JPH026322Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a displacement detection device that detects the displacement of an object to be detected by the amount of resistance change.

Conventionally, this type of device has a metal support plate fixed to a synthetic resin brush holder that moves in conjunction with the detected object, a brush attached to the support plate, and a resistor with the brush placed opposite the support plate. Brush holders are known to be in sliding contact with the body, but in this case, the fixation between the brush holder and the support plate is achieved by, for example, protruding a protrusion b on the brush holder a, as shown in FIG.
This is generally done by inserting the protrusion b into the through hole d and fusing the tip of the protrusion b with heat to fuse it to the support plate c. According to this, there is a gap between the protrusion b and the through hole d. If a gap is created to some extent, the position of the support plate c may be shifted due to vibrations, etc., and the relative positional relationship of the brush attached to the support plate c with respect to the brush holder a may be disturbed, which may cause detection errors. Accompany.

The purpose of the present invention is to provide a displacement detection device in which the support plate and the brush holder are immovably fixed to each other in order to eliminate such inconveniences, and the detection accuracy can be improved. will be explained with reference to the embodiments shown in FIGS. 2 to 6.

FIG. 2 shows an embodiment in which a pair of throttle valves 2, 2 of a dual carburetor 1 is used as an object to be detected, and the opening degree, that is, the amount of angular displacement thereof is detected by the present detection device. The casing 3 attached to the side of the carburetor 1 is provided with a rotating shaft 5 supported via a cylindrical bearing 4 as shown in FIG. The abutment pin 6 of the throttle valve 2 is engaged with a substantially L-shaped lever 2b at the end of the shaft 2a of the throttle valve 2, so that the rotation shaft 5 is rotated in accordance with the angular displacement of the throttle valve 2. I made it.

A disc-shaped brush holder 7 made of synthetic resin is connected to the rotating shaft 5 on the inner periphery of the rear part of the casing 3.
A pair of radially outer and inner wiring boards are arranged on the back side of the brush holder 7 through a metal support plate 9, as shown in FIG. 1 Attach the second brushes 10 and 11 so that these brushes 10 and 11 are angularly displaced around the axis of the rotating shaft 5 in response to the angular displacement of the throttle valve 2, and attach each brush 10 to the base plate 8. , 11 are attached so that the angular displacement can be detected as a change in resistance value.

Referring to FIG. 5, an input terminal 14 and a ground terminal 15 are connected to both ends of the first resistor 12 with which the first brush 10 on the outside comes into sliding contact, and a second resistor with which the second brush 11 on the inside comes into sliding contact. An output terminal 16 is connected to the main part of the body 13, and the input terminal 14 and the first
The first resistor 12 between the contact position of the brush 10
A detection signal corresponding to the resistance value of the support plate 9 and the second
The signal is outputted to the output terminal 16 via the brush 11 and the second resistor 13.

Note that the second resistor 13 functions as a conductor that outputs a detection signal to the output terminal 16, and in this case, for example, if the detection signal is output directly from the support plate 9 via a lead wire. , the second resistor 13 and the second brush 11 become unnecessary.

The overall configuration of the displacement detection device has been described above, and according to the present invention, the brush holder 7 and the support plate 9 are fixed together as described below to prevent the support plate 9 from being displaced.

That is, the brush holder 7 is provided with a pair of protrusions 17, 17 protruding as shown in FIGS. 4 and 6, and the support plate 9 is provided with a transparent hole having a diameter smaller than that of the protrusions 17 at a position matching each protrusion 17. A hole 18 and a plurality of notches 19 in the radial direction of the periphery of the through hole 18 are formed, and each cut-and-raised tongue piece 20 between each of the notches 19 is formed in the through hole 18.
When the protrusion 17 is press-fitted, it is bent in the press-fitting direction, and after the protrusion 17 is press-fitted, each tongue piece 20
The distal end portion 17a of the protrusion 17 protruding forward was thermally melted to form an enlarged head 21 welded to each tongue piece 20. According to this, the support plate 9 is attached to each tongue piece 2.
Due to the elasticity of 0, the projection 17 is fitted without a gap, and is firmly held in this state by welding to each tongue piece 20 of the head 21, and thus the support plate No misalignment of 9 occurs.

As described above, according to the present invention, the support plate is immovably fixed to the brush holder, and displacement due to vibration etc. is reliably prevented, and detection accuracy is improved. It is sufficient to form a through hole, and the structure is simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view of a conventional example, FIG. 2 is a cutaway side view showing an example of the use of the device of the present invention, FIG. 3 is a cutaway side view of an example of the device of the present invention, and FIGS. Figure 6 is a sectional view taken along the - line and - line.
It is an enlarged cross-sectional view taken along the line - in the figure. 2...Throttle valve (object to be detected), 7...Brush holder, 9...Support plate, 10, 11...Brush, 12, 13...Resistor, 17...Protrusion, 18
...Through hole, 19... Notch, 20... Tongue piece, 21
...A huge head.

Claims (1)

[Scope of utility model registration request] A metal support plate is fixed to a synthetic resin brush holder that moves in conjunction with the object to be detected, a brush is attached to the support plate, and the brush is brought into sliding contact with a resistor placed opposite the support plate. In the displacement detection device, a protrusion is provided on the brush holder, and a through hole having a diameter smaller than the protrusion is formed on the support plate, and a plurality of notches extending radially outward at the periphery of the through hole are formed. Then, each uncut tongue piece between each notch is bent in the press-fitting direction by press-fitting the protrusion into the through hole, and the tip of the protrusion protruding forward of each tongue piece is bent. A displacement detection device consisting of an enlarged head welded to each tongue piece.