JPH03293515A - Inclination sensor - Google Patents

Abstract

PURPOSE:To detect the angle of inclination stably by constituting the sensor of a housing fixed to a target object, a pendulum, a lead switch, and a highly viscous liquid filled in a cell. CONSTITUTION:This inclination sensor is fixed to an arm light of, e.g., a power shovel. A silicone oil is filled in a cell 9 of the sensor. At a reference position, a pendulum 7 shuts the line of magnetic force of a magnet 18 acting to the lead switches 15, 16. When an arm is inclined together with the light, a main body 2 of the housing is inclined as well. If the main body 2 is inclined a predetermined angle or more, the pendulum 7 comes not to obstruct the line of magnetic force acting to the switch 15 which is opposite to the inclining direction. As a result, the switch 15 is turned ON and a motor is rotated in a direction to return the main body 2 to the reference position. Aa the main body 2 comes close to the reference position, the line of magnetic force to the switch 15 is shut by the pendulum 7, thereby turning the switch 15 OFF. The same goes true when the arm is inclined in an opposite direction. Therefore, the light can illuminate with the same angle while the horizontal surface is made a reference.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tilt sensor. More specifically, the present invention relates to a tilt sensor used to detect the tilt of a light attached to the arm of a power shovel. Note that the inclination sensor of the present invention is used not only for detecting the inclination of a light, but also for collision detection, earthquake detection, etc.

[Prior Art] Inclination sensors have been used in agricultural machinery and the like to detect the inclination of a machine body.

As a conventional tilt sensor, it itself adjusts to 0 depending on the tilt angle.
Mercury switches with N-OFF operation are known. It is also known to use a magnetoresistive element in the sensitive part and combine this with a pendulum. However, if a mercury switch is used, the size will be large and the cost will be high.
There are problems such as being extremely sensitive to vibrations.

Further, if a magnetoresistive element is used, the cost is high, and when used as a switch, electrical processing such as amplification or interposition of a relay is required.

On the other hand, JP-A-50-10!54 discloses a tilt sensor that has a permanent magnet and is equipped with a pendulum arm that swings in a horizontal plane, and a reed switch that turns ON and OFF according to the swing angle of the pendulum arm. Disclosed.

As shown in Figs. 6 and 7, this device is rotatably supported by a support frame (51), a support metal (52), and a pivot (53) arranged approximately perpendicular to the support frame. A pendulum arm (54) extending almost horizontally, a permanent magnet (55) fixed to the tip of the pendulum arm, and three reed switches (56), (56) for detecting the position of the permanent magnet.
7) and (58).

When the sensor is in the horizontal position, the permanent magnet (55)
is located above the reed switch (56) in the center position,
The reed switch (56) is activated by the magnetic force of the permanent magnet (55).
) is turned on and horizontal display is performed.

Also, when the sensor is tilted, the pendulum arm (54) moves in the tilt direction (arrow (A)) around the pivot (53) due to its own weight.
- (B) direction), and the permanent magnet (55) moves above the reed switch (57) or (58) to turn it on.

[Problems to be Solved by the Invention] The above-mentioned conventional tilt sensor using a reed switch is suitable for detecting minute angles because the tilt arm swings significantly even with a slight tilt angle. However, since the swing speed of the pendulum arm (54) changes depending on the inclination of the pivot (53),
Stable detection cannot be expected for objects where the angle of the axis (53) changes frequently.

Furthermore, since the magnetic field moves together with the permanent magnet, changes in the magnetic field lines detected by the reed switch are relatively slow. Therefore, the hysteresis of the ON-OFF operation of the switch with respect to the position of the magnet becomes large, so that accurate control cannot be expected when used, for example, to control the irradiation angle of a light.

The present invention has been made to solve the above-mentioned problems, and it is possible to stably detect the tilt angle even when the detection target is tilted in a direction other than the angle to be detected, and has a small number of components and a simple structure. Easy, low manufacturing cost, 0N-OFF
It is an object of the present invention to provide a tilt sensor with small hysteresis of operation.

[Means for Solving the Problems] The inclination sensor of the present invention includes a housing fixed to an object for inclination detection, a pendulum rotatably suspended within the housing, and a pendulum with a swinging surface of the pendulum in between. It consists of a magnet and a reed switch fixed to a housing so as to face each other, and a high viscosity liquid filled in the housing.

Preferably, the liquid is silicone oil. Further, it is preferable that the pendulum is made of a fan-shaped plate, and a main part of the pendulum is pivotally supported by the housing.

[Function] When a tilt sensor attached to a tilt detection object such as a power shovel light tilts, the housing tilts accordingly.

Since the square pendulum attempts to maintain a vertically suspended state due to the action of gravity, it rotates about its pivot relative to the housing.

When the pendulum is detached from the reference position, the pendulum made of magnetic material enters between the reed switch and the magnet according to the inclination, and the lines of magnetic force are instantly attracted to the pendulum, cutting off the lines of magnetic force against the reed switch. do. This turns the reed switch OFF.

Further, when the inclination angle returns to O and the pendulum leaves, the reed switch is instantaneously turned on, contrary to the above.

In the case of the type in which the lines of magnetic force are interrupted at the reference position, the ON-OFF operation is performed in the opposite manner to the above.

Since ON-OFF operates instantaneously in this way, the angular range (F2) of the pendulum corresponding to the t stable region (Fl) of the reed switch is narrow, as shown in FIG.

Therefore, stable operation can be achieved.

In addition, hysteresis occurs in the 0N-OFF operation of the reed switch (arrow (P) indicates ON, 1 arrow (Q) indicates 0FF).
), but the corresponding pendulum angle difference (F2) is small. Therefore, the tilt angle can be detected with less hysteresis with respect to changes in the tilt angle.

In addition, since a highly viscous liquid is sealed in the compartment in which the pendulum is housed, viscous frictional resistance acts on the movable parts, which produces a damper effect. That is, when the inclination angle changes, the pendulum smoothly reaches the final hanging position, and even if shocks or vibrations are applied, they are damped.

Furthermore, when a semi-disc pendulum is used, the viscous frictional resistance received from the liquid is large, further improving the damping effect.

Furthermore, when silicone oil is used as the damper liquid, the viscosity change due to temperature changes is small, and more stable damper characteristics can be obtained.

[Example] Next, a tilt sensor of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the tilt sensor of the present invention before assembly; FIG. 2 is a perspective view of the inside of the housing of the tilt sensor of FIG. 1; and FIG. 3 is the tilt sensor of FIG. 1. A fourth circuit diagram showing an example of a control circuit of a direction control device using
Figures A to 40 are explanatory diagrams of the operation of the inclination sensor of Figure 1, respectively, and Figure 5 is a graph showing the relationship between the angle of the pendulum and the magnetic force applied to the reed switch.

In FIGS. 1 and 2, (1) is a housing, which is composed of a main body (2) and a lid (3).

The main body (2) and the lid (3) have a sealing gasket (4) sandwiched therebetween and are fastened at their four corners with bolts (5) to form a housing (1). Note that the bolt (
5) is also used to fix the sensor to the tilt sensing object.

A cylindrical shaft (6) is located approximately in the center of the inner surface of the lid (3).
is provided protruding toward the main body ('2J side). Also, the shaft (6) is fitted into the boss (8) provided at the center of the upper end side of the semicircular pendulum (7). It is supported so that it can swing freely.

A compartment (9) in which the pendulum (7) is housed is provided below the center of the main body (2), and the compartment (9)
has enough space for the pendulum (7) to swing. A communication hole communicating with the outside is provided in the upper part of the main body (2) and is closed by a removable plug 0υ.The communication hole or groove 02 bored in the main body connects the compartment (9 ) is communicated with.

A recess 0 and an opening are formed inside the lid (3) on both sides of the shaft (6), that is, at positions corresponding to the upper end of the pendulum (7), and a reed switch 6 is formed in each.
, (G) are inserted and fixed.

Approximately the center of the inside of the main body (21, that is, the lid (3)
When it is assembled, a rectangular recess 0''I) is formed in the part corresponding to the shaft (6), and a permanent magnet Oa is inserted and fixed to the four sides of the recess 0''I). (to) faces the inner portions of (5) of both reed switches.

Two relays (2) and (2) are fixed to the outside upper part of the main body (2), and the printed circuit board is secured to the outside of the lid (3) by the bolt (5) and the screw (211) in the center. It is fixed.

Further, the sealed compartment (9) is filled with silicone oil injected from the communication hole □□□.

The tilt sensor configured as described above detects the tilt of the object to be detected,
For example, it is fixed to the arm light of a power shovel. In that case, reed switch 6, (5) and relay capacitor,
M)) and the power supply (v). The motor is used to change the relative angle of the light to the arm, and when one reed switch 6 is turned on, it rotates in the forward direction (arrow (El) in Figure 3) L, and when the other reed switch 6 is turned on, it rotates in the reverse direction. (The wires are connected as indicated by arrow (E2) in FIG. 3 (see FIG. 3).

Next, the operating state of the tilt sensor will be explained with reference to FIGS. 4A to 40.

The reference position of the sensor is located at the housing (as shown in Figure 4A).
1) The upper end surface is the horizontal position. In the reference position, the pendulum (7) is in a state where it blocks the lines of magnetic force of the magnet OF3 acting on the reed switch (8, [).

Next, when the arm of the power shovel tilts with the light,
The housing (1) also tilts accordingly, for example as shown in FIG. 4B. At this time, the pendulum (7) maintains a vertical state due to the action of gravity, and therefore rotates in the direction of arrow (A) about the boss (8) relative to the housing (1).

When the pendulum ('7) is tilted at a predetermined angle or more in this way, the pendulum (7) is moved to the reed switch 5 on the opposite side of the tilt.
The lines of magnetic force acting on the magnetic field are no longer blocked. Then, the reed switch G is turned ON, and the motor moves the light, that is, the housing (1), in the direction (arrow (A)
rotation (direction) (forward rotation).

Next, when the housing (1) approaches the reference position, the lines of magnetic force acting on the reed switch 6 are blocked by the pendulum (sword), the reed switch 6 is turned off, and a brake (for example, regenerative brake) is applied to the motor. Return to the state shown in Figure 4A.

On the other hand, if the housing is tilted in the opposite direction to that shown in Fig. 4B, as shown in Fig. 4C, the other reed switch is turned on, causing the motor to rotate in the opposite direction, returning the housing (1) to the standard position ( Rotate it in the direction of arrow (B). Then, the motor brake operates at a predetermined position.

Therefore, even if the angle of the arm with respect to the horizontal plane changes,
The light can always illuminate the same angle relative to the horizontal plane (for example, diagonally downward).

Although the pendulum (7) swings as the housing (1) tilts, it is damped by the silicone oil in the compartment (9) and smoothly returns to the hanging position without any vibration. Furthermore, even if vibrations or shocks are applied to the housing (1), the pendulum (force vibrations, etc.) will be attenuated.

The high viscosity liquid for the damper used in the inclination sensor of the present invention is preferably one whose viscosity changes little due to temperature changes, such as silicone oil.

The viscosity of the silicone oil can be selected depending on the intended use of the inclination sensor. For example, when sensitive detection such as vibration detection is required, a low viscosity oil is used to eliminate the influence of external vibrations. A high viscosity material is used.

Furthermore, the shape of the pendulum is not limited to a semi-disc shape, and may be a circular shape of a clock, such as a disc with an arm.

The size of the gap between the flat part of the pendulum and the flat part of the compartment of the main body affects the viscous frictional force on the pendulum and is a factor that determines the magnitude of the damping effect. The dimensions vary depending on the shape of the chamber and pendulum, and the type of high viscosity liquid, but for example, in the above embodiment, it is 0.5 to
Approximately 1.0 mm is preferable.

Various types of reed switches can be used for the inclination sensor of the present invention.

Furthermore, although permanent magnets are used in the embodiments described above, since the magnets are used in a fixed state, electromagnets can also be used if desired.

The main body and lid of the housing may be made of synthetic resin such as polyacetal or polyamide, but are not limited thereto; for example, they may be made of aluminum die-casting. Further, as the magnetic material constituting the pendulum, for example, iron or ferritic stainless steel is used.

[Effects of the Invention] The inclination sensor of the present invention has the advantages of a simple structure, low manufacturing cost, and small hysteresis of ON-OFF operation, thereby enabling accurate control.

Furthermore, since a high viscosity liquid is sealed inside the sensor,
Another advantage is that the pendulum moves smoothly and prevents malfunctions from occurring due to external forces such as shocks and vibrations.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a perspective view of an embodiment of the inclination sensor of the present invention before assembly; Fig. 2 is a perspective view showing the inside of the housing of the inclination sensor of Fig. 1; Fig. 3; 4 is a circuit diagram showing an example of a control circuit of a direction control device using the tilt sensor shown in FIG.
Figures A to 40 are explanatory diagrams of the operation of the tilt sensor in Figure 1, Figure 5 is a graph showing the relationship between the angle of the pendulum and the magnetic force received by the reed switch, and Figure 6 is a plane diagram showing an example of a conventional tilt sensor. 7 is a sectional view taken along the line 1-1 in FIG. 6. (Main symbols in the drawings) (1): Housing (7): Pendulum (9): Drawing room 6, 泵: Reed switch (G): Magnet patent applicant Nippon Cable Fist System Co., Ltd.

Claims (1)

[Scope of Claims] 1. A housing fixed to a tilt detection target, a pendulum rotatably suspended within the housing, and a pendulum fixed to the housing so as to face each other across the swinging surface of the pendulum. A tilt sensor comprising: a magnet and a reed switch; and a high viscosity liquid filled in the housing. 2. The tilt sensor according to claim 1, wherein the liquid is silicone oil. 3. The inclination sensor according to claim 1, wherein the pendulum is a fan-shaped plate, and a main part thereof is pivotally supported by the housing. 4. A pair of reed switches are arranged so as to face each other near both ends of the pendulum in the standard state, and in the standard position, the pendulum covers both reed switches so as to block the lines of magnetic force from the magnet, and when the pendulum swings, it swings. The tilt sensor according to claim 1, wherein the reed switch on the opposite side is exposed.