JP4232104B2 - Reach forklift assist wheel mounting structure - Google Patents

Description

  A reach forklift equipped with a reach type lift device in front of the vehicle body and having drive wheels at the rear lower part of the vehicle body, and attaching assist wheels on the left and right sides of the drive wheel at the lower rear part of the vehicle body in the reach forklift This relates to an assist wheel mounting structure.

  As the reach forklift, as shown in FIG. 7, a reach type lift device 21 is mounted in front of the vehicle body 2, and the reach type lift device 21 is directed to the front lower part of the vehicle body 2 toward the front and a pair of left and right reach legs. 22, a pair of left and right masts 23 that move back and forth along the pair of left and right reach legs 22, and a lift bracket 24 that moves up and down along the pair of left and right masts 23. A finger bar 25 and a pair of left and right fork claws 26 are attached to the bracket 24.

  The reach forklift is provided with driving wheels 3 at the center of the left and right (vehicle width direction) at the rear lower part of the vehicle body 2, and the driving wheels 3 are connected to a driving unit such as a motor provided in the vehicle body 2 at the upper part thereof. In addition, it is also connected to a steering wheel 27 provided on the side of the driving unit 6 formed on the right rear side of the vehicle body 2, thereby performing driving and steering.

  And in the lower back part of the vehicle body 2, the drive wheel 3 that performs the above-mentioned drive and steering is provided at the substantially right and left centers, and the assist wheels 1 are attached to the left and right sides. The assist wheel 1 has a function as an auxiliary wheel for stabilizing the vehicle body posture during traveling and turning.

  As this assist wheel mounting structure, conventionally, for example, as shown in FIG. 8, a base plate 28 is fixed to each of the left and right sides of the vehicle body 2, and a swing plate 30 is attached to each of the left and right base plates 28 via pins 29. By providing each, the left and right swing plates 30 swing up and down around the pin 29. Then, the assist wheels 1 are attached to the lower portions of the left and right swing plates 30, respectively. Further, springs 31 are interposed between the left and right base plates 28 and the left and right swing plates 30, respectively. Accordingly, the swing plate 30 and the assist wheel 1 can swing up and down, and the spring 31 interposed between the base plate 28 and the swing plate 30 allows the swing plate 30 and the assist wheel 1 to swing up and down. The movement is suppressed.

  The assist wheels 1 mounted on the right and left sides stabilize the vehicle body posture during running and turning, and the shock received from the road surface is absorbed by the spring 31 interposed between the base plate 28 and the swing plate 30 to thereby improve the riding comfort. Can be improved.

  In such a conventional assist wheel mounting structure, the springs are provided between the left and right base plates and the left and right swing plates, that is, the left and right, respectively, which increases the number of parts and increases the cost. In addition, since the spring is mounted almost directly above each of the left and right assist wheels, a space for arranging the spring is necessary on the assist wheel, and conversely, a space for arranging the spring above. There is a possibility that the assist wheel can be attached only under a certain place, and the attachment position of the assist wheel may be limited.

  In order to solve the above-described problems, the present invention reduces the number of parts to reduce the cost, and the mounting positions of the left and right assist wheels are different from each other by installing the left and right assist wheels and the damper cylinder separately. It is an object of the present invention to provide an assist wheel mounting structure of a reach forklift that can be mounted at a somewhat free position without being limited.

The present invention is a reach forklift equipped with a reach type lift device in front of the vehicle body and provided with a drive wheel at the rear lower part of the vehicle body, and assists the right and left sides of the drive wheel at the lower rear part of the vehicle body in this reach forklift. In the assist wheel mounting structure of the reach forklift that attaches the wheels, the assist wheels arranged on the left and right sides are respectively attached to the left and right swing arms, and the left and right swing arms are fixed to the connecting shafts that are directed to the left and right. The moving arm and the connecting shaft are integrated, and the connecting shaft is rotatably attached to the vehicle body so that the integrated left and right swing arms and connecting shaft can be swung up and down around the connecting shaft. Reach forklift with one damper cylinder attached to the left and right swing arms and the connecting shaft and the vehicle body It is a strike wheel mounting structure. The damper cylinder 9 has an assist wheel mounting structure for a reach forklift that is a cylinder that locks when contracted.

  According to the present invention, in the above-described invention, when the damper cylinder is attached to the left and right swing arms and the connecting shaft, the arm is provided at any position of the connecting shaft. This is an assist wheel mounting structure of a reach forklift with one end attached.

  Further, according to the present invention, in the above-described invention, when the left and right swing arms integrated in the damper cylinder and the attachment to the connecting shaft are provided, a central arm is provided at the approximate center of the connecting shaft. This is an assist wheel mounting structure for a reach forklift with one end of a damper cylinder mounted.

According to the present invention, the swing of the left and right assist wheels as in the prior art is suppressed by using a single damper cylinder or a single cylinder that locks when contracted. It is possible to eliminate the provision of springs for suppressing movement on the left and right sides, thereby reducing the number of parts, thereby reducing the cost.

  Further, according to the present invention, the installation location of the damper cylinder can be set to a certain degree of freedom without being restricted to the left and right assist wheels, and the installation location of the left and right assist wheels and the damper cylinder can be set to different locations. By doing so, the attachment positions of the left and right assist wheels can be freely attached to some extent, that is, without being restricted, at the optimum position of the vehicle body.

One form of the assist wheel attachment structure of the reach forklift according to the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG.
First, the assist wheel 1 is attached to each of the left and right sides of the drive wheel 3 for driving and steering at the lower rear portion of the vehicle body 2, that is, the left assist wheel 1a is attached to the left end portion of the vehicle body 2 and the right end. The right assist wheel 1b is arranged in each part.

  As the assist wheel mounting structure, first, the assist wheels 1 arranged on both the left and right sides are respectively mounted on the left and right swing arms 4. This is because the left assist wheel 1a is attached to the lower rear part of the left swinging arm 4a heading forward and backward via a downward U-shaped holding bracket 5 so as to be rotatable in the horizontal direction, and the right wheel heading forward and backward. A right assist wheel 1b is attached to a lower rear portion of the swing arm 4b via a downward U-shaped holding bracket 5 so as to be rotatable in the horizontal direction. In the left and right swing arms 4, the left swing arm 4 a has a shape that faces diagonally forward right (goes to the left and right center of the vehicle body 2), and the right swing arm 4 b goes diagonally left forward ( In other words, the left and right oscillating arms 4 are arranged in a substantially square shape.

  Next, a connecting shaft 7 directed to the left and right is attached to the inside of the vehicle body 2 in front of the driving wheel 3 and the drive unit provided at the rear center of the vehicle body 2 and the driving unit 6 formed on the rear right side of the vehicle body 2. The connecting shaft 7 is rotatably attached to the vehicle body 2 via a substantially Ω-shaped fixing bracket 8 on the left and right sides thereof. The front end portion of the left swing arm 4 a is fixed to the left end portion of the connection shaft 7, and the front end portion of the right swing arm 4 b is fixed to the right end portion of the connection shaft 7. In short, the left and right swing arms 4 are respectively fixed to the left and right ends of the connecting shaft 7 so that the left and right swing arms 4 and the connecting shaft 7 are integrated. As a result, the integrated left and right swing arms 4 and the connecting shaft 7 can swing up and down around the connecting shaft 7.

  A single damper cylinder 9 is attached to the left and right swing arms 4 and the connecting shaft 7 and the vehicle body 2. The damper cylinder 9 has a single effect structure in which only the contraction side generates a drag and the extension side is in a free state. Although not shown, a restoring spring for restoring the expansion side of the damper cylinder 9 is provided inside or outside the damper cylinder 9. The damper cylinder 9 is specifically mounted on the left rear side of the vehicle body 2 on the upper side slightly behind the left swinging arm 4a and on the front side of the left assist wheel 1a. 11, the damper cylinder 9 is attached to one end side of the damper cylinder 9, and the damper cylinder 9 is inclined obliquely upward to the front. The other end side of the damper cylinder 9 is attached to the vehicle body 2 via the attachment bracket 12 and the pin 13. In addition, by arranging the damper cylinder 9 on the rear left side of the vehicle body 2, space can be used effectively. In the rear of the vehicle body 2, the driving wheel 3 and the driving unit are formed at the center of the left and right, the driving unit 6 is formed on the right side, and there is a relatively vacant part on the left side. Therefore, the space is effectively used by arranging the damper cylinder 9 in the vacant part.

  In the reach forklift having such an assist wheel mounting structure, a load F1 is applied to the left assist wheel 1a during turning by the reach forklift, specifically, as shown in FIG. The reaction force F2 from the road surface is received by the load F1 applied to the left assist wheel 1a. A force F3 for contracting the damper cylinder 9 acts on the damper cylinder 9 via the left and right swing arms 4 and the connecting shaft 7 integrated by the reaction force F2. On the other hand, the damper cylinder 9 itself generates a drag F4 so as to suppress the contraction operation. As a result, the left assist wheel 1a is stretched and the vehicle body posture is stabilized when turning right. Conversely, when turning left, a load F1 is applied to the right assist wheel 1b, and a reaction force F2 from the road surface is received by the load F1 applied to the right assist wheel 1b. A force F <b> 3 is applied to the damper cylinder 9 via the moving arm 4 and the connecting shaft 7 in order to shrink the damper cylinder 9. On the other hand, the damper cylinder 9 itself generates a drag F4 to suppress the contraction operation, so that the right assist wheel 1b is stretched and the vehicle body posture during left turn is stabilized. In this way, the vehicle body posture can be stabilized during both the left and right traveling turns by attaching the damper cylinder 9 to the left and right sides of the drive wheel 3 and the left and right assist wheels 1. In addition, the posture of the vehicle body 2 at the time of running and turning can be stabilized in this way, and the shock received from the road surface at the time of running can be absorbed by the damper cylinder 9, thereby improving the riding comfort.

  By adopting such a structure, conventionally, the swing of the left and right assist wheels 1 is suppressed by the springs 31 provided on the left and right respectively. Therefore, the springs 31 for suppressing the swing must be provided on the left and right respectively. However, in the assist wheel mounting structure according to the present invention, the number of parts can be reduced by adopting a structure in which the swing of the left and right assist wheels 1 is suppressed by the single damper cylinder 9. And the cost can be reduced. Moreover, the conventional structure having the springs 31 on the left and right requires adjustment of the left and right springs 31 in order to make the balance between the left and right the same. In the assist wheel mounting structure according to the present invention, Since one damper cylinder 9 is used in place of the spring 31, no such adjustment work is required, and the work of attaching the left and right assist wheels 1 in the reach forklift is facilitated and the workability is improved. Can be achieved.

  In addition, the attachment of one damper cylinder 9 that suppresses the swinging of the left and right assist wheels 1 is not a type in which the spring 31 is attached substantially above each of the left and right assist wheels 1 as in the prior art. In this way, it is possible to make a vacant space inside the vehicle body 2, this time a space vacant part on the rear left side of the vehicle body 2, and thus the installation location of the damper cylinder 9 is limited to the left and right assist wheels 1. It can be a free place to some extent. Thus, it is necessary to provide a large pace (space for arranging the spring 31 in the past) above the left and right assist wheels 1 by setting the left and right assist wheels 1 and the damper cylinder 9 at different locations. In other words, the left and right assist wheels 1 can be attached to the optimal position of the vehicle body 2 with some freedom, that is, without being limited by the attachment positions of the left and right assist wheels 1.

  Further, in particular, by arranging the damper cylinder 9 in a space-vacant part on the left rear side of the vehicle body 2 as in this time, the driving unit 6 is formed on the rear right side of the vehicle body 2, Even if the assist wheel 1 is attached to the lower part of the driving unit 6, there is no need to provide a space for arranging the spring 31 and the like on the assist wheel 1. The position can be lowered, and the low fork structure of the operating unit 6 can provide a reach forklift with good boarding / exiting performance.

  Moreover, the damper cylinder 9 that suppresses the swinging of the left and right assist wheels 1 generates resistance against the reaction force received from the road surface during traveling and turning due to its structure, but gradually ( Resistance to the force acting on the contraction side is less likely to occur. Due to the characteristics of the damper cylinder 9, the following effects can be obtained. This is because when the drive wheel 3 is worn due to long-term operation of the reach forklift, the structure having the conventional spring 31 has a somewhat higher spring constant in order to stabilize the posture of the vehicle body 2 at the time of traveling turning. For this reason, the ground pressure of the left and right assist wheels 1 is increased due to wear of the drive wheels 3, causing problems such as slip of the drive wheels 3 and wear of the left and right assist wheels 1. However, in the damper cylinder 9 used in the present invention, when the driving wheel 3 is worn, a force is gradually applied to the damper cylinder 9, so that no drag is generated and a high ground pressure is applied to the left and right assist wheels 1. Even if it tries to act, this is absorbed by the damper cylinder 9, and it is possible to suppress the contact pressure of the left and right assist wheels 1 from increasing. As a result, problems such as slip of the drive wheel 3 when the drive wheel 3 is worn or wear of the left and right assist wheels 1 can be eliminated, and the height adjustment of the drive wheel 3 and the left and right assist wheels 1 when the drive wheel 3 is worn. (Adjustment of the vehicle height in the drive wheels 3) can be eliminated.

  Further, in the damper cylinder 9, since it is not controlled by a control device such as a controller provided outside, the control device is unnecessary, and the cost is reduced and the reliability is improved by simplifying the configuration. Can do.

  In addition, in the assist wheel mounting structure of the reach forklift according to the present invention, the mounting of one damper cylinder 9 is not limited to the above-described one, and may be directed to another position or another direction.

  For example, as shown in FIG. 6, the central arm 14 is fixed to the left and right center of the connecting shaft 7 that is integrated with the left and right swing arms 4 so as not to interfere with the drive wheels 3 and the drive unit. The one end side of the damper cylinder 9 is attached to the rear upper part of the central arm 14 via the mounting bracket 15 and the pin 16, and the other end side of the damper cylinder 9 is attached to the vehicle body 2 via the mounting bracket 17 and the pin 18. . In this way, the damper cylinder 9 may be attached to the vicinity of the left and right center of the connecting shaft 7. The attachment of the damper cylinder 9 is not limited to the vicinity of the center of the left and right, but an arm is provided at any position on the left and right of the connecting shaft 7 so that one end of the damper cylinder 9 is attached to the arm. Also good.

  The damper cylinder 9 is not limited to a normal one. For example, the damper cylinder 9 may be a cylinder that locks when the swing cylinder 4 is operated and the damper cylinder 9 contracts.

It is explanatory drawing in the upper part in the assist wheel attachment structure of the reach forklift by this invention. It is explanatory drawing in the back in the assist wheel attachment structure of the reach forklift by this invention. It is explanatory drawing of the side in the assist wheel attachment structure of the reach forklift by this invention. It is a schematic perspective view of the assist wheel attachment structure of the reach forklift by this invention. It is explanatory drawing which shows the action state of the force in the assist wheel attachment structure of the reach forklift by this invention. It is a schematic perspective view of the other example of the assist wheel attachment structure of the reach forklift by this invention. It is a perspective view of a reach forklift. It is explanatory drawing in the back in the assist wheel attachment structure of the conventional reach forklift.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Assist wheel, 1a ... Left assist wheel, 1b ... Right assist wheel, 2 ... Vehicle body, 3 ... Drive wheel, 4 ... Swing arm, 4a ... Left rocking arm, 4b ... Right rocking arm, DESCRIPTION OF SYMBOLS 5 ... Holding bracket, 6 ... Driving part, 7 ... Connecting shaft, 8 ... Fixing bracket, 9 ... Damper cylinder, 10 ... Mounting bracket, 11 ... Pin, 12 ... Mounting bracket, 13 ... Pin, 14 ... Center Arm, 15 ... Mounting bracket, 16 ... Pin, 17 ... Mounting bracket, 18 ... Pin, 21 ... Lifting device, 22 ... Reach leg, 23 ... Mast, 24 ... Lift bracket, 25 ... Finger bar, 26 ... Fork claw 27 ... Steering, 28 ... Base plate, 29 ... Pin, 30 ... Swing plate, 31 ... Spring.

Claims (4)

A reach forklift is provided with a reach type lift device 21 in front of the vehicle body 2 and provided with drive wheels 3 at the lower rear portion of the vehicle body 2, and both left and right sides of the drive wheels 3 at the lower rear portion of the vehicle body 2 in this reach forklift. Reach forklift assist wheel mounting structure for attaching the assist wheel 1 to the
The assist wheels 1 arranged on the left and right sides are respectively attached to the left and right swing arms 4, and the left and right swing arms 4 are fixed to the connecting shafts 7 facing left and right. The connecting shaft 7 is integrally attached to the vehicle body 2 so that the left and right swing arms 4 and the connecting shaft 7 can swing up and down around the connecting shaft 7 and integrated. 1. A reach forklift assist wheel mounting structure in which a single damper cylinder 9 is mounted across the left and right swing arms 4 and the connecting shaft 7 and the vehicle body 2. 2. The assist wheel mounting structure for a reach forklift according to claim 1, wherein the damper cylinder is a cylinder that locks when contracted. When mounting the damper cylinder 9 on the left and right swing arms 4 and the connecting shaft 7, an arm is provided at any position of the connecting shaft 7, and one end of the damper cylinder 9 is attached to this arm. 3. The assist wheel mounting structure for a reach forklift according to claim 1 or 2 . For attachment to the left and right swing arms 4 and the connecting shaft 7 in the damper cylinder 9, a central arm 14 is provided at the approximate center of the connecting shaft 7, and one end of the damper cylinder 9 is provided on the central arm 14. The assist wheel mounting structure for a reach forklift according to claim 1 or 2, wherein

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