JPS636413A - Support mechanism for receiving coil - Google Patents

Abstract

PURPOSE:To store receiving coils in an extremely small space by supporting a 2nd shaft rotatably at right angles on the intermediate part of a 1st shaft supported rotatably on a bracket and supporting and fixing receiving coils at both side part of the 2nd shaft. CONSTITUTION:Both end parts of the 1st shaft 1 are supported rotatably on right and left brackets 2 rotatably and the intermediate part of the 2nd shaft 3 is supported at the intermediate part of the 1st shaft 1 at right angles to the 1st shaft. Then, the upper parts of the receiving coils 4a and 4b are fixed at both end parts of the 2nd shaft 3 at positions of the same size from the support parts for the 1st shaft 1. Thus, the receiving coils 4a and 4b are fixed and then stored in the extremely small space. Further, both receiving coils 4a and 4b shift in phase by 90 deg. to right and left when viewed from the front and are equal in weight, and they can be held at invariably constant attitudes to gravitation by their own weights.

Description

[Detailed Description of the Invention] Industrial Application Fields Underground excavators are used to bury water pipes and gas pipes underground. For this purpose, it is essential to measure the underground position of the underground excavator.

The present invention relates to a support mechanism that supports a magnetic field receiving coil installed in an underground excavator in order to measure the underground position of the underground excavator.

Conventional technology The attitude of the receiving coil in relation to the outside world in an underground excavator greatly affects the number of magnetic fluxes received by the magnetic field. By supporting this, an important basis for measurement system design has been obtained.

As shown in Fig. 4, a conventional example of the support mechanism is as shown in Fig.
There are two types of mechanisms: a free neck mechanism in which the body is supported so as to be able to swing freely, and a cardan frame mechanism as shown in Fig. 5. This Cardan frame mechanism is shown in Japanese Patent Application Laid-Open No. 57-110915, in which d is a receiving coil, # is a weight, and f is a receiving coil.
is the first rotating frame, l is the second rotating frame, and is the fixed frame.Despite changes in the fixed frame's attitude, the receiving coil d always maintains a constant attitude due to the weight 1. There is.

Problems to be Solved by the Invention In both of the conventional support mechanisms described above, the inner diameter of the underground excavator is 200 mm.
Although it can be applied to underground excavators with an inner diameter of IQQ or less, which is called an ultra-small-diameter underground excavator, it is almost impossible to apply this method to an underground excavator with an inner diameter of IQQ or less.

The reason for this is that in the case of the above-mentioned ultra-small diameter underground excavator, the remaining space 1 after subtracting the area occupied by hydraulic piping and electrical cables, that is, the space allocated to the receiving coil and the mechanism that supports it, is extremely small. It is. Moreover, the design reason is to keep the product of the number of windings and the cross-sectional area of the receiving coil as tight as possible in order to secure space for the receiving coil to be displaced due to pitching and rolling of the underground excavator and to improve the reception level. This is because the space allocated to the support mechanism can be kept as small as possible.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems, and provides a method for ensuring that the receiving coil always maintains a constant attitude with respect to gravity even when the underground excavator pitches or rolls. The purpose of the present invention is to provide a support mechanism for a receiving coil that can be installed inside an ultra-small diameter underground excavator, and can be housed in an extremely small space. a first shaft rotatably supported at the center; a second shaft perpendicular to the intermediate portion of the first shaft and rotatably supported around the axis; It consists of two receiving coils that are fixedly supported, and the receiving coil always takes a constant attitude with respect to gravity regardless of the attitude of the bracket. The above bracket is fixed inside the underground excavator.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 3.

In the figure, 1 is a first shaft, and both ends of this fiC1 shaft 10 are rotatably supported by left and right brackets 2. Reference numeral 3 denotes a second shaft, and the intermediate portion of the second shaft is rotatably supported by the intermediate portion of the first shaft 1 in a direction perpendicular to the first shaft 1. At both ends of this second shaft 3 and at the first shaft 1
The receiving coil 4α is located at the same dimensional position from the support part.

The upper part of 4b is fixed. Both receiving coils 4a,
When viewed from the front, the receiving coils 4b are out of phase by 90 degrees to the left and right, and in a stationary state, both receiving coils 4a.

4b is the same weight, so there are 4 from the center to the left and right.
The postures are divided by 5 degrees. 5 is a lead wire connected to each of the receiving coils 4a, 4A, and this lead wire 5 is connected to the first shaft 1. 6 is a case that firmly supports the bracket 2, 7 is a plate that is fixed to the end of the case 6 via an oxygen/glue 8, 9 is a spacer, and 10 is a connector, which is connected to the case 6 with the connector 10. A printed card 11 is fixed thereto, and the lead wire 5 is connected to this printed card 11. The case 6 is fixed to an underground excavator (not shown). I2α and 12b are stoppers that determine the respective rotation ranges of the first shaft 1 and the second shaft 3.

In the above configuration, even if the underground excavator pitches or rolls, both receiving coils 4a and 4b always maintain a constant attitude with respect to gravity due to their own weights. Since the heads of the TFC receiving coils 4a, 4b are fixed to the second shaft 3, the two receiving coils 4a, 4b can be accommodated in an extremely small space, and an angle of 90° between them can be easily secured. When the receiving coils 4a, 4b swing relative to the bracket 2, the coil lead wires do not come into contact with the receiving coils 4a, 4b or the bracket 2 because their intermediate portions are connected to the first shaft 1. Furthermore, by connecting the intermediate portion of the coil lead wire 5 to the first shaft 1, the length from the receiving coils 4a, 4b to the knot and the length from the knot to the print card 11 are respectively reduced. Receiving coil 4α.

Regardless of the load depending on the direction of movement of the receiving coils 4b, the coil lead wire 5 does not impede the swinging of the receiving coils 4a, 4A. The wiring of each lead wire 5 may be adjusted for movement in one direction. In other words, it is easier to adjust the wiring for movement in two directions. This is because, in the case of ultra-small diameter underground excavators, the space allowed for wiring the coil lead wire is limited, and the effectiveness of this is enhanced.

Effects of the Invention According to the present invention, even if the underground excavator pitches or rolls, the receiving coils 4a and 4b can always maintain a constant attitude with respect to gravity, and can be housed in an extremely small space. , it can be installed inside an ultra-small diameter underground excavator.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention.
The figure is a front view, FIG. 2 is a cross-sectional view taken along the -U line in FIG. 1, FIG. 3 is a partially cutaway side view, and FIGS. . 1 is the first shaft, 2 is the bracket, 3 is the second shaft, 4a, 4b
is the receiving coil.

Claims (3)

[Claims] (1) A first shaft 1 rotatably supported by a bracket 2, a second shaft 3 supported perpendicularly to the intermediate portion of the first shaft 1 and rotatably about its axis, and a second shaft 3 rotatably supported by a bracket 2; A receiving coil support mechanism comprising two receiving coils 4a and 4b fixedly supported on both sides of two shafts 3 in the axial direction. (2) Claims characterized in that the heads of the receiving coils 4a, 4b are fixed to the second shaft 3, and the two receiving coils 4a, 4b are supported so as to form an angle of 90° to each other. 2. The receiving coil support mechanism according to claim 1. (3) The first claim characterized in that the coil lead wires of the receiving coils 4a and 4b are connected to the first shaft 1.
The support mechanism for the receiving coil described in Section 1.