JPS628143Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a rotary joint for an electric circuit of a civil engineering construction machine such as a crane, an aerial work vehicle, or a backhoe.

As shown in Fig. 1, the conventional rotary joint A is formed into a double cylinder shape with an outer cylinder 2 fixed to the swing table 1 side and an inner cylinder 3 fixed to the chassis side. By bringing brushes 5, 5 attached to the circumferential wall of the outer tube 2 into contact with annular slip rings 4, 4 attached at appropriate intervals in the axial direction on the outside of the tube 3, the chassis side and the swivel base 1 side are electrically connected. Connected. The slip rings 4, 4 attached to the inner cylinder 3 are made of a conductive material and are attached to the inner cylinder 3.
The inner cylinder 3 and the other adjacent slip rings 4, 4 are electrically insulated by annular insulators 6, 6 fixed to the sides.

The present invention utilizes the insulators 6, 6 as a cam for operating a limit switch, and detects the orientation of the swivel base by operating the limit switch.

The above-mentioned civil engineering construction machinery detects the turning work area because the work performance differs depending on the turning work area, but the conventional detection method is to attach a cam plate to the chassis side and set a limit switch. Since the limit switch is disposed on the rotating base side, the actuator (the part that contacts the cam) of the limit switch is inevitably exposed to wind and rain, which causes the limit switch to malfunction. As mentioned above, in the present invention, the insulators 6, 6 are also used as cams, and since the actuator of the limit switch is located inside the rotary joint A facing the insulators 6, 6, it is exposed to wind and rain. It has the characteristic that it never happens.

Next, the configuration of the present invention will be explained in detail based on one specific embodiment.

7, the outer cylinder 2 is fixed, and the actuator 7' is
This is a limit switch facing insulator 6. Therefore, this actuator 7' is not exposed to wind and rain, and since the insulator 6 has a convex shape in the range from a to b as shown in FIG. 2, it is ON in this range. be. Furthermore, since the height of the remaining portion corresponding to the concave portion in the radial direction is higher than the height of the slip ring 4, the outer cylinder 2 and the inner cylinder 3
This prevents the actuator of the limit switch 7 from coming into contact with the slip ring 4 due to the axial deviation of the limit switch 7. Furthermore, in this figure, the range in which limit switch 7 operates is 90 degrees, but
Of course, the angle can be selected freely, and the outer cylinder 2 side is fixed, and the slip rings 4, 4 and the insulator 6 are provided on the outer cylinder 2 side, and the brushes 5, 5 are installed on the outer cylinder 2 side.
In the case where the limit switch 7 is provided on the inner cylinder 3 side supported on the swivel table, the limit switch 7 is of course located on the inner cylinder 3 side.

In summary, the present invention has an inner cylinder disposed within an outer cylinder, and slip rings are disposed in one of the two cylinders at appropriate intervals in the axial direction, and each slip ring is In a rotary joint for an electrical circuit of a civil engineering construction machine, an insulator is disposed between the two cylinders, and a brush is disposed facing the slip ring in the other cylinder, and the cylinder in which the brush is disposed is connected to the insulator. A limit switch is provided facing the insulator, and a cam is applied to the insulator so that the limit switch is activated when the swivel base reaches a specific swivel work area.A separate cam is installed to detect the swivel work area of the swivel base. There is no need to provide a limit switch, and furthermore, it has an excellent practical effect of ensuring that the limit switch operates properly at all times.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a rotary joint showing an embodiment of the present invention, and FIG. 2 shows an insulator with cam processing. 1: Swivel base, 2: Outer cylinder, 3: Inner cylinder, 4: Slip ring, 6: Insulator, 5: Brush,
A: Rotary joint, 7: Limit switch.

Claims (1)

[Scope of utility model registration request] An inner cylinder is arranged within an outer cylinder, and slip rings are arranged in one of these cylinders at appropriate intervals in the axial direction, and an insulator is arranged across each slip ring. , the other tube is
In a rotary joint for an electric circuit of a civil engineering and construction machine in which a brush is disposed facing the slip spring, a limit switch facing the insulator is disposed in the tube in which the brush is disposed, and this limit switch is connected to the swivel base. 1. A rotary joint for an electric circuit of a civil engineering and construction machine, characterized in that the insulator is cam-processed so as to be activated when the insulator comes into a specific turning work area.