JPH02107938A - Handy pressure calibrator - Google Patents

Abstract

PURPOSE:To achieve a simpler operation and a lighter weight by arranging a piston member for pressurizing a pressure medium, an elastic member for applying an elastic force to the piston member, a pressure adjusting means therefor, and a displacement detecting means for detecting an elastic displacement of the elastic member. CONSTITUTION:An inlet plug 22 is removed to inject an oil, a stop valve 18 is opened and a piston 26 is pulled out by turning a handle 40 to introduce the oil into a cylinder path 8. The valve 18 is closed while a stop valve 20 is opened and the piston 26 is lifted by turning the handle 40. When an oil surface fully reaches a connection member 10, a manometer is mounted. A pressure adjusting spring 46 is compressed by turning the handle 10 to apply a force to the piston 26. The force is determined by multiplying a value of a displacement of the spring 46 read with a dial gauge 48 by a spring constant. A pressure generated from the piston 26 is determined by dividing the force applied to the piston 26 by a pressure receiving area (area of the path 8) of the piston 26. Readings of a manometer for a value are compared to calibrate the manometer. With further turning of the handle 40, a desired measured pressure can be obtained.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a reference device for calibrating pressure gauges that are generally used to measure the pressure of gases and liquids, and particularly to a reference device that can easily calibrate pressure. Regarding pressure calibrators.

<Prior art> Conventional pressure calibration is performed using a weight-type pressure cutter. The structure is roughly divided into a pressurizing part, a cylinder part, and a weight part (weight or weight).The handle of the pressurizing part is operated using fluid (oil or gas) as a medium. The generated pressure is transmitted to the cylinder, and from the mass of the weight and the area on which the weight acts, the pressure equation, (
A predetermined pressure was generated from the equation (pressure - force (mass)/area on which the weight acts) and that pressure was utilized. The pressure gauge to be tested is operated at this pressure to calibrate whether it is correct or incorrect.

<Problems to be Solved by the Invention> With the above calibrator, when changing the target pressure to be tested, the weight must be replaced or several types of weights must be used in combination. Also, the measurement pressure is 2Q Kg/cttt
Even in this case, a weight of about 10 kg is required. Therefore, the operation is troublesome and troublesome, and attention to the weight is required.

In addition, the main body itself is heavy in order to support a large weight and to perform stable measurements, and even a small one weighs 5 to 2
There is also 0Kt;t. Therefore, there are problems in that it lacks portability and the frequency of calibration is limited.

However, the above-mentioned calibrator has the characteristic of being able to calibrate with very high precision. However, when performing a simple experiment, you may not need much precision and may want to easily check the reliability of the pressure gauge you are about to use. In such cases, the calibrator of the present invention is required.

Therefore, the technical problem of the present invention is to provide a pressure calibrator that does not require high precision, but is easy to operate and has excellent portability.

Means for solving the above problems> The technical means of the present invention taken to solve the above problems are as follows:
A cylinder member that holds a pressure medium therein, a connecting means for attaching a calibration target attached to an end of the cylinder member, and a piston member that is slidably disposed inside the cylinder member and pressurizes the pressure medium. and an elastic member that determines the elastic modulus in advance and applies elastic force to the piston member, pressure adjustment means that adjusts the elastic force of the elastic member, and displacement detection means that detects the amount of elastic displacement of the elastic member. be.

The pressure medium may be a gas or a liquid, but preferably an incompressible liquid. Furthermore, the displacement detection means may be measured directly with a scale or may use a dial cage.

Action> An object to be calibrated, such as a pressure gauge, is attached to the connecting means at the end of the cylinder member, and the pressure adjusting means is operated to compress the elastic member and apply force to the piston member.

The piston member generates pressure in the pressure medium within the cylinder. At this time, the force applied to the piston is determined by the product of the previously known elastic modulus of the elastic member and the amount of displacement (compression) of the elastic member, and is generated by dividing this force by the area of the piston member that acts on the pressure medium. You can see the pressure. Calibration is then performed by comparing the generated pressure with the actual reading of the pressure gauge of the object to be calibrated.

<Example> Examples showing specific means of the present invention will be described.

(See Figure 1) The main body 2 is composed of a cylinder part 4 and a pressurizing part 6. The cylinder part 4 has a cylindrical shape with a cylinder passage 8 that holds a pressure medium formed in the center, and a pressure gauge (to be calibrated) at the upper end.
(not shown) is provided. In this embodiment, oil is used as the pressure medium. The inside of the connecting member 10 is provided with a female thread 12 to be screwed into the male thread of the pressure gauge, and an O-ring 13 for maintaining airtightness with the cylinder part 4.
Place. The pressure gauge is attached by aligning the male thread of the pressure gauge with the female thread 12 of the connecting member 10, and by rotating the connecting member 10, the cylinder member 4 and the pressure gauge are pulled together and fixed.

An oil reservoir 14 is provided on the side wall of the cylinder portion 4, and a communication pipe 16 is provided.
Connect with. A stop valve 18 is provided in the communication pipe 16, and a stop valve 20 is provided above the connection portion between the communication pipe 16 and the cylinder portion 4.

They open and close the passage by rotating and moving them forward and backward. Part number @22 is an inlet plug for injecting oil.

A pressure section 6 is provided at the bottom of the cylinder section 4 .

The pressurizing part 6 has a cylindrical shape, and has two grooves 24a, b in the axial direction.
is formed. A piston 26 is slidably inserted into the cylinder passage 8, and an O-ring 28 is arranged to maintain airtightness with the cylinder inner wall. A force receiving portion 30 is formed at the other end of the piston and slides within the cylinder of the pressurizing portion 6. In addition, the spring holder [
Similarly, the pipe 32 is disposed within the cylinder of the pressurizing section 6, and is rotatably connected to the upper end of the adjusting screw 34. Part number 36
is an E-ring. The adjustment screw 34 has a male thread and is threaded into a female threaded portion of the lid member 38, and a handle 40 is attached thereto for easy rotation. Therefore, when the handle 40 is rotated, the adjusting screw 34 is displaced in the axial direction, and at the same time the spring receiver 32
advances and retreats. A pressure adjustment spring 46 is provided between both the force receiving part 30 and the spring receiver 32. Further, locking portions 30a, 32a and arms 42, 44 are provided so that both the force receiving portion 30 and the spring receiver 32 slide in the axial direction but do not rotate.

The spring constant of the pressure adjustment spring 46 is known in advance.

Further, a dial gauge 48 is installed between the arms 42 and 44 to enable the distance between them to be measured.

The measurement procedure is as follows. First stop valve 18.20
Close the valve, remove the inlet plug 22, inject oil that has passed through the pressure horn medium, fill it up, and close the inlet plug 22.

Next, the stop valve 18 is opened and the handle 40 is turned to pull out the piston and introduce oil into the cylinder passage 8.

Stop valve 18 is closed, stop valve 20 is then opened, and handle 40 is turned in the opposite direction to raise the piston.

As the piston rises, the curved surface also rises, and when the connecting member 10 is filled, a pressure gauge is attached. The pressure gauge is installed (
Since no load is applied to the piston 26 until it is pulled, the pressure adjustment spring 46 is not displaced. Once the pressure gauge is attached, the handle 40 is gradually rotated to compress the pressure adjustment spring 46 and apply force to the piston 26. The force at this time is determined by changing the position of the pressure adjustment spring 46 on the dial gauge 4.
8 and is determined by multiplying that value by the known spring constant of the pressure adjustment spring 46. The pressure generated by the piston 26 can be found by dividing the above horn by the pressure receiving area of the piston 26 (the area of the cylinder passage 8). The pressure gauge can be calibrated by comparing this value with the actual value indicated by the pressure gauge. Then, by further turning the handle 40 and applying force, an arbitrary measurement pressure (calibration target pressure) can be obtained.

From the second measurement onwards, it is sufficient to leave the stop valves 18, 20 in place and simply rotate the handle 40 to move the piston 26 up and down. However, if the oil in the cylinder passage 8 decreases after several measurements, the oil in the oil sump 14 may be introduced using the procedure described above.

The pressure adjustment spring 46 can be replaced depending on the measurement range. Further, if the pressure adjustment spring 46 is not replaced, the pressure value may be written directly on the dial gauge 48.

Easy to carry. Additionally, any pressure can be generated within the full range.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment showing specific means of the present invention. Body pressure section Force receiving section Handle Dial Gauge: Cylinder section: Piston: Spring receiver: Pressure adjustment spring Figure 1

Claims (1)

[Claims] 1. A cylinder member that holds a pressure medium inside, a connecting means for attaching a calibration target attached to the end of the cylinder member, and a cylinder member that is slidably arranged inside the cylinder member and pressurizes the pressure medium. The apparatus includes a piston member, an elastic member that determines the elastic coefficient in advance and applies an elastic force to the piston member, a pressure adjustment means that adjusts the elastic force of the elastic member, and a displacement detection means that detects the amount of elastic displacement of the elastic member. Simple pressure calibrator.