JPH0718204U - Capacitance type displacement meter - Google Patents

Abstract

(57) [Abstract] [Purpose] To stabilize and improve the detection accuracy by stabilizing the behavior of the sliding member and by obtaining good movement response to the neutral position. [Structure] An L-shaped positive electrode terminal 22 is fixed in a cylindrical body 12 fixed to an upper part of a case 11 by a connecting pin 13. On the other hand, a minus pole plunger 25 is provided in the housing space 24 of the body 12 along the plus pole terminal 22 so as to be slidable in the axial direction. The plunger 25 is
First and second coil springs 28 mounted at both ends,
It is provided so as to be movable to a neutral position in the sliding direction by a spring force of 29.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a capacitance type displacement meter that detects acceleration and inclination of a vehicle.

[0002]

[Prior art]

 Conventionally, various detecting devices for detecting the acceleration of a vehicle and the like have been provided, and one of them is disclosed, for example, in Japanese Patent Laid-Open No. 63-109374.

The outline will be described with reference to FIG. 7. A storage space 3 is formed inside the bobbin 1 whose one end is closed by a stopper 2, and an iron ball as a displacement magnetic body is formed in the storage space 3. 4 is stored so as to be rollable in the longitudinal direction. Further, the detection coils 6 and 6 are arranged on the inner circumference of the housing 5 provided on the outer circumference of the bobbin 1, and the annular permanent magnet 7 is arranged at the boundary position between the both detection coils 6 and 6. Furthermore, a connector 9 is inserted and fixed to the lid 8 of the housing 5, and the terminals of the connector 9 are connected to the detection coils 6 and 6 through lead wires passing through the holes of the spacers. A control unit 10 including an AC constant voltage generating circuit, a signal processing circuit, and the like is connected to the one-way connector 9.

When the vehicle does not accelerate or the like, the iron ball 4 is attracted by the magnetic force of the permanent magnet 7 and is located in the center of the storage space 3. Therefore, the operation outputs of both detection coils 6 1, 6 become zero.

On the other hand, when the vehicle accelerates to the left or right, the iron ball 4 receives an inertial force in a direction opposite to the acceleration direction and rolls against the magnetic force of the permanent magnetic force 7. Therefore, the change of the position of the iron ball 4 changes the self-inductance of the detection coils 6 and 6 to generate a differential output.

[0006]

[Problems to be solved by the device]

 However, in the above-described conventional detection device, the iron ball 4 is used as the displacement magnetic body, and the iron ball 4 easily rolls in the storage space 3 in a point contact state. Although it can be rapidly displaced in response to acceleration, its behavior becomes extremely unstable and the return speed to the neutral position of the storage space 3 after the acceleration is slowed down. That is, at the time of acceleration of the vehicle or deceleration after the acceleration, the iron ball 4 violently rolls in the storage space 3 in the longitudinal direction due to a rapid change in the inertial force, and the closed end 1a of the bobbin 1 and the plug are stopped. Repeated collision and recoil to the inner end surface of 2. For this reason, not only the accuracy of detection of acceleration and the like by the detection coils 6 and 6 becomes unstable, but also repeated collisions cause deterioration of durability.

Further, even when the acceleration / deceleration ends, the iron ball 4 continues to roll due to the inertial force, and it becomes difficult to quickly return the iron ball 4 to the neutral position of the storage space 3 due to the attractive force of the permanent magnet 7. Therefore, the movement response to the neutral position deteriorates, and this also leads to a decrease in detection accuracy.

[0008]

[Means for Solving the Problems]

 The present invention has been devised in view of the above-mentioned conventional problems, and uses a capacitance type displacement meter as a detection device, and a fixed member that is fixed inside the body on the case and forms one electrode. A capacitance type displacement gage provided slidably along the fixed member inside a case and comprising a sliding member forming the other electrode, wherein the sliding member is slid by an elastic member. It is characterized in that it is slidably held in a neutral position in the moving direction.

[0009]

[Action]

 According to the present invention having the above-mentioned configuration, for example, when the vehicle is in normal operation without accelerating, the sliding member is held at the sliding neutral position inside the casing by the elastic member.

On the other hand, when the vehicle is accelerated, the sliding member slides along the fixed member due to the inertial force in the direction opposite to the acceleration direction. Therefore, the capacitance changes according to the relative displacement between the fixed member and the sliding member.

Here, when the acceleration of the vehicle ends, the sliding member is quickly returned to the neutral position in the sliding direction by the elastic member. Therefore, the displacement detection response at the neutral position becomes good, and the detection accuracy can be improved.

Moreover, the behavior of the sliding member is stabilized by a slight sliding frictional resistance in the casing, and the detection accuracy can be stabilized.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment in which the capacitance type displacement sensor of the present invention is applied to a four-wheel drive vehicle.

That is, in the figure, 11 is a non-conductive rectangular case, 12 is a cylindrical body fixed to the upper end of the case 11 via a central connecting pin 13, and 14 is the inner upper end of the case 11. It is a circuit board fixed to the side by bolts 16 via washers 15.

A lid 17 is welded and fixed to the lower end of the case 11, and a plate-shaped magnet 18 that enables attachment to devices is attached to the lower end of the lid 17 with an adhesive. It is fixed. A mold 19 is filled inside the case 11. The base of the connecting pin 13 is preliminarily adhered and fixed to the fixing hole of the case 11, and the tip of the connecting pin 13 is press-fitted into the insertion hole of the body 12 to connect the two.

The body 12 has one end opening closed by a cylindrical end stopper 20, and the other end opening closed by an adjusting screw 21. Further, inside the body 12, a + pole terminal 22 bent in a substantially L shape toward the end stopper 20 is fixed via a terminal guide 23, and the terminal guide 23 and the adjusting screw 21 are connected to each other. A plunger 25, which is a negative pole sliding member, is provided in the storage space 24 between them so as to be slidable in the axial direction.

The + pole terminal 22 has a substantially rod shape, and has a base portion 22a that penetrates the upper wall of the case 11 and the peripheral wall of the body 12 in the radial direction, and is integrally coupled to the tip of the base portion 22a to form an axial center. And a terminal portion 22b extending in the direction. The base portion 22a has a lower end edge soldered to the + pole of the circuit board 14, and an upper end portion embedded in the terminal guide 23. A substantially cylindrical insulator 26 is attached to the outer peripheral surface of the base portion 22a. The terminal portion 22b connected to the upper end portion of the base portion 22a at a right angle is extended in the axial direction of the body 12 to be exposed in the body 12, and an insulating material 27 is attached to the outer peripheral surface thereof. ing.

The plunger 25 has a substantially columnar shape, and the outer peripheral surface 25 a is in sliding contact with the inner peripheral surface of the storage space 24 to give a slight sliding resistance, and the inner peripheral surface is formed in the inner axial direction. A sliding contact hole 25b is formed to penetrate the outer peripheral surface of the insulating material 27 of the terminal 22b. The plunger 25 includes a first coil spring 28, which is an elastic member elastically mounted between the tubular one end 25c and the terminal guide 23, and an elastic member between the tubular other end 25d and the adjusting screw 21. The second coil spring 29 is attached to maintain the neutral position. The plunger 25 is energized to the-pole terminal 30 screwed to the body 12 and the case 11, and the lower end of the-pole terminal 30 is soldered to the-pole of the circuit board 14. .

Further, the coil springs 28 and 29 are set to have a weak spring force that does not impede the free slidability of the plunger 25 in accordance with the inclination of the capacitance type displacement meter, and at the same time, While they are press-fitted and fixed in the holding grooves 25e and 25f in the inner end portions 25c and 25d on the 25 side, the outer end portions are free from the terminal guide 23 and the adjusting screw 21. The plunger 25 is adjusted by the adjusting screw 21 via the coil springs 28 and 29 to a neutral position in the sliding direction.

Further, on the outer peripheral side of the base portion 22 a of the positive electrode terminal 22 and the outer peripheral side of the negative electrode terminal 30, O-rings 31, 32 for sealing between the case 11 and the body 12 and the terminals 22, 30 are provided. Is installed.

The circuit board 14 is mounted with electrical components that form a period conversion circuit and a voltage conversion circuit, and the voltage conversion circuit of the electrostatic capacitance output from the + pole terminal 22 is connected to one end of the harness 33. Are connected. The harness 33 is connected to an external control device while being sealed by a grommet 34 held in a through hole in the side wall of the case 11.

Therefore, according to this embodiment, when the displacement type displacement meter tilts downward in the left direction in FIG. 1, for example, when the vehicle is traveling on a bad road, the plunger 25 moves to the first position due to its own weight. It quickly slides to the left while slidingly contacting the inner peripheral surface of the body 12 against the spring force of the coil spring 28. As a result, the relative area with the positive electrode terminal 22 is increased and the electrostatic capacitance is also increased. Therefore, the voltage output from the circuit board 14 greatly changes from a black dot to a white dot as shown in FIG.

On the other hand, when the capacitance type displacement meter tilts downward to the right side in the drawing, the plunger 25 swiftly slides to the right against the second coil spring 29 against the spring force. As a result, the relative area with the positive electrode terminal 22 becomes smaller and the electrostatic capacitance also becomes smaller. Therefore, the output voltage changes from the black point to the white point as shown in FIG.

Further, when the vehicle shifts from a bad road to a flat road and the electrostatic capacitance type displacement meter becomes horizontal, the plunger 25 moves to a position where the spring forces of the coil springs 28 and 29 are balanced, that is, the sliding direction. It quickly moves to the neutral position (Fig. 1 position). As a result, the relative area with the + terminal 22 is also halved, and the generation of capacitance is a medium value. Therefore, the output voltage generates the output at the center point as shown by the white point in FIG. To do.

As described above, in this embodiment, the plunger 25 moves in the left-right direction while receiving a slight sliding resistance according to the inclination of the vehicle, so that the plunger 25 is restrained from violently moving within the storage space 24. , Always stable detection accuracy can be obtained.

Moreover, when the vehicle returns to the horizontal state, the plunger 25 also quickly moves to the neutral position by the spring force of the coil springs 28, 29, so that the movement responsiveness becomes good and the detection accuracy is improved also in this respect. To do.

Further, since the magnet 18 is fixed to the lower end of the case 11, it becomes possible to attach the electrostatic capacitance type displacement gauge to various devices as they are without using mounting screws or the like.

Furthermore, since the overall structure is simple, the number of parts is relatively small, and they can be assembled in a stacking manner, the manufacturing work efficiency is improved and the cost is reduced.

Further, since the neutral position of the plunger 25 can be easily adjusted by operating the adjusting screw 21 to the left and right, the adjusting workability is also improved.

It should be noted that in the present embodiment, a description has been given of the detection of the inclination state of the vehicle when traveling on a bad road, but it goes without saying that the pitching state such as the acceleration of the vehicle can also be detected.

[0032]

[Effect of device]

 As is clear from the above description, according to the capacitance type displacement sensor of the present invention, the inclination of the tilting member is increased by the sliding member sliding along the fixed member according to, for example, the tilting of the vehicle. The state can be detected with high accuracy, and in particular, since the sliding member has stable slidability within the body, the displacement detection accuracy can be stabilized and durability can be improved.

Moreover, when the vehicle changes from the inclined state to the horizontal state, the elastic member causes the sliding member to quickly move to the neutral position in the sliding direction, so that the detection response at the neutral position can be improved. .

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is an output voltage characteristic diagram when the vehicle leans in one direction.

FIG. 5 is an output voltage characteristic diagram when the vehicle leans in the other direction.

FIG. 6 is an output voltage characteristic diagram in a horizontal state of the vehicle.

FIG. 7 is a sectional view showing a conventional structure.

[Explanation of symbols]

 11 ... Case 12 ... Body 22 ... + Polar terminal (fixing member) 24 ... Storage space 25 ... Plunger (sliding member) 28, 29 ... First and second coil springs (elastic member) 30 ...- Polar terminal

Claims (1)

[Scope of utility model registration request] 1. A fixing member which is fixed inside a body on a case and constitutes one electrode, and a sliding member which is slidably provided inside the case along the fixing member and constitutes the other electrode. An electrostatic capacity type displacement gauge, comprising: the sliding member elastically held by an elastic member so as to be slidable to a neutral position in the sliding direction.