JPH0518320Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a support device for a manhole cover of a tank car, etc., which can be opened and closed with a small amount of force and whose opening angle can be easily adjusted.

(Prior art) The manhole cover (hereinafter sometimes referred to as "cover") of a manhole installed on the top surface of a tank such as a tank car is required not only to have close contact with the manhole edge but also to have mechanical strength. Therefore, it is heavy.

A pin is horizontally attached to a bracket that is erected and fixed to the top surface of the tank outside the manhole, and one end of the lid is rotatably supported by this pin via an arm.

To open a lid that is closed tightly against the manhole edge, first unlock the lid, use the pin that supports one end of the lid as the center of rotation, and manually lift the other end to an appropriate opening angle. Rotate the lid to tilt it to the open position. Next, the bracket is manually rotated in a horizontal plane with the bracket as the center of rotation,
Move the cover completely away from the manhole opening.

However, since the lid is heavy, it requires a lot of force to lift or turn it manually. Moreover, exerting a large amount of force on a tank with poor footing poses a safety problem.

In order to make the above work possible with a small amount of force, Jikosho
57-49017 uses a plate spring. According to this, when the lid is untightened, the spring force lifts one end of the lid and maintains the lid in the open position, so that only a small amount of manual force is required to lift the lid and the force required for turning the lid.

(Problems to be Solved by the Invention) However, this leaf spring is not adjustable due to its mounting structure. Therefore, even if the spring force is not appropriate due to manufacturing errors or the like, it is not possible to adjust the spring force to the optimum state before shipping. Furthermore, even if the spring becomes fatigued due to use, no countermeasures can be taken. That is, in addition to variations in quality, it is inevitable that durability will also be poor.

The present invention aims to eliminate the above-mentioned drawbacks.

(Means for solving the problem) In order to achieve the above object, in the present invention,
In a manhole cover rotatably supported via an arm on a pin attached to a bracket fixed to a tank, a support device for the manhole cover includes a cover shaft, a tank shaft, a rod, a compression coil spring, and the pin. The lid shaft is rotatable on a lid protrusion that is erected and fixed to the manhole cover and is mounted parallel to the pin, and the tank shaft is rotatable on the bracket and mounted parallel to the pin, and The pin is positioned above the axis on a plane that includes the axes of the lid shaft and the tank shaft, and the rod connects the lid shaft and the tank shaft, with one end supported by the lid shaft and the middle part attached to the tank shaft. It slidably penetrated through the rod, and the spring was attached to the rod and biased between the tank shaft and the other end of the rod so that the spring force could be adjusted.

(Operation) When the lid is unlocked, the moment in the opening direction to open the lid due to the spring force is greater than the moment in the closing direction to close the lid due to its own weight. Therefore, the lid can be opened without any human effort. However, as the opening angle of the lid increases, the spring length increases and the spring force decreases, so it is balanced at a certain opening angle.

(Example) Examples will be described with reference to the drawings.

The manhole 1 of the tank 4 is always closed with a lid 2 except when the manhole 1 is in use. When closed, the lid 2 is attached to the upper end 1a of the side edge of the opening of the manhole 1.
The lower surfaces 2a of the joints are in contact with each other with a gasket interposed therebetween.

A bracket 3 is rotatably fixed to the upper surface of the tank 4 outside the manhole 1.

A pin 5 is horizontally attached to the bracket 3. The pin 5 may be fixed to the bracket 3, or may be openable.

A lid protrusion 6 is erected and fixed at a location near the outer periphery of the lid 2 corresponding to the bracket 3, and a lid shaft 7 can be opened into the lid protrusion 6 and is attached to the pin 5 in parallel.

An arm 8 protruding from the lid 2 is rotatably supported by the pin 5 near its tip. Therefore, the lid 2 is rotatable around the pin 5.

A tank shaft 9 is rotatably mounted on the bracket 3 and parallel to the pin 5. A plane including the axes of the tank shaft 9 and the lid shaft 7 is located above the axis of the pin 5. This is to apply a moment in the opening direction to the lid 2 by the spring force described later.

The lid shaft 7 and the tank shaft 9 are connected by a rod 10, one end of the rod 10 is supported by the lid shaft 7, the rod 10 is slidably penetrated at right angles to the tank shaft 9 through the middle part, and the other end is projected.

A compression coil spring (hereinafter sometimes referred to as "spring") 11 is attached to the protrusion at the other end of the rod 10 between the tank shaft 9 and the other end of the rod, and biased with adjustable spring force. Regarding the specific configuration,
A nut 13 for adjusting the spring force is screwed into a threaded portion formed on the end 10a of the protruding portion of the rod 10. A disk-shaped stopper 12a is fitted into the rod 10 and brought into contact with the tank shaft 9, and the spring 11, stopper 12b, and nut 13 are assembled in this order.

The spring force of spring 11 acts in the axial direction of rod 10 and tends to pull rod 10 to the right in FIG.

Since the axis of the rod 10 is included in a plane including the axes of the lid shaft 7 and the tank shaft 9, the pin 5 is located below the line of action of the spring force. Therefore, the spring force acts as a moment that tends to rotate the lid shaft 7 upward about the pin 5 located below. Since the lid shaft 7 is rotatably supported by the lid protrusion 6 fixed to the lid 2, the moment due to the spring force causes the lid 2 to rotate toward the opening side about the pin 5 supported on the fixed side. This is the moment in the opening direction.

When the lid 2 is opened and closed, when the lid 2 rotates around the pin 5 to the open position, the lid shaft 7 moves to the tank shaft 9.
approach. Since one end of the rod 10 is supported by the lid shaft 7, the other end, the protrusion end 10a side, further protrudes from the penetrating portion of the tank shaft 9. Stoppa 1
Since the stopper 2a is always in contact with the tank shaft 9 due to the spring force, the distance between the stoppers 12a and 12b becomes longer.
The spring 11 expands by this amount, the amount of compression decreases, and the spring force decreases. Therefore, as the open state of the lid 2 progresses, the moment in the opening direction due to the spring force decreases.

By the way, the lid 2 tends to move downward with the pin 5 as the center of rotation due to its own weight. A moment in the closing direction and a moment in the opening direction due to the spring force act constantly.

In the present invention, the spring force is adjusted so that the moment in the opening direction due to the spring force is slightly larger than the moment in the closing direction due to its own weight so that the lid 2 is in a shallow open state in the free state.

When using the manhole 1, when the lock (not shown) is released and the lid 2 is in a free state, the moment in the opening direction is made slightly larger than the moment in the closing direction, so the lid 2 does not require any manual effort. also begins to open.

When opening and closing, the moment in the opening direction due to the spring force is slightly larger than the moment in the closing direction due to its own weight, and since the difference is small, the lid will not open suddenly. This is extremely effective in preventing danger compared to the case where it opens suddenly.

As the opening angle of the lid 2 increases, the moment in the opening direction due to the spring force decreases and the difference in moments decreases, so the opening speed becomes slower. When both moments are balanced, the opening operation of the lid 2 stops.

When the opening angle of the lid 2 becomes constant, rotate the lid 2 in a horizontal plane around the bracket 3,
Completely away from the opening of manhole 1.

Note that the spring force can be adjusted using the adjusting nut 1.
Fine adjustment is extremely easy as all you have to do is turn 3. It is effective to adjust the target value of the spring force adjustment so that the lid 2 is in an open state and the opening angle is appropriate.

In addition, this invention can be used for applications other than tank car manholes.
It is applicable to the lid of an opening with a similar structure. It is also applicable to devices that do not require the lid to be rotated after opening.

Further, although two rods 10 are used in the illustrated example, it is also possible to use one or more than two rods so as not to interfere with other members.

(Effect of the invention) Since only a small amount of force is required to open and close the lid, the work becomes extremely easy. Moreover, since the opening speed is not sudden, it is extremely effective in preventing danger. Moreover, since the above-mentioned work is carried out on a tank or the like with poor footing, the above-mentioned effect becomes even more remarkable.

Furthermore, since the spring is extremely easy to adjust, it can be adjusted to an ideal state at the factory before being shipped. Moreover, even if some trouble occurs during use, it can be easily dealt with.

[Brief explanation of the drawing]

Figure 1 is a plan view explanatory diagram of the present invention, Figure 2 is the first
The cross-sectional view taken along the line A-A in FIG. 3 shows the closed state, and FIG. 3 shows the same opened state. 1...manhole, 2...manhole cover, 3...
...Bracket, 4...Tank, 5...Pin, 6...
...Lid projection, 7...Lid shaft, 8...Arm, 9...Tank shaft, 10...Rod, 11...Compression coil spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A manhole cover rotatably supported via an arm on a pin attached to a bracket erected and fixed to a tank, which includes a cover shaft, a tank shaft, a rod, a compression coil spring, and the pin. a manhole cover support device comprising: a lid shaft rotatable on a lid protrusion erected and fixed to the manhole cover and mounted in parallel to the pin; a tank shaft rotatable on the bracket and attached to the pin; The rod connects the lid shaft and the tank shaft, and the rod connects the lid shaft and the tank shaft, with one end attached to the lid shaft. The rod is supported, and the intermediate portion thereof is slidably passed through the tank shaft, and a spring is attached to the rod and biased between the tank shaft and the other end of the rod so that the spring force can be adjusted. Manhole cover support device.