KR100806959B1 - Pressure balance with non-rotation piston - Google Patents

Abstract

A pressure balance with a non-rotation piston is provided to perform accurate measurement by measuring force while moving a piston up and down. A pressure balance with a non-rotation piston includes a piston(1), a cylinder(2), and a moving unit(3). The piston is provided with a weight-holder(5) to put a weight(4) thereon. The cylinder is supported by a housing(6) and connected to a pressure room(61) supplied with oil pressure or air pressure through a passage. The piston is installed in the cylinder to be movable up and down. The moving unit is installed at one side of the cylinder to move up and down the cylinder, where the moving unit is a piezoelectric disk whose thickness is changed by power supplied through a power connection terminal.

Description

Pressure balance with non-rotation piston

1 is a cross-sectional view showing an example of a cylinder piston device provided in the deadweight tester does not rotate according to the present invention,

2 is a cross-sectional view showing another example of a cylinder piston device provided in a deadweight tester in which the piston does not rotate according to the present invention;

3 is a cross-sectional view showing another example of a cylinder piston device provided in a deadweight tester in which the piston does not rotate according to the present invention;

Figure 4 is a cross-sectional view showing another example of the cylinder piston device provided in the deadweight tester does not rotate according to the present invention,

Figure 5 is a cross-sectional view showing another example of the cylinder piston device provided in the deadweight tester does not rotate according to the present invention,

6 is a cross-sectional view showing an example of a cylinder piston device provided in a conventional deadweight tester.

<Code Description of Main Parts of Drawing>

1: piston

  11: jam jaw

2: cylinder

3: exercise means

4 weight

5: weight hanger

  51: piston hook wing

  52: dead weight wing

6: housing

  61: pressure chamber

7: elastic body

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deadweight tester, and more particularly, to a deadweight tester that does not rotate a piston capable of detecting a more accurate pressure by reducing friction between the cylinder and the piston.

More specifically, the present invention relates to a cylinder piston device of a deadweight type pressure gauge that can reduce the measurement error due to friction by reducing the friction by forcibly moving the cylinder to convert the static friction between the cylinder and the piston into motion friction.

The rapid development of pressure measurement technology has spurred the development of precise pressure gauges, requiring the development of more precise pressure standards to calibrate them.

Such a pressure standard is composed of several types of deadweight testers, and the deadweight pressure gauge is provided with a piston cylinder device configured as shown in FIG.

As shown in the figure, a piston cylinder device configured in a deadweight tester can be attached to or detached from a piston 100 having a known diameter, a cylinder 200 in which the piston 100 is inserted, and a weight hanger 310 extending from the piston. It is composed of a plurality of weights 300 installed.

By the weight 300, the piston 100 generates a force by gravity downward, and a force due to the pressure acting on the transmission medium is generated inside the cylinder 200 of the bottom of the piston 100, the two forces There is a balance of forces in between.

The pressure generated at this time is a force exerted on the piston 100 and is determined by the effective cross-sectional area determined by the piston 100 and the cylinder 200.

In other words, the deadweight tester has a simple structure capable of measuring the force acting on the unit area, the area of which is determined by the effective cross-sectional area of the piston cylinder device, and the weight is the mass of the weight 300 applied on the piston 100. Is determined as the product of gravity.

In order to obtain accurate pressure in the deadweight tester equipped with the piston cylinder device configured as described above, only the force from the dead weight should act on the piston, so there should be no friction between the piston and the cylinder.

That is, to prevent pressure leakage between the piston and the cylinder and to minimize friction, the distance between the piston and the cylinder is extremely narrow but has a very good cylinder degree.

However, this alone cannot minimize the friction between the piston and the cylinder, so in the case of using a deadweight tester, a method of minimizing the static friction by rotating the piston or the cylinder is generally used.

That is, in the stationary state, there is an inertial force to maintain the stationary state at the moment when the movement starts, and therefore, the moment when the movement starts from the stationary state has a considerable friction force (hereinafter referred to as 'static friction'). Since the friction force (hereinafter referred to as 'kinetic friction') decreases after the start of movement, the error is minimized by using a pressure gauge while moving the piston or cylinder.

However, in the related art, the cylinder or piston is artificially moved by a separate device or manually, and the static friction is changed to motion friction by rotating the piston. The force acted on the piston and the entire system became unstable.

The present invention has been invented to solve the above problems, an object of the present invention is to provide a deadweight pressure gauge that does not rotate the piston to be able to move the cylinder up and down to measure the force in the motion friction state.

The piston pressure gauge does not rotate the piston according to the present invention for achieving the above object in the cylinder piston device of the deadweight pressure gauge, the piston with a weight hanger so that the weight can be raised; A cylinder having a pressure chamber actuated by hydraulic or pneumatic pressure supplied through a flow path formed by the housing and supported by the housing, wherein the piston is provided to move up and down; It is provided on one side of the cylinder is characterized in that it comprises a movement means for lifting the cylinder.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce the present invention.

1 is a cross-sectional view showing an example of a cylinder piston device according to the present invention, Figure 2 is a cross-sectional view showing another example of the cylinder piston device according to the present invention, Figure 3 is still another view of the cylinder piston device according to the present invention 4 is a cross-sectional view showing another example of the cylinder piston device according to the present invention, Figure 5 is a cross-sectional view showing another example of the cylinder piston device according to the present invention.

As shown, the deadweight type pressure gauge in which the piston does not rotate according to the present invention is provided on one side of the cylinder 2 and is characterized in that it comprises a movement means 3 for lifting and lowering the cylinder.

As described above, the cylinder piston device provided in the deadweight tester does not rotate the piston according to the present invention.

That is, the cylinder 2 which has the cylinder chamber which communicates with the said pressure chamber 61 in the housing 6 provided with the pressure chamber 61 is provided, and the piston 1 is inside the said cylinder 2; It is configured by lifting the installation.

In addition, the piston 1 is detachably provided with a weight 4 for generating a force by gravity.

As shown in FIGS. 1 to 5, the weight 4 is caught by the piston 1 by the weight hanger 5 to exert a force by gravity on the piston 1.

As shown, the weight hanger 5 has a cylindrical cylindrical shape, the upper end of which is formed with a piston engaging blade 51 bent inward, the lower end is completely open, the weight (4) outside the open end The weight engaging blade 52 which hangs) is formed.

Of course, such a weight hanger (5) can be configured by installing a weight (4) directly on top of the piston (1) as an embodiment.

The cylinder 2 is installed to be moved up and down with respect to the housing 6 as described above, and the movement means 3 is provided as a means for moving the cylinder 2 up and down.

The movement means 3 is a means for raising and lowering the cylinder 2 buried in the interior of the housing 6, and it is preferable that the configuration is simple. For the simplicity of the configuration, a piezoelectric disk made of a piezoelectric body is used.

The piezoelectric body constituting the movement means 3 is capable of converting electrical energy into mechanical energy by supplying electricity, which is suitable for obtaining precise movement, and finely moves the cylinder 2 so that the cylinder 2 and the piston ( The friction between the cylinder 2 and the piston 1 is reduced by causing the static friction between 1) to be transformed into motion friction.

The movement means 3 may be installed at either one of the upper end or the lower end of the cylinder 2 as shown in FIGS. 1 to 5, or may be installed at both ends of the cylinder 2, respectively.

In order to allow the cylinder 2 to move up and down by driving the movement means 3, a free space must be secured at a portion where the cylinder 2 of the housing 6 is installed. In order to prevent the hydraulic or pneumatic leak through the O-ring (8) was installed between the cylinder (2) and the housing (6) of the portion where the pressure chamber 61 is formed.

In addition, an elastic body 7 is further provided to more elastically support the movement of the cylinder 2 which moves up and down by driving the movement means 3, that is, by operating the piezoelectric disk.

The elastic body 7 is preferably installed between the upper end of the cylinder 2 and the housing 6 as shown. In addition, when the movement means (3) is installed on the upper end of the cylinder (2), it should be installed between the movement means (3) of the housing (6), and thus by installing the elastic body (7) on the upper end of the cylinder (2) It is possible to prevent a change in the space in which the pressure formed in the pressure chamber 61 formed in the housing 6 acts. That is, when the elastic body 7 is installed at the lower end of the cylinder 2 opposite to the pressure chamber 61, a part of the space in which the elastic body 7 is installed may be connected to the pressure chamber 61. Since the calculation may be complicated and an error may occur in the calculation of the pressure applied per unit area, the elastic body 7 is preferably installed at the upper end of the cylinder 7 which is separated from the pressure chamber 61.

The action of the deadweight tester having the cylinder piston device provided in the deadweight tester does not rotate as configured above is the same as the operation of the conventional pressure gauge, so a detailed description thereof will be omitted.

However, in the present invention, as the air, gas or fluid is supplied to the pressure chamber 61 through the flow path formed in the housing 6 and the gravity force is applied to the piston 1 by the weight 4, the piston 1 Since the cylinder 2 is already moving finely up and down when moving, movement friction, not static friction, exists on the surface where the piston 1 and the cylinder 2 face each other. In addition, the force can be detected in a state where the error is reduced by the frictional force.

While the invention has been described with reference to the preferred embodiments, many modifications and variations are possible without departing from the scope and spirit of the invention as set forth by the claims below.

As described in detail above, the present invention provides a means for moving the cylinder up and down at the top or bottom of the cylinder to move the force up and down, that is, in the state where the motion friction is made between the piston By enabling the measurement, there is an effect that can reduce the frictional force to measure a more accurate force.

Although the present invention has been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that many various obvious modifications are possible without departing from the scope of the invention from this description. Accordingly, the invention can only be construed limited by the words of the appended claims.

Claims (7)

In a deadweight tester comprising a cylinder piston device, A piston (1) provided with a weight hook (5) to lift the weight (4); A cylinder (2) supported by the housing (6) and installed in communication with a pressure chamber (61) in which hydraulic or pneumatic pressure is supplied, and in which the piston (1) is liftable; It is provided on one side of the cylinder (2) comprises a movement means (3) for lifting and lowering the cylinder, And said movement means (3) are piezoelectric disks whose thickness is changed by the power supplied through the power connection terminals respectively connected to the upper and lower surfaces. The method of claim 1, wherein the movement means 3 is installed on the upper end of the cylinder (2), A piston pressure gauge without rotation, characterized in that an elastic body (7) is further installed between the movement means (3) and the housing (6) or between the cylinder (2) and the housing (6). The method of claim 1, wherein the movement means 3 is installed at the lower end of the cylinder (2), A piston pressure gauge without rotation, characterized in that an elastic body (7) is further installed between the movement means (3) and the housing (6) or between the cylinder (2) and the housing (6). According to claim 1, wherein the movement means 3 are respectively installed on the upper and lower ends of the cylinder (2), Deadweight pressure gauge, the piston does not rotate, characterized in that the elastic body (7) is further installed between the movement means (3) and the housing (6). delete 5. A deadweight tester according to claim 4, wherein the elastic body (7) is a coil spring. 7. The piston according to claim 6, wherein an O-ring (8) is further provided between the end of the cylinder (2) and the housing (6) to prevent leakage of pressure. pressure gauge.

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