JPH0134105Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a Bourdon tube type pressure gauge that is configured to display pressure by converting deformation of the Bourdon tube into rotational movement of a pointer via a rack and pinion.

In conventional pressure gauges of this type, when there is fluid pressure pulsation or instrument vibration, the pointer vibrates, making it difficult to read the indicated value and accelerating wear between the rack and pinion, shortening its life. . To solve this problem, there are methods to increase durability by rotating the rack and pinion in oil, and methods to slow down pressure fluctuations in the Bourdon tube by installing a throttle valve in the flow path leading to the Bourdon tube. etc. were used.

However, the former method requires a complicated structure, and the latter method often has problems such as the throttle valve becoming clogged with foreign matter such as dust and becoming inoperable, and furthermore, it is not possible to stop the pointer from swinging.

Therefore, this invention eliminates the drawbacks of the conventional example, eliminates the pointer vibration even when there is pressure pulsation or vibration of the instrument, and reduces the load on the rack, pinion, etc., and increases durability. The object of the present invention is to provide a Bourdon tube type static needle dynamic pressure type pressure gauge with a built-in needle dynamic pressure internal unit.

The technical means taken by this invention to achieve the above object are such that the movement of the tip of the Bourdon tube is transmitted to the sector only when the pressure increases, and the pinion shaft is directed in the direction of returning to the stopped position. In addition, an impeller is rotatably attached to one end of the pinion shaft and placed in a viscous fluid, so that only the pinion shaft rotates when the pressure increases.
A non-reversing clutch is provided so that the impeller rotates together with the pinion shaft when the pressure decreases.

Next, an example showing a specific example of the above technical means will be described.

Reference numeral 1 denotes an arc-shaped Bourdon tube, the fixed end of which is fixed to a connecting portion 2, and one end of a connecting rod 3 is rotatably connected to the tip of the tube.

4 is a support plate fixed to the upper part of the connecting part 2. The sector 5 is rotatably attached to the support plate 4 around a pin 6. One end of the sector 5 is rotatably and slidably engaged with a long hole 7 formed in the connecting rod 3 via a pin 8.
An arc-shaped rack 9 is formed at the other end of the sector 5, and meshes with a pinion 11 fixed to a rotatably provided pinion shaft 10.

With this configuration, when the tip of the Bourdon tube 1 moves upward, the pin 8 comes into contact with the lower end of the elongated hole 7, so this movement is transmitted to the sector 5, but when it moves downward, the pin 8 sliding in the long hole 7,
It will not be transmitted to sector 5.

12 is an impeller rotatably mounted on the rear end of the pinion shaft 10, and this impeller 12 is attached to the closed case 1.
It is housed within 3. Since the sealed case 13 is more than half filled with viscous fluid such as silicone oil, the impeller 12 rotates quietly while receiving resistance from the viscous fluid.

14 is a non-reversing clutch, which in this embodiment has a coil spring 15 and a spring retainer 16. The coil spring 15 is tightly wound around the outer periphery of the cylindrical portion 17 of the impeller 12, and the spring retainer 16 is fitted onto the pinion shaft 10 and fixed with a machine screw 18. A pin 19 is provided through the spring holder 16, and one end of the coil spring 15 is connected to the pin 19.
It is locked to.

Due to the action of the non-reversing clutch 14, the impeller 12 does not rotate when the pressure increases, but rotates together with the pinion shaft 10 only when the pressure decreases. That is, as described above, the coil spring 15 is attached to the cylindrical portion 17 of the impeller 12.
It is tightly wound around the outer circumference, and one end of the pin 19 is fixed to a pin 19 inserted through a spring retainer 16 that rotates together with the pinion shaft 10.
0 rotates, a torsional load is applied to the coil spring 15. The inner diameter of the coil spring 15 decreases when the end portion is twisted in the same direction as the winding direction, so the coil spring 15 is crimped to the cylindrical portion 17 of the impeller 12, and due to the frictional force between the coil spring 15 and the cylindrical portion 17. The impeller 12 will rotate together with the pinion shaft 10. On the other hand, when the coil spring 15 is twisted in the opposite direction to the winding direction, the inner diameter does not decrease as described above, so the pinion shaft 10
rotates freely, and the impeller 12 does not rotate.

Reference numeral 20 denotes a spiral spring that biases the pinion shaft 10 in the direction of returning the scale plate 21 to the zero position. A pointer 22 is attached to the tip of the pinion shaft 10. The casing 23 is fixed to the connecting portion 2, and a scale plate 21 and a glass lid 24 are attached to the front surface of the casing 23.

Since the movement of the tip of the Bourdon tube 1 is not transmitted to the pinion shaft 10 when the pressure decreases, the spring spring 20 acts to rotate the pinion shaft 10 in the opposite direction by its elastic force.

The elastic force of the mainspring spring 20 is the same as that of the impeller 12.
The rotational speed of the pinion shaft 10 at the time of return is determined so as not to become too slow in relation to the resistance force received by the pinion shaft 10.

Next, the usage condition of the pressure gauge according to this invention will be explained.

When pressure is applied inside the Bourdon tube 1 and its tip moves, this movement causes the connection rod 3 and the sector 5 to move.
is transmitted to the pinion shaft 10 via. At this time, the non-reversing clutch 14 is disconnected and the impeller 1
Since the pinion shaft 2 does not rotate, the pinion shaft 10 quickly rotates, and the maximum value of the dynamic pressure at that time is indicated.

When the pressure decreases, the movement of the tip of the Bourdon tube 1 is not transmitted to the sector because the pin 8 slides in the elongated hole 7 of the connecting rod 3, and the movement of the tip of the Bourdon tube 1 is not transmitted to the sector.
Due to the elastic force of 0, the pinion shaft 10 receives a moment in the opposite direction. At this time, the non-reversing clutch 14 is connected, and the impeller 12 is connected to the pinion shaft 10.
Therefore, the rotational speed of the pinion shaft 10 becomes extremely small due to the resistance of the viscous fluid.
For this reason, the pointer 2 attached to the pinion shaft 10
2 does not drop instantaneously even if the pressure inside the Bourdon tube 1 decreases rapidly, but remains stationary and maintains the state indicated at the maximum pressure.

Therefore, according to this invention, the pointer 22 hardly vibrates even if there is a sudden change in pressure or vibration of the meter, making it easy to read the indicated value and always displaying the highest value of fluctuating pressure. I can do it. Also, the movement of Bourdon tube 1 is sector 5
can only be transmitted in one direction, so the Bourdon tube 1
Even if the rack 9 and pinion 11 vibrate, the rack 9 and pinion 11 do not vibrate, and the load on the rack 9 and pinion 11 can be significantly reduced. Therefore, the durability of the pressure gauge is improved and accuracy can be maintained for a long time.

[Brief explanation of the drawing]

FIG. 1 is a front view of a pressure gauge showing an embodiment of the invention, with the scale plate partially removed. FIG. 2 is a longitudinal side view of the same. FIG. 3 is an enlarged sectional view of the inside of the sealed case. 1...Bourdon tube, 3...Connecting rod, 5...
Sector, 7... Long hole, 9... Rack, 10...
Pinion shaft, 11... Pinion, 12... Impeller, 14... Non-reversing clutch, 15... Coil spring, 17... Cylindrical portion, 20... Spring spring.

Claims (1)

[Claims for Utility Model Registration] 1. A bourdon configured to transmit the movement of the tip of a bourdon tube to a sector via a connecting rod, and to rotate a pinion fixed to a pinion shaft using a rack formed in the sector to display pressure. In a pipe pressure gauge, a long hole is formed in the connecting rod so that one end of the sector is rotatably and slidably engaged, so that the movement of the tip of the Bourdon tube is transmitted to the sector only when pressure increases. At the same time, a spiral spring is provided to bias the pinion shaft in a direction to return it to the stopped position, and an impeller is rotatably attached to one end of the pinion shaft and placed in a viscous fluid.
Bourdon tube type static needle drive with a built-in static needle dynamic pressure internal mechanism, featuring a non-reversing clutch so that only the pinion shaft rotates when pressure increases, and the impeller rotates together with the pinion shaft when pressure decreases. Pressure type pressure gauge. 2. The non-reversing clutch has a coil spring tightly wound around the outer periphery of the cylindrical part of the impeller and a spring holder fixed to the pinion shaft, and one end of the coil spring is locked to the spring holder. A Bourdon tube type static needle-dynamic pressure gauge according to claim 1 of the utility model registration claim.