JP2000173424A - Contactless switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability and operational reliability of a switch by making a switch structure non-contact, furthermore, making a constitution capable of preventing the oil from infiltrating inside a transmission between a switch operating axis and a bearing body supporting the switch operating axis. SOLUTION: In a switch case 31, a bearing body 40 which pivotally supports the vicinity of inside end of the switch case 31 of a switch operating axis 38 slidably in the axial direction of the operating axis 38 is attached, and adjacent to the outside of the switch case outer than the attaching position of the bearing body 40, an O-ring 39 is attached to make the space between the switch case 31 and the operating axis 38 fluid tight, and the bearing body 40 is formed with a sintered metal which contains carbon, in addition to that, a magnet carrier 41 of non-magnetic material is attached to an inner end of the switch case 31 of the operating axis 38, and a magnet 42 magnetized in the moving direction of operating axis 38 is installed on the magnet carrier 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact switch used for, for example, an automobile, and more particularly to a non-contact switch having a structure capable of improving durability and operation reliability.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional switch structure mounted on a transmission for detecting and displaying a shift gear position of an automatic vehicle. The switch structure 1 has a lower housing 3 which is screwed integrally with the transmission so as to penetrate the wall surface 2 of the transmission, and has a shaft hole 5 which supports the operating shaft 4. Its operating shaft 4
At the inner end surface of the lower housing 3, the center of a rubber diaphragm 6 is fixed in a fluid-tight manner by a shaft 7, and the periphery of the diaphragm 6 extends over the entire periphery thereof with the first spacer 8 and the first spacer 8. 2 and is held in a liquid-tight state on the inner peripheral surface of the housing 3 by the two spacers 9.

[0003] A spring receiving plate 10 is provided on the shaft 7.
A coil spring 13 is provided between the spring receiving plate 10 and the upper portion of the non-conductive upper housing 12 for constantly urging the operating shaft 4 downward. Is interposed.
The upper housing 12 is hermetically covered with the lower housing 3 via a packing 14. The upper housing 12 further includes a pair of terminals 1.
Inserts 5A and 15B are held in an insulated state.

[0004] Reference numeral 16 denotes both terminals 15A and 15B.
The contact holding plate 16 is an insulating contact holding plate that is positioned between the shafts. The contact holding plate 16 is axially supported by the shaft 7 so as to be movable in the axial direction. , A movable contact 17 is attached. Reference numeral 18 denotes a spring provided to increase the contact pressure between the movable contact 17 and fixed contact portions 19 formed on the terminals 15A and 15B. Reference numeral 20 denotes a cap. Reference numeral 21 denotes an inner surface of the cap 20 and an outer surface of the upper housing 12. Filler 22 is a steel ball located between the gears in the transmission 2 and the operating shaft 4.

[0005]

In the conventional switch structure having such a structure, the steel ball 22 is pushed upward in accordance with the gear position in the transmission 2, and the steel ball 22 is moved upward. The operating shaft 4 is moved by the coil spring 13
The contact holding plate 16 is pushed up by the sleeve 11 fixed to the shaft 7, so that the movable contact 17 and the terminal 15A attached to the lower surface of the contact holding plate 16 are pushed up. , 15B is released from the contact with the fixed contact portion 19 formed at the distal end portion, and the space between both terminals 15A and 15B is opened (see FIG. 7).

When the pressing force on the steel ball 22 is released due to the gear position in the transmission 2, the shaft 7 and the operating shaft 4 are pushed down by the elastic restoring force of the coil spring 13,
As a result, the pushing force of the contact holding plate 16 by the sleeve 11 fixed to the shaft 7 is released, and the contact holding plate 16 is lowered by receiving the elastic restoring force of the spring 18,
Thereby, as shown in FIG. 6, the movable contact 17 provided on the lower surface of the contact holding plate 16 and the fixed contact portion 19 formed on the terminals 15A and 15B are brought into contact with each other, whereby the gear position of the transmission is adjusted. Can be detected.

[0007] As described above, the switch structure used in the transmission is a switch having a mechanical contact structure between the movable contact 17 and the fixed contact portion 19. The use may cause poor contact due to, for example, contact corrosion or adhesion of impurities.

In the above switch structure, as means for preventing oil filled in the transmission 2 from adhering to the contacts of the switch structure,
Since the rubber diaphragm 6 is provided inside the lower housing 3 for separating the contact equipment side and the transmission side in a liquid-tight manner, the switch stroke of the operating shaft 4 to which the diaphragm 6 is fixed is naturally limited. And
It is difficult to secure a long stroke of the operating shaft 4. As a means for making it possible to set the stroke of the operating shaft 4 long, it is conceivable to use a bellows-shaped diaphragm as the above-mentioned diaphragm. If the switch is used without knowing the damage, the oil in the transmission will penetrate into the switch through the damaged part of the diaphragm, causing a switch contact failure. Conceivable.

Further, in the above-mentioned conventional switch structure, a bearing surface (gap) formed between the outer peripheral surface of the operating shaft 4 and the inner peripheral surface of the shaft hole 5 of the lower housing 3 that supports the operating shaft 4.
However, since it communicates with the inside of the transmission, impurities such as foreign metal powder and rust in the transmission may enter the gap together with the oil in the gap, which may cause malfunction of the operation shaft 4. is there.

Furthermore, the above-mentioned conventional switch structure is a push-off type switch, and in order to make it compatible with the push-on type switch, there is a problem that a drastic structural change is required.

The present invention has been made in view of the fact that such a conventional switch structure is used. For example, a switch structure to be mounted and used on a transmission has a non-contact structure, and further, a switch operation shaft and a switch support shaft are supported. It is an object of the present invention to provide a contactless switch having a configuration capable of preventing oil from entering the transmission into a transmission between the bearing and a contact body, and a configuration capable of enhancing the durability and operation reliability of the switch.

[0012]

According to the first aspect of the present invention, a Hall element is fixed inside a switch case, penetrates through the inside and outside of the switch case, and slides in the axial direction. In a non-contact switch in which a magnet for operating the Hall element is mounted on an operating shaft that is movably supported, the switch case includes a portion near an inner end of the operating shaft of the operating shaft in an axial direction of the operating shaft. An O-ring for slidably mounting a bearing body, and further providing an O-ring provided adjacent to the outside of the switch case from the mounting position of the bearing body so as to make the switch case and the operating shaft liquid-tight. It is a contactless switch provided.

According to a second aspect of the present invention, in addition to the first aspect, the bearing is a contactless switch made of sintered metal containing carbon.

According to a third aspect of the present invention, in addition to the first or second aspect, a magnet support, which is a non-magnetic material, is integrally provided at the inner end of the switch case of the operation shaft, and the movement of the operation shaft is provided on the magnet support. It is a contactless switch that supports a magnet that is magnetized in one direction.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings.

1 and 2, the structure of the contactless switch will be described first. Reference numeral 31 denotes a switch case having an open upper surface, and a screw portion 32 to the transmission 2 is provided at a lower central portion of the switch case 31 so as to protrude therefrom. Shaft hole 3
3 are drilled.

The shaft hole 33 is provided in the switch case 31.
A steel ball storage part 34, an O-ring storage step part 35, and a bearing body storage step part 36 are sequentially formed along the inside from the outside of the steel ball storage part. The steel ball 37 to be moved is stored so as to be movable upward in the switch case 31.

In the O-ring storage step 35, an O-ring for maintaining the liquid-tightness between the peripheral surface of the operating shaft 38 inserted into the shaft hole 33 and the inner peripheral surface of the shaft hole 33 is provided. 39 is located, and in the bearing body housing step 36,
A bearing body 40 that supports the operating shaft 38 slidably in the axial direction is located. The material of the bearing body 40 is
For example, it is a sintered metal containing carbon and is set so that the operating shaft 38 can be smoothly slidably supported without lubrication.

A magnet support 41, which is a non-magnetic material, is attached to the inside end of the switch case of the operating shaft 38, and a tip end of the magnet support 41 is parallel to the axial direction of the operating shaft 38. A magnet 42 having N and S poles magnetized therein is held, and this magnet 42 is molded inside a magnet support 41 by a molding material 43. Further, a flange portion 44 is formed on the operating shaft 38, and the flange portion 44
5 can be received.

Reference numeral 46 denotes a spacer located in the switch case 31. Between the spacer 46 and the spring receiving plate 45, a spring for pressing down the operating shaft 38 via the spring receiving plate 45 is provided. 47 are interposed. 48 is an O-ring 4 inside the switch case 31.
9, a circuit board 50 is attached and housed inside the connector 48 in a liquid-tight manner.

A Hall element 52 held by an IC holder 51 and a plurality of terminals 53 are connected to the circuit board 50. The sensitivity axis of the Hall element 52 is orthogonal to the operating direction of the operating shaft 38. So as to be close to the magnet 42.

Reference numeral 54 denotes a harness connected to each of the terminals 53, and reference numeral 55 denotes a filler filled between the harness 54 and the connector 48.

The above is the contactless switch structure of the present embodiment. Next, the operation will be described. When the steel ball 37 is pushed (moved up and down in FIG. 1) due to a change in the gear position in the transmission, Since the operating shaft 38 moves up and down in response to the elastic force of the spring 47 in accordance with the amount of movement of the steel ball 37, the magnet 42 molded in the magnet support 41 connected to the operating shaft 38. Moves up and down.

The vertical movement of the magnet 42 operates the Hall element 52 provided near the magnet 42, and the output from the Hall element 52 detects the gear position of the transmission. That is, the magnet 42 is operated in accordance with the gear position in the transmission, and when the magnet 42 reaches a predetermined position, the Hall element 52 is operated to detect the gear position of the transmission by a non-contact switch operation. Is available.

One of the features of the contactless switch structure having such a configuration is that the switch case 31 has a shaft support near the inner end of the switch shaft of the operation shaft 38 so as to be slidable in the axial direction of the operation shaft. Bearing body 40 to be mounted, and further disposed outside the switch case 31 outside the mounting position of the bearing body 40, the switch case 31 and the operating shaft 38
And an O-ring 39 for liquid-tightness between them. In other words, the structure in which the bearing member 40 is positioned above the operating shaft 38 allows the operating shaft 38 supported by the bearing member 40 to swing in the eccentric direction, that is, the steel ball 3.
7, when the operating shaft 38 is moved in the axial direction by the pressing force, the operating shaft 38 is less likely to swing in the eccentric direction, so that the magnet 42 and the Hall element 52
And a stable and highly accurate gear position detection is always possible.

Further, according to the above configuration, the O-ring housing step 35 is provided in the shaft hole 33 of the switch case 31 outside the switch case 31 from the mounting position of the bearing body 40. Is provided with an O-ring 39, so that oil and impurities such as metal powder do not enter between the bearing body 40 and the operating shaft 38, so that the oil enters the switch case 31. Further, it is possible to prevent the sliding of the operating shaft 38 due to the impurities beforehand, and the operation reliability of the contactless switch is good.

The second feature of the contactless switch structure is that the bearing body 40 is formed of a sintered metal containing carbon to enhance the smooth sliding of the operating shaft 38. Thus, even if oil does not enter (penetrate) between the bearing body 40 and the operating shaft 38 due to the action of the O-ring 39, the operation of the operating shaft 38 can be maintained smoothly.

The third feature of the contactless switch structure is that the magnetizing direction of the magnet 42 displaced together with the operating shaft 38 is set in a direction parallel to the direction of displacement of the magnet 42. The Hall element 52 corresponding to the magnet 42 is disposed so that the sensitivity axis is orthogonal to the direction of displacement of the magnet 42. That is, by setting the magnetization direction of the magnet 42 to a direction orthogonal to the displacement direction, as shown in FIG.
Of the Hall element 52a of the Hall element 52
The direction of the magnetic flux when passing through is reversed.

At this time, when the magnetic flux density received by the Hall element body 52a of the Hall element 52 is at the lowest position of the magnet 42 shown in FIG.
2 (a), and at the uppermost position of the magnet 42, the rightward magnetic flux can pass through the Hall element main body 52a as shown in FIG. 3 (b). The operating point of the Hall element 52 (Bo
p) can be located on the + side of the magnetic flux density reference value (0), and the return point (Brp) of the Hall element 52 can be located on the-side.

Therefore, the operating point (Bop) and the return point (B) of the Hall element 52 are increased by increasing the slope of the curve at the zero cross point of the characteristic line (A) of the present invention shown in FIG.
rp) is a symmetrical position with respect to the magnetic flux density reference value (0), whereby the amount of voltage change for turning on and off the Hall element 52 can be increased. The reliability and reliability of the on / off operation of the hall element 52 can be improved. The characteristic line (B) shows a conventional characteristic line in which the magnetizing direction of the magnet is set in a direction parallel to the axial direction of the operating shaft 38. In this case, the magnet is displaced from the lowermost position to the uppermost position. At this time, the direction of the magnetic flux passing through the Hall element main body 52a does not reverse. That is, it becomes a gentle curve like the curve (B) in FIG.

[0031]

As described above, according to the contactless switch of the present invention, the distance between the axis of the magnet 42 and the Hall element 52 does not vary, and the Hall element 5
Since the amount of voltage change for causing the on / off operation of the switch 2 can be increased, the operation accuracy of the contactless switch can be improved, and the operation reliability and reliability thereof can be improved.

Further, the bearing of the operating shaft can be smoothed without lubrication of oil or the like between the operating shaft 38 and the bearing body 40, thereby providing a non-contact point having excellent durability. A switch can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a contactless switch according to the present invention.

FIG. 2 is a bottom view of FIG.

FIGS. 3A and 3B are diagrams for explaining the action of magnetic flux by a magnet on a Hall element, wherein FIG. 3A shows when the operating shaft is lowered, and FIG. 3B shows when the operating shaft is raised.

4 is a characteristic diagram showing a magnetic flux density acting on a Hall element and an output change amount of the Hall element in FIG. 3;

FIG. 5 is an explanatory sectional view showing a conventional switch.

FIG. 6 is an explanatory diagram of an operation of a main part of the switch structure in FIG. 5;

FIG. 7 is an operation explanatory diagram of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 ... Switch case 32 ... Screw part 33 ... Shaft hole 34 ... Steel ball storage part 35 ... O-ring storage step part 36 ... Bearing body storage step part 37 ... Steel ball 38 ... Operating shaft 39 ... O-ring 40 ... Bearing body 41 ... Magnet support 42 ... Magnet 43 ... Mold material 44 ... Flange 45 ... Spring receiving plate 46 ... Spacer 47 ... Spring 48 ... Connector 49 ... O-ring 50 ... Circuit board 51 ... IC holder 52 ... Hall element 53 ... Terminal

Claims (3)

[Claims] An operating shaft (38) which fixes a Hall element (52) inside a switch case (31), penetrates the inside and outside of the switch case (31), and slidably supports in the axial direction. Further, in the non-contact switch having a magnet (42) for operating the Hall element (52) attached thereto, the switch case (31) includes the operating shaft (3).
In the vicinity of the inner end of the switch case 8), the operating shaft (3
8) A bearing body (40) that is slidably supported in the axial direction is attached, and the switch body (31) and the switch case (31) are disposed adjacent to the outside of the switch case from the mounting position of the bearing body (40). A non-contact switch characterized by comprising an O-ring (39) for liquid-tightness between the operating shaft (38). 2. The contactless switch according to claim 1, wherein the bearing body is a sintered metal containing carbon. 3. A switch case (3) for an operating shaft (38).
1) A non-magnetic magnet support (4
The magnet support (41) is provided integrally with the magnet support (41) and supports a magnet (42) magnetized in the moving direction of the operating shaft (38).
Or the non-contact switch according to 2.