JPH0117689Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a control cable with a sensor. More specifically, the present invention relates to a control cable with a sensor that can detect relative displacement between an inner cable and an outer casing.

[Prior Art] A control cable generally includes an inner cable and an outer casing for slidably or rotatably guiding the inner cable.

Inner cables are generally composed of a single metal wire or twisted wires made of metal, synthetic resin, or the like. Also used are toothed cables in which spiral teeth are provided around the core wire.

As the outer casing, flexible materials such as a metal spiral tube whose inner and outer peripheries are coated with synthetic resin, or multi-layered synthetic resin tubes are used, but if a rigid metal tube is used, There is also.

The control cable configured in this manner transmits the operation to the other end by pulling, pushing, pulling, or rotating one end of the inner cable. Operation can be divided into two types: those that transmit force accurately and those that primarily transmit an amount of operation accurately, but are usually used when obtaining an appropriate amount of operation with a certain range of force. Ru.

By the way, since the inner cable and the outer casing are made of metal wires as described above, elastic elongation or permanent elongation occurs. Therefore, it is difficult to accurately control the manipulated variable. In other words, certain operations (for example,
Even if a Lmm pulling operation is applied, there is no guarantee that the same movement (Lmm pulling into the outer casing) will occur at the other end, and there is usually some error involved.

For this reason, conventional control cables can only provide accurate operating amounts in certain cases, such as when the driven member is stopped by a stopper.
There is a problem in that the scope of its use is limited.

[Purpose of the invention] An object of the present invention is to provide a control cable that can accurately transmit a desired operation amount to a driven device in order to expand the scope of application of the conventional control cable.

[Structure of the invention] In order to achieve the above object, the control cable with a sensor of the invention includes an inner cable consisting of a core wire, an insulating layer coated on the surface of the core wire, and a conductive layer coated on the surface of the insulating layer. an outer casing that slidably guides the inner cable and whose inner surface is coated with an insulating layer; a conductive brush that is fixed to the outer casing and slides into contact with the conductive layer of the inner cable; A conductive fixing member fixed to the conductive layer of the inner cable is electrically connected to the brush, and the amount of resistance of the conductive layer of the inner cable between the fixing member and the brush is detected. It is characterized in that it has a resistance detector for detecting.

[Embodiment] Next, a control cable with a sensor according to the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of a control cable with a sensor according to the present invention, and FIG. 2 is a sectional view taken along the line X--X in FIG. 1.

In FIG. 1, 1 is an outer casing, and an inner cable 2 is slidably inserted into the outer casing 1.

In the inner cable 2, the surface of a core wire 2a is coated with an insulating layer 3a, and the surface of the insulating layer 3a is further coated with a conductive layer 4 (see FIG. 2). With such a configuration, the insulating layer 3a serves to break electrical contact between the conductive layer 4 and the core wire 2a. In particular, the conductive layer 4 is coated so that the resistance per unit length of the inner cable 2 is uniform in the sliding direction. As the conductive layer 4, for example, carbon paste, conductive resin, conductive rubber, etc. can be used.

The outer casing 1 has an insulating layer 3b on its inner surface.
is coated, thereby serving to break electrical contact with the conductive layer 4 of the inner cable 2.

The brush 5 is fixed to the outer casing 1 by a fixing member 7 provided on the outer casing 1, and is arranged so as to be in constant contact with the conductive layer 4 covering the core wire 2a via the insulating layer 3a. .

A fixing member 6 is fixed to the conductive layer 4,
This allows it to move together with the sliding movement of the inner cable 2.

The brush 5 and the fixing member 6 are each connected to a resistance detector in a manipulated variable detector 9 by a conductive wire 8.

The resistance detector consists of, for example, a power supply capable of applying a constant voltage and an ammeter connected in series with the power supply. A display is provided for displaying the amount of movement relative to 1.

In the control cable configured as described above, when the inner cable 2 slides inside the outer casing 1, an insulating layer 3a is formed on the core wire 2a.
The length between the brush 5 and the fixing member 6 in the sliding axis direction of the conductive layer 4 coated via the brush 5 changes. As a result, the resistance between the brush 5 and the fixed portion 6 changes. Since the voltage applied between the brush 5 and the fixing member 6 is constant, the resistance value can be determined from the current value read by the ammeter according to Ohm's law. As a result, the amount of movement of the inner cable 2 can be detected.

As mentioned above, the sensor-equipped control cable of the present invention can be operated as a means for transmitting operating force in substantially the same way as conventional control cables, and can also accurately measure the operating amount. Therefore, it is possible to operate the driven member while checking the amount of operation of the driven member using, for example, a voltmeter or a display panel.

Such control cables with sensors can be applied to various industrial machines, such as remote control devices inside nuclear reactors, optical axis adjustment devices for lights, shutter and valve opening/closing devices, and blind adjustment devices. .

Furthermore, by combining the sensor-equipped control cable of the present invention with a drive element (especially an electrical drive element) such as a servo motor or a unit that combines a servo valve and a hydraulic cylinder, the operation amount measured by the sensor part can be used as the drive element. A servomechanism can also be constructed by providing feedback directly or via an appropriate nonlinear gain compensation circuit. The control section of such a servo mechanism can be composed of, for example, a microcomputer.

Such a servo mechanism can be applied to, for example, a drive transmission mechanism for a robot, a shutter or valve adjustment mechanism, and the like.

As mentioned above, the sensor-equipped control cable of the present invention can be widely applied to various fields based on its characteristics, and therefore has extremely great practical value.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of a control cable with a sensor according to the present invention, and FIG. 2 is a cross-sectional view of an inner cable according to the present invention. Main symbols in the drawing: 1: Outer casing;
2: Inner cable, 2a: Core wire, 3a, 3
b: insulating layer, 4: conductive layer, 5: brush, 6: fixing member, 9: manipulated variable detector.

Claims (1)

[Scope of utility model registration request] An inner cable consisting of a core wire, an insulating layer coated on the surface of the core wire, and a conductive layer coated on the surface of the insulating layer; a conductive brush fixed to the outer casing and slidingly in contact with the conductive layer of the inner cable; a conductive fixing member fixed to the conductive layer of the inner cable; electrically connect between the brush and
A control cable with a sensor and a resistance detector for detecting the amount of resistance of a conductive layer of an inner cable between a fixing member and a brush.