JPS6221826Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an emergency shutoff valve having a butterfly valve structure.

Conventionally, this type of emergency shutoff valve has an underground butterfly valve structure that is operated by a switch installed on the ground, for example, by extending the valve stem of the butterfly valve to the ground and installing a bevel gear at its tip. It was meshed with a bevel gear installed on the output shaft of the switch. However, since the valve shaft usually rotates 90 degrees while the weight provided as a biasing means for the output shaft of the opening/closing machine rotates 90 degrees, the ratio of the number of teeth of the bevel gear must be 1:1. Since it is difficult to obtain a commercially available or existing bevel gear with a tooth ratio of 1:1, it was necessary to specially manufacture it. Also, depending on the installation space of the switch, it may be necessary to limit the rotation range of the weight, and the rotation angle ratio between the output shaft of the switch and the valve shaft may be set as required. There are cases where the tooth ratio is required to be a predetermined value,
It is often difficult to obtain commercially available or existing bevel gears with a specific tooth ratio.

The present invention was developed in view of the above circumstances, and includes an intermediate shaft interposed between the output shaft of the switch and the valve shaft,
A power transmission mechanism using gears is provided between the output shaft and the intermediate shaft of the switch and between the intermediate shaft and the valve shaft, and the increase/deceleration ratio in both mechanisms can be adjusted by using commercially available or existing gears. It is an object of the present invention to provide an emergency shutoff valve that can easily obtain a required rotation angle ratio between the output shaft of the opening/closing machine and the valve shaft by the combination of the following.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 is a front view of the present emergency shutoff valve, FIG. 2 is a side view, and FIG. 3 is a sectional view illustrating the power transmission mechanism. In the figure, 1 is a fluid pipe buried underground, such as a water supply and distribution pipe, and 2 is a butterfly valve of the present emergency shutoff valve installed therein. A valve box 3 of the butterfly valve 2 is fixed on a ground floor 4. Further, 5 is a valve body of the butterfly valve 2, and 6 is a valve stem.

On the other hand, at a position above the butterfly valve 2, on the ground floor 7, an operating table 9 of a switch 8 is installed. This opening/closing device 8 rotates an output shaft 13 via a reduction gear 11 and a clutch 12 by operating a handle wheel 10 or by power means. A bevel gear 14a is attached to the output shaft 13, and a bevel gear 14b meshes with the bevel gear 14a. Both bevel gears 14a and 14b constitute a speed increasing device 14 within a gear case 15. The bevel gear 14b
The upper part of the intermediate shaft 16 is attached to. The intermediate shaft 16 has a structure made of a bar with split joints 17, 17 provided at appropriate locations through a hole 7a in the ground floor 7, and a spur gear 18a is attached to the lower end of the intermediate shaft 16.
A spur gear 18b meshes with the gear 8a. Both spur gears 18
a, 18b are connected to the speed reducer 18 on the upper cover 20 of the yoke 19 mounted on the valve box 3 of the butterfly valve 2.
Configure. The spur gear 18b is attached to the upper end of the valve shaft 6 of the butterfly valve 2. Therefore, the opening/closing machine 8
When the output shaft 13 rotates, the valve body 5 rotates together with the valve shaft 6 via the speed increaser 14 and the deceleration device 18 to open and close the pipeline.

A weight lever 22 having a weight 21 is fixed to the output shaft 13 of the opening/closing machine 8.
Due to the gravitational action, the valve body applies a rotation biasing force to the output shaft 13 in a direction to close the conduit. Further, a support plate 23 is attached to the operation table 9, and a weight lever 22 is attached to the support plate 23 during normal operation.
A locking device 25 consisting of a plurality of levers that holds the weight lever 22 in a position where the valve body opens the pipeline and releases the weight lever 22 by the action of an electromagnetic solenoid 24 that receives an emergency signal transmitted in the event of an emergency such as an earthquake. is provided. Note that 26 and 27 are limit switches that sense when the weight lever 22 reaches a predetermined angle position, and 28 is the weight lever 22.
29 is a hydraulic cylinder that adjusts the rotation speed of the weight lever 22. The biasing means for the output shaft 13 of the switch 8 and the locking means for the biasing means are not limited to those described above and illustrated, but any known means may be used.

The emergency shutoff valve according to the present invention has the above-mentioned configuration, and the valve body can be rotated via the intermediate shaft by the operation or movement of the opening/closing machine, and in the event of an emergency, the valve body can be closed upon receiving an emergency signal without rotating. However, its characteristic functions and effects are summarized as follows.

Since two gears are used to transmit power between the output shaft of the switch and the valve shaft, when the rotation angle ratio between the output shaft of the switch and the valve shaft is 1:1, The gear ratio of the speed reduction device 18 is set to the speed increase device 14.
It is sufficient to take the reciprocal of the gear ratio of the gears, and there is no need to set the gear ratio of both devices to 1:1. Therefore, it is possible to relatively freely select and use gears from commercially available or existing gears.

Adapted to the situation of the installation space of the opening/closing machine,
Also when setting the rotation angle ratio of the output shaft and the valve shaft to a required value in order to set the rotation range of the weight as a biasing means with respect to the output shaft of the opening/closing machine,
In the present invention, gears are selected by combining the ratios of the number of gears of the two gear devices, so that gears can be selected more freely from commercially available or existing gears than in the prior art, which includes only one gear device.

Since the intermediate shaft is located off the upper extension line of the valve shaft, the emergency shutoff valve of the present invention can be installed even if an obstacle is buried above the location where the butterfly valve is installed in the pipeline.

As shown in the example, when speed increasing transmission is performed from the output shaft of the switchgear to the intermediate shaft, and deceleration transmission is performed from the intermediate shaft to the valve shaft, the torque applied to the intermediate shaft is Since the torque applied to the valve stem is smaller than the torque applied to the valve stem when the torque is transmitted directly from the valve to the valve stem, the diameter of the intermediate shaft can be made smaller.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a front view of the emergency shutoff valve, FIG. 2 is a side view, and FIG. 3 is a sectional view of the main part. 2...Butterfly valve, 5...Valve body, 6...Valve shaft, 8...Opening/closing machine, 13...Output shaft, 14a, 1
4b...Bevel gear, 16...Intermediate shaft, 18a,
18b... Spur gear, 21... Weight, 25...
Locking device.

Claims (1)

[Scope of utility model registration request] An underground butterfly valve structure in which the valve body is rotated around an upright valve shaft to open and close a pipeline is installed on the ground. In an emergency shutoff valve that applies a biasing force in the direction of closing a valve body and locks the valve in an open state in normal times, and releases the lock in an emergency and rotates the valve body to close, the output shaft of the switch A bevel gear is provided at one end of the intermediate shaft, and a bevel gear is provided at one end of the intermediate shaft, and a gear provided at the other end of the intermediate shaft is provided in speed-up meshing with a gear provided on the valve shaft, and the number of teeth in the reduction mesh is set at one end of the intermediate shaft. An emergency shutoff valve characterized in that the number of teeth of each of the bevel gears and the number of teeth of each gear are selected so that the ratio is the reciprocal of the ratio of the number of teeth of the speed increasing mesh.