JPH0733777U - Front axle - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the shape of the spring seat surface of the front axle beam so that the caster angle can be set easily. A protrusion 23 having an area substantially equal to the area on which the leaf spring 27 is seated is formed at a portion of the front axle beam 24 on which the leaf spring 27 is seated, and the protrusion 23 is flattened to form a spring. By forming the seat surface, the caster angle can be finished to a predetermined accuracy in a short time.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a front axle in which the shape of a spring seat surface of a front axle beam is improved so that a caster angle can be easily set.

[0002]

[Prior art]

 The front wheels of the vehicle are steered wheels and are attached at an angle different from the rear wheels in order to improve maneuverability and keep driving stability. This angle is called the front wheel alignment. The caster angle is known as one of the alignments, and the caster angle is generally considered to be about 1 ° to 3 °, and if the caster angle exceeds this range, shimmy motion is likely to occur. , Need attention.

Therefore, in the front axle, the spring seat surface of the front axle beam that supports the kingpin at both ends and the leaf seat that seats on the spring seat surface and supports the front axle beam. There is a structure in which a wedge-shaped angle adjusting member called a caster wedge is inserted between the spring and the bottom surface, and the caster angle can be adjusted according to the wedge angle of the angle adjusting member.

In the front axle 1 shown in FIG. 4, a front axle beam 2 made by forging hard steel having an I-shaped cross section is supported by a leaf spring 3, and the leaf spring 3 is provided. Both ends of the bracket are joined to the bracket 5 of the chassis frame 4. The vehicle weight applied to the chassis frame 4 acts on the front axle beam 2 with the leaf spring 3 as a cushioning material, and is supported by the front wheels 6 attached to both ends of the front axle beam 2. As shown in FIG. 5, the front axle beam 2 has kingpin holes 7 at both ends, and a spring bearing surface 8 on which the leaf spring 3 is seated is machined at a position slightly inward from the kingpin holes 7. Since the leaf spring 3 is formed by stacking several sheets, a center bolt hole (not shown) for positioning and alignment is formed in the central portion of each single leaf spring. By inserting the center bolt 9 into the hole and screwing it into the center bolt hole 8a at the center of the spring seat surface 8, all the leaves of the leaf spring 3 can be positioned and aligned. After the positioning by the center bolt 9, a pair of U bolts 10 straddling the leaf spring 3 are directed from above to the positions before and after sandwiching the insertion portion of the center bolt 9, and the tip of the U bolt 10 is set on the spring seat surface 8. The U bolt hole 8b formed is inserted, and the nut 11 is tightened from the lower side. As a result, the leaf spring 3 supports the front axle beam 2, and the lower surface of the central portion of the lowermost single leaf spring is seated on the spring seat surface 8 of the front axle beam 2 to form the spring seat surface 8. Fix it.

[0005]

[Problems to be solved by the device]

 In the conventional front axle 1 described above, the U-bolt is formed in four places by surrounding the spring bearing surface 8 of the front axle beam 2 on which the leaf spring 3 is seated with the center bolt hole 6a and the center bolt hole 6a. The region including any opening of the hole 8b is cut to form the entire region flat.

However, the U-bolt 10 that locks the front axle beam 2 to the leaf spring 3 is inserted through the U-bolt hole 8b of the front axle beam 2 while straddling the leaf spring 3. The width of the leaf spring 3 is narrower than the space between the U bolt holes 8b on the left and right. Therefore, although the seating area of the leaf spring 3 seated on the spring seat surface 8 is naturally smaller than the area of the spring seat surface 8, the conventional spring seat surface 8 is seated on the leaf spring 3. There was a lot of waste because the area that exceeds the area was processed flat. The spring seat surface 8 of the front axle beam 2 needs to be carefully and accurately machined because the inclination angle θ (shown in FIG. 4) with respect to the kingpin (not shown) determines the caster angle itself. This means that the wedge angle of the caster wedge 12 can be adjusted when the spring seat surface 8 is cut perpendicularly to the axis of the kingpin, or the caster wedge 12 shown in FIG. The situation is the same when the seat surface 8 is cut only by inclining from the axis of the kingpin. Moreover, the front axle beam 2 is generally made of forged hard steel that is not easily machined, and the larger the machined area, the more difficult it is to finish the caster angle accuracy.

The present invention aims to simplify the cutting process of the spring seat surface by limiting the area of the spring seat surface of the front axle beam to the minimum area required for seating the leaf springs. .

[0008]

[Means for Solving the Problems]

 The present invention comprises a front axle beam provided with a spring seat surface which is perpendicular to the axis of a kingpin passing through both ends or inclined at a constant angle, and the spring seat surface is fixed to a leaf spring. In the front axle, the portion of the front axle beam processed on the spring seat surface is formed as a convex portion having an area substantially equal to the area on which the leaf spring is seated. The object is achieved by providing a front axle that

[0009]

[Action]

 Based on the above structure, the caster angle can be finished to a predetermined accuracy in a short time by forming the spring seating surface by cutting or the like so that the convex portion is flat or inclined by a certain angle.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2 are respectively a plan view and a front view of a main part of an embodiment of a front axle of the present invention, and FIG. 3 is a spring seat surface of the front axle beam shown in FIG. FIG. 3 is a partially enlarged perspective view showing the shape of FIG.

The front axle 21 shown in FIGS. 1 and 2 has a front axle 23 having a convex portion 23 that is machined into a spring seat surface that is vertical or inclined by a certain angle with respect to the axis of the kingpin 22 that passes through both ends. The leaf spring 27 is provided with the beam 24, and the leaf spring 27 is seated by positioning the center bolt 25 on the spring seat surface formed by processing the convex portion 23. It is attached to the leaf spring 27 by tightening the U bolt 26. A knuckle 29 that rotatably supports a front wheel 28 is swingably supported by an end portion of a front axle beam 24 by a kingpin 22. 1 and 2, 30 is a knuckle arm and 31 is a tie rod.

As shown by cross-hatching in FIG. 3, the convex portion 23 formed on the spring seat surface of the front axle beam 24 has the center bolt hole 23a of the center bolt 25 substantially at the center, It is formed in a region that is inscribed in the opening edge portions of four U bolt holes 23b surrounding the bolt hole 23a. That is, the convex portion 23 processed on the spring seat surface has a width substantially equal to the width of the leaf spring 27, and has a minimum area required for the leaf spring 27 to be seated.

Therefore, after the convex portion 23 is formed into a spring seat surface by cutting or the like, the leaf spring 27 is seated on the spring seat surface and is aligned and aligned by the center bolt 25, before and after sandwiching the center bolt 25. The front axle beam 24 is attached to the leaf spring 27 when the U bolt 26 is applied to the two places from above and the nut 32 is screwed into the U bolt 26 which is inserted through the U bolt hole 23b and tightened. At this time, the lowermost layer of the leaf spring 27 does not protrude from the spring seating surface at all, and seats at the specified location accurately. Further, since the nut 32 is locked to the back surface of the front axle beam 24, the fastening is not hindered even if the opening of the U bolt hole 23b that is opened adjacent to the spring seat surface is not flat. Further, in the case of the embodiment, since the caster wedge 12 and the like are not used, the spring seat surface 23 is machined perpendicularly to the axis of the king pin 22, but compared with the conventional spring seat surface 8, the U bolt hole 23b. Since the opening part of is not cut, a considerable area is excluded from the cutting target, and the cutting work efficiency can be improved accordingly. In addition, as the cutting area is reduced, errors in cutting are less likely to occur, and quality control is easier, even with the same precision caster angle requirement.

As described above, in the front axle 21, four U bolt holes 23b surrounding the center bolt hole 23a are formed outside the seating surface of the leaf spring 27 with respect to the front axle beam 24. Needless to say, it is not always necessary to open the U-bolt hole 23b on a flat surface. Therefore, even if only the region inscribed in the opening edge of the U-bolt hole 23b is cut flat, the spring of the leaf spring 27 is There is no problem in sitting on the seat. Therefore, by forming the spring seat surface with the minimum necessary processing, the caster angle, which is the rearward tilt angle of the king pin 22 held by the front axle beam 24 at both ends, can be finished to a predetermined accuracy in a short time. it can.

In the above embodiment, the case where the convex portion 23 of the front axle beam 24 is processed to be perpendicular to the axis of the kingpin 22 to form the spring seat surface is taken as an example. Alternatively, it may be processed so as to be inclined at a constant angle.

[0016]

[Effect of device]

 As described above, according to the present invention, the portion of the front axle beam machined on the spring seat surface on which the leaf spring is seated is formed in the convex portion having an area substantially equal to the area on which the leaf spring is seated. Therefore, the spring seat surface can be formed by adding the necessary minimum cutting work, and the excellent effects such as the improvement of finishing accuracy and the reduction of manufacturing time can be achieved.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts showing an embodiment of a front axle of the present invention.

FIG. 2 is a front view of a main part of the front axle shown in FIG.

FIG. 3 is a partially enlarged perspective view showing a shape of a convex portion of the front axle beam shown in FIG.

FIG. 4 is a side view showing an example of a conventional front axle.

5 is a perspective view showing the front axle beam shown in FIG. 4. FIG.

[Explanation of symbols]

 21 Front Axle 22 King Pin 23 Convex Part Processed on Spring Seating Surface 23a Center Bolt Hole 23b U Bolt Hole 24 Front Axle Beam 25 Center Bolt 26 U Bolt 27 Leaf Spring 28 Front Wheel

Claims (1)

[Scope of utility model registration request] 1. A front axle beam provided with a spring seat surface which is perpendicular to the axis of a kingpin passing through both ends or inclined by a certain angle, and the spring seat surface is fixed to a leaf spring. In the front axle, the portion of the front axle beam processed on the spring seat surface is formed as a convex portion having an area substantially equal to an area on which the leaf spring is seated. Front axle.