JP4328574B2 - Switch waterproof boots - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waterproof boot used for a switch having a shaft for switching contacts by operating in a linear direction.
[0002]
[Prior art]
[Patent Document 1]
Japanese Utility Model Publication No. Hei 7-19925 [0003]
As a conventional boot of this type, a structure as described in Patent Document 1 is known, and water, mud, dust, dust, and the like are prevented from entering from a fitting portion between the switch case and the shaft depending on the use environment. Therefore, the shaft is surrounded by a flexible boot that opens at both ends, and one end of the boot is fixedly fitted to the end of the switch case, and the other end of the boot is fitted into a groove formed in the shaft. It is glued to.
[0004]
FIG. 5 shows an example in which this type of conventional boot is mounted on a switch, and is a side view partly in section. The switch 21 includes a switch body 22 and a terminal base 23. A shaft 25 protrudes from a shaft insertion hole 24 formed in the switch body 22 in which a fixed contact and a movable contact (not shown) are built, and the shaft 25 is an arrow. The contact is switched by sliding in the 5A direction. Here, in order to prevent water and dust from entering through the gap between the shaft insertion hole 24 and the shaft 25, the shaft insertion hole 24 is covered with a flexible boot 26 formed of a flexible material such as rubber. The boot 26 has a uniform bellows portion 27 having a uniform thickness so that the boot 26 can expand and contract. The switch tightening portion 28 of the boot 26 is fixedly fitted to an attachment portion 29 formed on the switch body 22, and the shaft tightening portion 30 of the boot 26 is fixedly fitted to a groove portion 31 formed on the shaft 25. A boot 26 is attached to the switch body 22 and the shaft 25. When the shaft 25 slides in the direction of the arrow 5A, the bellows portion 27 of the boot 26 expands and contracts to absorb the stroke of the shaft 25. The bellows portion 27 includes a first peak portion 32 and a second peak portion 33, and each peak portion includes inclined portions 34, 35, 36, a lead-out portion 37, top portions 38, 39, and a valley portion 40.
[Problems to be solved by the invention]
[0005]
The operation of such a conventional switch will be described with reference to FIGS. 6 (a), 6 (b), and 6 (c). The switch 21 is used, for example, to detect an operating position of a brake pedal (not shown) of the vehicle. As shown in FIG. 6A, when the switch 21 attached to the vehicle body is in a normal state, the shaft 25 of the switch 21 is pushed leftward in the drawing by the operating member 41 formed integrally with the brake pedal. As described above, since the shaft tightening portion 30 of the boot 26 is fixedly fitted to the groove portion 31 formed at the tip of the shaft 25, the inclined portion 34 of the boot 26 is deformed into a concave shape, and the top portion 38 is the operating member. 41 is in contact. When the operator of the vehicle depresses the brake pedal from this state, the actuating member 41 moves in the right direction in the drawing, and the shaft 25 urged in the right direction in the drawing by a spring (not shown) incorporated in the switch 21 accordingly. Move to. At this time, the shape of the boot 26 having elasticity is restored, but the force that restores the shape of the second mountain portion 33 by the lead-out portion 37 that is substantially parallel to the central axis of the shaft 25 is deformed into a concave shape inside the boot 26. Since the force is larger than the force for restoring the shape of the inclined portion 34, the shapes of the inclined portion 36 and the inclined portion 35 are first restored as shown in FIG. 6B, and the top portion 38 of the first peak portion 32 is the actuating member 41. Remains in contact with. When the brake pedal is further depressed from here, the shaft 25 also moves to the right as the actuating member 41 moves to the right in the drawing, the boot 26 moves away from the actuating member 41, and the shape of the mountain portion 32 is restored. As shown in FIG. 6C, the shaft 25 extends to the maximum position.
[0006]
Conversely, if the vehicle operator weakens the force of stepping on the brake pedal from the state of FIG. 6 (c), the actuating member 41 moves to the left in the drawing, and accordingly the shaft 25 also moves to the left, The boot 26 is compressed. At this time, the force for compressing the boot 26 is transmitted from the shaft tightening portion 30 of the boot 26 fitted to the groove portion 31 of the shaft 25 to the boot 26, and the inclined portion 34 closest to the shaft tightening portion 30 is first deformed into a concave shape. Then, the peak portion 33 is maintained without changing its shape, and the top portion 38 is in contact with the actuating member 41 as shown in FIG. When the force to depress the brake pedal is further weakened, the actuating member 41 and the shaft 25 move to the left in the drawing, the boot 26 is further compressed, and when the operator of the vehicle releases the foot from the brake pedal, FIG. As shown, the bellows portion 27 is compressed by the actuating member 41.
[0007]
Thus, in the conventional switch 21, as shown in FIG. 6 (a), when the top portion 38 of the mountain portion 32 is normally in pressure contact with the operating member 41 and the operating member 41 is made of metal, this state If this is a long period of time, the top 38 that is in pressure contact with the operating member 41 may be welded to the operating member 41 due to heat. In addition, when the shaft 25 of the switch 21 shown in FIG. 6C is pressed leftward from the maximum position, the inclined portion 34 of the boot 26 is deformed into a concave shape in the state shown in FIG. 6B. Therefore, the top portion 38 of the peak portion 32 comes into contact with the operating member 41, and the top portion 38 is pushed in while contacting the operating member 41 until the state shown in FIG. Therefore, the top portion 38 of the boot 26 is a portion that is easily worn by friction with the operating member 41. If such an operation is repeated for a long period of time, the top portion 38 of the boot 26 will be worn and cracked, causing the waterproof and dustproof function of the switch 21 to be impaired.
[0008]
In view of the circumstances described above, it is an object of the present invention to provide a waterproof boot for a switch that can suppress wear and improve durability and ensure waterproofness and dustproofness.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, according to a first aspect of the present invention, there is provided a switch body having a built-in contact and a shaft projecting from the switch body sliding in response to an operating member attached to a vehicle. A switch comprising a flexible boot that opens and closes and tightly surrounds a shaft insertion hole of the switch body, wherein the boot includes a shaft tightening portion that elastically tightens a distal end portion of the shaft, and the switch A switch tightening portion attached to the body, and at least two peak portions of a second peak portion that forms a valley between the first peak portion and the first peak portion that extends from the shaft tightening portion, and is connected to the first peak portion. The first inclined portion from the connecting portion of the shaft tightening portion of the first peak portion to the top of the first peak portion has an inclination angle formed with respect to the central axis of the shaft. The second inclined portion extending from the top of one mountain portion to the valley portion has an acute angle with respect to the central axis of the shaft, and the inclined angle formed by the second mountain portion with respect to the central axis of the shaft. The thickness of the first inclined portion is larger than the thickness of the second inclined portion and the second peak portion.
[0010]
According to a second invention, in the first invention, an inclination angle formed by the second inclined portion with respect to the central axis of the shaft is greater than an inclination angle formed by the second peak portion with respect to the central axis of the shaft. An acute angle is used, and the thickness of the first peak is thicker than that of the second peak.
[0011]
According to a third invention, in the first invention, an inclination angle formed by an inner surface side of the first inclined portion with respect to a central axis of the shaft is defined, and an inner surface side inclination of the second inclined portion is defined by the shaft. The inclination angle formed with respect to the central axis of the shaft and the inclination on the inner surface side of the second peak portion are set to be more acute than the inclination angle formed with respect to the central axis of the shaft.
[0012]
According to a fourth invention, in the third invention, an inclination angle formed by an inner surface side of the second inclined portion with respect to a central axis of the shaft, and an inner surface side inclination of the second mountain portion is the shaft. It is set as the structure made into an acute angle rather than the inclination-angle made with respect to the center axis line.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, the waterproof structure of the switch according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a state in which the switch 1 of the first embodiment is attached to an automobile. Reference numeral 1 denotes a switch, and a fixed contact (not shown) and a movable body (not shown) provided with a movable contact are built in the switch body 2. The switch body 2 is formed with an engaging portion 2a that engages with a terminal base 4 to be described later, and a screw portion 2b for attaching the switch body 2 to a desired attachment position. The shaft 3 connected to the movable contact is slidably fitted in the axial direction. Reference numeral 4 denotes a terminal base formed of a resin material. A claw portion 4 a formed on the terminal base 4 is engaged with an engaging portion 2 a of the switch body 2. The terminal base 4 is connected to an external device (not shown), and is configured so that an ON-OFF signal of the switch 1 is transmitted to the external device via the terminal base 4. The switch body 2 is provided with a boot 5 that covers the shaft 3. The boot 5 is made of an elastic material such as rubber.
[0014]
The switch 1 is used for detecting the position of an operating member 6 formed integrally with a brake pedal (not shown) of an automobile. An attachment hole (not shown) for fitting the bush 8 is formed in the bracket 7 of the vehicle body, and the bush 8 is attached to the attachment hole. The bush 8 is provided with an insertion hole (not shown) for inserting a screw portion 2b formed in the switch body 2 of the switch 1, and the screw portion 2b of the switch 1 is inserted into the insertion hole of the bush 8. The switch 1 is mounted at a desired position by fixing the screw portion 2b to the bush 8.
[0015]
FIG. 2 is a side view of a part of the switch 1 in cross section. The switch body 2 has a boot mounting portion 2c formed with an annular groove, and the shaft 3 is slidable in the direction of arrow 2A from a shaft insertion hole 2d formed at the center of the boot mounting portion 2c. It protrudes. An annular groove 3 a is formed at the tip of the shaft 3. In FIG. 2, an annular switch tightening portion 5 a formed at one end of the boot 5 is fixedly fitted to the boot mounting portion 2 c of the switch body 2, and an annular formed at the other end of the boot 5. The shaft tightening portion 5 b is fixedly fitted to the groove portion 3 a of the shaft 3. In this way, the boot 5 is pressure-bonded to the switch body 2 and the shaft 3 to improve airtightness, and waterproof and dustproof from the shaft insertion hole 2d are ensured.
[0016]
The boot 5 has a cylindrical shape and expands and contracts when a force in the axial direction of the shaft 3 is applied to the bellows portion 9. The bellows part 9 of the boot 5 of this embodiment is comprised from the 1st peak part 10, the 2nd peak part 11, and the trough part 12, and if it says in detail, the 1st peak part 10 will be the 1st inclination part 10a, the 2nd. The second peak portion 11 includes a third inclined portion 11a, a lead-out portion 11b, and a top portion 11c. Here, the inner surface inclination angle formed by the inclination of the first inclined portion 10 a on the inner surface side of the boot 5 with respect to the central axis 2 A of the shaft 3 is θ _1, and the inclination of the third inclined portion 11 a on the inner surface side of the boot 5 is When the inner surface inclination angle formed relative to the central axis 2A and theta _3, the inner surface inclination angle theta ₁ is formed at an acute angle (inner angle of inclination theta _{1 <inner} surface inclination angle theta ₃₎ from the inner surface inclination angle theta _3. On the other hand, the outer surface inclination angle of the first inclined portion 10a is the same as that of the second inclined portion 10b. Accordingly, the thickness in the vicinity of the top portion 10c of the thickness of the first inclined portion 10a is formed to be thicker than the thickness of the second inclined portion 10b and the third inclined portion 11a. Thus, the thickness of the first inclined portion 10a can be increased only by changing the inner surface inclination angle of the boot 5, and the outer shape of the boot 5 remains unchanged, so that the mold is changed greatly. This is unnecessary, and the strength of the boot 5 can be improved while suppressing the manufacturing cost.
[0017]
Next, the operation of the switch 1 of the present embodiment will be described with reference to FIGS. 3 (a) to 3 (c). 3A is a side view showing the boot 5 in a state before the operation of the switch 1, FIG. 3B is a side view showing the boot 5 in a state immediately after the operation of the switch 1, and FIG. It is a side view which shows the boot 5 in the state in which the shaft 3 of the full stroke was carried out. As shown in FIG. 3A, when the switch 1 attached to the vehicle body is in a normal state, the shaft 3 of the switch 1 is pushed leftward by the operating member 6 such as a brake pedal, for example, and the boot 5 is operated by the operating member 6. Is pressed and pressed. Here, as described above, since the thickness of the first inclined portion 10a is formed to be thicker in the vicinity of the top portion 10c, the top portion 10c of the first peak portion 10 does not come into contact with the operating member 6 and is curved first. A part of the inclined portion 10 a is in pressure contact with the operating member 6. When the operator of the vehicle depresses the brake pedal from the state of FIG. 3A, the actuating member 6 moves to the right in the drawing, and accordingly the shaft 3 also moves to the right. Here, the inner inclination angle of the boot 5 of the first inclined portion 10a is θ ₁ , and the inner inclination angle of the boot 5 of the third inclined portion 11a is more acute than θ ₃ (inner inclination angle θ ₁ <inner inclination angle θ ₃ ). The thickness of the first inclined portion 10a in the vicinity of the top portion 10c is thicker than the thickness of the second inclined portion 10b and the third inclined portion 11a. The restoring force due to the elasticity of the boot 5 of the portion 10a is larger than the restoring force of the second inclined portion 10b and the third inclined portion 11a, and the shape of the first inclined portion 10a is first as shown in FIG. Will be restored. Thereafter, when the brake pedal is further depressed, the shaft 3 moves to the right as the actuating member 6 moves to the right in the drawing, and the shaft 25 extends to the maximum position as shown in FIG. Become.
[0018]
Conversely, if the vehicle operator weakens the force of stepping on the brake pedal from the state of FIG. 3 (c), the actuating member 6 moves to the left in the drawing, and accordingly the shaft 3 also moves to the left, The boot 5 is compressed. Here, as described above, the inner surface inclination angle θ ₁ of the first inclined portion 10 a is formed at an acute angle (inner surface inclination angle θ ₁ <inner surface inclination angle θ ₃ ) than the inner surface inclination angle θ ₃ of the third inclination portion 11 a. Moreover, since the thickness of the 1st inclination part 10a is formed thicker than the thickness of the 2nd inclination part 10b and the 3rd inclination part 11a, the 1st inclination part 10a is concave like conventional. While the shape is maintained without being deformed, the second inclined portion 10b centering on the valley portion 12 and the third inclined portion 11a are compressed so as to overlap each other, and as shown in FIG. Ten top portions 10c and the top portion 11c of the second peak portion 11 are in contact with each other. When the force to step on the brake pedal is further weakened, the actuating member 6 and the shaft 3 move to the left in the drawing and the boot 5 is further compressed. However, the thickness of the first inclined portion 10a is formed thicker in the vicinity of the top portion 10c. Therefore, the top portion 10c of the first peak portion 10 does not come into contact with the actuating member 6 as in the prior art, and a part of the curved first inclined portion 10a comes into contact, so that the operator takes his foot from the brake pedal. When released, the bellows portion 9 comes into pressure contact with the actuating member 6 as shown in FIG.
[0019]
Thus, in the course of the boot 5 is expanded and contracted, since the first inclined portion 10a can maintain the shape while maintaining the inner surface inclination angle theta _1, top 10c first inclined portion 10a are deformed in a concave shape is the actuating member 6 The boot 5 is prevented from being worn by friction with the actuating member 6 without being pushed in while abutting. 3A, even when the bellows portion 9 of the boot 5 is pressed against the operating member 6 and completely compressed, the operating member 6 is different from the top portion 10c of the first peak portion 10 as in the prior art. The first inclined portion 10 a having a large thickness is not curved but is configured to be curved and to be in contact with the operating member 6. For this reason, wear and deterioration of the boot 5 due to pressure contact and friction with the actuating member 6 can be suppressed to a minimum, and durability is enhanced for long-term use.
[0020]
Next, the waterproof structure of the switch according to the second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the configuration of the boot in the waterproof structure of the switch according to the first embodiment described above is changed. Therefore, the same configuration is denoted by the same reference numeral, and the description thereof is omitted.
[0021]
FIG. 4 is a side view of a part of the switch 1 according to the second embodiment. In the boot 13 in this embodiment, the inner surface inclination angle θ ₁ formed by the inclination of the inner surface side of the boot 13 of the first inclined portion 15 a of the first mountain portion 15 with respect to the central axis 4 B of the shaft 3, and the second mountain portion 11. The inner surface inclination angle θ ₃ formed by the inclination of the inner surface side of the boot 13 of the third inclined portion 11a with respect to the central axis 4B of the shaft ₃ is the same as in the first embodiment, and the second inclined portion 15b of the first peak portion 15 is the same. the inner surface inclination angle as theta ₂ which forms with respect to the central axis 4B the inner surface of the side inclination of the shaft 3 of the boot 13, the inner surface inclination angle inner surface inclination angle theta ₂ in the same manner as the inner surface inclination angle theta ₁ of the first inclined portion 15a It is formed at an acute angle than θ _3. That is, the inner surface inclination angle θ ₁ <the inner surface inclination angle θ ₃ and the inner surface inclination angle θ ₂ <the inner surface inclination angle θ ₃ . Moreover, since the outer surface inclination | tilt angle of the 1st peak part 15 is the same as that of a 1st Example, the thickness of the top part 15c vicinity is the 3rd inclination part among the thickness of the 1st inclination part 15a and the 2nd inclination part 15b. It is formed to be thicker than the wall thickness of 11a or valley 12. That is, the thickness of the top portion 15 c of the first peak portion 15 is formed to be thicker than the thickness of the valley portion 12 and the top portion 11 c of the second peak portion 11. In this way, the thickness of the first peak portion 15 can be increased simply by changing the inner surface inclination angle of the boot 13, and the outer shape of the boot 13 remains unchanged, so the mold is greatly changed. Therefore, the strength of the boot 13 can be improved while suppressing the manufacturing cost.
[0022]
Although the operation of the second embodiment of the boot 13 is similar to the first embodiment, in the second embodiment is an acute angle the inner surface inclination angle theta ₂ of the second inclined portion 15b, and a second inclined portion 15b Unlike the configuration of the first embodiment in that the thickness of the top portion 15c is increased, when the bellows portion 14 of the boot 13 is extended, the shape of the first peak portion 15 is first restored, and then The shape of the second mountain portion 11 is restored. When the bellows portion 14 of the boot 13 to the compression operation, the second convex portion 11 is compressed first with the third inclined portion 11a of the inner surface inclination angle theta ₃ is most obtuse, the first crest portion 15 thereafter Is compressed. Further, when the shaft 3 of the switch 1 is pressed by the operating member 6 and the bellows portion 14 of the boot 13 is in pressure contact with the operating member 6, the portion closer to the top portion 15 c of the first peak portion 15 is closer to the first inclined portion 15 a. And since the thickness of the 2nd inclination part 15b is formed thickly, the top part 15c of the 1st peak part 15 contact | abuts a part of the bent 1st inclination part 15a, without contact | abutting with the action | operation member 6. FIG. Thus, since the shape of the 1st peak part 15 can be maintained more reliably, the friction with the operating member 6 and the top part 15c of a vehicle can be eliminated, and the location which frictions with the operating member 6 is thick. Since the first inclined surface 15a is formed to be thick and has a low burden, wear and deterioration of the boot 13 due to pressure contact and friction with the actuating member 6 can be minimized, and it is durable against long-term use. Increases nature.
[0023]
In the first and second embodiments described above, the bellows-structured boot having two ridges has been described. However, the present invention is not limited to this and can be applied to boots having more bellows structures. . Moreover, you may use for not only the switch which detects the operating position of a brake pedal as described in the Example but various switch apparatuses. Although the inner surface inclination angle of the boot has been described, the same effect can be obtained even when the outer surface inclination angle and the inner surface inclination angle are formed equal in the case of newly making a mold.
[0024]
【The invention's effect】
The waterproof structure of the switch according to the present invention can maintain the inclination angle of the first inclined portion when the switch is operated to expand and contract the boot, and the portion where the boot is pressed against the operating member is formed thick. Since the first inclined surface is formed, the wear and deterioration of the boot due to the pressure contact and friction with the operating member can be minimized, and the durability becomes high for long-term use.
[0025]
According to the second invention, when the bellows part expands and contracts, the shape of the first peak part is more reliably maintained, so that the durability of the boot can be further improved.
[0026]
According to the third aspect of the present invention, the thickness of the first inclined portion can be increased only by changing the inner surface inclination angle of the boot, and the outer shape of the boot remains unchanged, so that the die must be changed greatly. Therefore, it is possible to improve the strength of the boot while suppressing the manufacturing cost.
[0027]
According to the fourth invention, the thickness of the first peak portion can be increased only by changing the inner surface inclination angle of the boot, so that the outer shape of the boot remains unchanged, so the die is greatly changed. There is no need, and the strength of the boot can be improved while suppressing the manufacturing cost.
[0028]
[Brief description of the drawings]
FIG. 1 is a side view showing a state in which a switch according to a first embodiment of the present invention is attached to an automobile.
FIG. 2 is a side view showing a cross section of a part of the switch according to the first embodiment of the present invention.
3A is a side view showing the boot 5 in a state before the operation of the switch 1, and FIG. 3B is a boot in a state immediately after the operation of the switch 1, in the switch according to the embodiment of the present invention. FIG. 3C is a side view showing the boot 5 in a state where the shaft 3 of the switch 1 has made a full stroke.
FIG. 4 is a side view, partly in section, of a switch according to a second embodiment of the present invention.
FIG. 5 is a side view showing an example of a conventional switch, partly in cross section.
6A and 6B show an example of a conventional switch. FIG. 6A is a side view showing a main part of the switch in a state before the operation, and FIG. 6B is a side view showing a main part of the switch immediately after the operation. FIG. 6 (c) is a side view showing the main part of the switch in a state where the shaft has a full stroke.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Switch 2 Switch body 2b Screw part 2c Boot attachment part 2d Shaft insertion hole 3 Shaft 3a Groove part 4 Terminal base 5, 13 Boot 5a, 13a Switch tightening part 5b, 13b Shaft tightening part 6 Actuating member 7 Bracket 8 Bushing 9, 14 Bellows parts 10 and 15 first crest portion 10a, 15a first inclined portion 10b, 15b second inclined portions 10c, 15c apex 11 second convex portion 11a third inclined portion 11b deriving unit 11c apex 12 valleys theta ₁ first inclined portion The inner surface inclination angle θ ₂ The inner surface inclination angle θ of the second inclined portion ₃ The inner surface inclination angle of the third inclined portion

Claims (4)

A switch body with a built-in contact and a shaft projecting from the switch body slide in response to an operating member attached to the vehicle to open and close the contact, and the shaft insertion hole of the switch body is hermetically sealed In the switch including the flexible boot that surrounds, the boot includes a shaft tightening portion that elastically tightens a tip end portion of the shaft, a switch tightening portion that is attached to the switch body, and the shaft tightening portion. Providing a bellows part having at least two peak parts of a second peak part connecting and forming a valley part between the extended first peak part and the first peak part; A second inclined portion extending from the top of the first peak to the trough formed by the first inclined portion extending from the connecting portion of the shaft tightening portion to the top of the first peak with respect to the central axis of the shaft. The inclination angle formed with respect to the central axis of the shaft is more acute than the inclination angle formed with the second peak portion with respect to the central axis of the shaft, and the thickness of the first inclined portion is A waterproof boot for a switch, wherein the waterproof boot is formed thicker than the thickness of the second inclined portion and the second peak portion. The inclination angle formed by the second inclined portion with respect to the central axis of the shaft is set to an acute angle than the inclination angle formed by the second peak portion with respect to the central axis of the shaft, and the thickness of the first peak portion is 2. The waterproof boot for a switch according to claim 1, wherein the waterproof boot is formed thicker than the two mountain portions. The inclination angle formed by the inner surface side of the first inclined portion with respect to the central axis of the shaft, the inclination angle formed by the inner surface side of the second inclined portion with respect to the central axis of the shaft, and the second 2. The waterproof boot for a switch according to claim 1, wherein an inclination on an inner surface side of the mountain portion is an acute angle than an inclination angle formed with respect to a central axis of the shaft. The inclination angle formed by the inclination on the inner surface side of the second inclined portion with respect to the central axis line of the shaft is more acute than the inclination angle formed by the inclination on the inner surface side of the second peak portion with respect to the central axis line of the shaft. The waterproof boot for a switch according to claim 3, wherein the switch is waterproof.

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