JPH0777915B2 - Balancing device for loading arm - Google Patents

Description

The present invention relates to a balance adjusting device for a loading arm used for supplying liquid to a tank truck or the like.

(Prior Art) Generally, as shown in FIG. 5, a loading arm used when liquid is supplied to a tank truck or the like is a horizontally rotating inboard arm 1, an elbow 2, and a vertically rotating arm. The outboard arm 3 and the swivel joint SJ that connects these three parts together are used. By interposing a coil spring as a balance between the elbow 2 and the outboard arm 3, the load of the outboard arm 3 is increased. It has a structure that cancels.

By the way, the balance adjusting device proposed by the present applicant in Japanese Patent Laid-Open No. 60-134900 has a spring seat a that is integral with the coil spring when the spring force of the coil spring changes due to long-term use. The support frame c on the elbow 2 is relatively rotated by a spring adjusting bolt e provided between them to tighten the coil spring, and the load of the outboard arm 3 and the spring force of the coil spring are balanced. A spring seat a and a bolt f are inserted through the bolt holes b and d provided in the support frame c to fix them.

This device is excellent in that it can tighten a strong coil spring with a small amount of force, and it is also excellent in being able to perform delicate balance adjustment, but on the other hand, at the adjusted position, each bolt hole b, d If they don't match,
Since it is necessary to slightly rotate the spring seat a so that the nearest holes b and d are aligned with each other and then to fix them through the bolts f, the balance is damaged by this rotation despite the adjustment. There was a problem that it would end up.

(Purpose) The present invention has been made to solve such problems.
It is an object of the present invention to provide an improved loading arm balance adjusting device capable of accurately fixing a spring seat and a spring bracket at a balance adjusted position.

(Means for Achieving the Purpose) That is, the present invention, as a loading arm balance adjusting device for solving the above-mentioned problems, provides a support frame with an arc-shaped elongated hole that matches the hole on the spring receiving seat. A taper surface is formed on the surface of the support frame in the long hole part so that the thickness of the arm gradually increases in the direction in which the tip of the arm hangs down, while the bolt inserted into the hole on the spring receiving seat and the long hole on the support frame. Is fastened and fixed via a washer with a taper that comes into surface contact with the tapered surface.

(Examples) Therefore, the details of the present invention will be described below based on illustrated examples.

1 to 3 show an embodiment of the present invention, in which reference numeral 6 is a U-shaped support frame fixed to the elbow 2 for supporting the spring adjusting mechanism 4, Is a spring seat 9 in which the upper and lower ends of the coil spring 5 are fixed,
10 is rotatably mounted. Reference numeral 12 is an adjusting bracket for winding and tightening the coil spring 5. This base end has screw holes 11 equidistantly formed around the lower spring seat 10.
Is attached with bolts 13 and 13, and one end of a spring pressure adjusting bolt 15 is pivotally supported at its free end protruding from the spring seat 10 to the outer periphery, and the other end is projected to one end of the support frame 6. It is inserted into the hole of the formed bracket 17 and is fixed by the nut 16.

By the way, in the above-mentioned support frame 6, an arc-shaped elongated hole 7 is bored in a portion corresponding to the screw holes 11 provided in the lower spring seat 10, and in this portion of the surface of the support frame 6, A taper surface 8 is formed so that the wall thickness gradually increases in the direction of the arrow in the figure, that is, in the direction in which the tip of the outboard arm 3 hangs down (Fig. 3), and the taper mounted on the taper surface 8 is formed. A bolt 20 inserted into the elongated hole 7 via a washer 19 is screwed into the screw hole 11 of the spring seat 10 to position and fix the support frame 6 and the spring seat 10.

Reference numeral 22 in the drawing denotes a connecting rod that connects the upper spring seat 9 and the outboard arm 3 and transmits the load of the outboard arm 3 to the coil spring 5.

Therefore, in order to adjust the spring force of the coil spring 5 by the device configured as described above, the bolt 20 that fixes the support frame 6 and the lower spring seat 10 is first removed. As a result, the restraint of the spring seat 10 is released, and then the nut 16 screwed to the bolt 15 for adjusting the spring pressure is turned to wind up the coil spring 5 integrated with the spring seat 10 to tighten the outboard arm. Balance the load of 3.

Then, in a balanced state, the tapered washer 19 is placed on the tapered surface 8 of the support frame 6, and this washer is
If the other end of the bolt 20 inserted into the elongated hole 7 via 19 is screwed into the screw hole 11 on the lower spring seat 10 located therebelow and tightened, the outboard arm 3 rotates in the hanging direction. Even if an attempt is made, the taper surface 8 whose wall thickness is gradually increased in this direction is firmly coupled and fixed to each other.

(Effect) As described above, according to the present invention, the support frame is provided with the arc-shaped long hole that matches the hole on the spring receiving seat, and the direction in which the tip of the arm hangs down on the support frame surface of this long hole portion. While forming a tapered surface that gradually increases the wall thickness toward
Since the bolts inserted into the holes on the spring seat and the slots on the support frame are tightened and fixed via the tapered washers that make surface contact with the tapered surface, the balance adjustment can be done steplessly simply by the slots. In addition to doing so, even if the heavy outboard arm tries to hang down due to its own weight, the support frame formed to increase the thickness in the hanging direction enters into the wedge shape between the bolt and the washer. While further strengthening the frictional force with the washer and suppressing the hanging of the outboard arm as much as possible,
By joining the taper surface provided on the washer and the taper surface of the support frame in opposite directions, the load can be correctly applied in the axial direction of the bolt, and the bending and breakage thereof can be suppressed in advance.

[Brief description of drawings]

FIG. 1 is a plan view of an apparatus showing an embodiment of the present invention, FIG. 2 is a side view of the same apparatus, FIG. 3 is an enlarged sectional view of an essential part of the same apparatus, and FIG. It is a top view which shows an example of an apparatus. 3 …… Outboard arm 5 …… Coil spring 6 …… Support frame, 7 …… Long hole 8 …… Tapered surface, 10 …… Lower spring seat 19 …… Tapered washer 20 …… Bolt

Claims (1)

[Claims] 1. A spring receiving seat having a plurality of holes on the same circumference fixed to a coil spring which is connected to an arm swinging up and down to support its load, and the hole provided in the spring receiving seat. And a hole provided in a support frame that pivotally supports the spring receiving seat to fix the spring receiving seat and the supporting frame by inserting a bolt into the balance adjusting device of the loading arm. , A tapered surface provided with an arc-shaped elongated hole that matches the hole of the spring receiving seat, and the wall thickness of the elongated hole portion gradually increases in the direction in which the tip of the arm hangs down. On the other hand, the loading arm characterized in that the bolt inserted into the hole on the spring receiving seat and the elongated hole on the support frame is tightened and fixed via a tapered washer that makes surface contact with the tapered surface. Balance of Straightening device.