JP2020159861A - Stroke sensor - Google Patents

Abstract

To provide a stroke sensor which can reduce the cost by making the structure simpler.SOLUTION: A stroke sensor 1 for detecting the amount of movement S of a detection shaft 10 moving from an original position O in association with a detection target body includes: the detection shaft 10; a first housing 20; a second housing 30 supporting the detection shaft 10 and taking out the detection shaft to the outside; and a spring 40 for returning the detection shaft 10 having moved from the original position O to the original position O. The detection shaft 10 has an elliptical flange 14 and the flange 14 holds a washer 18 supporting the spring 40.SELECTED DRAWING: Figure 2

Description

The present invention relates to a stroke sensor.

As a sensor that detects the amount of movement of a moving body such as a lever of an automobile or a two-wheeled vehicle, for example, there is one disclosed in Patent Document 1.
The shift rod device described in Patent Document 1 includes a piston, a first plunger, a second plunger, a first spring, a second spring, a stopper pin, and a magnet, and these components have the same axis inside the shift rod body. A structure for stroking along the line was provided.

Japanese Unexamined Patent Publication No. 2015-105002

However, the shift rod device described in Patent Document 1 has a problem that the structure becomes complicated and the number of parts increases because the origin return mechanism includes a piston, two plungers, and two springs.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a stroke sensor having a simplified structure and reduced cost.

In order to achieve the above object, the stroke sensor according to the present invention is
A stroke sensor that detects the amount of movement of the detection shaft that follows the object to be detected and moves from the origin position.
With the detection shaft
The first housing and
A second housing that supports the detection shaft and takes it out,
A spring for returning the detection shaft after moving from the origin position to the origin position is provided.
The detection shaft has a large diameter portion formed by two substantially D-shaped notches.
The spring is in contact with the first housing and the large diameter portion when the detection shaft is at the origin position.
It is characterized by that.

According to the present invention, it is possible to provide a stroke sensor having a simplified structure and reduced cost.

It is a top view of the stroke sensor of this invention. It is sectional drawing of AA of the stroke sensor of this invention. It is a figure for demonstrating the washer in the stroke sensor of this invention. It is a figure for demonstrating the flange and washer in the stroke sensor of this invention. It is a cross-sectional view of AA when the detection shaft of the stroke sensor of this invention moves in the direction of the first housing. FIG. 5 is a cross-sectional view taken along the line AA when the detection shaft of the stroke sensor of the present invention is moved toward the second housing.

The stroke sensor according to the present invention will be described below with reference to the accompanying drawings.

Refer to FIGS. 1 and 2. FIG. 1 shows a plan view of the stroke sensor 1, and FIG. 2 shows a cross-sectional view taken along the line AA of the stroke sensor 1.
The stroke sensor 1 includes a detection shaft 10, a first housing 20, a second housing 30, and a spring 40. Further, the stroke sensor 1 includes a magnet 51 that moves together with the detection shaft 10 and a magnetic detection element 52 that detects the movement amount S of the magnet 51.

The detection shaft 10 is a detection medium that is followed by the movement of the detected body. For example, the detection shaft 10 is connected to the detected body, an external force is transmitted, and the detection shaft 10 reciprocates and follows in the axial direction. The detection shaft 10 is preferably made of a non-magnetic material having a certain degree of rigidity, and is made of, for example, austenitic stainless steel (SUS: Steel Use Stainless).

The detection shaft 10 has a columnar large diameter portion 11, a middle diameter portion 12, and a small diameter portion 13 having different diameters. The detection shaft 10 may be formed by cutting a rod-shaped workpiece, or may be formed by casting or injection molding.

The large diameter portion 11 is arranged in the first housing 20 and supports the first washer 18a.

The middle diameter portion 12 is formed so as to project from the large diameter portion 11, has a magnet storage portion 19 described later, is arranged in the first housing 20, and slides a shaft support portion 22 described later.

The small diameter portion 13 projects outward from the shaft hole 33 of the second housing 30 and is connected to a body to be detected (not shown).

The flange 14 is an elliptical overhang provided on the small diameter portion 13. The flange 14 supports the second washer 18b. The length of the flange 14 in the longitudinal direction is equal to the inner diameter d of the washer 18 described later, and the thickness of the flange 14 is formed to be thicker than the depth of the hole portion 32 described later.

The airtight member 15 is an O-ring made of rubber and is held by a groove provided in the small diameter portion 13. The airtight member 15 is used to maintain the airtightness of the stroke sensor 1, and the groove is configured to satisfy the groove structure necessary for exerting the airtight function of the airtight member 15.

3 and 4 are also referred to. FIG. 3 is a diagram for explaining the structure of the washer 18, and FIG. 4 is a diagram for explaining the relationship between the flange 14 and the washer 18.
3 (A) is a perspective view of the washer 18, FIG. 3 (B) is a bottom view of the washer 18, and FIG. 3 (C) is a sectional view taken along line BB of the washer 18.
The washer 18 is a plate-shaped washer made of a non-magnetic material, and is formed in an oval track shape having two sides 181 and 182 notched by a circle. The washer 18 is larger than the hole 32 and the spring 40 of the second housing 30 described later, and is configured to be the same as the inner surface of the wall 35 of the second housing 30 described later. The washer 18 is designed to withstand the thrust load when it comes into contact with another member due to the movement of the detection shaft 10.
The inner diameter d of the washer 18 is equal to the length in the longitudinal direction of the flange 14, and the inner diameter thereof has protrusions 183 that support the flange 14 and grooves 184 and 185 that fit the flange 14 on both sides of the protrusion 183. The protrusion 183 is provided in the longitudinal direction of the washer 18, and the depth of the grooves 184 and 185 is formed to be shallower than the thickness of the flange 14.
As a result, the operator can allow the washer 18 to pass through the flange 14 by aligning the longitudinal direction of the flange 14 with the lateral direction of the washer 18 (without the protrusion 183) (FIG. 4A). After that, the operator rotates the washer 18 by 90 degrees (FIG. 4B) so that the flange 14 supports the protrusion 183, and the flange 14 and the groove 184 or 185 are fitted to detect the washer 18. It is held by the shaft 10.
Even if the washer 18 is composed of only the protrusion 183 and one groove 184 (or groove 185), the washer 18 can be fitted to the flange 14 and held on the detection shaft 10. However, since the washer 18 has the protrusion 183 and the two grooves 184 and 185, it is not necessary to worry about the vertical orientation of the washer 18 when assembling the stroke sensor 1, and the assembling property is improved.
The stroke sensor 1 has a first washer 18a in contact with the large diameter portion 11 and a second washer 18b in contact with the flange 14. The first washer 18a may be a general O-shaped washer. However, by sharing the first washer 18a and the second washer 18b, the types of parts are reduced, and the parts are not mistaken for each other when the stroke sensor 1 is assembled, so that the assembling property is improved.

The magnet storage portion 19 is formed by hollowing out the tip of the middle diameter portion 12, and stores the magnet 51 and fixes and holds the magnet 51 with an adhesive or the like.

The first housing 20 includes a first receiving portion 21 that receives the large diameter portion 11 of the detection shaft 10, a shaft support portion 22, a first washer support portion 23, a substrate accommodating portion 25, and a female screw portion 29. Consists of having.

The first housing 20 is preferably made of a non-magnetic material such as aluminum or stainless steel, and is formed in a substantially cylindrical shape.

The first receiving portion 21 is a surface provided inside the first housing 20 and comes into contact with the large diameter portion 11 of the detection shaft 10 to limit the movement amount S of the detection shaft 10. The length from the origin position O to the first receiving portion 21 is configured to be smaller than the maximum amount of deflection of the spring 40.

The shaft support portion 22 is provided inside the first housing 20 and is formed as a groove that supports the middle diameter portion 12 of the detection shaft 10.

The first washer support portion 23 is a surface provided inside the first housing 20, and is in contact with the first washer 18a when the detection shaft 10 is at the origin position O.

The substrate housing portion 25 is configured by digging down the surface of the first housing 20, and is used for arranging the magnetic detection element 52, which will be described later, close to the magnet 51 of the detection shaft 10. The board housing portion 25 is provided with screw holes for mounting the board 50, which will be described later.

The female screw portion 29 is provided on the inner diameter surface of the first housing 20, and is used to connect the first housing 20 and the second housing 30.

The second housing 30 includes a second receiving portion 31 that receives the flange 14 of the detection shaft 10, a hole portion 32, a shaft hole 33, a second washer support portion 34, a wall 35, and a surface processing portion 38. And a male screw portion 39.

The second housing 30 is preferably made of a non-magnetic material such as aluminum or stainless steel, and is formed in a substantially cylindrical shape.

The second receiving portion 31 is a surface provided at the bottom of the hole portion 32, which will be described later, and receives the flange 14 of the detection shaft 10 to limit the movement amount S of the detection shaft 10. The length from the origin position O to the second receiving portion 31 is configured to be smaller than the maximum amount of deflection of the spring 40.

The hole 32 is provided inside the second housing 30, and its diameter is larger than the flange 14 and smaller than the washer 18.

The shaft hole 33 slidably supports the small diameter portion 13 of the detection shaft 10 and takes it out.

The second washer support portion 34 is a surface provided on the outer periphery of the hole portion 32, and its diameter is larger than that of the hole portion 32 and is substantially the same as that of the second washer 18b.

The wall 35 is a wall provided inside the second housing 30, and has a base portion 35a formed in an oval shape under the wall 35, which is fitted with a washer 18.
The base portion 35a is formed at a height in contact with the second washer 18b even if the detection shaft 10 moves in the direction of the first housing 20 by the amount of movement S.
As a result, the detection shaft 10 is prevented from rotating by fitting the second washer 18b held by the flange 14 with the inner surface of the base portion 35a of the wall 35, and sliding can be performed with high accuracy.

The chamfered portion 38 is a portion where the end of the second housing 30 is chamfered so as to have a polygonal shape. As a result, the second housing 30 can be turned with a wrench or a spanner, and the connection with the first housing 20 becomes easy.

The male threaded portion 39 is provided on the outer surface of the wall 35 and is used to connect the first housing 20 and the second housing 30. At the time of the connection, a reinforcing adhesive (for example, a seal lock agent) may be used to further prevent the screws from loosening.

The spring 40 is preferably a stainless steel wire, an oil tempered wire made of iron or an iron alloy, or the like, and is composed of, for example, a cylindrical coil spring made of SUS304WPB, SWOSC-B, SWOSC-V, or the like.

The spring 40 is configured to pass the detection shaft 10 inside, and when the detection shaft 10 is at the origin position O, one end of the spring 40 is a first washer 18a and another end of the spring 40 is a second washer. It is in contact with 18b.

See FIG. FIG. 5 is a cross-sectional view taken along the line AA when the detection shaft 10 is moved so as to be pushed in the direction of the first housing 20.
When the detection shaft 10 at the origin position O is moved so as to be pushed in the direction of the first housing 20, the second washer 18b supported by the flange 14 pushes the spring 40, and the first washer support portion 23 Supports the first washer 18a, the spring 40 is crushed, and the large diameter portion 11 of the detection shaft 10 moves by the amount of movement S until it hits the first receiving portion 21 of the first housing 20. be able to.
Then, when the force for pushing the detection shaft 10 disappears, the spring force accumulated in the spring 40 returns the detection shaft 10 to the origin position O.

See FIG. FIG. 6 is a cross-sectional view taken along the line AA when the detection shaft 10 is moved so as to be pulled in the direction of the second housing 30.
When the detection shaft 10 at the origin position O is moved so as to be pulled in the direction of the second housing 30, the first washer 18a supported by the large diameter portion 11 pushes the spring 40 and supports the second washer. The second washer 18b supported by the portion 34 supports the spring 40, so that the spring 40 is crushed and the flange 14 of the detection shaft 10 moves until it hits the second receiving portion 31 of the second housing 30. It can be moved by the amount S.
Then, when the force for pulling in the detection shaft 10 disappears, the spring force accumulated in the spring 40 returns the detection shaft 10 to the origin position O.

The magnet 51 is made of a rare earth magnet (for example, a magnet made of a material such as SmCo or NdFeB) formed in a columnar shape, and is attached to a magnet storage portion 19 of the detection shaft 10.

The magnet 51 provides a magnetic field to the magnetic detection element 52, and the magnet 51 moves together with the detection shaft 10 to change the direction and strength of the magnetic field applied to the magnetic detection element 52, resulting in the magnetic detection element 52. Detected as the amount of movement S. The magnet 51 may be either a sintered magnet or a plastic magnet that is compressed or molded by mixing with plastic according to a manufacturing method. Sintered magnets have stronger magnetic force, while plastic magnets have characteristics such as higher mass productivity and crack resistance. Therefore, they may be appropriately selected according to usage conditions and design requirements.

The magnetic detection element 52 detects changes in the position and amount of movement of the object to be detected by the direction and strength of the magnetic field. The change is converted into an electric signal and output to the outside.

The detection of the movement amount S of the detection shaft 10 by the magnetic detection element 52 detects a change in the direction and strength of the magnetic field generated by the magnet 51 provided in the detection shaft 10 and converts it into an electric signal corresponding to the magnetic field. Output to the outside.

The substrate 50 is a printed circuit board (PCB) made of glass epoxy or the like, and includes a magnetic detection element 52. The substrate 50 is fixed to the substrate accommodating portion 25 with screws, and is hermetically sealed by filling the substrate accommodating portion 25 with a sealing member 60 such as epoxy resin.

The electric code 53 is used to take in the power supply to the magnetic detection element 52 of the substrate 50 and output the electric signal to the outside. The grommet 54 protects the electric cord 53 from the end surface of the substrate housing portion 25.
A direct connector, a coupler, or the like may be used instead of the electric cord 53 for taking in the power supply to the magnetic detection element 52 of the substrate 50 and outputting the electric signal to the outside.

For the sealing member 60, for example, an epoxy resin or the like is used. The sealing member 60 is injected into the substrate housing portion 25 of the first housing 20 and cured to hermetically seal the magnetic detection element 52 and the substrate 50.

The embodiments described above have the following effects.

A stroke sensor 1 that detects the amount of movement S of the detection shaft 10 that follows the object to be detected and moves from the origin position O.
Detection shaft 10 and
The first housing 20 and
A second housing 30 that supports the detection shaft 10 and takes it out,
A spring 40 for returning the detection shaft 10 after moving from the origin position O to the origin position O is provided.
The detection shaft 10 has an elliptical flange 14.
The flange 14 holds a washer 18 that supports the spring 40.

In the stroke sensor 1, the flange 14 holds the washer 18 that supports the spring 40, so that the origin return mechanism of the detection shaft 10 can be configured, the number of parts can be reduced, and the structure can be simplified.

In the stroke sensor 1,
The washer 18 has a protrusion 183 supported by the flange 14 and a groove 184 that fits the flange 14.

In the stroke sensor 1, the flange 14 supports the protrusion 183, and the flange 14 and the groove 184 are fitted so that the washer 18 can be held on the detection shaft 10.

In the stroke sensor 1,
The protrusion 183 is sandwiched between the two grooves 184 and 185.

Since the stroke sensor 1 has two grooves 184 and 185 on both sides of the protrusion 183, it is not necessary to worry about the vertical orientation of the washer 18 when assembling the stroke sensor 1, and the assembling property is improved.

In the stroke sensor 1,
The washer 18 has an oval shape having two sides 181, 182 notched out of a circle.
The second housing 30 has a wall 35 that fits into the oval shape of the washer 18.

The stroke sensor 1 is prevented from rotating by fitting the washer 18 held on the flange 14 and the wall 35, and the detection shaft 10 can be slid with high accuracy.

The present invention is not limited to the above aspects and drawings. Changes (including deletion of components) can be made as appropriate without changing the gist of the present invention.

1 Stroke sensor 10 Detection shaft 11 Large diameter 12 Large middle diameter 13 Small diameter 14 Flange 18 Washers 181, 182 Sides 183 Protrusions 184, 185 Grooves 20 First housing 21 First receiving part 23 First washer support 30 Second housing 31 Second receiving part 32 Hole part 34 Second washer support part 35 Wall 35a Base part 40 Spring 50 Board 51 Magnet 52 Magnetic detection element 60 Sealing member O Origin position S Movement amount

Claims (4)

A stroke sensor that detects the amount of movement of the detection shaft that follows the object to be detected and moves from the origin position.
With the detection shaft
The first housing and
A second housing that supports the detection shaft and takes it out,
A spring for returning the detection shaft after moving from the origin position to the origin position is provided.
The detection shaft has an elliptical flange and
The flange holds a washer that supports the spring.
Stroke sensor. The washer has a protrusion supported by the flange and a groove that fits the flange.
The stroke sensor according to claim 1. The protrusion is sandwiched between the two grooves.
The stroke sensor according to claim 2. The washer has an oval shape having two sides cut out of a circle.
The second housing has a wall that fits into the oval shape of the washer.
The stroke sensor according to any one of claims 1 to 3.

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