JP2002090242A - Pressure gage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure gage with no air leakage and high reliability, which can easily perform connection between a bourdon tube and a frame and soldering work for the connection part. SOLUTION: In the pressure gage a fixed end 3b is inserted to be fixed at an air blowing out hole 21 that is opened on a side face 8a of a frame 1, compressed air is introduced into a bourdon tube 3 from the fixed end 3b, a free end of the tube 3 is displaced by the introduced compressed air, the displacement as the compressed air pressure is displayed by rotating a pointer through a pointer driving mechanism that is attached to the free end. The hole 21 is formed diagonally to the side face 8a with individually making the fixed end 3b of the tube 3 and the hole 21 a substantially circular shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Bourdon tube type pressure gauge which is attached to, for example, a large truck or bus equipped with an air brake system, and more particularly to a connection structure between a Bourdon tube and a frame.

[0002]

2. Description of the Related Art As a pressure gauge using a Bourdon tube, for example, a pressure gauge disclosed in Japanese Patent No. 2857311 is known. As shown in FIG. 7, the pressure indicating instrument has a frame 10 in which, for example, an air brake hose is connected to the connection fitting 101 and communicates with the connection fitting 101.
2, a fixing plate 103 for fixing the connection fitting 101 and the frame 102, an arcuate Bourdon tube 104 having one end 104a fixed to the frame 102, and a pointer driving mechanism 105 attached to the other end 104b which is a free end. When,
The pointer shaft 10 provided at the center of the pointer driving mechanism 105
6 is comprised of a pointer 107 attached to the scale 6 and a scale plate (not shown) on which scales are engraved.

[0003] The Bourdon tube 104 is, as shown in FIG.
It is formed as a hollow tube having a substantially elliptical cross section, and is formed in a substantially circular arc shape by using an elastic metal material. The Bourdon tube 104 is sealed by soldering the other end 104b which is a free end, and the one end 104a is formed at the opening end of a ventilation hole 108 (see FIG. 9) formed in the frame 102. It is adapted to be inserted and fixed in a certain air outlet hole 109.

The air outlet hole 109 is formed in an elliptical shape having the same shape as the one end 104a of the Bourdon tube 104, and the one end 104a is fitted therein.
Then, as shown in FIG.
The air leak is prevented by fixing with zero.

[0005] Since the other end 104b, which is the free end, is sealed, when compressed air is introduced into the Bourdon tube 104 from the air brake hose via the frame 102,
As the internal pressure increases, the Bourdon tube 104 is displaced in a direction in which it is going to be straight. Such displacement is caused by the Bourdon tube 104
Drive mechanism 105 attached to free end 104b
Is driven to rotate the pointer shaft 106. When the pointer 107 attached to the pointer shaft 106 rotates, the pressure of the compressed air as the braking source is displayed as a number.

[0006]

However, in the pressure gauge having the above structure, the Bourdon tube 104 and the frame 1
02 are both elliptical in shape,
Their insertability is poor. In addition, since it is necessary to perform solder connection around the elliptical shape, the work is difficult and a pinhole is easily formed in the solder 110. Processing the elliptical air outlet hole 109 in the frame 102 according to the shape of the one end 104a of the Bourdon tube 104 requires a lot of work.

Accordingly, an object of the present invention is to provide a highly reliable pressure gauge which can easily perform the work of connecting the Bourdon tube and the frame and the soldering of the connection portion and which does not leak air.

[0008]

According to the first aspect of the present invention,
A fixed end is inserted and fixed in an air blowing hole opened on one side of the frame, compressed air is introduced into the Bourdon tube from the fixed end, and the free end of the Bourdon tube is displaced by the introduced compressed air, and the In a pressure gauge configured to display the pressure of the compressed air by rotating a pointer through a pointer driving mechanism attached to a free end of the displacement, the fixed end of the Bourdon tube and the air blowing hole are each substantially in cross section. The air outlet hole is formed obliquely with respect to the one side surface.

According to the first aspect of the present invention, since the fixed end of the Bourdon tube and the air outlet are each formed in a substantially circular cross section, it becomes easier to insert the fixed end into the air outlet and to simplify the connection. . Further, since the connection portion is circular, the soldering operation can be easily performed. Further, in order to process the air outlet hole into a circular shape, it can be easily processed with a drill or the like.

According to a second aspect of the present invention, there is provided the pressure gauge according to the first aspect, wherein an inclination angle θ of the air blowing hole with respect to the one side surface is set to 20 ° <θ <30 °.

According to the second aspect of the present invention, in addition to the operation of the first aspect, the inclination angle θ of the air blowing hole with respect to the one side surface is set to 20 ° <θ <30 °, so that the Bourdon The diameter of the tube itself can be reduced, and the size of the pressure gauge can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to a Bourdon tube type pressure gauge that displays the pressure of compressed air that is a braking source in an air brake system such as a large truck or a bus.

<Structure of Pressure Gauge>
As shown in FIGS. 1 and 2, a frame 1 to which an air brake hose (not shown) is connected and compressed air is introduced, and one end 3a, which is a free end, is attached to a pointer driving mechanism 2 and a fixed end side. The other end 3b of the frame 1
, A hand drive mechanism 2 for changing the displacement of the Bourdon tube 3 into a rotational force and rotating a hand 5 attached to the hand shaft 4, and a scale plate 6 having a scale on its surface.
And

"Frame" Frame 1 is shown in FIGS.
As shown in the figure, the air brake hose is connected to a hose connection portion 7 and a main body portion 8 having the hose connection portion 7 at the lower end, and is fixed on the base frame 23. The hose connection part 7 has a thread part 7 around it.
The air brake hose is fitted around the screw portion 7a by fitting the air brake hose. The hose connection portion 7 has an air insertion hole 22 on the lower end surface as shown in FIG. The air insertion hole 22 communicates with an air blowout hole 21 (see FIGS. 5 and 6) opened through one side surface 8 a to which the Bourdon tube 3 is fixed via the main body 8.

The main body 8 is formed as a rectangular parallelepiped (quadratic prism), and has the air outlet 21 on one side surface 8a. Therefore, the compressed air A introduced from the air insertion hole 22 is sent from the lower end of the hose connection portion 7 to the air blowout hole 21 through the inside of the main body portion 8 and is blown into the Bourdon tube 3. Become.

The air outlet hole 21 is provided in FIG. 5 and FIG.
As shown in the figure, the main body 8 is formed at a predetermined inclination angle θ with respect to one side surface 8a to a position reaching the center of the main body. The inclination angle θ is set to 20 ° <θ <30 ° as shown in FIG. 5 in order to reduce the diameter of the Bourdon tube 3 and realize the downsizing of the pressure gauge itself. If the inclination angle θ is less than 20 °, the diameter of the Bourdon tube 3 becomes large, and the pressure gauge itself becomes large. On the other hand, when the inclination angle θ is 30
When the angle exceeds 0 °, the air blowing holes 21 are formed up to the other side surface 8b orthogonal to the one main surface 8a, and it becomes difficult to process the ridge line 8c where these surfaces 8a and 8b intersect.

Further, as shown in FIG. 6, the air blowing hole 21 is formed as a circular hole, similarly to the shape of the other end 3b of the bourdon tube 3 described later. If it is a circular hole, it can be easily processed by drilling or the like, and the number of working steps can be reduced.

"Indicator driving mechanism" The pointer driving mechanism 2 is shown in FIG.
As shown in FIG. 1, a fixing plate 9 fixed to the frame 1, a mounting plate 11 mounted on the fixing plate 9 via a pair of columns 10, 10, and a rotatable space between the fixing plate 9 and the mounting plate 11. And a pointer shaft 4 having a pinion 12 at the center of the shaft portion and a sector gear 13a meshing with the pinion 12 at the tip.
And a Bourdon tube 3 whose other end 3b is fixed to the frame 1.
An adjustment rod 14 soldered to the tip 3a of the Bourdon tube 3; a tip 14a of the adjustment rod 14 and the sector 13
The link 15 pivotally supported by the pin and the base end 13b of the
And a return coil spring 16 as urging means for urging the pinion 12 counterclockwise in FIG.

In the pointer driving mechanism 2 having such a configuration, when the compressed air A is introduced into the Bourdon tube 3, the Bourdon tube 3 having the sealed distal end portion 3a is compressed air A within the elastic limit.
2 in the direction indicated by the arrow X in FIG. And the displacement is Bourdon tube 3
Is transmitted to the sector 13 via a link 15 which is connected to an adjustment rod 14 fixed to the tip 3a, and the sector 13 rotates. The rotation of the sector 13 causes the pinion 12 to rotate.
Is rotated to rotate the pointer shaft 4 to which the pinion 12 is fixed. As a result, the pointer 5 fixed to the tip of the pointer shaft 4 rotates in the arrow Y direction (clockwise direction) in FIG.

"Bourdon tube" The Bourdon tube 3 is formed into a substantially circular arc shape by processing a pipe made of a metal material such as brass, as shown in FIGS. When the compressed air A is blown into the pipe from the base end 3b, the distal end 3a on the free end side is attached so as to be displaceable. The bourdon tube 3 has a base end 3b opened, and a distal end 3a.
Are sealed by being connected to the adjustment rod 14 by soldering.

The Bourdon tube 3 is connected to the frame 1
Except for the other end 3b, which is fixed to the section, the section is substantially elliptical. As shown in FIG. 6, the other end 3b inserted into the air outlet 21 of the frame 1 has a circular shape as in the case of the air outlet 21. Therefore, the Bourdon tube 3 can be easily inserted into the frame 1. Then, by joining the outer periphery of the other end 3b inserted into the air blowing hole 21 with the solder 24, these connection portions are sealed without air leakage. In particular, since the soldering operation may be performed by forming the solder 24 in a circular shape, the soldering operation can be easily performed without generating pinholes or the like.

[Scale Board] As shown in FIGS. 1 and 2, the scale board 6 is formed as a rectangular thin plate having a scale 17, a numeral 18, and the like engraved thereon. The graduation plate 6 is fixed to the fixing plate 9 via the prism plate 19 by fixing screws 20, 20.

Although the specific embodiments to which the present invention is applied have been described above, the present invention is not limited to these embodiments, and various changes accompanying the gist of the configuration of the present invention are possible.

For example, in the above-described embodiment, the air blowing holes 21 are processed by a drill, but the processing method is not particularly limited.

[0025]

As is apparent from the above description, according to the first aspect of the present invention, the fixed end and the air outlet of the Bourdon tube have substantially circular cross sections, respectively, so that the fixed end has the air outlet. The connection work between the Bourdon tube and the frame can be simplified. Further, since the connecting portion is circular, the soldering operation can be easily performed, and the number of working steps can be reduced. Furthermore, in order to process the air outlet hole into a circular shape, it can be easily processed with a drill or the like.

According to the second aspect of the invention, in addition to the effect of the first aspect, the inclination angle θ of the air blowing hole with respect to one side of the frame is set to 20 ° <θ <30 °. The pipe itself can be reduced in diameter, and as a result, the pressure gauge can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a plan view of a pressure gauge according to the present embodiment.

FIG. 2 is a perspective view of a pressure gauge according to the embodiment.

FIG. 3 is a plan view showing a connection state of a frame and a Bourdon tube in the pressure gauge of the present embodiment.

FIG. 4 is a front view showing a connection portion between a frame and a Bourdon tube in the pressure gauge of the present embodiment.

FIG. 5 is a sectional view taken along line AA of FIG. 4 in the pressure gauge of the present embodiment.

FIG. 6 is an exploded perspective view showing a state before a Bourdon tube is attached to a frame in the pressure gauge of the present embodiment.

FIG. 7 is a perspective view showing a conventional pressure gauge.

8 is a sectional view of the Bourdon tube shown in FIG. 7 taken along line BB.

9 is an exploded perspective view showing a state before a Bourdon tube is attached to the frame shown in FIG. 7;

FIG. 10 is a front view showing a state where a Bourdon tube is connected to the frame shown in FIG. 7 by soldering.

[Explanation of symbols]

 Reference Signs List 1 frame 2 pointer driving mechanism 3 Bourdon tube 3a One end of Bourdon tube (free end) 3b The other end of Bourdon tube (fixed end) 3c Flat surface of Bourdon tube 3d Curved surface of Bourdon tube 4 Pointer shaft 5 Pointer 6 Scale plate 8 Body

Continuation of the front page (72) Inventor Akio Takahashi 566-6 Nakasu Osu, Suwa City, Nagano Prefecture Inside Takahashi Works, Ltd. (Reference) 2F055 AA39 BB20 CC03 DD01 EE01 FF43 FF49 GG12

Claims (2)

[Claims] 1. A fixed end is inserted and fixed into an air blowing hole opened on one side of a frame, compressed air is introduced into the Bourdon tube from the fixed end, and the free end of the Bourdon tube is introduced by the introduced compressed air. Is displaced, and the displacement is rotated by a pointer driving mechanism attached to a free end so as to display the pressure of the compressed air. The fixed end of the Bourdon tube and the air outlet A pressure gauge, wherein each of the holes has a substantially circular cross section, and the air blowing hole is formed obliquely to the one side surface. 2. The pressure gauge according to claim 1, wherein an inclination angle θ of the air outlet with respect to the one side surface is set to 20 ° <θ <30 °.