JPH0822743A - Rotary limit switch - Google Patents

Abstract

PURPOSE:To lengthen the service life of a rotary limit switch by heightening waterproof performance and dustproof performance in a slidingly movable part of a rotary shaft. CONSTITUTION:In a rotary limit switch where a rotary shaft 4 to press and displace an internally trimmed switching actuator 6 is rotatably supported with a head 3 of a case body 2 and a detecting lever 5 is connected to a projecting part of this rotary shaft 4, an oil seal 10 having a lip is provided in an outside part of a slidingly movable part between the rotary shaft 4 and the head 3. A grease storage groove 11 is arranged on the inmost side, and a cross- sectional X-shaped sealing ring 13 is provided further on the inmost side of the slidingly movable part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary type limit switch used for detecting an operation limit position of various mechanical devices.

[0002]

2. Description of the Related Art A rotary type limit switch has a structure in which a rotary shaft for pressing and displacing an internal switching actuator is rotatably supported by a head of a case, and a detection lever is connected to a protruding portion of the rotary shaft. In addition, an O-ring was attached to the sliding portion of the rotating shaft for waterproofing and dustproofing. Further, in order to improve durability, grease is applied to the sliding portion of the rotary shaft.

[0003]

In the above conventional structure, the following problems may occur.

When the contact pressure is set high in order to make the O-ring sufficiently waterproof and dustproof,
The rotation resistance of the rotating shaft increases.

The applied grease may flow out and become out of oil after a long period of use, and the rotation resistance of the rotating shaft may be significantly increased.

When used in a machine tool or the like, cutting oil may swell the O-ring and increase the contact pressure, which may increase the rotational resistance of the rotary shaft, resulting in poor return of the rotary shaft.

The present invention has been made in view of such a situation, and an object thereof is to suppress the occurrence of the above-mentioned problems by improving the seal structure.

[0008]

In order to achieve the above object, the present invention has the following constitution. That is, the invention according to claim 1 is a rotary type in which a rotary shaft for pressing and displacing an internal switching actuator is rotatably supported by a head of a case, and a detection lever is connected to a protrusion of the rotary shaft. In the limit switch, a seal member is provided at an outer portion of a sliding portion between the rotary shaft and the head, and a grease storage groove is provided on the inner back side thereof.

A second aspect of the invention is the invention of the first aspect, wherein the grease storage groove is formed in a spiral shape.

A third aspect of the present invention is the invention of the first aspect, wherein a plurality of the grease storage grooves are formed.

According to a fourth aspect of the invention, in any one of the first to third aspects of the invention, the seal member is an oil seal with a lip.

According to a fifth aspect of the invention, in any one of the first to third aspects of the invention, the seal member is a seal ring having a C-shaped cross section.

According to a sixth aspect of the present invention, in the first aspect of the invention, a seal ring having an X-shaped cross section is provided further inside the sliding portion of the grease storage groove. .

[0014]

According to the structure of the invention according to claim 1, the waterproof and dustproof functions by the seal member and the waterproof and dustproof functions by the liquid sealing function by the grease stored in the grease storage groove are exhibited.

According to the configuration of the invention according to claim 2, while exhibiting the above-mentioned function of the invention according to claim 1, a large amount of grease stored in the grease storage groove is supplied to a wide range in the axial direction.

According to the configuration of the invention of claim 3, the above-mentioned function of the invention of claim 1 is exerted, and the liquid sealing parts are formed at a plurality of positions in the axial direction and the grease is widely spread in the axial direction. Is supplied.

According to the structure of the invention of claim 4, since the lip portion, which is easily elastically deformed, is brought into sliding contact with the lip portion, good waterproofness and dustproofness can be obtained without particularly increasing the contact pressure. Further, even if the oil seal swells due to cutting oil or the like, the swelling is easily absorbed by the elastic deformation of the lip portion.

According to the structure of the fifth aspect of the invention, even if the seal ring having a C-shaped cross section swells with cutting oil or the like, C
Since the cavity inside the shape is deformed, the increase of contact pressure is suppressed.

According to the sixth aspect of the invention, the waterproof and dustproof functions of the oil seal, the waterproof and dustproof functions of the liquid seal function of the grease stored in the grease storage groove, and the waterproofing of the X-shaped seal ring. And the dustproof function works threefold. In addition, the grease filled by the oil seal and the seal ring is prevented from flowing in and out.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of a rotary type limit switch according to the present invention will be described below with reference to the drawings.

[First Embodiment] FIGS. 1 to 4 show a first embodiment and a modification thereof.

As shown in FIG. 1, a rotary type limit switch 1 has a main body case 2 having a not-shown switching mechanism, an operating head 3 connected to the upper portion of the main body case 2, and the head 3 rotatably mounted on the head 3. A pressing member 8 urged downward by a spring 7 on the upper surface of a flat portion 4a formed by cutting and forming a part of the rotary shaft 4 and including a rotary shaft 4 and a detection lever 5 connected and fixed to the outer end of the rotary shaft 4. The lower end flat surface is pressed and abutted, the rotary shaft 4 is held in a neutral posture, and the actuator (plunger) 6 biased upwardly is received and supported by the lower surface of the flat portion 4a. And
When the detection target object comes into contact with the roller 5a at the tip of the detection lever 5 from either the left or right direction and a rotational operation force is applied to the rotation shaft 4 in either the left or right direction, the flat portion 4 of the rotation shaft 4 is applied.
a rotates while pushing up the pressing member 8 against the urging force of the spring 7 to displace it, and pushes down the actuator 6 at the lower surface of the flat portion 4a to switch on, and the operating force to the detection lever 5 is released. Then, the rotating shaft 4 is returned to the original neutral posture by the pressing force applied from the pressing member 8 to the upper surface of the flat portion 4a, and accordingly, the actuator 6 is also returned and lifted to return to the switch-off state. Has become.

In the rotary type limit switch 1 having the above structure, the seal structure in the sliding portion between the shaft insertion hole 9 formed in the head 3 and the rotary shaft 4 is constructed as follows.

That is, an oil seal 10 with a lip, which is an example of a seal member, is press-fitted to the outer end of the shaft insertion hole 9, and the lip 10a is in contact with the outer peripheral surface of the rotary shaft 4. In addition, a V-shaped grease storage groove 11 is formed on the outer peripheral surface of the rotary shaft 4 at the inner rear portion of the sealing portion, and an annular groove 12 formed on the outer peripheral surface of the rotary shaft 4 at the inner rear portion. A seal ring 13 having an X-shaped cross section is fitted in and attached to.

According to this seal structure, the oil seal 1
Waterproof and dustproof function by 0 and grease storage groove 11
The waterproof and dustproof functions by the liquid sealing function by the grease stored in and the waterproof and dustproof functions by the X-shaped seal ring 13 work threefold to exert extremely high sealing performance. Also, the oil seal 10 and the seal ring 1
3 suppresses the grease filled in and out from the inside and outside.

As shown in FIG. 4, when a plurality of grease storage grooves are formed between the oil seal and the seal ring, higher sealing performance and lubricity can be exhibited.

[Second Embodiment] FIGS. 5 to 8 show a second embodiment and a modification thereof.

Since the structure of the limit switch 1 itself in this embodiment is similar to that of the previous example, the description of the structure is omitted and only the seal structure of the rotary shaft 4 will be described.

In this example, an O-ring 14 similar to the conventional one is used as a seal member, and is fitted and mounted in an annular groove 15 formed in the rotary shaft 4, and further on the inner peripheral side thereof, on the outer peripheral surface of the rotary shaft 4. Groove 16 for storing grease with V-shaped cross section
Are formed in a spiral shape, and both ends of the grease storage groove 16 are connected to the annular groove 16a.

According to this seal structure, the O-ring 14 provides a waterproof and dustproof function, and the grease stored in the grease storage groove 16 provides a waterproof and dustproof function due to the liquid sealing function. A large amount of stored grease is supplied to a wide range in the axial direction, and high lubrication performance is exhibited.

As shown in FIG. 7, by making the grease storage groove 16 into a reciprocating spiral groove and intersecting it on the way, a larger amount of grease can be stored and the grease can be evenly distributed on the sliding surface. Can be supplied.

Further, as shown in FIG. 8, by forming a plurality of annular grooves 16 for storing grease, it is possible to secure a liquid sealing function by grease and a high lubricating performance.

[Third Embodiment] FIGS. 9 and 10 show a third embodiment.
Is shown, and also in this example, only the seal structure of the rotary shaft 4 will be described.

In this example, an annular groove 1 having a seal ring 17 having a C-shaped cross section formed on the rotary shaft 4 as a seal member.
8, and a grease storage groove 19 having a V-shaped cross section is formed on the outer peripheral surface of the rotary shaft 4 inside and inside the seal portion.

According to this structure, the waterproof and dustproof function of the seal ring 17 and the waterproof and dustproof function of the liquid seal function of the grease stored in the grease storage groove 19 are exhibited, and the seal ring 17 is made of cutting oil or the like. As a result, even if it swells, the cavity inside the C-shape is deformed into a crocodile shape, so that an increase in contact pressure is suppressed, so that an increase in sliding resistance is suppressed, and the occurrence of poor return is avoided.

[Fourth Embodiment] FIGS. 11 and 12 show a fourth embodiment. In this embodiment, too, the rotary shaft 4
Only the seal structure of will be described.

In this example, an O-ring 20 similar to the conventional one is used as a seal member, and is fitted and mounted in an annular groove 21 formed obliquely on the rotary shaft 4, and further on the inner back side thereof, the outer circumference of the rotary shaft 4 is provided. A grease storage groove 22 having a V-shaped cross section is formed on the surface.

According to this construction, the seal circumference becomes longer and the seal width in the axial direction becomes larger, so that higher waterproofness and dustproofness can be achieved than when the O-ring is simply attached.

[Fifth Embodiment] FIGS. 13 and 14 show a fifth embodiment. In this embodiment, too, the rotary shaft 4
Only the seal structure of will be described.

In this example, a bellows-shaped rubber seal tube 23 is used as a seal member, and is fitted and mounted in a wide annular groove 24 formed in the rotary shaft 4, and further, at the inner back side thereof, a rotation is made. A grease storage groove 25 having a V-shaped cross section is formed on the outer peripheral surface of the shaft 4.

According to this structure, the number of sealing points in the axial direction is increased, high waterproofness and dustproofness are exhibited, and swelling due to cutting oil or the like can be easily absorbed,
It also has a high function of suppressing an increase in sliding resistance.

[Other Modifications] The present invention can be carried out by appropriately combining the above-mentioned embodiments, and can also be carried out in a form in which the following configuration is added.

(1) In each of the above embodiments, an annular groove for mounting the seal member or a grease storage groove may be formed in the shaft insertion hole of the head.

(2) When the O-ring is used as the sealing member, if the outer layer and the inner layer of the O-ring are formed in different colors, the wear state of the O-ring can be easily visually recognized during disassembly and maintenance. It is convenient because it can be determined whether or not replacement is required.

(3) If a waterproof coating is applied to the outer peripheral surface of the rotary shaft in advance, it is possible to more effectively prevent water from entering the sliding portion, and it is possible to prolong the service life.

(4) By applying grease coating to the outer peripheral surface of the rotary shaft in advance, a uniform grease oil film can be formed, and the lubricating performance can be further enhanced.

[0047]

As is apparent from the above description, according to the present invention, the following effects can be obtained.

That is, according to the invention of claim 1,
The waterproof and dustproof functions of the sealing member and the liquid seal function of the grease stored in the grease storage groove provide the waterproof and dustproof functions, and high waterproofness and dustproofness can be obtained, extending the life of the limit switch. Can be planned.

Further, according to the invention of claim 2, the effect of the invention of claim 1 is exhibited, and a large amount of grease stored in the grease storage groove is supplied to a wide range in the axial direction. By exerting a high liquid sealing function and lubricity, it is possible to extend the life of the limit switch and stabilize its performance.

According to the invention of claim 3, the function of the invention of claim 1 is exerted, and the liquid sealing parts are formed at a plurality of positions in the axial direction, and
The grease is widely supplied in the axial direction, and the higher liquid sealing function and lubricity are exhibited, so that the life of the limit switch can be extended and the performance can be stabilized.

Further, according to the invention of claim 4, in the invention of any one of claims 1 to 3, by using an oil seal with a lip as the seal member, the contact pressure is good without particularly increasing. Excellent waterproofness and dustproofness can be obtained. Further, even if the oil seal swells due to cutting oil or the like, the swelling is easily absorbed by the elastic deformation of the lip portion, and thus it is easy to avoid the occurrence of a defective return due to an increase in sliding resistance.

Further, according to the invention of claim 5, in the invention of any one of claims 1 to 3, since the seal member has a seal ring having a C-shaped cross section having high absorption performance against swelling, Even if it swells with oil or the like, the increase in contact pressure can be suppressed, and it is easy to avoid the occurrence of poor recovery due to an increase in sliding resistance.

Further, according to the invention of claim 6, the waterproof and dustproof functions by the oil seal, the waterproof and dustproof functions by the liquid seal function by the grease stored in the grease storage groove, and the waterproof by the X-shaped seal ring. Also, the dustproof function works in triplicate to exert extremely high sealing performance, which is effective for extending the life of the limit switch. Further, the grease filled by the oil seal and the seal ring is prevented from flowing in and out, which is also effective in improving the durability of the limit switch.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a limit switch according to a first embodiment.

FIG. 2 is a perspective view of a rotating shaft according to the first embodiment.

FIG. 3 is an enlarged side view of a main part of the first embodiment.

FIG. 4 is an enlarged side view of an essential part showing a modified example of the first embodiment.

FIG. 5 is a partially cutaway side view showing a limit switch according to a second embodiment.

FIG. 6 is a perspective view of a rotating shaft according to a second embodiment.

FIG. 7 is a side view showing a modified example of the rotating shaft in the second embodiment.

FIG. 8 is a side view showing another modified example of the rotary shaft in the second embodiment.

FIG. 9 is a partially cutaway side view showing a limit switch according to a third embodiment.

FIG. 10 is an enlarged side view of an essential part of the third embodiment.

FIG. 11 is a partially cutaway side view showing a limit switch according to a fourth embodiment.

FIG. 12 is a perspective view of a rotating shaft according to a fourth embodiment.

FIG. 13 is a partially cutaway side view showing a limit switch according to a fifth embodiment.

FIG. 14 is a perspective view of a rotary shaft and a seal member in a fifth embodiment.

[Explanation of symbols]

 2 Case Body 3 Head 4 Rotating Shaft 5 Detection Lever 6 Actuator 10 Oil Seal (Seal Member) with Lip 11 Grease Storage Groove 13 Seal Ring 14 O-Ring (Seal Member) 16 Grease Storage Groove 17 Seal Ring (Seal Member) 19 Grease storage groove 20 O-ring (seal member) 22 Grease storage groove 23 Seal tube (seal member) 25 Grease storage groove

Claims (6)

[Claims] 1. A rotary limit switch in which a rotary shaft for pressing and displacing an internal switching actuator is rotatably supported by a head of a case, and a detection lever is connected to a protrusion of the rotary shaft. A rotary type limit switch characterized in that a seal member is provided on the outer side of the sliding portion between the rotary shaft and the head, and a groove for storing grease is provided on the inner back side thereof. 2. The rotary limit switch according to claim 1, wherein the grease storage groove is formed in a spiral shape. 3. The rotary type limit switch according to claim 1, wherein a plurality of the grease storage grooves are formed. 4. The rotary type limit switch according to claim 1, wherein the seal member is an oil seal with a lip. 5. The rotary limit switch according to claim 1, wherein the seal member is a seal ring having a C-shaped cross section. 6. The rotary type limit switch according to claim 1, wherein a seal ring having an X-shaped cross section is provided further inside the sliding portion of the grease storage groove.