CN109540701B

CN109540701B - Be applied to rock shear test's LVDT displacement sensor fixed establishment

Info

Publication number: CN109540701B
Application number: CN201811529887.8A
Authority: CN
Inventors: 张希巍; 王刚; 石磊
Original assignee: Northeastern University China
Current assignee: Northeastern University China
Priority date: 2018-12-14
Filing date: 2018-12-14
Publication date: 2021-08-17
Anticipated expiration: 2038-12-14
Also published as: CN109540701A

Abstract

A LVDT displacement sensor fixing mechanism applied to a rock shear test comprises an upper shear box connecting block, a sensor mounting frame, a guide column, a linear bearing, a lower shear box follow-up block and a connecting block; the sensor mounting frame is fixedly connected with the upper shearing box through an upper shearing box connecting block, and the lower shearing box follow-up block is fixedly connected with the lower shearing box through a lower shearing box connecting block; the linear bearing and the LVDT displacement sensor are fixedly inserted on the sensor mounting frame, and the guide post is inserted in the linear bearing; the guide post is parallel to an iron core of the LVDT displacement sensor, and the guide post is fixedly connected with the iron core of the LVDT displacement sensor through a positioning rod; a return spring is sleeved on the iron core between the positioning rod and the LVDT displacement sensor coil; the upper surface of the lower shear box follow-up block is a plane and is provided with an antifriction layer, and an iron core of the LVDT displacement sensor is vertical to the upper surface of the lower shear box follow-up block; the iron core end of the LVDT displacement sensor is in abutting contact fit with the upper surface of the lower shear box follow-up block, and the end of the iron core is provided with a ball.

Description

Be applied to rock shear test's LVDT displacement sensor fixed establishment

Technical Field

The invention belongs to the technical field of rock shear tests, and particularly relates to a fixing mechanism of an LVDT displacement sensor applied to a rock shear test.

Background

Lvdt (linear Variable Differential transformer) is an abbreviation of linear Variable Differential transformer, belonging to the linear displacement transducer.

At the present stage, in a rock shearing test, deformation of a rock in a shearing process is mainly measured through the LVDT displacement sensors, the LVDT displacement sensors are still fixed in a traditional mode, in the rock shearing process, a rock structural surface sample can not only generate shear expansion in a normal direction, but also generate relative sliding displacement in a shearing direction, at the moment, an iron core of the normal LVDT displacement sensors can generate corresponding radial deflection, and therefore shear expansion data measured by the normal LVDT displacement sensors are distorted.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the LVDT displacement sensor fixing mechanism applied to the rock shear test, which can effectively avoid the radial deflection of the iron core of the normal LVDT displacement sensor, so that the shear-expansion data measured by the normal LVDT displacement sensor is more accurate.

In order to achieve the purpose, the invention adopts the following technical scheme: a LVDT displacement sensor fixing mechanism applied to a rock shear test comprises an upper shear box connecting block, a sensor mounting frame, a guide column, a linear bearing, a lower shear box follow-up block and a lower shear box connecting block; the upper shearing box connecting block is fixedly matched with an upper shearing box of the rock shearing instrument, and the sensor mounting frame is fixedly connected with the upper shearing box connecting block; the sensor mounting rack is of an L-shaped structure, one support arm of the sensor mounting rack is connected to the upper shear box connecting block, and the other support arm of the sensor mounting rack is provided with a linear bearing mounting hole and an LVDT displacement sensor mounting hole; the linear bearing is fixedly arranged in a linear bearing mounting hole of the sensor mounting frame, and the guide post is arranged in the linear bearing in a penetrating manner; the LVDT displacement sensor is arranged in the LVDT displacement sensor mounting hole of the sensor mounting frame in a penetrating way, and a coil of the LVDT displacement sensor is fixedly connected with the sensor mounting frame; the guide post is parallel to an iron core of the LVDT displacement sensor, the bottom end of the guide post is fixedly connected with the lower end of the iron core of the LVDT displacement sensor through a positioning rod, and a reset spring is sleeved on the iron core of the LVDT displacement sensor between the positioning rod and a coil of the LVDT displacement sensor; the lower shear box connecting block is fixedly connected and matched with a lower shear box of the rock shearing instrument, and the lower shear box follow-up block is fixedly connected with the lower shear box connecting block; the upper surface of the lower shear box follow-up block is a plane, and an iron core of the LVDT displacement sensor is vertical to the upper surface of the lower shear box follow-up block; and the end part of an iron core of the LVDT displacement sensor is in abutting contact fit with the upper surface of the lower shear box follow-up block.

And an antifriction layer is arranged on the upper surface of the lower shear box follow-up block, and a ball is additionally arranged at the end part of an iron core of the LVDT displacement sensor.

The invention has the beneficial effects that:

the fixing mechanism for the LVDT displacement sensor applied to the rock shearing test can effectively avoid radial deflection of the iron core of the normal LVDT displacement sensor, so that the shearing and expansion data measured by the normal LVDT displacement sensor is more accurate.

Drawings

FIG. 1 is a schematic structural diagram of an LVDT displacement sensor fixing mechanism applied to a rock shear test according to the present invention;

FIG. 2 is a side view of FIG. 1;

in the figure, 1-upper shear box connecting block, 2-sensor mounting frame, 3-guide column, 4-linear bearing, 5-lower shear box follow-up block, 6-lower shear box connecting block, 7-LVDT displacement sensor, 8-positioning rod, 9-reset spring and 10-ball.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

As shown in fig. 1 and 2, an LVDT displacement sensor fixing mechanism applied to a rock shear test comprises an upper shear box connecting block 1, a sensor mounting frame 2, a guide post 3, a linear bearing 4, a lower shear box follower block 5 and a lower shear box connecting block 6; the upper shearing box connecting block 1 is fixedly matched with an upper shearing box of a rock shearing instrument, and the sensor mounting frame 2 is fixedly connected with the upper shearing box connecting block 1; the sensor mounting frame 2 is of an L-shaped structure, one support arm of the sensor mounting frame 2 is connected to the upper shear box connecting block 1, and the other support arm of the sensor mounting frame 2 is provided with a linear bearing mounting hole and an LVDT displacement sensor mounting hole; the linear bearing 4 is fixedly arranged in a linear bearing mounting hole of the sensor mounting frame 2, and the guide post 3 is arranged in the linear bearing 4 in a penetrating manner; the LVDT displacement sensor 7 is arranged in the LVDT displacement sensor mounting hole of the sensor mounting frame 2 in a penetrating way, and a coil of the LVDT displacement sensor 7 is fixedly connected with the sensor mounting frame 2; the guide post 3 is parallel to an iron core of the LVDT displacement sensor 7, the bottom end of the guide post 3 is fixedly connected with the lower end of the iron core of the LVDT displacement sensor 7 through a positioning rod 8, and a return spring 9 is sleeved on the iron core of the LVDT displacement sensor 7 between the positioning rod 8 and a coil of the LVDT displacement sensor 7; the lower shear box connecting block 6 is fixedly connected and matched with a lower shear box of the rock shearing instrument, and the lower shear box follow-up block 5 is fixedly connected with the lower shear box connecting block 6; the upper surface of the lower shear box follow-up block 5 is a plane, and an iron core of the LVDT displacement sensor 7 is vertical to the upper surface of the lower shear box follow-up block 5; and the end part of an iron core of the LVDT displacement sensor 7 is in abutting contact fit with the upper surface of the lower shear box follow-up block 5.

An anti-friction layer is arranged on the upper surface of the lower shearing box follow-up block 5, and a ball 10 is additionally arranged at the end part of an iron core of the LVDT displacement sensor 7.

The one-time use process of the present invention is described below with reference to the accompanying drawings:

after a rock structural surface sample is clamped in a rock shearing instrument, firstly installing an LVDT displacement sensor in the shearing direction, and then installing a normal LVDT displacement sensor.

Before installing a normal LVDT displacement sensor, a fixing mechanism of the invention needs to be installed in advance, an upper shear box connecting block 1 is fixed on an upper shear box of a rock shear apparatus through bolts, and then a sensor mounting frame 2 is fixed on the upper shear box connecting block 1 through bolts; meanwhile, the lower shearing box connecting block 6 is fixed on a lower shearing box of the rock shearing instrument through a bolt, and then the lower shearing box follow-up block 5 is fixed on the lower shearing box connecting block 6 through a bolt.

Next, the linear bearing 4 is inserted into the linear bearing mounting hole of the sensor mounting bracket 2, and then the linear bearing 4 is fixed to the sensor mounting bracket 2 by bolts; the LVDT displacement sensor 7 is then inserted into the LVDT displacement sensor mounting hole of the sensor mount 2, and the coil of the LVDT displacement sensor 7 is fixed together with the sensor mount 2 by means of bolts.

And the positions of the linear bearing 4 and the LVDT displacement sensor 7 are finely adjusted, so that the readings of the LVDT displacement sensor 7 are within the test measuring range.

After all the preparation work is finished, the rock shearing test can be started, horizontal shearing force is applied to the rock structural surface sample through the upper shearing box and the lower shearing box, and normal shearing and expansion data of the sample can be accurately acquired through the normal LVDT displacement sensor 7.

The embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. The utility model provides a be applied to rock shear test's LVDT displacement sensor fixed establishment which characterized in that: the device comprises an upper shearing box connecting block, a sensor mounting frame, a guide post, a linear bearing, a lower shearing box follow-up block and a lower shearing box connecting block; the upper shearing box connecting block is fixedly matched with an upper shearing box of the rock shearing instrument, and the sensor mounting frame is fixedly connected with the upper shearing box connecting block; the sensor mounting rack is of an L-shaped structure, one support arm of the sensor mounting rack is connected to the upper shear box connecting block, and the other support arm of the sensor mounting rack is provided with a linear bearing mounting hole and an LVDT displacement sensor mounting hole; the linear bearing is fixedly arranged in a linear bearing mounting hole of the sensor mounting frame, and the guide post is arranged in the linear bearing in a penetrating manner; the LVDT displacement sensor is arranged in the LVDT displacement sensor mounting hole of the sensor mounting frame in a penetrating way, and a coil of the LVDT displacement sensor is fixedly connected with the sensor mounting frame; the guide post is parallel to an iron core of the LVDT displacement sensor, the bottom end of the guide post is fixedly connected with the lower end of the iron core of the LVDT displacement sensor through a positioning rod, and a reset spring is sleeved on the iron core of the LVDT displacement sensor between the positioning rod and a coil of the LVDT displacement sensor; the lower shear box connecting block is fixedly connected and matched with a lower shear box of the rock shearing instrument, and the lower shear box follow-up block is fixedly connected with the lower shear box connecting block; the upper surface of the lower shear box follow-up block is a plane, and an iron core of the LVDT displacement sensor is vertical to the upper surface of the lower shear box follow-up block; the end part of an iron core of the LVDT displacement sensor is in abutting contact fit with the upper surface of the lower shear box follow-up block; and an antifriction layer is arranged on the upper surface of the lower shear box follow-up block, and a ball is additionally arranged at the end part of an iron core of the LVDT displacement sensor.