JP2004106564A - Steering angle detection sensor mounting structure of forklift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering angle detection sensor mounting structure of a forklift, wherein lower cost and easy work are realized as an alternative to a prior art. <P>SOLUTION: A body 22 of a rotation sensor 21 is fixedly supported on a supporting member 11a for rotatably supporting a king pin 12, and an input shaft 23 of the rotation sensor 21 is inserted into the king pin 12 through a spacer 27 formed out of an elastic body. The spacer 27 is inserted so as not to rotate relatively to the king pin 12, and the input shaft 23 is inserted so as not to rotate relatively to the spacer 27. The input shaft 23 rotates together with the king pin 12, and its rotation is detected by a body 22 equipped with a detection element. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure for mounting a steering angle detection sensor that detects a steering angle of a steered wheel provided in a forklift.
[0002]
[Prior art]
Conventionally, when detecting the steering angle of a steered wheel in a forklift, a body of a rotation sensor as a steering angle detection sensor such as a potentiometer or a rotary encoder is mounted on a support member that supports an end of a kingpin that rotates together with the steered wheel. A mounting structure is used in which the input shaft of the rotation sensor is supported and internally fitted to the end of the kingpin so that the input shaft cannot be relatively rotated.
[0003]
As a mounting structure of this type of steering angle detection sensor, for example, as shown in FIG. 6, a bracket 104 is fixed to a support member 103 in which a king pin 101 is rotatably fitted via a bearing 102, and the bracket 104 is attached to the bracket 104. In some cases, the body 106 of the rotation sensor 105 is fixed, and the input shaft 107 of the rotation sensor 105 is inserted into the kingpin 101. Further, there has been proposed a structure in which the mounting structure shown in FIG. 6 is improved so that the rotation sensor 105 can be easily mounted (see the following document).
[0004]
[Reference 1] Japanese Patent Application Laid-Open No. 10-310077 (page 4, FIG. 1)
[Reference 2] Japanese Patent No. 3175645 (page 3-4, FIG. 1-6)
[Reference 3] JP-A-2001-334953 (page 2-3, FIG. 3-5)
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a mounting structure for a steering angle detection sensor of a forklift, which is cheaper and can be easily implemented instead of the above-mentioned conventional technology.
[0006]
[Means for Solving the Problems]
In order to achieve this object, a forklift steering angle detection sensor mounting structure of the present invention is a mounting structure for a steering angle detection sensor for detecting rotation of a kingpin rotatably supported by a support member, wherein the steering angle detection sensor includes one of the kingpins. A spacer insertion hole is recessed from the end face along the axis thereof, and a spacer made of an elastic body having an input shaft insertion hole recessed in the spacer insertion hole makes it impossible to rotate relative to the rotation axis around the axis. At the same time, the input shaft of the steering angle detection sensor is inserted into the input shaft insertion hole so as not to rotate relative to the spacer around the axis, and the body of the steering angle detection sensor is fixedly supported by the support member. The spacer insertion hole may be a circular main hole recessed around the axis of the kingpin and a bottom of the main hole at a position eccentric from the axis of the kingpin. A cylindrical main part in which the spacer is fitted in the main hole, and a cylindrical projection in which the spacer is fitted in the main body; A non-circular shape which is coaxial with the axis of the kingpin when the main portion is fitted in the main hole at an end of the main portion opposite to the side fitted in the main hole. Technical means is adopted in which the input shaft insertion hole is recessed.
[0007]
According to the present invention, the axial displacement between the kingpin and the input shaft can be absorbed by the elastic deformation of the spacer made of an elastic body interposed between the kingpin and the input shaft. Can be simplified, and required accuracy can be secured. In addition, the elasticity of the spacer has the effect of damping vibrations and shocks transmitted from the kingpin to the input shaft of the steering angle detection sensor, so that the steering angle detection sensor is protected from vibrations and shocks, and It is also possible to obtain an effect that a decrease in the detection accuracy of the steering angle detection sensor can be prevented. Also, since the protrusion of the spacer is fitted into the anti-rotation hole of the kingpin, the relative rotation becomes impossible, so that the shape of the main hole and the anti-rotation hole can be easily formed such as a circular shape, In addition, the spacer insertion hole can be formed at low cost.
[0008]
As the steering angle detection sensor of the present invention, for example, a sensor generally known as a rotation sensor such as a potentiometer and a rotary encoder can be used. The spacer of the present invention may be formed of an elastic body such as a chain polymer compound (elastic rubber) having rubber elasticity at normal temperature. Further, the input shaft insertion hole of the present invention can be polygonal such as a square or a hexagon, an ellipse, a semicircle, or the like, and the input shaft insertion hole matches the cross-sectional shape of the input shaft of the steering angle detection sensor. It is necessary to make the shape.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The mounting structure of the steering angle detection sensor according to one embodiment of the present invention will be specifically described below with reference to the drawings. 1 is a side view of a forklift, FIG. 2 is a plan view of a rear axle assembly provided in the forklift, FIG. 3 is a rear view of the rear axle assembly, and FIG. 4 is a steering angle detection sensor. FIG. 5 is a sectional view of the mounting structure, and FIG. 5 is an exploded perspective view of the steering angle detection sensor mounting structure.
[0010]
As shown in FIG. 1, the forklift according to this embodiment has a counter in which a mast 2 is supported at a front portion of a vehicle body 1 so as to be tiltable, and a fork 4 is supported by the mast 2 via a lift bracket 3 so as to be able to move up and down. The balance type forklift is designed to be driven by left and right front wheels 5 which are driving wheels and left and right rear wheels 6 which are steering wheels. The left and right rear wheels 6 are attached to a rear axle assembly 10 described later, and the rear axle assembly 10 is attached to the vehicle body 1. A driver's seat 8 is provided on a battery case 7 provided at the center of the vehicle body 1. A driver sits on the driver's seat 8, and a steering handle 9 provided opposite the driver's seat 8. Is operated to rotate the rear wheel 6.
[0011]
As shown in FIGS. 2 and 3, a rear axle assembly 10 includes a rear axle frame 11 that is attached to a vehicle body 1 via a suspension device (not shown), and king pins 12 at left and right ends of the rear axle frame 11. And a rear wheel shaft 13 rotatably supported through the rear wheel shaft 13. The rear wheel 6 is fitted to the rear wheel shaft 13. A gearbox 14 is fixed to the center of the rear axle frame 11 in the tread direction, and a steering rod 15 is supported via the gearbox 14 so as to be movable in the left-right direction. The left-right movement of the steering rod 15 is performed by driving the gearbox 14 in accordance with the rotation of the steering handle 9. One end of a connecting arm 16 is connected to each of the left and right ends of the steering rod 15 via a joint pin 17, and the connecting arm is connected to the rear end of a steering arm 18 which is rearwardly extended from the base end of the rear wheel shaft 13. The other end of 16 is connected by another joint pin 19. Here, since the rear wheel axle 13 and the kingpin 12 cannot rotate relative to each other, when the steering handle 9 is rotated to move the steering rod 15 from the neutral position to the left or right, the connecting arm 16 , The rear wheel 6, the kingpin 12, and the rear wheel shaft 13 integrally rotate clockwise or counterclockwise around the axis of the kingpin 12 as a rotation center, and steering is performed.
[0012]
As shown in FIG. 3, the king pin 12 is rotatably supported by upper and lower support members 11 a and 11 b provided on both right and left ends of the rear axle frame 11 via bearings or the like. A rotation sensor 21 as a steering angle detection sensor is attached to detect rotation of the king pin 12.
[0013]
In this embodiment, the rotation sensor 21 is composed of a rotary potentiometer, and as shown in FIG. 4, includes a body 22 with a built-in variable resistor and an input shaft 23 protruding from the body 22. The body 22 of the rotation sensor 21 is fixedly supported via a cap 24 on a support member 11a that rotatably supports the upper end of the king pin 12. The distal end side of the input shaft 23 is formed in a crescent shape in cross section, and is used for preventing relative rotation with respect to a spacer 27 described later.
[0014]
As shown in FIG. 4, a spacer insertion hole 26 is formed in the upper end surface 25 of the king pin 12 on which the rotation sensor 21 is mounted, and a spacer 27 made of an elastic material such as rubber is provided in the spacer insertion hole 26. Is inserted into the king pin 12 so as not to rotate around the axis of the king pin 12. The spacer insertion hole 26 has a main hole 28 formed along the axis from the end face 25 of the king pin 12, and an anti-rotation hole deeply recessed in the axial direction further from the eccentric position of the bottom of the main hole 28. 29. The main hole 28 and the rotation preventing hole 29 are formed at low cost by drilling. 4 is a cover provided so as to cover the body 22 of the rotation sensor 21. The cover 33 is fixed to the support member 11a together with the cap 24.
[0015]
FIG. 5 is an exploded perspective view of the mounting structure of the steering angle detection sensor. The spacer 27 according to this embodiment includes a main portion 30 fitted in the main hole 28 and a projection 31 fitted in the rotation preventing hole 29. And An input shaft insertion hole 32 into which the input shaft 23 of the rotation sensor 21 is inserted is formed in the main portion 30 of the spacer 27, and the cross-sectional shape of the input shaft insertion hole 32 is the same chord as the cross-sectional shape of the input shaft 23. Moon-shaped.
[0016]
When the spacer 27 is inserted into the spacer insertion hole 26 of the king pin 12, the main portion 30 is fitted into the main hole 28 and the protrusion 31 is inserted into the rotation preventing hole 29, so that the spacer 27 is The rotation is disabled, and the spacer 27 rotates together with the king pin 12. Further, by inserting the input shaft 23 of the rotation sensor 21 into the input shaft insertion hole 32 of the spacer 27 through a through hole provided in the cap 24, the input shaft 23 cannot be relatively rotated with respect to the spacer 27. Will rotate with the kingpin 12 via the spacer 27. Here, since the body 22 of the rotation sensor 21 is fixed to the cap 24 fixed to the support member 11a, as a result, the rotation of the king pin 12 is detected by the rotation sensor 21. Since the king pin 12 is configured to rotate integrally with the rear wheel 6 as described above, the rotation amount of the rear wheel 6, that is, the steering angle can be indirectly detected by detecting the rotation amount of the king pin 12. For example, a detection signal output from the rotation sensor 21 can be used as a signal indicating the steering angle of the rear wheel 6 for controlling a steering system or the like.
[0017]
By the way, according to this embodiment, even if the kingpin 12 and the input shaft 23 of the rotation sensor 21 are slightly misaligned for some reason, the axial misalignment is absorbed by the elastic deformation of the spacer 27. In addition, the work of aligning the axes can be simplified, and the required accuracy can be ensured. When the forklift travels, the rear wheel 6 may vibrate together with the kingpin 12 due to the unevenness of the road surface. Since the shock is buffered, the rotation sensor 21 can be protected from vibration and shock, and the detection accuracy of the rotation sensor 21 due to vibration and shock can be prevented from lowering.
[0018]
【The invention's effect】
As described above, according to the present invention, the rotation sensor can be mounted in a short time and easily, and the rotation sensor is protected from vibrations and shocks by the buffer function of the spacer. A decrease in detection accuracy can be prevented, and durability can be improved.
[Brief description of the drawings]
FIG. 1 is a side view of a forklift.
FIG. 2 is a plan view of a rear axle assembly provided in the forklift.
FIG. 3 is a rear view of a rear axle assembly included in the forklift.
FIG. 4 is a sectional view of a structure for mounting a steering angle detection sensor according to the present invention.
FIG. 5 is an exploded perspective view of a structure for mounting a steering angle detection sensor according to the present invention.
FIG. 6 is a sectional view of a conventional example.
[Explanation of symbols]
10 Rear axle assembly 11a Support member 12 King pin 21 Rotation sensor (steering angle detection sensor)
22 Body 23 Input shaft 25 End face 26 Spacer insertion hole 27 Spacer 28 Main hole 29 Rotation prevention hole 30 Main part 31 Projection 32 Input shaft insertion hole

Claims (1)

A mounting structure for a steering angle detection sensor for detecting rotation of a kingpin rotatably supported by a support member, wherein a spacer insertion hole is recessed from one end surface of the kingpin along its axis. In addition, a spacer made of an elastic body having an input shaft insertion hole recessed is inserted into the input shaft insertion hole such that the input shaft of the steering angle detection sensor is inserted into the input shaft insertion hole. Is inserted relative to the axis around the axis so that it cannot rotate relatively, and the body of the steering angle detection sensor is fixedly supported by the support member,
The spacer insertion hole is formed by a main hole recessed about the axis of the kingpin and an anti-rotation hole recessed in the axial direction from the bottom of the main hole at a position eccentric from the axis of the kingpin. The spacer has a columnar main portion fitted in the main hole, and a columnar projection fitted in the rotation preventing hole. The main portion is fitted in the main hole. A steering angle of a forklift, wherein an input shaft insertion hole which is coaxial with the axis of the kingpin when the main portion is fitted in the main hole is recessed at an end opposite to the side. Detection sensor mounting structure.

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