JPH0676936B2 - Pressure gauge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pressure gauge that has a small number of parts and can be downsized.

[Conventional technology and its problems]

Conventionally, a pressure gauge using a Bourdon tube is generally used to measure the pressure of fluids such as air, oil, and water. In this pressure gauge, a link is projected at the tip of the Bourdon tube, a fan gear is pivotally attached to the tip of this link, and this fan gear is meshed with a pinion fixed to a pointer shaft to link the displacement of the Bourdon tube and the fan gear. , The fan-shaped gear and the pinion are used to change the rotational motion to transmit the desired pressure, and a desired pressure is displayed, and a balance spring is provided on the pointer to automatically return the pointer. For this reason, the number of parts of the pressure gauge increases and there is a limit to miniaturization, and there is also a limit to cost reduction.

An object of the present invention is to eliminate the fan gear and the pinion, directly transmit the displacement of the Bourdon tube to the pointer, and to reduce the size and cost of the pressure gauge.

[Means for solving problems]

A pin shaft is protrudingly provided on the outer end side surface of the Bourdon tube formed by winding the flat pipe material multiple times, and the pin shaft is penetrated into the arcuate window hole formed in the scale plate, and the mounting bolt is attached. The Bourdon tube and scale plate are housed in the casing provided, the pointer is fitted and supported by the pointer shaft protruding from the scale plate, and the pin shaft is locked in the long hole of the pointer to displace due to the pressure change of the Bourdon tube. Is directly transmitted to the guideline.

〔Example〕

The pressure gauge of the present invention will be described below based on the illustrated embodiment.

In the figure, 1 is a casing, 2 is a mounting bolt fixed by caulking to the bottom of the casing 1, 3 is a scale plate with a window hole to be inserted into the casing 1, and 4 is a pointer shaft planted in the scale plate.
A pointer 5 pivotally supported by 32 is a cover, and 6 is a Bourdon tube housed in the inner chamber 1H of the casing 1 and fixed to the mounting bolt 2.

The casing 1 has an outer peripheral wall 14 having an outer diameter of a pressure gauge to be formed.
The inner bottom 13 is bent horizontally inwardly and continuously connected to the bottom of the inner bottom 13 and the outer circumference of the inner bottom 13 is further bent substantially vertically in the same direction as the outer peripheral wall 14 to provide a volume necessary for housing the Bourdon tube 6. A peripheral wall 12 is continuously provided so as to form an inner chamber 1H.
Is formed by bending the front end of the casing 1 to be parallel to the inner bottom, and forming a locking hole 15 in the center of the bottom 11 for locking the mounting bolt by caulking. The casing 1 is made of metal. In the case of, it is formed by pressing from one plate,
In the case of synthetic resin, it is formed by injection or other method, and has a desired size as a whole.

The mounting bolt 2 transmits fluid pressure to the inside in the longitudinal axis direction,
In addition, a stock insertion hole 24 for inserting the stock of the Bourdon tube is formed, and a hexagon nut portion 22 (or a square nut) for mounting is integrally formed on the outer periphery, and a bolt portion is provided on one end side of the hexagon nut portion 22. 21 is projected, and a locking piece 23 is projected on the side opposite to the bolt portion 21.To fix this mounting bolt to the casing, insert the locking piece 23 into the locking hole 15 of the casing. As shown in FIG. 2, the locking piece 23 is caulked to be integrated. Instead of this caulking, welding or adhesion is also possible.

The graduation plate 3 has a flat plate disk shape and has a graduation 33 on its surface, and a pointer shaft 32 is bossed in the center and on the surface side of the graduation plate.
A circular arc-shaped window hole 31 is formed on the outer peripheral portion of the pointer shaft 32 over a range in which the pointer moves or at an angle larger than that. The center of the arcuate window hole 31 should be the pointer axis. The scale plate 3 is mounted on the inner bottom 13 when inserted into the casing 1.

A Bourdon tube 6 is inserted and fixed in the casing before the scale plate 3 is inserted and installed in the casing 1. The Bourdon tube 6 is formed by winding a flat pipe material in a spiral shape. The pipe-shaped stock 63 is welded to the inner end side of the pipe material which is the center of 6, and this stock 63 is projected from the Bourdon tube 6, and this is inserted into the stock insertion hole 24 of the mounting bolt,
Weld and fix by soldering. This Bourdon tube 6 uses a flat pipe material, but in the pressure change range of the fluid to be measured or an allowable safe pressure range higher than that, the set pressure, that is, the Bourdon tube deviation is not directly increased with respect to the fluid pressure change. The development length is determined so as to obtain a deviation amount enough to swing the pointer, and this is spirally wound. The outer end of the Bourdon tube closes the flat pipe material, and the bracket 61 is fixed to the outer part by welding or bonding, and the pin shaft 62 is projected on the bracket in a direction parallel to the projecting direction of the stock 63. . At this time, the position of the pin shaft projecting from the Bourdon tube is changed and adjusted so that the pointer accurately swings within the set range by the change in the pressure of the fluid measured. This is done by changing the mounting position of the bracket attached to the outside of the Bourdon tube.

The pointer 4 has a boss portion 41 fixed thereto, a shaft hole 42 is bored in the boss portion 41, the pointer shaft 32 of the scale plate 3 is fitted into the shaft hole 42, and the pointer 4 swings around the shaft 32. A long hole 43 is formed in the pointer longitudinal direction at the rear end side of the pointer, and the pin shaft 62 of the Bourdon tube 6 is fitted into this long hole 43. Therefore, when the Bourdon tube 6 is housed in the casing 1 and fixed, and then the scale plate 3 is stored in the casing, the pin shaft 62 penetrates through the window hole 32 of the scale plate and projects above the scale plate surface. Is.

In the pointer 4 thus formed, when the fluid pressure is transmitted to the Bourdon tube 6, the Bourdon tube is displaced. This displacement naturally changes the position of the pin shaft 62. By this movement of the pin shaft 62, the pin shaft slides in the pointer 43, and the pointer 43 is rotated about the shaft 32 to display the pressure.

At least the front surface of the cover 5 is transparent so that the scale plate and the pointer can be seen from the outside, and a peripheral wall 51 is integrally formed on the periphery. In the illustrated embodiment, the peripheral wall 51 of the cover is formed on the inner surface of the outer peripheral wall 14 of the casing. It is fixed by fitting, and the scale plate is pressed and fixed at its tip.
The peripheral wall 51 may be externally fitted and locked to the outer peripheral wall 14 of the casing.

〔The invention's effect〕

According to the present invention, a pin shaft is projectingly provided on the outer end side surface of a Bourdon tube formed by winding a flat pipe material a plurality of times, and the pin shaft is penetrated into an arc-shaped window hole formed on the scale plate. The Bourdon tube and the scale plate are housed in a casing provided with mounting bolts, and the pointer is fitted and supported on the pointer shaft protruding from the scale plate, and the pin shaft is locked in the long hole of the pointer. Since the displacement due to the pressure change is directly transmitted to the pointer, there are advantages that the number of parts is small, the assembly is simple, the cost can be provided, and the size can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view, and FIG. 2 is a sectional view showing an assembled state. 1 is a casing, 1H is an inner chamber, 14 is an outer peripheral wall, 2 is a mounting bolt, 23 is a locking piece, 3 is a scale plate, 31 is a window hole, 32 is a pointer shaft,
4 is a pointer, 42 is a shaft hole, 43 is a long hole, 5 is a cover, 6 is a Bourdon tube, 61 is a bracket, 62 is a pin shaft, 63 is a stock

Claims (1)

[Claims] 1. A Bourdon tube formed by winding a flat pipe material a plurality of times is provided with a pin shaft projecting from the outer end side face thereof, and the pin shaft is penetrated into an arc-shaped window hole formed in a scale plate. The Bourdon tube and the scale plate are housed in a casing provided with mounting bolts, and the pointer is fitted and supported on the pointer shaft protruding from the scale plate, and the pin shaft is locked in the long hole of the pointer. A pressure gauge characterized in that it is configured to directly transmit the displacement due to the pressure change of the needle to the pointer.