JPH0542356Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention A-1 Industrial Application Field This invention relates to a pressure gauge with a printer used for purposes such as gas tightness inspection and pressure adjustment in gas supply businesses.

A-2 Prior Art A water column manometer has traditionally been used as a pressure gauge for performing tasks such as checking the airtightness of gas piping or checking the pressure of low-pressure and intermediate-pressure pipes. Pressure gauges using semiconductor pressure sensors have come to be used because of the inconveniences such as the need for installation and the ease of damage due to the use of glass tubes.

Unlike water column manometers, pressure gauges that use semiconductor pressure sensors do not need to be filled with water at the work site prior to measurement. Work can be done on time.

Pressure gauges are usually battery operated. Turn on the power switch of the pressure gauge, connect the measurement pressure inlet and gas piping, and then press the measurement switch to start measurement and display the measured pressure. Note the displayed measurement value in a notebook. do. Recently, it has become possible to prepare a dedicated printer separate from the pressure gauge, connect the pressure gauge and printer electrically with a connector, and print the measured values of the pressure gauge on the recording paper of the dedicated printer. .

A-3 Problems to be solved by the invention In conventional pressure gauges using semiconductor pressure sensors, the temperature characteristics of the semiconductor pressure sensor itself are not very good. If there is a large temperature difference between the place where the pressure gauge is stored and the work site, the temperature of the semiconductor pressure sensor will change during measurement, resulting in a problem that accurate measurements cannot be made due to temperature errors. In addition, the operation of connecting a dedicated printer to the pressure gauge with a connector and printing out the measurement results is complicated and difficult to use, and there is a problem that the pressure gauge is not satisfactory as a measuring instrument for use at a work site.

B. Structure of the invention B-1 Means for solving the problems In order to solve the above problems, this invention has a printer 8 integrated into the lower case 11, and a semiconductor pressure sensor in the center. The main body case 1 has a main body case 1 having a sealed structure with an upper case 10, and a mobile case 21 having a lid portion 21b and covering the inside with heat insulating materials 22 and 23. The main body case 1 is configured to be small enough that a space 25 is formed between the upper case 10 of the main case 1 and the lid portion 21b of the mobile case 21 when the main body case 1 is stored in the mobile case 21. It is characterized by housing a hose.

RO-2 EMBODIMENT The pressure gauge of this invention consists of a pressure gauge main body shown in FIGS. 1 to 4, and a carrying case shown in FIGS. 5 and 6. As shown in Figures 3 and 4, the pressure gauge main body 1 has measured values and function displays such as ``Measuring'', ``Initial value'', ``Final value'', and ``Measuring time'' in the center of the front. The LCD display 2 that displays
Also, below it is a power switch 3, a measurement switch 4 that is pressed when starting measurement, a print switch 5, a paper feed switch 6 that performs a blank feed of the recording paper, and a pressure measurement time that can be selected from 2 minutes, 5 minutes, or any desired time. A measurement time switch 7 is arranged at the top of the front.
A printer 8 is arranged. 9 is a measuring pressure inlet.

The main body of the pressure gauge has an upper case 10 and a lower case 11 made of plastic, which are joined together as shown in FIGS. 1 and 2 to form a sealed structure against the outside air. In the figure, 12 is the front cover of the printer 8, 13 is the battery, 14 is the battery cover, 15 is the display window provided in the upper case 10, 16 is the switch sheet provided in the front of the various switches, 17 and 18 are the electronic A printed wiring board with components mounted thereon, 19 a semiconductor pressure sensor, 20 a silicone rubber tube that guides measurement pressure to the semiconductor pressure sensor, and communicates the pressure pipe of the semiconductor pressure sensor 19 with the measurement pressure introduction port 9. . In FIG. 5 and FIG. 6, 21 is a carrying case made of synthetic leather, which has a box-shaped part 21a with an open front, a lid part 21b extending from the bottom of the box-shaped part 21a, and a handle part 21c. Consisting of
The polyethylene foam insulation material 22 provided inside the box-shaped portion 21a and the polyethylene foam insulation material 23 pasted on one side of the lid portion 21b are as follows:
It also functions as a cushioning material. 24 and 25 are magic tapes, and the pressure gauge main body 1 is housed in the box-shaped heat insulating material 22, and the lid portion 21b is marked with symbol 2 in FIG.
When the lid is closed as shown at 1b', the tip of the lid portion is fixedly held on the box-shaped portion 21a. Note that space 25 in FIG. 6 is a hose storage space, and symbol 26 in FIG. 5 is a pocket for storing dry batteries and hose ends. FIG. 7 is a block diagram of the pressure gauge. The pressure sensor 19 is constructed with a bridge circuit, and the bridge output changes depending on the applied pressure. This bridge output is first amplified by an amplifier to the voltage level required for the next stage A/D converter, converted to a digital signal by the A/D converter, processed by a microcomputer, and the measurement results are displayed on the liquid crystal display. It is also printed out using a printer. Figure 8 shows semiconductor pressure sensor 1
In the cut drawing of 9, 19a is the pressure pipe, 19b
19c is a plastic housing, 19c is a silicon sensor chip with a strain gauge formed directly on a silicon single crystal, and one is an atmospheric pressure opening 1.
When the strain gauge is opened to the atmosphere through the strain gauge 9d and the pressure to be measured is applied through the pressure guiding pipe 19a, the resistance value of the strain gauge changes due to the piezoresistance effect, which can be taken out as an electrical signal of the bridge circuit. FIG. 9 shows an example of a printing format when performing an airtight inspection of piping.

In the pressure gauge of the embodiment, when the power switch 3 is pressed, the microcomputer starts operating, zero point adjustment is automatically performed, and the liquid crystal display displays 0. Thereafter, measurement pressure is applied to the measurement pressure introduction port 9, measurement time is selected by operating the measurement time changeover switch 7, and measurement is started by pressing the measurement switch 4. When the measurement is completed, the microcomputer alternately displays the initial value and final value of the measured pressure on the liquid crystal display. Then, when the print switch 5 is pressed, printing in a predetermined format is performed.

C. Effects of the invention Due to the above-mentioned configuration, the present invention is able to prevent rapid temperature changes of the semiconductor sensor during measurement due to the large amount of heat insulation structure, even when there is a large temperature difference between the storage location and the work site. Measurement errors due to temperature changes during airtightness inspection of gas piping can be reduced.

Also, since we have provided space to store the hose,
It is convenient to carry with you to the work site.

[Brief explanation of the drawing]

Figures 1 to 7 show examples of this invention.
The figure is a vertical side view of the pressure gauge body, Figure 2 is a front view explaining the arrangement of the pressure sensor, Figures 3 and 4 are a front view and left side view of the pressure gauge body, respectively. It is shown on a smaller scale compared to Figure 2. Figures 5 and 6 are a perspective view and a longitudinal side view of the mobile case;
The figure shows a block diagram, FIG. 8 shows a cut-out drawing of the semiconductor pressure sensor, and FIG. 9 shows the printing format of the recording paper. 1... Pressure gauge body, 10... Upper case of main body,
11...Lower case of main body, 21...Mobile case,
22, 23... Insulation material.

Claims (1)

[Scope of utility model registration request] A printer 8 is integrally incorporated in the lower case 11, and a semiconductor pressure sensor 19 is arranged in the center with a gap around the upper case 10.
The main body case 1 and the lid part 2 have a sealed structure.
1b and a mobile case 21 whose inside is covered with heat insulating materials 22 and 23, and when the main body case 1 is stored in the mobile case 21, the upper case 1 of the main body case 1
0 and a lid portion 21b of a mobile case 21, the main body case 1 is configured to be small enough to form a space 25, and the space 25 accommodates a hose. Total.