JPS5842918Y2 - load detection device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a load detection device, and particularly to one that operates effectively even in a high temperature and high pressure atmosphere and converts mechanical displacement etc. into electrical energy.

Conventionally, most load detection devices measure strain or displacement at normal temperature and pressure, and it is difficult to measure in a high temperature and high pressure atmosphere.

However, if the surrounding pressure or temperature is significantly different from normal,
This is because the sensor will be distorted to an extent that cannot be compensated for.

Therefore, when measuring loads in a high temperature and high pressure atmosphere, for example when measuring the jet reaction force that occurs when the water tube of an operating water tube boiler breaks, the load detection device must be protected from high temperature and high pressure. In order to do this, it must be placed in a housing and transmitted to the sensor via a load transmission rod or the like.

However, in this case, since a tight seal is required between the load transfer rod and the housing, the response operation of the transfer rod may lack accuracy, and one end of the load transfer rod that is in contact with the object to be measured may be exposed to an external atmosphere. Despite being subjected to high pressure, the other end of the housing is at normal pressure, so the pressure cannot be balanced, and the sensor uses the sum of the load to be measured and the pressure of the external atmosphere as the measured value. , accurate measurements cannot be expected.

Furthermore, in a high pressure atmosphere, the load to be measured is often a pressure load.

As described above, there are various problems in an atmosphere of high temperature and high pressure, and it is no exaggeration to say that no load detection device that can be used in an atmosphere of high temperature and high pressure has hitherto appeared.

However, in order to accurately measure the jet reaction force of a water tube, it is necessary to perform dynamic measurement under actual usage conditions, and there is a strong desire for a load detection device that can be used in such a high temperature and high pressure atmosphere.

The present invention responds to such demands, and aims to provide a detection device that operates effectively and accurately in a high-temperature, high-pressure atmosphere and detects a load.

The configuration of the present invention to achieve such an object includes a load detection rod having a load receiving member at one end, which is disposed in a high temperature and high pressure atmosphere, and a load detecting rod disposed at an intermediate portion of the load detection rod and having a load receiving member interposed therebetween. a load detection mechanism that detects a load acting on the load detection rod; an outer cylinder that airtightly and slidably surrounds the load detection rod by exposing only an end portion of the load detection rod having the load receiving member; a pressure chamber arranged inside the cylinder and slidably surrounding the other end of the load detection rod in an airtight manner and communicating with the outside of the outer cylinder; and a pressure chamber arranged inside the outer cylinder and arranged in the middle of the load detection rod. and a cooling chamber that slidably surrounds the load detection mechanism in a watertight manner, and a cooling medium that is introduced into and flows through the cooling chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a load detection device according to the present invention will be described in detail based on an embodiment shown in the drawings.

The load transmitting rod 3 that transmits the load applied to the load receiving member 1 to the strain generating disk 2 includes an inner cylinder 4, a presser plug 5 that is screwed to close the lower end of the inner cylinder 4, and the inner cylinder 4. so as to pass through the cooling chamber 7 of the housing constituted by the lower plug 6 which is fitted with a continuous fillet weld in the middle.
The retainer plug 5 and the lower plug 6 are fitted through bushings 8, such as oil-less bearings, fitted in such a way that they can slide in the axial direction, while metal bushings 9 are screwed or A metal bellows sealing material 10 with an extremely small spring constant is welded between the screw-fastened gasket 9 and the rear end of the load transmitting rod 3 and the load receiving member 1 at the tip. The transmission rod 3 is surrounded by the cooling chamber 7 in an airtight and watertight manner from the external high-temperature and high-pressure atmosphere, and is provided so as to be able to slide and move without any load.

Therefore, even if a certain amount of pressurized cooling medium is introduced into the cooling chamber 7, the bushing 8 and the packing 9 will prevent it from flowing out of the room. It can be prevented.

Note that since the bellows sealing material 10 is made of metal and has an extremely small spring constant, there is no risk of applying a load that would affect the movement of the load transmission rod 3.

Further, above the rear end of the load transmitting rod 3, an upper plug 12 having a protrusion 11 on its lower surface is continuously welded to the inner cylinder 4.

The function of this upper plug 12 is to determine the maximum value of the axial movement of the load transmitting rod 3, that is, the maximum measured value, thereby preventing damage to the strain generating disk due to excessive load.

Moreover, the space 13 formed by the upper plug 12, the lower plug 6, and the inner cylinder 4 is connected to the inner cylinder 4 and the outer cylinder 14.
connected to the outside by a pressure introduction pipe 15 penetrating through the
It is configured as a pressure chamber that introduces high-temperature, high-pressure outside air.

In this way, since the ambient pressure on the load receiving member 1 side and the ambient pressure on the rear end side are the same pressure, zero balance is maintained under any pressure unless the load to be measured is applied. The transmission rod 3 is provided to slide in the axial direction depending on the load to be measured.

The load receiving member 1 is not limited to a plate-like member as shown in the drawings.

When measuring the jet reaction force of a broken pipe, which was the motivation for this invention, it is used like a chuck that grips the pipe.

The detection mechanism for detecting the load applied to the load transmission rod 3 includes:
It is composed of a diaphragm-shaped strain generating disk 2 that bends in the axial direction as the load transmission rod 3 moves, and a strain gauge 16 attached to the disk 2.

The strain-generating disk 2 includes a protrusion 4a of an inner cylinder 4 that protrudes inwardly from other parts and is formed into a double cylinder, and a presser plug 5 that applies a clamping force via a presser ring 17. It is fixed to the inner cylinder 4 so that the entire outer peripheral edge thereof is held between the rods, and is provided so as to be bent, that is, to be distorted, in response to the load applied to the load transmission rod 3.

Note that this detection mechanism is not limited to the one described above, and if the piezoelectric effect of a piezoelectric element is utilized, it becomes suitable for impact load measurement.

...An outer cylinder 14 surrounding the inner cylinder 4 is attached to the outside of the inner cylinder 4, which is a housing, and a cooling medium flow path consisting of a cylindrical space is provided between the inner cylinder 4 and the outer cylinder 14. 18 are formed.

The cooling medium passage 18 is connected to the lower part of the cooling chamber 7 by a passage 19 and is provided so as to introduce the cooling medium flowing out from the lower part of the cooling chamber 7.
The inner cylinder 4 that fixedly supports the strain generating disk 2 is cooled by the cooling medium flowing to the cooling medium supply source 20 behind the protrusion 4a, and the temperature of the inner cylinder 4 near this detection means is kept constant and the outer cylinder is It is provided so as not to cause deformation due to the heat of the external atmosphere transmitted through the cylinder 14.

Further, a disc-shaped inner cover 21 is continuously welded on top of the upper plug 12 so as to cover it, and a cooling medium inlet chamber 22 is formed between the inner cover 21 and the upper plug 12.

This cooling medium inlet chamber 22 is connected to a cooling medium supply source (not shown) through a supply pipe 23, while the pressure chamber 1
It is connected to the upper part of the cooling chamber 7 by three communication pipes 24 passing through the cooling chamber 7 .

Furthermore, an upper lid 25 is screwed onto the inner lid 21, and the inner lid 21
A cooling medium outlet chamber 26 is formed between the two.

This coolant outlet chamber 26 is connected to a coolant supply source by a discharge pipe 27, and is also connected to the upper part of the cooling chamber 7 and the coolant flow path 18 by passages 28 and 29, respectively.

Therefore, the cooling medium is 1. Supply source → Supply pipe 23 → Cooling medium inlet chamber 22 → Communication pipe 24 → Cooling chamber 7 passage 28 7 Upper sound t'h passage 3〇 - Cooling chamber 7 lower part - Passage 19 - Cooling medium outlet chamber 26 Cooling medium flow It circulates as follows: passage 18 → passage 29 → discharge pipe 27 → supply source.

Further, the lead wire 31 of the strain gauge 16 is drawn out through the passage 28 and the discharge pipe 27.

At this time, the lead wire outlet is made watertight by inserting a filler 32 such as adhesive or rubber packing.

Note that the base end portion is formed into a flange in order to securely install the inner cylinder 4 as a housing that supports the entire load detection device according to the present invention.

In this way, a cooling chamber is formed by surrounding the strain generating disk, strain gauge, and load transmitting rod, which are the detection means, from the outside with an inner cylinder, which is a housing, and the cooling medium filled in this cooling chamber is used to absorb the strain. Since the generation disk, the strain gauge, etc. are cooled and always kept at a constant temperature, zero drift and the like can be prevented from occurring and measurement accuracy can be significantly improved.

In addition, a cooling medium is introduced into a cooling medium flow path surrounding the cooling chamber, filling this flow path with the cooling medium, forming a cooling medium layer between the inner cylinder and the outer cylinder, and transmitting the cooling medium through the outer cylinder. If the inner cylinder that fixes and supports the strain-generating disk is designed to block the heat from the high-temperature atmosphere outside and prevent it from deforming due to heat, it will further prevent the occurrence of zero drift, etc., and significantly improve measurement accuracy. It can be improved.

Conventional strain gauge types had the drawback of large zero drift and very poor accuracy, but the present invention can eliminate this drawback.

In addition, the load transfer rod is attached to the housing of the cooling chamber, that is, the inner cylinder and the plug, etc. so that it can slide freely in the axial direction, and then a bellows sealing material with an extremely small spring constant is used to connect both ends of the load transfer rod and the cooling chamber, respectively. While connecting the rods in an airtight and watertight manner so that they can slide under light loads, both ends of the load transmission rods are exposed to a high pressure atmosphere, and the ambient pressure at both ends of the load transmission rods is set to the same pressure, and the applied external pressure is compensated for. As long as the load to be measured is not applied, the zero balance will be maintained under any pressure, and once the load to be measured is applied, it will slide in the axial direction according to the load to be measured, and the strain-generating disk etc. Deflection (strain) and pressure corresponding to the load to be measured can be accurately transmitted to the detection means.

Therefore, even under high temperature and high pressure atmospheres, load, displacement, acceleration,
It is possible to provide a detection device that can directly measure pressure, etc., and has high accuracy and excellent responsiveness.

[Brief explanation of drawings]

FIG. 1 is a central longitudinal cross-sectional view of the detection device according to the present invention, FIG. 2 is a cross-sectional view taken along the line A-A shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line B-B shown in FIG. be. In the drawing, 1 is a load receiving member, 2.16 is a strain generating disk and strain gauge that constitute the detection means, 3 is a load transmission rod, 4.5.6
The inner cylinder, presser plug and lower plug that constitute the housing, 7 are the cooling chamber, 8 and 9゜10 are the sealing means between the load transmission rod and the cooling chamber, the seal, the packing and the bellow sealing material, 12 13 is the upper plug, 13 is the pressure chamber, 14 is the outer cylinder, 15 is the pressure introduction pipe, 17 is the holding ring,
18 is a cooling medium flow path, 21 is an inner lid, 22 is a cooling medium inlet chamber, 23 is a supply pipe, 24 is a communication pipe, 25 is an upper lid, 26 is a cooling medium outlet chamber, 27 is a discharge pipe, 19° 28.29 .3
0 is a passage connecting each chamber, and 31 is a lead wire.

Claims (1)

[Scope of utility model registration request] a load detection rod having a load receiving member at one end disposed in a high temperature and high pressure atmosphere; a load detection mechanism disposed at an intermediate portion of the load detection rod for detecting a load acting through the load receiving member; an outer cylinder that airtightly and slidably surrounds the load detection rod by exposing only the end portion of the load detection rod having the load receiving member; A pressure chamber that surrounds the end in an airtight and slidable manner and communicates with the outside of the outer cylinder, and a middle part of the load detection rod and the load detection mechanism that are disposed inside the outer cylinder and that are slidable and watertight. 1. A load detection device in a high-temperature, high-pressure atmosphere, comprising a cooling chamber surrounding the cooling chamber, and a cooling medium introduced into and flowing through the cooling chamber.