JP3303437B2 - Industrial vehicle frame structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame structure of an industrial vehicle such as a forklift, and more particularly, to a vehicle front portion,
In particular, the present invention relates to a frame structure near a tilt cylinder mounting portion.

[0002]

2. Description of the Related Art FIGS. 11 and 12 schematically show a frame structure near a conventional tilt cylinder mounting portion. As shown, the mast 31 is rotatably mounted on a front axle 33 (more specifically, a front axle housing) via a mast support 32 provided on the back surface of the lower end portion, and is tilted forward and backward by a tilt cylinder 34. ing. The base of the tilt cylinder 34 is a tilt bracket 36 erected on a tilt base plate 35.
The rod 34a is rotatably mounted via a pin 37, and the distal end of the rod 34a is
8 so as to be rotatable. The tilt base plate 35 (which may also serve as a fender) is welded to a side member 40 for connecting the side frame 39 and the front axle 33, and projects outward. And, in such a frame structure, due to its structure, the center of the tilt cylinder 34
The center of the mast support 32 is offset in the vehicle width direction, and the mast support 32 and the side members 40 are also offset in the vehicle width direction.

[0003]

In the above-described conventional frame structure, the load W applied to the fork 41 is transmitted as a tensile force from the mast 31 to the frame via the tilt cylinder 34 and the mast support 32. In this case, due to the offset, an outward load acts on the side frame 39 and the side member 40 to push the side frame 39 and the side member outward as shown by the arrows in the figure.
Therefore, conventionally, in order to support this load, the left and right side members 40 are connected to each other by a cross member 42 as shown, or the left and right side members 40 and the front axle housing are connected to each other by a reinforcing member 43. Increases rigidity. The connection is generally welded.

However, in the coupling method using the cross member 42 or the reinforcing member 43, the side frame 39 is not used.
When an outward load is applied to the side member 40, a load is applied to the cross member 42 and the reinforcing member 43 fixed to the side member 40 so as to bend the same. When the load, that is, the bending force is applied, the stress is concentrated particularly on the welded portion, which is the joint portion. Therefore, it is necessary to set the welded section to be large in order to cope with this. Also, in connection with that, not only the welded parts but also the whole parts inevitably become larger,
As a result, there arises a problem that the weight is increased and the cost is increased. In general, the increase in the size of the cross member 42 and the reinforcing member 43 causes a problem that serviceability when performing maintenance work on a transmission, a differential device, or various pipes disposed thereunder is deteriorated. Has occurred.

In view of the above-mentioned problems, the present invention can effectively support an outward load acting on a side frame or a side member, and furthermore, does not apply a bending force to a tie rod itself provided therefor. It is a technical problem to be solved to provide a devised frame structure.

[0006]

Means for Solving the Problems In order to solve the above problems, the present invention is configured as follows. That is, the invention according to claim 1 is provided with left and right side members extending forward and backward for coupling the front axle and the side frame, and on a tilt base plate extending outward from the upper ends of these side members, A frame structure for an industrial vehicle in which bases of left and right tilt cylinders for mast front-rear inclination are rotatably mounted, wherein the left and right tilt base plates or side members are arranged in a vehicle width direction in the vicinity of a mounting portion of the tilt cylinder. The tie rods are connected to each other by extending tie rods, the tie rods being prevented from moving in the axial direction with respect to the tilt base plate or the side members, and having a degree of freedom in a horizontal direction intersecting the axial direction. It is characterized by being combined.

According to a second aspect of the present invention, in the industrial vehicle frame structure of the first aspect, the tie rod is provided with a turnbuckle for adjusting a length.

[0008]

In the frame structure according to the first aspect of the present invention, the load acting on the fork is transmitted as a tensile force from the mast to the frame side via the mast support and the tilt cylinder, and this tensile force is applied between the mast support and the tilt cylinder. When the tie rods are applied to the side frame or the side member as an outward load that pushes it outward due to the offset in the vehicle width direction or the offset between the mast support and the side member in the vehicle width direction, the tie rod is not attached to the outside. Acts to support directional loads. At this time, since the tie rod has a degree of freedom in a horizontal direction intersecting with the axial direction, the tie rod does not receive a bending force.

In the frame structure according to the second aspect of the present invention, when assembling the tie rod, the effective length of the tie rod is adjusted by adjusting the turnbuckle so that the tie rod can be properly supported against the outward load. Can be

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2,
A pair of left and right masts 1 are attached to a front axle 3 (front axle housing) via a mast support 2 fixed to a lower end portion of a rear surface of the mast 1 so that the masts 1 can be tilted back and forth. Has become. In the drawing, reference numeral 5 denotes a fork mounted so as to be able to move up and down along the mast 1.

The tilt cylinder 4 is disposed in the front-rear direction slightly outside of the mast 1 and has a base end parallel to a tilt bracket 7 erected on the upper surface of a tilt base plate 6 in a vehicle width direction. 8 so as to be rotatable, and the piston rod 4a is
Are rotatably connected via a joint member 9 on the outer surface of the. Therefore, the tilt cylinder 4 and the mast support 2 are offset E1 in the vehicle width direction.

The tilt base plate 6 is fixed to the upper end of the side member 10 and extends outward. In general, the tilt base plate 6 often serves also as a fin that covers the front wheels. Further, the side member 10 includes the front axle 3 and the side frame 11.
And is generally fixed to each of the front axle 3 and the side frame 11 by bolts. In this case, due to its structure, the front axle 3
Is fixed inside the mast support 2, so that the mast support 2 and the side member 10 are offset E2 in the vehicle width direction.

By the way, the above-mentioned frame structure is the same as the conventional one. Therefore, when loading, the load W acting on the fork 5 is changed from the mast 1 to the mast support 2.
When it acts as a tensile force on the frame side via the tilt cylinder 4, an outward load as shown by an arrow in the figure acts on the side frame 11 and the side member 10 due to the existence of the offsets E 1 and E 2.

In this embodiment, a tie rod 12 for connecting the left and right tilt base plates 6 to each other is provided to support the outward load.
The tie rod 12 extends substantially horizontally in the vehicle width direction, and both left and right end portions are coupled to the left and right tilt base plates 6 via spherical pins 13 near the mounting portion of the tilt cylinder 4. .

That is, as shown in FIG. 3, a spherical pin 13 with a spherical portion 13a having a flat upper end is welded upright to the upper surface of the tilt base plate 6. Then, the spherical portion 13a is screwed to the terminal portion of the tie rod 12, and the lock nut 1
4, the circular hole 15a of the rod end 15 fixed is fitted, and the rod end 15 is
Is stopped by a stopper plate 17 fixed to an upper end surface by bolts 16. Thus, the tie rod 12 can freely move in a substantially horizontal direction intersecting the axial direction while being restricted from moving in the axial direction with respect to the tilt base plate 6, that is, the tie rod 12 has a coupling structure with a degree of freedom. .

The frame structure of this embodiment is constructed as described above. Therefore, when an outward load acts on the side frames 11 and the side members 10 as described above, the tie rods 12 act to support this load. I do. That is, the tie rod 12 resists an outward load acting on the side frame 11 and the side member 10 with a tensile force, and prevents the side frame 11 from opening outward.

In this case, if the conventional welding structure,
Although a bending force acts on the tie rod 12 in the front-rear direction, in this embodiment, the tie rod 12 is allowed to be displaced in the front-rear horizontal direction due to relative spherical slip with respect to the tilt base plate 6 via the spherical pin 13. Therefore, no bending force is applied. Therefore, the tie rod 12 only needs to have a tensile strength, and is smaller than a conventional large member.

Next, a second embodiment of the present invention will be described with reference to FIGS.
Explanation will be given based on FIG. The tie rod 12 in this embodiment is configured to be connected to the left and right tilt base plates 6, more specifically, the tilt bracket 7 via a spherical washer 18. Specifically, tie rod 1
Screws 12a are provided at both left and right end portions of 2, and these screw portions 12a are loosely inserted into through holes 19 formed through the tilt bracket 7, and one end surface is formed into a spherical surface as shown in FIG. It is fastened with a nut 20 via a spherical washer 18. The other components are configured in the same manner as in the above-described first embodiment.

Therefore, in this embodiment, when an outward load is applied to the side frame 11 and the side member 10 as shown by the arrow in the figure, the tie rod 12 acts to support the load. In this case, the tie rod 12 has a spherical surface. Through hole 1 of tilt bracket 7 via washer 18
The relative sliding with respect to the seating surface 9 (preferably formed into a spherical surface or a tapered surface) prevents a bending load from acting on itself.

FIG. 7 shows a third embodiment of the present invention. This embodiment is different from the tie rod 1 in the second embodiment described above.
The structure for connecting the tilt bracket 7 to the second tilt bracket 7 is partially changed. That is, it is fastened with a nut 20 via a flat washer 21 instead of the spherical washer 18.

In this case, the tilt bracket 7 of the tie rod 12 is compared with the case of the spherical washer 18 described above.
Although the degree of freedom of displacement in the horizontal direction intersecting the axial direction with respect to the tie rod 12 is somewhat inferior, in practice, a certain degree of freedom of displacement of the tie rod 12 can be set by controlling the tightening torque of the nut 20. Becomes for that reason,
As in the first and second embodiments described above, the tie rod 12 can be prevented from being subjected to a bending load, and can be downsized.

8 to 10 show a fourth embodiment of the present invention. In this embodiment, left and right side members 10 are connected by a tie rod 12 with a turnbuckle 22. In other words, the tie rod 12 is constituted by two threaded rods having a square head (a hexagonal shape is shown in the drawing) at one end and two opposite screws 12b at the outer periphery of the other end. . The two rods are connected to the through holes 23a of the detent plate 23 welded to the outer surfaces of the left and right side members 10 and the side members 10 respectively.
Are loosely inserted through cutout holes 10a penetrating through the holes, and are connected by turnbuckles 22 at the opposite shaft ends. Although FIG. 9 shows a case where the turnbuckle 22 is set to the left in the axial direction, the setting position does not particularly matter.

The rotation preventing plate 23 is provided with a projection 24 for stopping rotation of the tie rod 12 by abutting on one side surface of the head 12a of the tie rod 12. It is desirable to set it on the upper surface side (or the lower surface side) of the head 12a so as not to disturb the degree of freedom of displacement of the head 12a.

The tie rod 1 which is prevented from rotating as described above
2, the effective length of the tie rod 12 is adjusted by adjusting the turnbuckle 22 so that the tie rod 12 is properly supported against the outward load acting on the side frame 11 and the side member 10 after the adjustment. Is locked by a lock nut 25. The other components are configured in the same manner as in the above-described first embodiment.

Therefore, also in this embodiment, as in the case of the third embodiment, by controlling the adjustment torque of the turnbuckle 22, it is possible to impart a horizontal degree of freedom to the tie rod 12 to apply a bending load. Can be avoided.

The sectional shape of the tie rod 12 described in each of the above embodiments may be not only circular but also rectangular in shape. Example 2 and Example 3
In the case of the fastening type using the nut 20 described in the above, it is desirable to prevent the nut 20 from being loosened.

[0027]

As described in detail above, according to the present invention,
Since a bending load can be prevented from acting on the tie rod set to support the outward load on the front end side of the frame, the size of the tie rod can be reduced. Thus, the weight and cost of the frame structure can be reduced. In addition, with the miniaturization of the tie rods, there is less obstruction area when performing maintenance work for maintenance and inspection of transmissions, differential devices or various piping arranged under the frame, and serviceability is improved. Is done.

[Brief description of the drawings]

FIG. 1 is a plan view of a frame structure according to a first embodiment of the present invention.

FIG. 2 is a side view of the frame structure.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a plan view of a frame structure according to a second embodiment of the present invention.

FIG. 5 is a side view of the frame structure.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a cross-sectional view of a tie rod connecting portion structure according to a third embodiment of the present invention.

FIG. 8 is a side view of a frame structure according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view taken along the line CC of FIG. 8;

FIG. 10 is a perspective view of a detent plate according to a fourth embodiment.

FIG. 11 is a plan view showing a conventional frame structure.

FIG. 12 is a side view showing a conventional frame structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mast 2 ... Mast support 3 ... Front axle 4 ... Tilt cylinder 6 ... Tilt base plate 7 ... Tilt bracket 10 ... Side member 11 ... Side frame 12 ... Tie rod 13 ... Spherical pin 18 ... Spherical washer 20 ... Nut 22 ... Turnbuckle 23 … Detent plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 21/18 B66F 9/00-11/04

Claims (2)

(57) [Claims] A left and right side member extending forward and backward for coupling a front axle and a side frame is provided, and a tilt base plate extending outward from an upper end of the side member is provided on a tilt base plate for tilting a mast longitudinally. A base structure of the left and right tilt cylinders is rotatably mounted on the industrial vehicle, wherein the left and right tilt base plates or side members extend in the vehicle width direction in the vicinity of the tilt cylinder mounting portion. The tie rods are prevented from moving in the axial direction with respect to the tilt base plate or the side members, and are connected with a degree of freedom in a horizontal direction intersecting the axial direction. Frame structure. 2. The frame structure according to claim 1, wherein the tie rod has a turnbuckle for adjusting a length.