JPH058834U - Movable plunger device of limit switch - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a movable plunger device of a limit switch in which grease does not spread over the entire sliding portion and seizure, wear and the like do not occur. [Structure] A wide range of grease reservoir 13 is formed in the axial direction of the movable plunger 7 on at least one of the movable plunger 7 and the sliding portion 4 of the movable plunger 7,
The range of the grease reservoir 13 due to the reciprocating movement is increased to allow the grease to rotate over the entire sliding portion, thereby preventing problems such as seizure and abrasion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a movable plunger device for a limit switch.

[0002]

[Prior Art]

 In the conventional movable plunger device of this type, as shown in FIG. 6, a grease formed by a single annular V groove is provided at a portion of the movable plunger 40 that is in sliding contact with the peripheral surface of the sliding hole 42 of the case 41. A reservoir 43 is formed, and grease is stored in the grease reservoir 43, and the movable plunger 40 reciprocates to perform grease lubrication.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional example, since the grease reservoir 43 is a single annular V groove formed in the movable plunger 40, the range of movement of the grease reservoir 43 due to the reciprocating movement of the movable plunger 40 is narrow, For this reason, there is a problem that the entire sliding portion does not have grease and seizure and wear.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a limit switch in which grease does not spread around the entire sliding portion and seizure, wear and the like do not occur. To provide a movable plunger device of the above.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a limit switch, which is actuated by the reciprocating motion of a movable plunger, in a wide range in the axial direction of the movable plunger on at least one of the movable plunger and its sliding portion. It is characterized by forming a grease reservoir.

[0006]

[Action]

 With such a configuration, the range of movement of the grease reservoir due to the reciprocating movement of the movable plunger becomes large, and therefore grease can be spread over the entire sliding portion, and imperfections such as seizure and abrasion can be prevented.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a limit switch equipped with a movable plunger device according to the present invention, and FIG. 2 is a front view of the same portion broken.

The limit switch 1 is provided with a case 2, and a cylindrical plunger guide portion 3 is formed on the upper surface of the case 2, and the inside of the plunger guide portion 3 is a sliding portion 4 and a spring accommodating portion. 5 and a stopper portion 6 which is a step portion between them are formed. A plunger mechanism 10 is provided in the plunger guide portion 3.

The plunger mechanism 10 is provided with a movable plunger 7 and an auxiliary plunger 8. The movable plunger 7 has a flange portion at its inner end portion formed on a spring receiving portion 9, and a roller 11 is provided on the front side thereof. It is attached by a shaft 12. A grease reservoir 13 is formed on the outer peripheral surface portion 7a of the movable plunger 7. The grease reservoir 13 is formed in a spiral shape on the outer peripheral surface portion 7a of the movable plunger 7 between the annular grooves 14 and 15 and the grooves 14 and 15 which are separated from each other in the axial direction of the movable plunger 7, and the groove 14 at the end portion. , 15 and a communication groove 16 communicating with the grooves 15. The grooves 14, 15, 16 have a V-shaped cross-section. An auxiliary plunger 8 is inserted into the inner end of the movable plunger 7, and a stopper 17 is attached to the inner end of the movable plunger 8. The stopper 17 prevents the auxiliary plunger 8 from falling off. The auxiliary plunger 8 is urged outward by a spring 18 incorporated therein.

The plunger machine groove 10 configured as described above is inserted into the plunger guide portion 3, and in this case, the outer peripheral surface portion 7 a of the movable plunger 7 is brought into sliding contact with the sliding portion 4 of the plunger guide portion 3. A return spring 19 is accommodated in the plunger guide portion 3, and the return spring 16 holds the plunger mechanism 10 close to the return spring 16. Note that the grease is supplied to the grease reservoir 13 during assembly.

A switch cover 20 and a switch mechanism 21 are housed in the case 2, and the cover 2 is connected to a terminal protection cover 22. The switch cover 20 is provided with a push button mechanism 23. The push button mechanism 23 is provided with a push button 25 held by a rubber cap 24 and a push button slidably provided in a guide hole 26 of the switch cover 20. 27 and the end of the push button 25 is in contact with the end of the auxiliary plunger 8.

The switch mechanism 21 is provided with a common terminal 29, a normally open terminal 30, and a normally closed terminal 31 in an insulating case 28, and a movable piece 32 is provided in the common terminal 29 while being held reversibly by a movable spring 33. The movable contact 34 provided at 32 is brought into contact with the fixed contact 35 of the normally closed terminal 31. The push button 27 is in contact with the movable piece 32 of the switch mechanism 21.

Next, the operation will be described. By the movement of the moving body, the moving body interferes with the roller 11 and pushes down the movable plunger 7 against the return spring 19. By pushing down the movable plunger 7, the push button mechanism 23 is pushed down via the auxiliary plunger 8, and the movable piece 32 of the switch mechanism 21 is pushed in to switch the switch.

When the moving body does not interfere with the roller 11, the return force of the return spring 19 causes the movable plunger 7 to return to its original position. In this way, the movable plunger 7 reciprocates due to the operation of the limit switch 1. In this case, the grease reservoir 13 has annular grooves 14 and 15 spaced apart from each other in the axial direction of the movable plunger 7 and the grooves 14 and 15 thereof. Between the movable plunger 7 and the communicating groove 16 formed in a spiral shape on the outer peripheral surface portion 7a of the movable plunger 7 and communicating with the grooves 14 and 15 at the end, and the grease accumulated in the grease reservoir 13 passes from the groove 14 to the groove 16 through the groove 16. While moving to the groove 15 and vice versa, it is supplied between the outer peripheral surface portion 7a of the movable plunger 7 and the sliding portion 4 to perform lubrication. Therefore, the grease is in a wide range corresponding to the space between the groove 14 and the groove 15, which improves the slidability.

Another embodiment of the present invention is shown in FIGS. 4 and 5. In this embodiment, a grease reservoir 36 is formed on the peripheral surface of the sliding portion 4 of the plunger guide portion 3 along the axial direction of the movable plunger 7. Also in this case, the grease accumulated in the grease reservoir 36 moves due to the reciprocating movement of the movable plunger 7, and is supplied between the outer peripheral surface portion 7a of the movable plunger 7 and the sliding portion 4 for lubrication. Therefore, the grease is in a wide range corresponding to the length of the grease reservoir 36, and the slidability is improved.

[0016]

[Effect of the device]

 As described above, according to the present invention, a wide range of grease reservoir is formed in the axial direction of the movable plunger on at least one of the movable plunger and the sliding portion of the movable plunger. The range of movement of is increased, and therefore grease can be spread over the entire sliding portion, and problems such as seizure and abrasion can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a limit switch having a movable plunger device according to the present invention.

FIG. 2 is a front view in which the same portion is broken.

FIG. 3 is a structural explanatory view of a movable plunger device according to the present invention.

FIG. 4 is a structural explanatory view of a movable plunger device according to another embodiment of the present invention.

FIG. 5 is an explanatory diagram of a sliding hole portion of the movable plunger device.

FIG. 6 is a diagram illustrating the configuration of a conventional movable plunger device for a limit switch.

[Explanation of symbols]

 7 Movable plunger 13,36 Gris reservoir

Claims (1)

[Claims for utility model registration] [Claim 1] In a limit switch actuated by the reciprocating motion of a movable plunger, at least one of the movable plunger and its sliding portion has a wide range of grease in the axial direction of the movable plunger. A movable plunger device for limit switches characterized by forming a pool.