JPH0443939Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a tactile switch applied to industrial robots, machine tools, vending machines, and various other mechanical devices.

<Summary of the invention> The tactile switch of this invention is configured to open and close the switch mechanism by converting the tilting motion of an actuator into the axial motion of a plunger made of synthetic resin, and the actuator has a flat portion on the bottom surface. On the other hand, the plunger is provided with a support surface for supporting the flat part of the support part of the actuator on the upper surface of the sliding shaft part, and a recessed part with a smaller diameter than the flat part in the center of this support surface. is forming. Therefore, even if abrasion powder is generated due to friction between the actuator and the plunger, the abrasion powder does not accumulate in the abutment area between the actuator and the plunger, but is accommodated in the recess, thereby stabilizing the operation of the plunger.

<Conventional technology> There are various configurations of conventional tactile switches, but all of them have an actuator that tilts upon detection of a workpiece, and is linked to a switch mechanism via a plunger that converts this tilting motion into linear motion. ing.

For example, a limit switch proposed in Japanese Patent Application Laid-Open No. 118280/1980 is configured to have a recess with a tapered inner surface on the upper surface of the plunger, and to support the base end of the actuator within this recess.

However, in this type of structure, the base end of the actuator fits into the recess of the plunger, so when friction between the actuator and the plunger generates abrasion powder, this abrasion powder forms the recess, that is, the actuator and the plunger. There is a problem in that the plunger is constantly pushed and the operating distance changes, resulting in unstable switch operation.

<Purpose of the invention> The object of this invention is to provide a tactile switch that eliminates the inconvenience caused by abrasion powder caused by friction between an actuator and a plunger.

<Structure and effects of the invention> The tactile switch of this invention includes a cylindrical base, an actuator for detecting a workpiece disposed at the upper end opening of the cylindrical base so as to be tiltable and vertically movable, and a tactile switch in the cylindrical base. The plunger is made of a synthetic resin and is loaded into the cylindrical base and moves up and down when the actuator detects a workpiece, and the switch mechanism is fixed in the cylindrical base and opens and closes when the plunger moves up and down.

The actuator includes a mounting shaft supported by an upper end opening of a cylindrical base, and a conical support portion having a flat portion on the lower surface is integrally formed below the mounting shaft.

The plunger also includes a sliding shaft portion that fits into the inner hole of the cylindrical base, and a support surface that supports the flat portion of the support portion of the actuator on the upper surface of the sliding shaft portion, and a support surface that supports the flat portion of the support portion of the actuator on the upper surface of the sliding shaft portion. A concave portion having a smaller diameter than the flat portion is formed.

According to the above configuration, even if abrasion powder is generated due to friction between the actuator and the plunger, this abrasion powder is stored in the concave portion without accumulating in the abutment area between the actuator and the plunger, and Excess oil such as grease applied to the sliding part of the switch also collects in the recess, so the plunger is not constantly pushed and the operating distance does not change, improving the stability of the switch operation.

Furthermore, for plungers molded from synthetic resin, it is necessary to set the diameter and length of the sliding shaft large in order to obtain the required strength due to the change in the operating direction, but since a recess is formed on the bearing surface of the sliding shaft, It also has the advantage that burrs and sink marks do not occur during molding, there are no molding defects, and highly accurate molded dimensions can be obtained.

<Description of Embodiments> The illustrated tactile switch includes a cylindrical base 1 for attaching and fixing the tactile switch to a mechanical device, a switch base 2 having a built-in switch mechanism 3 and press-fitted into the cylindrical base 1, A plunger 4 that is slidably arranged into the cylindrical base 1 and operates the switch mechanism 3, a return spring 5 of the plunger 4 interposed between the plunger 4 and the switch base 2, and a tip end of the cylindrical base 1. and an actuator 6 which is connected to the plunger 4 and actuates the plunger 4 when it comes into contact with a workpiece and moves in the tilting or axial direction.

The cylindrical base 1 has a flat surface 11 on opposing parts of the outer peripheral surface and a screw groove 12 formed on the shaft peripheral surface between the two flat surfaces 11, 11 to screw together the tightening nuts 13, 13. A conical flange 14 is formed protruding from the upper end of the inner hole of the base 1, a plunger chamber 15 is formed in the upper part of the inner hole, a switch loading part 16 is formed in the lower part, and the switch base 2 is press-fitted and fixed. be.

The switch stand 2 has a cylindrical shape with an outer diameter that can be press-fitted into the inner hole of the cylindrical base 1, and integrally connects a main body 2a and a lid 2b, which are offset from the center of the cylinder axis and divided along the cylinder axis direction. This switch stand 2 is provided with a switch mechanism 3.

The switch mechanism 3 engages a pair of terminals 31, 31 having inwardly bent contact portions 32 at the upper ends in parallel with the engaging portion 21 of the main body 2a, and both terminals 3
A coil spring 34 forming a normally closed contact is engaged between the contact portions 1 and 31 to bias the upper end to both contact portions 32. An engagement groove 22 is provided in the upper wall of the main body 2a, and the operating shaft 42 of the plunger 4 is inserted into the inner hole of the coil spring 34 through the engagement groove 22. This operating shaft 42
The actuating protrusion 4 pushes down the upper end of the coil spring 34.
3 is provided. Each of the contact portions 32 is provided with a plurality of contact protrusions 33 protruding from the lower surface to improve the contact properties of the contacts. Both terminals 31, 3
1, a lead wire 36 is connected to a cable 35, and a portion of this lead wire 36 is coated with epoxy resin 37.
It is molded in.

The plunger 4 is a molded body made of synthetic resin, and has a sliding shaft portion 41 that fits into the inner hole of the cylindrical base 1.
A switch base 2 is provided at the bottom of this sliding shaft portion 41.
An actuating shaft 42 that reaches the inner hole of the coil spring 34 from the engaging groove 22 of the actuating shaft 42 and actuating protrusions 43 are integrally formed on both sides of the actuating shaft 42. As shown in FIG.
A support surface 44 for supporting the mounting shaft 61 is formed, and a recess 45 having an appropriate depth and a smaller diameter than a flat portion 64 of the actuator 6, which will be described later, is formed in the center of the support surface 44. The plunger 4 is biased upward with a return spring 5 interposed between the lower surface of the sliding shaft portion 41 and the upper surface of the switch base 2, and the operating protrusion 43 is held at the switch release position.

The actuator 6 includes a mounting shaft 61 tiltably supported on the upper end of the cylindrical base 1, and a workpiece detector 65 of an arbitrary shape is mounted on the mounting shaft 61 as shown in FIGS. 5 and 6. Ru. A conical portion 63 corresponding to the conical flange 14 of the cylindrical base 1 and a flat portion 6 on the lower surface of the mounting shaft 61 are provided at the bottom of the mounting shaft 61.
4 is integrally formed, and this support part 62 is engaged between the bearing surface 44 of the plunger 4 and the conical flange 14 of the cylindrical base 1, and the return spring 5 causes the plunger 4 to be The conical flange 14 is biased through the conical flange 14.

Between the cylindrical base 1 and the workpiece detector 65,
An elastic sealing material 7 made of a rubber cylinder is fitted. This elastic sealing material 7 is provided with flanges 72 and 73 that protrude inward at the upper and lower cylinder openings of a cylinder body 71 whose cylinder wall is curved in the axial direction.
Engagement grooves 66 and 17 are formed around the lower outer peripheral surface of the workpiece detector 65 and the upper part of the cylindrical base 1, and the flanges 72 and 73 at both ends of the cylindrical body 71 are tightly engaged by the elasticity of the material, respectively. The upper end of the cylindrical base 1 including the mounting shaft 61 is sealed.

Therefore, the actuator 6 is normally biased by the elasticity of the return spring 5 and the elastic sealing material 7, and the flat part 64 of the mounting shaft 61 is attached to the support surface of the plunger 4.
4, and the operating protrusion 4 of the plunger 4
3 is apart from a coil spring 34 which forms a normally closed contact in the switch mechanism 3 (FIG. 4a).

Now, when the workpiece detector 65 contacts the workpiece and the actuator 6 tilts with respect to the central axis P of the cylindrical base 1 (FIG. 4b), the lower support part 62 of the actuator 6 With respect to the flange 14, the inclined side is displaced to a large diameter portion, and the opposite side is displaced to a small diameter portion, and at this time, the flat portion 64 corresponding to the large diameter side descends according to the inclination, and the support surface 4 of the plunger 4 is displaced.
The plunger 4 is lowered while being displaced from the plunger 4. When the inclination of the actuator 6 reaches a predetermined value (FIG. 4c), the protrusion 43 protruding from the plunger 4 presses down the coil spring 34.
The contact portions 32 and 32 of both terminals 31 and 31 are opened, and an electric signal for workpiece detection is generated between both terminals 31 and 31.

Further, when an axial input is applied to the actuator 6, the support part 6 directly pushes down the support surface 44 of the plunger 4, and the lowering of the plunger 4 causes the coil spring 34 to separate from both contact parts 32, 32, and as described above, both ends An electrical signal is output by opening between the terminals 31 and 31.

When the actuator 6 is separated from the workpiece, the restoring force of the coil spring 34, the return spring 5, and the sealing material 7 is applied to the plunger 4 and the actuator 6.
to return to its original state.

Note that during the tilting and returning operations of the actuator 6, if abrasion powder or surplus oil such as pre-applied grease is generated on the rubbing area between the flat part 64 of the mounting shaft 61 and the bearing surface 44 of the plunger 4, The stroke of the plunger 4 does not change due to abrasion powder accumulated in the recess 45 of the bearing surface 44 due to repeated sliding, and no oil enters the switch mechanism 3, so that stable operation is always performed.

The plunger 4 that converts the tilting movement of the actuator 6 into a linear movement is formed of a synthetic resin material, and the actuator 6 has a flat portion 64 on its lower surface.
On the other hand, the plunger 4 is provided with a support surface 44 on the upper surface of the sliding shaft portion 41 for supporting the flat portion 64 of the support portion 62 of the actuator 6, and a support surface 44 at the center of the support surface 44. Since the concave portion 45 is formed with a smaller diameter than the flat portion 64, even if abrasion powder is generated due to friction between the actuator 6 and the plunger 4, this abrasion powder will not reach the contact area between the actuator 6 and the plunger 4. Excess oil that is accommodated in the recess 45 without accumulating and that is applied to the sliding portion between the actuator 6 and the plunger 4 also accumulates in the recess 45.
The plunger 4 is not constantly pressed and the operating distance does not change, improving the stability of the switch operation.

Furthermore, the plunger 4 is molded from synthetic resin.
Due to the required strength due to change in operating direction, the sliding shaft portion 41
Although it is necessary to set the shaft diameter and shaft length large, since the recess 45 is formed in the bearing surface 44 of the sliding shaft 41, burrs and sink marks do not occur during molding, there is no molding defect, and high precision is achieved. The molding dimensions are obtained.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the tactile switch according to this invention, Fig. 2 is an exploded perspective view, Fig. 3 is a side view showing a part of the plunger in cross section, and Figs. 4 a to c explain the operating state. 5 and 6 are perspective views showing other embodiments of the actuator. 1... Cylindrical base, 2... Switch stand, 3...
Switch mechanism, 4... Plunger, 41... Sliding shaft portion, 42... Operating shaft, 43... Operating protrusion, 4
4...Supporting surface, 45...Recess, 5...Return spring,
6... Actuator, 61... Mounting shaft, 64...
...Flat part, 65... Workpiece detector.

Claims (1)

[Claims for Utility Model Registration] A cylindrical base; an actuator for detecting a workpiece disposed in the upper opening of the cylindrical base so as to be tiltable and vertically movable; and a workpiece of the actuator loaded in the cylindrical base. A plunger made of synthetic resin that moves up and down in response to a detection operation, and a switch mechanism that is fixed within the cylindrical base and opens and closes as the plunger moves up and down, and the actuator is attached to an opening at the upper end of the cylindrical base. The plunger includes a mounting shaft to be supported, and a conical support portion having a flat portion on the lower surface is integrally formed below the mounting shaft, and the plunger includes a sliding shaft portion that fits into the inner hole of the cylindrical base. A tactile switch comprising: a support surface for supporting a flat portion of the support portion of the actuator on the upper surface of the sliding shaft portion; and a recessed portion having a smaller diameter than the flat portion formed in the center of the support surface.