JPH0419694Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to key switches used for control operation switches of various industrial equipment or information input operation switches of various office equipment, and is particularly applicable to the installation of key tops. The present invention relates to a key switch whose operability is improved by eliminating discomfort such as a feeling of collision when pressing the key top by improving the structure.

<Prior Art> As a conventional key switch, there is one in which a switch portion is constructed using a disk-shaped metal spring movable contact.
This key switch has a dish-shaped metal movable contact covered on the inner bottom of a case in which a central fixed contact and a peripheral fixed contact are fixed, and its peripheral part is in constant contact with the peripheral fixed contact, and its center part is A switch part is formed inside the case by facing away from the central fixed contact, and an operating rod is installed through the upper surface of the case, and its lower end abuts the center of the upper surface of the movable contact, and the operating rod extends upwardly outside the case. It has a structure with an operating key top fixed to the top end of the rod. In this configuration, when the key top is pressed and the operating rod is pushed down, the center part of the movable contact is pressed and reversed and comes into contact with the center fixed contact, and the center and surrounding fixed contacts are connected by the movable contact to close the switch. When the pressure on the key top is removed from this state, the movable contact returns to its original shape due to its own elasticity.
When the switch separates from the central fixed contact, the switch becomes open and the operating rod is pushed up to its original position to restore the initial state. This key switch is designed to provide a sense of moderation to the fingertips of the key top operator by the rapid reversal and recovery operations of the movable contacts when the switch is switched open and closed.

<Problems to be Solved by the Invention> In this type of conventional key switch, the amount of reversal operation of the movable contact relative to the central fixed contact cannot be made very large due to its structure, so the switching stroke of the switch portion is small. Furthermore, the key top mounting structure is such that the key top is fixed to the movable contact, that is, the operating rod that presses and drives the switch part, by means such as light press fitting, so the operating stroke of the key top is the same as the switching stroke of the switch part, which is very small. It is. For this reason, when pressing the key top to switch the switch part, the key top suddenly stops without any pressure being pressed, and the fingertips operating the key top are suddenly stopped, causing a strong sense of collision. I had a problem with sex. This also poses a problem in that when the switch is operated continuously, the burden on the fingertips increases, making the operator easily fatigued.

This invention was made in order to improve these drawbacks of conventionally known key switches.The key switch has a large key top operation stroke and has excellent operability without the feeling of collision, with a simple structure. The purpose is to realize this.

<Means for solving the problem> This invention is a key switch in which the switch part is opened and closed by pressing the key top and pushing down the operating rod, and an engaging groove is provided on the side surface of the operating rod, and this groove is provided with an engaging groove on the side surface of the operating rod. A slope is provided that gradually projects outward from the shaft of the operating rod as it goes downward, and the key top is arranged above the operating rod so as to be spaced apart from and opposite to the upper end surface of the operating rod. The elastic piece has an elastic piece that hangs down along the key top, and is attached to the operating rod by engaging the inward engaging protrusion at the lower end of the elastic piece with the engaging groove, and the engaging force of the engaging protrusion in the key top pressing direction is It is set slightly larger than the opening/closing force of the switch part,
When a pressing force greater than the above-mentioned opening/closing operation force is applied to the key top, the engagement protrusion disengages from the engagement groove and slides downward on the inclined surface, and the elastic piece bends outward, causing the key top to connect to the operating rod. The key switch is configured such that when the key top is pushed in and the pressing force is removed, the engagement protrusion moves back along the inclined surface due to the restoring force of the elastic piece, engages the engagement groove, and returns the key top to its original position. This achieves the above objectives.

<Example> Hereinafter, an example of this invention will be described using the drawings.

FIG. 1 is a longitudinal sectional view showing the whole key switch of this invention, and this key switch includes a case 10 made of synthetic resin. The case 10 includes a case body 12 having a recess 11 on the top surface, and a case body 12.
It consists of a top plate 13 which is fixed to the top surface by adhesive or other means and covers the top opening of the recess 11.
At the bottom of the recess 11 of the case body 12, a central fixed contact 20 and a pair of peripheral fixed contacts 30, 30, which are arranged opposite to each other with the central fixed contact 20 in between, have their contact portions protruding slightly above the bottom surface. It is buried and fixed. The central fixed contact 20 has external terminals 4 extending downward from one opposing side surface of the case body 12.
0 and 40 within the main body 12, these are integrally formed from a single conductive metal plate and fixed to the main body 12 by means of insert molding. Although the peripheral fixed contacts 30, 30 are not shown in the figure, they are formed integrally with similar external terminals 50, 50 from a conductive metal plate, and are fixed to the main body 12 by means of insert molding. and again,
The bottom of the recess 11 is covered with a dish-shaped metal spring movable contact 60 having a reversal characteristic and made of a conductive metal plate having spring properties, and its peripheral edge 61 is in constant contact with the surrounding fixed contacts 30, 30. , its central part 6
2 faces the central fixed contact 20 at a distance, thereby forming a switch section 70 within the case 10. The outer diameter of the movable contact 60 is slightly smaller than the inner diameter of the recess 11, and its lateral movement is restricted by the inner circumferential wall of the recess 11, so that it is positioned at a predetermined position. An operating rod 80 made of synthetic resin is inserted through a round hole 14 provided in the center of the top plate 13 of the case so as to be movable up and down. The lower end of this operating rod 80 is located at the center 6 of the upper surface of the movable contact 60.
2, and the operating rod 80 is always urged upward by the spring force of this movable contact 60. Further, a flange 81 is provided at a position inside the case 10 of the operation rod 80, and the upper surface of this flange 81 is connected to the upper surface plate 13.
By coming into contact with the peripheral edge of the lower surface of the hole 14, the operating rod 80 is prevented from slipping out above the case 10.

The above is similar to a conventional key switch, and conventionally the key top for operation is fixed to the upper end of the operating rod 80 extending above the case 10 by means such as press fitting. In such a configuration, when the key top is pressed and the operating rod 80 is pushed down, the center portion 62 of the movable contact 60 is pressed and reversed and comes into contact with the center fixed contact 20, thereby causing the center and surrounding fixed contacts 20, 30, 30 are short-circuited, and the switch section 70 is in a closed state. When the pressure on the key top is removed from this state, the movable contact 60 returns to its original shape due to its own elasticity, and as a result, its central portion 62 separates from the central fixed contact 20 to open the switch portion 70, and the operating rod 80 is Push it up to the original position to return to the initial state. As described above, since the conventional key switch has a structure in which the key top is fixed to the operating rod 80, the operating stroke (depression amount) of the key top is the reverse operation amount H of the movable contact 60 with respect to the central fixed contact 20, that is, the switching of the switch section. It was only the same as stroke H and was small. For this reason, the above-mentioned problems such as a feeling of collision occur when the key top is pressed.

This invention, as shown in FIG.
The key top 90 for operation is provided so that it can be pushed in without being fixed, thereby absorbing the feeling of collision when the key top is pressed, thereby solving the above problem. In other words, this idea applies to case 1
An annular engagement groove 82 having a semicircular cross section is formed on the side surface (periphery) of a cylindrical operation rod 80 extending upward from the top surface of the
A conical inclined surface 83 is provided that extends continuously downward from near the bottom of the lower surface of the groove 82 and gradually projects outward from the operating rod axis as it goes downward. Note that the continuous portion 8 of the curved surface of the groove 82 and the inclined surface 83
4 is not a smooth continuous surface as shown in the enlarged view in FIG. It is designed to provide an engagement force of . Further, a guide portion 85 is formed between the inclined surface 83 of the operating rod 80 and the flange 81 and fits into the hole 14 to guide the operating rod 80 in the vertical direction. On the other hand, the key top 90 is formed from a synthetic resin material into a rectangular flat plate shape, and is disposed above the operating rod 80 so as to face the upper end surface thereof by a predetermined distance S. Upper end columnar part 86
It has a cylindrical part 91 which is fitted into the cylindrical part 91 so as to be movable up and down, and an axial slit 92 is formed on the circumferential surface of the cylindrical part 91.
By providing a plurality (four in the figure) at equal intervals, a plurality (four in the figure) of cantilevered elastic pieces 93 that can be flexibly deformed outward from the axis are formed, and the lower end of this elastic piece 93 is provided with an inward engaging protrusion 94 having a semicircular cross section that engages with the engaging groove 82 . This key top 90 is constructed by elastically deforming the elastic piece 93 to open the space between the engagement protrusions 94 and fitting the upper end cylindrical part 86 of the operating rod 80 into the cylindrical part 91 formed by the elastic piece 93. 93 is restored by its own elasticity, the engagement protrusion 94 is closed, and the engagement groove 82 is closed.
It is attached to the operating rod 80 by engaging with. FIG. 1 shows such an attached state, in which the bottom part of the cylindrical part 91 of the key top 90, that is, the key top 9
The engagement protrusion 94 engages with the engagement groove 82 with a predetermined length S separating the lower surface of the operating rod 80 and the upper end surface of the operating rod 80 . Here, the engagement force of the engagement protrusion 94 with respect to the engagement groove 82 in the key top pressing direction (downward) is set to be slightly larger than the pressure reversal operation force of the movable contact 60, that is, the opening/closing operation force of the switch part 70. It is set. This engagement force is caused by the spring force of the elastic piece 93, the engagement protrusion 94, and the engagement groove 82.
It is determined by the relationship between the curved surface shape of the material and the coefficient of friction of the materials used.

In the key switch configured as described above, when the key top 90 is pressed downward, the engaging protrusion 94 in the same direction
Since the engagement force of the engagement groove 82 is set to be larger than the pressing and reversing operation force of the movable contact 60, the operating rod 80 is pushed down together with the key top 90, and as a result, the center portion 62 of the movable contact 60 is pushed down. The pressure is reversed and it comes into contact with the central fixed contact 20, thereby closing the switch part 70. Here, when a pressing force greater than the pressing reversing operation force of the movable contact 60 acts on the key top 90, the engaging force of the engaging protrusion 94 with respect to the engaging groove 82 in the key top pressing direction (downward) is greater than the pressing reversing operating force. Since the operating rod 90 is pushed down, the movable contact 60 is pressed and reversed, and when it comes into contact with the central fixed contact 20 and is restricted from being pushed down, the engagement protrusion 9
4 is disengaged from the engagement groove 82, rides on the inclined surface 83, and slides downward on that surface, and the elastic piece 93 is elastically deformed outward. Therefore, the key top 90 can be pushed into the operating rod 80 until the lower surface of the key top 90, that is, the bottom of the cylindrical portion 91 comes into contact with the upper end surface of the operating rod 80, as shown in FIG. Note that when the pressure on the key top 90 is removed from this pressed state, the movable contact 60 returns to its original shape due to its own elasticity, separates from the central fixed contact 20, and closes the switch portion 70.
is opened, and the operating rod 80 is pushed up to its original position. The key top 90 also has an elastic piece 93.
Due to the restoring force, the engagement protrusion 93 moves upwardly on the inclined surface 83, engages the engagement groove 82 again, returns to its original position, and restores the initial state as shown in FIG. In this manner, the key switch according to this invention, when the key top 90 is pressed, first pushes down the operating bar 80 together with the key top 90, and
Press and reverse the movable contact 60 to close the switch part 70, and then move the key top 90 to the operating rod 80.
It is designed to absorb the remaining pressing force that exceeds the operating force of the switch part 70 against the key top 90. Therefore, the feeling of collision caused by the sudden stop of the key top, which is seen in conventional key switches, is eliminated, and in addition, the operating rod 8 of the key top 90 is shorter than that of the conventional key switch.
Since the operating stroke of the key top is large by the pressing amount S relative to 0, operability is good. Also,
In the process of pushing the key top 90 into the operating rod 80, the elastic piece 93 is gradually elastically deformed along the inclined surface 83, its spring force is gradually strengthened, and the pushing resistance force of the key top 90 is gradually increased. Since it is designed to be pushed and stopped slowly, the feeling of collision is further alleviated and a soft-touch operation feeling can be obtained.

Although the above embodiments have been described using specific embodiments, the present invention is not limited thereto and can be modified in various ways. For example, in the above embodiment, the operating rod 80 is cylindrical, but it may be square or polygonal. In this case, it goes without saying that the elastic pieces 93 are provided along each side of the operating rod 80. stomach. Further, in the above embodiment, the switch portion 70 is constructed using the dish-shaped metal movable contact 60, but it may be of other types such as a membrane type.

<Effects of the invention> This invention is constructed as described above, but when the key top is pressed down, the operating rod is first pushed down together with the key top to open and close the switch section, and then the key top is pushed into the operating rod. The structure is designed so that the press force that exceeds the opening/closing force of the switch against the key top is absorbed, and the push resistance gradually increases, so the operation stroke is larger than conventional ones, and the feeling of collision during operation is reduced. As a result, a soft-touch operation feeling can be obtained, and therefore, even if the key tops are continuously operated, there is no large burden on the fingertips, reducing operator fatigue, and operability is greatly improved. This can be particularly applied to key switches with a small switching stroke in the switch section to obtain a great effect. Furthermore, the structure is extremely simple, does not require any special parts, and is easy to assemble and can be manufactured at the same cost as conventional products.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the entire key switch according to this invention, Fig. 2 is a partially enlarged view of the operating rod in the area surrounded by the dotted line in Fig. 1, and Fig. 3 shows the state in which the key top is pushed into the operating rod. It is a sectional view of the main part. 70...Switch part, 80...Operation rod, 82...
...Engagement groove, 83...Slope, 90...Key top, 93...Elastic piece, 94...Engagement protrusion.

Claims (1)

[Scope of utility model registration request] In a key switch in which the switch part is opened and closed by pressing the key top and pushing down the operating rod, the operating rod has an engaging groove on the side surface, and a groove that is continuous with the groove and gradually extends outward from the operating rod shaft as it goes downward. The key top is arranged above the operation rod so as to be spaced apart from and opposite to the upper end surface of the operation rod, and the key top has an elastic piece that hangs down along the side surface of the operation rod. The lower end inward engaging protrusion is attached to the operating rod by engaging with the engaging groove, and the engaging force of the engaging protrusion in the key top pressing direction is set to be slightly larger than the opening/closing operating force of the switch part. When a pressing force greater than the opening/closing force is applied to the key top, the engagement protrusion disengages from the engagement groove and slides downward on the inclined surface, and the elastic piece bends outward, causing the key top to close. is pushed into the operating rod, and then when the pressing force is removed, the engagement protrusion moves back along the inclined surface due to the restoring force of the elastic piece, engages the engagement groove, and returns the key top to its original position. A key switch that is characterized by: