state in which the drive steering wheel (tire) 19 is rotated by a predetermined amount.
Since the lower bracket 32 is connected to the drive steering wheel (tire) 19, it rotates to the left together with the drive steering wheel (tire) 19, and the lever 35 returns to the original angle, that is, the neutral position.

In this manner, the drive steering wheel 19 is steered by the electric motor 27 based on the steering of the steering wheel 15.
Generally, a torque detector is mounted just below the steering wheel. However, in the explosion-proof specification, the potentiometer must have an explosion-proof structure.

It is difficult to make the potentiometer alone an explosion-proof structure, and it is disadvantageous in terms of space and cost to make only the steering operation detection mechanism (torque detector) an explosion-proof structure.
In the present embodiment, a universal joint 28 is disposed between the steering wheel 15 and the steering operation detection mechanism 23 (torque detector 29), and the explosion-proof case 21 is shared with the controller 24 and the motor driver 25, thereby The mechanism can be integrated in the explosion-proof case 21.

  Thereby, space saving and low cost are achieved. In addition, the electrical equipment involved in the control can be mounted with only one explosion-proof case 21. Furthermore, the connection of equipment in the explosion-proof case 21 does not require the use of a cabtyre cable that is required for an explosion-proof structure. Further, a sensor that does not satisfy the explosion-proof specification as a single unit (potentiometer 34 for torque detection) can be used.

  Moreover, it is easy to adapt to a machine base in which the steering wheel 15 is disposed obliquely with respect to the detection unit. Specifically, when the potentiometer 34 and the upper and lower brackets 31 and 32 are installed horizontally, the universal joint 28 can be connected to the torque detector 29 by changing the direction of the rotation axis so that the direction of the rotation axis is vertical. Further, when the potentiometer 34 and the upper and lower brackets 31 and 32 are accommodated in the explosion-proof case 21, the explosion-proof case 21 can be made compact.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the forklift 10, a steering wheel 15, an electric motor 27 that steers a drive steering wheel 19 as a steering wheel based on steering of the steering wheel 15, an instrument 22, and a key switch as a switch 26. The forklift 10 includes a pressure-proof explosion-proof case 21 as one explosion-proof case. Inside the pressure-proof explosion-proof case 21, a controller 24 for controlling instruments 22, a key switch 26, a steering operation detection mechanism 23, an electric motor 27, and A motor driver 25 for driving the electric motor 27 is disposed. Therefore, it becomes a small explosion-proof structure. As a result, even when a device for electric power steering is provided, the explosion can be prevented without increasing the size. Thereby, space saving and cost reduction can be achieved, and modularization is achieved.

  (2) In the present embodiment, the controller 24 is for controlling in-vehicle devices including a travel motor, a cargo handling motor, and an electric motor 27 for electric power steering, and the motor driver 25 is a travel motor, cargo handling. This is for driving the motor and the electric motor 27. Therefore, the following effects are produced. Conventionally, in order to operate a forklift, a controller and a motor driver (inverter) are indispensable as components, and therefore an explosion-proof structure is required separately. Further, in a vehicle having an electric power steering, a mechanism for detecting a steering operation is also essential, and therefore an explosion-proof structure is required. Dividing the explosion-proof structure into multiple parts is disadvantageous in terms of space and cost. In the present embodiment, even when a device for vehicle operation and a device for electric power steering are provided, the explosion can be prevented without causing an increase in size.

  (3) In the explosion-proof case 21, the instruments 22, the key switch 26, the steering operation detection mechanism 23, the controller 24, and the motor driver 25 are connected and arranged by at least one connection means having no explosion-proof performance. Therefore, it can arrange | position in the state modularized (commonization), and also can achieve a required explosion-proof performance with an inexpensive connection means. That is, the connection between the components in the explosion-proof case 21 is facilitated and the size can be easily reduced.

  (4) The steering operation detection mechanism 23 includes a universal joint 28 as a rotation axis direction changing means and a torque detector 29, and the steering shaft 44 to which the rotation of the steering wheel 15 is transmitted detects the torque via the universal joint 28. Since it is connected to the device 29, it is possible to cope with the case where the steering wheel 15 is disposed obliquely.

  (5) The explosion-proof case 21 has a first bearing holder 30 on the upper surface and a second bearing holder 42 on the lower surface, and the torque detector 29 is provided closer to the second bearing holder 42 than the first bearing holder 30. It has been. Therefore, by providing the torque detector 29 having a relatively large physique below the explosion-proof case 21, the degree of freedom of arrangement of other components in the explosion-proof case 21 is improved.

  (6) The torque detector 29 is a potentiometer having an upper bracket 31 that rotates by the rotation of the steering shaft 44, a lower bracket 32 that rotates by the steering angle of the drive steering wheel 19, and a rotating rod 39 that is rotatably supported. 34 and a lever 35 that is fixed to the rotary rod 39 of the potentiometer 34 and rotates when the upper bracket 31 rotates against the spring force of the spring 33 in a state where the lower bracket 32 is stationary. Does not have. Therefore, the torque detector 29 itself need not be explosion-proof, which is advantageous in terms of cost.

The embodiment is not limited to the above, and may be embodied as follows, for example.
Although the case 21 has a flameproof structure, it may be a dustproof structure or a waterproof structure.
-Although it applied to the reach type forklift 10 as an industrial vehicle, you may apply to other industrial vehicles, such as a construction machine, for example.

  DESCRIPTION OF SYMBOLS 10 ... Forklift, 13 ... Driver's seat, 15 ... Steering wheel, 19 ... Drive steering wheel, 21 ... Explosion-proof case, 22 ... Instrument, 23 ... Steering operation detection mechanism, 24 ... Controller, 25 ... Motor driver, 26 ... Key Switch, 27 ... Electric motor, 28 ... Universal joint, 29 ... Torque detector.

Claims (6)

A steering wheel deployed in the driver's seat;
An electric motor that steers the steered wheel based on steering of the steering wheel;
Instruments arranged in the driver's seat;
Switches arranged in the driver's seat;
An industrial vehicle with
With one explosion-proof case,
In the explosion-proof case, the instruments, the switches, a steering operation detection mechanism for detecting steering of the steering wheel, a controller for controlling the electric motor, and a motor for driving the electric motor An industrial vehicle comprising a driver.   In the explosion-proof case, the instruments, the switches, the steering operation detection mechanism, the controller, and the motor driver are connected and arranged by at least one connection means having no explosion-proof performance. The industrial vehicle according to claim 1.   The steering operation detection mechanism includes a rotation axis direction changing unit and a torque detector, and a steering shaft to which rotation of the steering wheel is transmitted is connected to the torque detector via the rotation axis direction changing unit. The industrial vehicle according to claim 1 or 2.   The industrial vehicle according to claim 3, wherein the rotation axis direction changing means is a universal joint.   The explosion-proof case has a first bearing holder on an upper surface and a second bearing holder on a lower surface, and the torque detector is provided closer to the second bearing holder than the first bearing holder. The industrial vehicle according to claim 3 or 4. The torque detector is
An upper bracket that rotates by rotation of the steering shaft;
A lower bracket that rotates according to the steering angle of the steered wheel;
A potentiometer having a rotating rod rotatably supported;
A lever that is fixed to a rotating rod of the potentiometer and rotates when the upper bracket rotates against the spring force of a spring in a state where the lower bracket is stationary;
The industrial vehicle according to claim 3, comprising no explosion-proof performance.