JP2001297671A - Sensor switch structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor switch structure having a high safety level for preventing the permeation of cutting water or the like therein. SOLUTION: A sensor element 24, to which a cord 21 is connected, is mounted in a sensor case 10. A cord bush 25 is provided at the rear rend of the sensor case 10 and the cord 21 is passed through a cord insertion groove 27 of the cord bush 25 and pulled outside of the sensor case 10. A fill passage 31, communicating inside/outside the sensor case 10, is formed by an opening portion 29 of the cord insertion groove 27 and the inner face of the sensor case. A fill 30 is refilled from the fill passage 31, and the sensor case 10 is sealed. If the cord 21 is bent by the cord bush 25, the bending of the cord 21 in the sensor case 10 is prevented, no gap is formed between the cord 21 and the fill 30, and producing an increase in water-proofing safety is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor switch structure in which a filler is filled in a sensor case containing a sensor element, and more particularly, to a sensor mounting groove provided along an axial direction on an outer peripheral surface of a hydraulic cylinder. And a sensor switch structure for detecting a piston position.

[0002]

2. Description of the Related Art Conventionally, in a sensor switch, a filler is filled in the sensor case in order to prevent malfunction of the sensor switch due to intrusion of liquid such as cutting water into the sensor case. As such a sensor switch structure, for example, there is one disclosed in Design Publication H1-553. This is because the sensor case has a tubular shape with both ends opened in the longitudinal direction, a sensor element is provided inside the sensor case, a filler is filled, and a cord drawn from the sensor element is placed on one end of the sensor case. The sensor case is inserted through the attached cord bush to the outside of the sensor case, and the other end of the sensor case is closed by a lid.

[0003] In the device disclosed in Japanese Patent Application Laid-Open No. 6-324131, a sensor element is accommodated in a substantially box-shaped resin case, which is filled with a filler and hermetically sealed. In addition, the cable connected to the sensor element is drawn out of the resin case via a packing connector that is tightened by an elastic body. In the device disclosed in Japanese Patent Application Laid-Open No. 9-218111, the outer periphery of the stacked element is covered with a metal cylindrical protector in a state where the stacked element is protruded. A lead wire is connected to the laminated element, and the lead wire is inserted through a bush made of silicon rubber or the like. The inside of the cylindrical protector is filled with an inorganic adhesive, and the laminated element is covered and fixed to the upper end.When inserting the laminated element into the cylindrical protector filled with the inorganic adhesive, the bush and the cylindrical The fitting gap between the protector and the protector serves as an escape path for air, and after inserting the laminated element, the tubular protector is caulked to fix the bush.

[0004]

In the above, the sensor element is inserted into the sensor case and filled with the filler.
A cord bush for pulling out the cord is attached to one end, and a lid member is attached to the other end to close both ends of the sensor case.When closing the sensor case, air may remain in the sensor case. Yes, it is not possible to refill the filler, so the sensor element inside is not completely molded and the reliability is low, and the fact that the sensor element is located close to the lid member also lowers the reliability. I have. If there is no interference between the cord bush and the cord, a gap may be formed between the cord bush and the cord and between the cord and the filler due to a temperature change. Liquid or the like enters through this gap,
There is a possibility that the sensor switch may malfunction, and there is a problem that the safety of the sensor switch in holding the molded state is low. Furthermore, since the sensor case is cylindrical, both ends are open, so that the sensor case must be closed by attaching a lid, and there is a problem that the number of parts increases.

[0005] Further, since the cable connected to the detecting element is fastened by an elastic packing connector, a gap is hardly formed between the cable and the packing connector due to a temperature change, but when the packing connector is soft. When the cable is bent, the packing connector is also easily bent together with the cable, a gap is formed between the packing connector and the cable, and the bending of the cable is transmitted even inside the filler, and a gap is also formed between the cable and the filler. There is fear. Liquid or the like may enter through this gap, causing a malfunction of the sensor switch, and there is a problem that the safety of the sensor switch in holding the molded state is low.

When the packing connector is soft, the tightening is increased so that there is no gap between the cable and the packing connector when the cable is bent.
To increase the interference, the cable insertion hole for inserting the cable of the packing connector must be made relatively small with respect to the outer shape of the cable.If the cable insertion hole is made relatively small, the cable will be inserted into the packing connector. When the packing connector is passed, the packing connector expands greatly in the outer peripheral direction of the packing connector. Therefore, when this packing connector is provided in a cylindrical sensor case, the elastic force of the packing connector acts on the sensor case, and in a small sensor switch mounted in a sensor mounting groove or the like of a fluid pressure cylinder,
The sensor case may be damaged.

Further, since the lead wire is inserted through a bush made of silicon rubber or the like, a gap may be formed between the bush and the lead wire when the lead wire is bent as described above. In addition, the cylindrical protector is caulked after filling with the inorganic adhesive, and the cylindrical protector has both ends open, so it is necessary to devise a way to prevent the inorganic adhesive from flowing out when filling the inorganic adhesive. In addition, the assembling work becomes complicated, and it may be difficult to swage depending on the shape of the tubular protector.

[0008] An object of the present invention is to make it easier for air in the sensor case to escape when the sensor element is installed or when filling with a filler, thereby increasing the sealing performance in the sensor case, and bending the cord or changing the temperature of the cord. It is an object of the present invention to provide a highly safe sensor switch structure in which a gap is hardly formed between a cord and a filler due to shrinkage caused by the above, and a penetration of cutting water or the like can be prevented.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a sensor switch structure in which a filler is filled in a sensor case in which a sensor element is provided, and a cord connected to the sensor element is passed through a cord bush attached to the sensor case. It is drawn out and filled with a filler through a filling path provided so as to communicate with the inside and outside of the sensor case in this state (claim 1). According to this, since the cord is drawn out of the sensor case via the cord bush, even if the cord is bent, the cord bush prevents the cord in the case from being bent, so that no gap is generated between the cord and the filler, Cutting water does not enter the sensor case.
Further, since the filling path is provided, the filling material can be filled again after the sensor element is provided in the sensor case, and the reinforcement by the filling material in the sensor case is strengthened, which is preferable.

The filling path is also an air vent path. According to this, when the sensor element is mounted in the sensor case filled with the filler or when refilling, air is released from the filling path, so that the sensor element and the connection portion between the sensor element and the cord can be reliably molded. Thus, the reliability of the sensor switch is increased.

[0011] The cord bushing and the cord have an interference for tightening each other. According to this, even if the cord contracts due to a temperature change, it is possible to prevent the generation of a gap due to the interference.

[0012] The filling path is formed between the cord bush and the sensor case.

More specifically, a cord insertion groove through which the cord is inserted into the code bush is formed, and the cord bush having the cord inserted through the code insertion groove is attached to the sensor case. A filling path was formed between the opening and the inner surface of the sensor case.

The cord bush is provided with an insertion hole through which a cord is inserted, and the insertion hole is provided with a small-diameter hole having substantially the same diameter as the cord diameter, and the small-diameter hole when the code bush is attached to the sensor case. A filling space that can be filled with a filler between the cord outer peripheral surface on the inner side in the axial direction, a first filling hole communicating with the filling space from the cord bush outer surface is provided in the code bush, and the sensor case has: A second filling hole is provided at a position corresponding to the first filling hole with the cord bush attached to the sensor case to form a filling path.

[0015] Either the outer surface of the cord bush or the sensor case is provided with an engagement piece having elasticity and provided with an engagement claw at the tip, and an engagement hole with which the engagement claw is engaged is provided on the other side. Item 7). The code bush can be easily positioned in the sensor case by the engagement between the engagement claw and the engagement hole, and molding can be facilitated.

The sensor case can be mounted in a sensor mounting groove provided on the outer peripheral surface of the fluid pressure cylinder along the axial direction.

More specifically, a portion to be pressed is opposed to the opening of the sensor mounting groove along the axial direction of the cylinder tube in the width direction of the mounting groove, and the sensor case is pressed against the inner surface of the portion to be pressed. It was formed in a shape corresponding to the sensor mounting groove having a pressure contact portion (claim 9).

A receiving hole having a rectangular cross section penetrating in the width direction of the sensor case is provided at a tip portion of the sensor case, and a square nut having substantially the same shape as the receiving hole is inserted into the receiving hole. A through-hole was provided at a position corresponding to the threaded portion, and a screw member passed through the through-hole was screwed into a square nut, and the press-contact portion was configured to be able to press against the inner surface of the portion to be pressed by tightening the screw member. (Claim 10). According to this, the square nut is inserted into the accommodation hole provided in the sensor case, and the screw member passed through the through hole is screwed into the square nut. It does not fall from the sensor case.
By preventing the square nut from falling, the sensor case does not need a screw portion, which is preferable.

More specifically, the sensor case has an inclined surface in which the upper surfaces of the left and right pressure contact portions are inclined downward toward the outside in the width direction of the sensor case, and left and right side surfaces which are continuous with the left and right inclined surfaces and extend downward. And a semicircular bottom surface that is continuous on the left and right sides, and the sensor mounting groove is formed in a substantially similar shape corresponding to the shape of the sensor case. According to this,
When the sensor case is mounted in the sensor mounting groove, it is preferable that the sensor case is automatically positioned by the inclined surface.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a sensor mounting groove 3 is formed on the outer peripheral surface of a cylinder tube (cylinder main body) 2 of a rodless cylinder 1 shown as a fluid pressure cylinder over the entire length in the axial direction. As shown in FIG. 2, the sensor mounting groove 3 is provided with pressure-contacting parts 5 projecting from the opening 4 side of the sensor mounting groove 3 along the axial direction of the cylinder tube 2 in the width direction of the sensor mounting groove. A slit is formed between the press contact portions 5 so that the inside of the sensor mounting groove 3 is wide and the opening 4 side is narrow. As shown in FIG. 2, the inner surfaces of the pressed portions 5 face each other, and
The inclined surface 6 is inclined downward from the portion continuous to the groove width inner surface 8 (inclined from the portion continuous to the opening 4 toward the groove bottom surface 7 outwardly in the groove width direction). The sensor mounting groove 3 is continuous with the semicircular bottom surface 7 in FIG. 2, the left and right side surfaces 8, 8 of the groove width direction inner surface continuous with the bottom surface 7 and extending toward the outer peripheral surface of the cylinder tube 2, and the left and right side surfaces 8, 8. Inclined surfaces 6 and 6 of the pressed portion 5
And is formed from

The sensor switch 9 is provided in the sensor mounting groove 3.
And a magnet provided on a piston (not shown) moving back and forth in the axial direction in the cylinder tube 2 can be detected. The sensor case 10 corresponds to the cross-sectional shape of the sensor mounting groove 3 and has a slightly smaller size than the sensor mounting groove 3 so as to be accommodated in the sensor mounting groove 3. That is, a pressure contact portion 11 that presses against the pressure contact portion 5 is formed on both shoulder portions of the sensor case 10, and the upper surface of the pressure contact portion 11 has an inclined surface parallel to the inclined surfaces 6 and 6 of the pressure contact portion 5. 12, 12. The outer shape of the sensor case 10 is formed of a semicircular bottom surface 13, left and right side surfaces 14, 14 continuous with the bottom surface 13, and the left and right inclined surfaces 12, 12 continuous with left and right side surfaces 14, 14.

As shown in FIG. 2, a projection 15 is formed in the upper part of the sensor case 10 within the opening 4 of the sensor mounting groove 3. As shown in FIG. A receiving hole 16 having a quadrangular cross-section penetrating the sensor case 10 in the width direction is provided at a tip portion in the axial direction of the sensor case 10. A square nut 17, which is a fixing member having substantially the same shape as the accommodation hole 16, is inserted into the accommodation hole 16.

As shown in FIG. 4, the sensor case 10 has an interior space 23 in which the rear end opposite to the housing hole 16 is an open end 22. The sensor element 24 is inserted into the interior space 23 from the opening end 22. A signal or power supply cord 21 is connected to the rear end of the sensor element 24. This code 21
Are drawn out of the sensor case 10 via the code bush 25. The cord bush 25 is formed of a resin material such as nylon or PBT, and has an outer shape substantially similar to the inner shape of the sensor case 10 as shown in FIG. Groove 2
7 are provided. The cord insertion groove 27 is
A cord insertion portion 28 having substantially the same diameter as the outer diameter of the cord into which
And an opening 29 having a width dimension smaller than the inner diameter of the cord insertion portion 28.

The interior space 23 of the sensor case 10 is filled with a filler 30, and the sensor element 24 is inserted into the interior space 23 filled with the filler 30. Sensor element 24
As shown in FIG. 5, a cord bush 25 is inserted into the open end 22 of the interior space 23 in which the
The cord 21 is drawn out of the sensor case 10 via the cable 5. Also, the sensor case 10 and the cord bush 25
A filling path 31 is formed between the two. The filling path 31 is formed by the inner surface of the interior space 23, the opening 29 of the cord bush 25, and the outer peripheral surface 33 of the cord 21.
And the outside of the sensor case 10.

The filling material 30 is again filled into the interior space 23 provided with the sensor element 24 via the filling path 31, and the space between the sensor case 10 and the cord bush 25 or the filling path 3 is filled.
The filling material 30 is also filled in 1, and the sensor element 24 and the code bush 25 are molded and fixed in the sensor case 10. When the sensor element 24 is inserted into the interior space 23 or when the filler 30 is refilled, the filling path 31 serves as an air vent for discharging air from the interior space 23, and the inside of the sensor case 10 is filled with the filler 30. Thus, it is possible to securely seal. When the filler 30 is refilled with air from the air vent passage 31, air is released, so that the molding state of the filler 30 is assured and safety is enhanced. When the sensor case 10, the sensor element 24, the cord bush 25, and the cord 21 are integrated as described above, even if the cord 21 is bent, the cord 21 is reinforced at the portion where the cord bush 25 is inserted, and the bend is formed by the cord bush 25. The cord 21 and the filler (mold part) 30 in the sensor case 21 are obstructed.
Can be prevented from forming a gap therebetween, the reliability of the waterproof function of the sensor switch is improved, and malfunctions can be prevented. Since only one end of the sensor case 21 is open, it is not necessary to provide a cover as in the related art or to devise a way to prevent the filler from flowing out for filling the filler. Since the member 30 is integrated with the sensor case 21, there is no need to separately attach a code bush.

The thickness of the square nut 17 is
Sensor case 10 is thinner than the dimension T in the thickness direction,
6, when the sensor case 10 is stored in the left and right side surfaces 14,
14 is almost the same. Square nut 1
A thread (female thread) 18 is formed at the center of 7.
When the square nut 17 is accommodated in the accommodation hole 16, a through hole 19 penetrating in the thickness direction of the sensor case 10 is provided at a position corresponding to the screw portion 18 of the square nut 17 of the sensor case 10.
Is provided. A screw member 20 is passed through the through hole 19, and the screw member 20 is screwed to the square nut 17. In a state where the screw member 20 and the square nut 17 are screwed together, the screw member 20 and the square nut 17 are integrally formed with the sensor case 10 so as not to fall off without screwing the screw portion into the through hole 19. The rotation of the square nut 17 in the accommodation hole 16 having a quadrangular cross section is also prevented, so that the square nut 17 does not fall out of the accommodation hole 16.

The sensor switch 9 is inserted into the sensor mounting groove 3 from the axial direction of the cylinder tube 2 in a state where the screw member 20 and the square nut 17 are integrated with the sensor case 10, and detects an appropriate piston position. Placed in the position for When the screw member 20 of the sensor switch 9 inserted into the sensor mounting groove 3 is tightened, the square nut 1
7 presses against the upper surface of the housing hole 16, whereby the inclined surfaces 12, 12 of the sensor case 10 are
Is pressed against. At this time, the inclined surfaces 12, 1 of the press contact portion 11
Due to the pressure contact between the pressure contact portion 2 and the inclined surfaces 6, 6 of the pressed portion 5, a positioning force is applied to the sensor case 10 toward the center of the sensor mounting groove 3 in the width direction, and the sensor case 10 is automatically positioned. Further, since the sensor case 10 itself is pressed against the sensor mounting groove 3, the sensor case 10 is fixed to the sensor mounting groove 3 without rattling.

Next, another embodiment will be described with reference to FIGS.
This will be described below. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Cord bush 2
5A is provided with an insertion hole 34 for drawing out the cord 21 from the inside of the sensor case 10A to the outside. This insertion hole 34
The small diameter hole 35 having substantially the same diameter as the outer diameter of the cord 21 and the small diameter hole 3 when the cord bush 25A is attached to the sensor case 10.
5 between the notch groove 36 and the outer peripheral surface 33 of the cord formed in the sensor case 10A in the axial direction inside the sensor case 10A and radially outside the sensor case 10A from the small-diameter hole 35 so as to go around the inner periphery of the sensor case 10A. And a filling space 36a that can be filled with the filling material 30 formed therebetween. A first filling hole 37 communicating with the filling space 36a is provided on the bottom surface (lower side wall) of the cord bush 25A. The upper surface of the cord bush 25A is formed with an engagement piece 38 having elasticity and extending in the axial direction of the code bush 25A, and the tip of the engagement piece 38 is formed as an engagement claw 39. The sensor case 10A is provided with an engagement hole 40 in which the engagement claw 39 is engaged with the projection 15 at the rear end portion. When the code bush 25A is attached to the sensor case 10A, the first filling hole 37 of the code bush 25A is provided.
A second filling hole 41 is provided at a position corresponding to.

When the sensor element 24 is inserted into the sensor case 10A, the engaging claws 39 of the cord bush 25A engage with the engaging holes 40 to be fitted therein, whereby the cord bush 25A is easily positioned, and the cord bush 25A is easily positioned. The first filling hole 37 of 25A communicates with the second filling hole 41 of the sensor case 10A, and the interior space 23 and the outside communicate with each other through the first and second filling holes 37 and 41 and the filling space 36a. Filling path 3
1. The filling path 31 is for refilling the filler 30 after the insertion of the sensor element 24, as in the above-described embodiment, and for inserting the sensor element 24 and refilling the filler 30. And the air is exhausted by the refilling of the filler 30 to close the air, and the inside of the sensor case 10A is securely sealed. Further, similarly to the above-described embodiment, the bending of the cord 21 is prevented by the cord bush 25A and the molded state of the joint portion between the cord and the sensor case is maintained, so that a gap is generated between the cord 21 and the molded part. Intrusion of cutting water and the like is prevented, safety is enhanced, and malfunction of the sensor switch can be prevented.

In the first and second embodiments, the inner diameter of the small-diameter hole 35 of the cord insertion portion 28 and the code insertion hole 34 is made slightly smaller than the outer diameter of the cord 21, and the cord bush 2.
If the 5, 21A is provided with an interference that can be fitted to the outer periphery of the cord 21, even if the cord 21 contracts due to a temperature change, the gap created between the cord 21 and the cord bushing 25, 25A is absorbed by the interference, and further waterproof. The function is improved and is suitable. It is sufficient that the interference is such that a gap can be prevented. When the cord bushings 25, 25A in which the cords 21 are inserted are attached to the sensor cases 10, 10A, the influence of the bulging of the cord bushes 25, 25A is reduced. The sensor case 10, 10A is set to such an extent that it does not receive much.

[0031]

As described above, according to the present invention, since the cord connected to the sensor element via the cord bush from the sensor case is drawn out of the sensor case, the cord is prevented from being bent by the cord bush and the cord is bent. A gap is not formed due to this, and the waterproof function is improved. Further, since the filler can be refilled from the filling path and the filling path serves as an air vent path, the inside of the sensor case is reliably sealed, and the reliability of the sensor switch is increased. In addition, by providing the interference between the cord bush and the cord, the contraction of the cord due to the temperature change is absorbed, so that no gap is formed, and the holding of the molded state is further enhanced. In addition, by providing an engagement claw on one of the cord bush and the sensor case and providing an engagement hole on the other to engage, the code bush can be easily positioned on the sensor case, and the molding operation can be easily performed.

Further, the shoulder portion of the sensor case is formed in a pressure contact portion having an inclined surface, and the inclined surface of the sensor case is pressed against the inclined inner surface of the pressure contact portion of the sensor mounting groove provided in the fluid pressure cylinder. This is suitable because the sensor case is automatically positioned in the sensor mounting groove. Furthermore, a square nut is inserted into the accommodation hole provided in the sensor case, and the screw member that has passed through the through hole of the sensor case is screwed into the square nut. Does not fall from the sensor case.
By preventing the square nut from falling, the sensor case does not need a screw portion, which is preferable.

[Brief description of the drawings]

FIG. 1 is a diagram showing attachment of a sensor switch to a hydraulic cylinder.

FIG. 2 is a sectional view of a sensor mounting groove in which a sensor switch is mounted.

FIG. 3 is a perspective view schematically showing a sensor switch.

FIG. 4 is a longitudinal sectional view of the sensor switch.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is another embodiment.

FIG. 7 is a perspective view showing a cord bush according to another embodiment.

8 is a sectional view taken along line VIII-VIII in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid pressure cylinder 3 Sensor mounting groove 5 Pressure contact part 9 Sensor switch 10, 10A Sensor case 11 Pressure contact part 12 Inclined surface 13 Bottom surface 14 Side surface 16 Housing hole 17 Square nut 18 Screw portion 19 Through hole 20 Screw member 21 Code 22 Open end 24 sensor element 25, 25A cord bush 27 cord insertion groove 29 opening portion 30 filler 31 filling path (air vent path) 33 cord outer peripheral surface 34 insertion hole 35 small diameter hole 36a filling space 37 filling hole 38 engaging piece 39 engaging claw 40 Engagement hole 41 Filling hole

Claims (11)

[Claims] In a sensor switch structure in which a filler is filled in a sensor case in which a sensor element is mounted, a cord connected to the sensor element is drawn out of the sensor case through a cord bush attached to the sensor case. A sensor switch structure characterized by being filled with a filler through a filling path provided so as to communicate with the inside and outside of the case. 2. The sensor switch structure according to claim 1, wherein the filling path is also an air vent path. 3. The sensor switch structure according to claim 1, wherein the cord bushing and the cord have an interference for tightening each other. 4. The sensor switch structure according to claim 1, wherein the filling path is formed between the cord bush and the sensor case. 5. A cord outer peripheral surface and an opening portion of a code insertion groove in a state where a code insertion groove through which a code is inserted is formed in a code bush, and the code bush having the code inserted through the code insertion groove is attached to a sensor case. The sensor switch structure according to any one of claims 1 to 4, wherein a filling path is formed with an inner surface of the sensor case. 6. A cord bush is provided with an insertion hole through which a cord is inserted, and the insertion hole is provided with a small-diameter hole having substantially the same diameter as the cord.
When the code bush is attached to the sensor case, it is formed from a filling space that can be filled with filler between the small diameter hole of the sensor case in the axial direction of the sensor case and the outer peripheral surface of the code, and the code bush is filled from the outer surface of the code bush. A first filling hole communicating with the space is provided, and a second filling hole is provided in the sensor case at a position corresponding to the first filling hole in a state where the code bush is attached to the sensor case to form a filling path. The sensor switch structure according to any one of claims 1 to 4, wherein: 7. An engaging piece having elasticity on one of an outer surface of a cord bush and a sensor case and having an engaging claw provided at a tip thereof, and an engaging hole for engaging the engaging claw is provided on the other. The sensor switch structure according to any one of claims 1 to 6, wherein: 8. The sensor switch structure according to claim 1, wherein the sensor case is mountable in a sensor mounting groove provided along an axial direction on an outer peripheral surface of the fluid pressure cylinder. 9. A pressure contact portion which protrudes from the opening side of the sensor mounting groove along the axial direction of the cylinder tube in the width direction of the mounting groove and which presses the sensor case against the inner surface of the pressure contact portion. 9. The sensor switch structure according to claim 8, wherein the sensor switch has a shape corresponding to the sensor mounting groove. 10. A receiving hole having a quadrangular cross section penetrating in the width direction of the sensor case is provided at a tip portion of the sensor case, and a square nut having substantially the same shape as the receiving hole is inserted into the receiving hole. A through-hole is provided at a position corresponding to the threaded portion of the nut, and a screw member passed through the through-hole is screwed into a square nut, and the press-contact portion can be pressed against the inner surface of the portion to be pressed by tightening the screw member. The sensor switch structure according to claim 9, wherein: 11. The sensor case has an inclined surface in which the upper surfaces of the left and right press contact portions are inclined downward toward the outside in the width direction of the sensor case, left and right side surfaces which are continuous with the left and right inclined surfaces and extend downward, and left and right side surfaces. 11. The sensor switch structure according to claim 9, further comprising a continuous semicircular bottom surface, wherein the sensor mounting groove is formed in a substantially similar shape corresponding to the shape of the sensor case.