JP3864468B2 - Rubber key switch mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rubber key switch mounting structure used in various control devices such as timers and counters.
[0002]
[Prior art]
In general, various control devices such as a timer and a counter are provided with a display unit having a liquid crystal on the front surface of a case, and set values, elapsed time, count values, and the like are digitally displayed on the display unit. Further, on the front surface of the case, an operation rubber key for setting a timer time, a count value and the like is exposed at a position below the display unit.
[0003]
The case of this type of control device is formed by joining a front case and a case body. For example, as shown in FIG. 9, the front case 10 ′ is provided with a plurality of key insertion holes (not shown) below the display portion 13, and an operation block mounting portion 18 is formed on the rear surface. An operation block 80 having a plurality of up operation rubber keys 81 and down operation rubber keys 82 is mounted on the operation block mounting portion 18 and is fixed to the front case 10 ′ by an operation block holding member 70 (Japanese Patent Laid-Open No. Hei 9-315). 6-196870). The front panel 60 attached to the front surface of the front case 10 ′ is provided with a plurality of insertion holes 62 and 63 through which the rubber keys 81 and 82 are inserted.
[0004]
Here, the rubber key heads of the rubber keys 81 and 82 are as shown in FIG. 10 so that the rubber keys 81 and 82 can be operated like a seesaw key by gently moving the finger up and down. The inclined surfaces 81a and 82a are formed so that the sides facing each other are lower, and the rubber key 81 located above the rubber key 82 has a larger amount of protrusion from the front surface of the front panel 60.
[0005]
[Problems to be solved by the invention]
By the way, in the conventional key switch mounting structure, the operation block holding member 70 is necessary to fix the operation block 80 to the front case 10 ', and the front case 10' has a plurality of rubber key insertion holes. Therefore, there is a problem that the waterproof property on the front surface of the front case 10 ′ is insufficient.
[0006]
The present invention has been made in view of the above reasons, and an object of the present invention is to provide a rubber key switch mounting structure capable of enhancing waterproofness while ensuring operational stability.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, in order to achieve the above object, the movable contact portion at the tip of the rubber key leg is changed to the fixed contact portion in the case of the control device in accordance with the operation of the rubber key head provided on the front surface of the operation block. A rubber key switch mounting structure that comes in contact with and separates from the outer peripheral edge of the operation block is formed with a protruding piece protruding rearward, and a rubber key leg portion is inserted in the front surface of the case and the operation block A recessed groove into which the protruding piece is press-fitted is formed, and a protective cover that covers a portion other than the rubber key head of the operating block is attached to the front surface of the case. The operation block is securely fixed to the case by press-fitting into the concave groove formed on the front surface of the case, and the operation block can be prevented from being removed by the protective cover. It is possible to improve the waterproof case front while ensuring the operation stability over.
[0008]
Further, the invention of claim 1 is provided with a protrusion that contacts the front surface of the case on the rear surface of the protective cover, and a protrusion that contacts the rear surface of the protective cover on the front surface of the operation block. Since each protrusion part contacts the surface which opposes, the block for operation can be more reliably fixed to the front surface of a case, and rubber key operation becomes reliable and smooth.
[0009]
According to a second aspect of the present invention, in the first aspect of the present invention, the rubber key is composed of a rubber key head, two rubber key legs, and a protrusion protruding at a position between the two rubber key legs. Since a convex portion serving as a rotation fulcrum of the protruding portion is provided at a position in front of the fixed contact portion, a rubber key for obtaining the same stroke as compared with the case where a rotation fulcrum is provided near the fixed contact portion in the case Since the amount of movement of the head is reduced and the diameter of the rubber key head can be increased, the operability of the rubber key is improved.
[0010]
According to a third aspect of the present invention, in the first or second aspect of the invention, since the control device is a timer or a counter, it is possible to provide a timer or a counter having a high operation stability and a high waterproof property of the rubber key switch. it can.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(Reference Example 1)
In this reference example , as shown in FIGS. 1 and 2, a concave groove 11 for attaching the operation block 20 to the front surface of the front case 10 of the control device, and an insertion hole 12 through which each rubber key leg 8b is inserted, Is formed. The operation block 20 is formed of an elastic material such as rubber or synthetic resin, and a protruding piece 20a protruding rearward is formed on the outer peripheral edge of the operation block 20, and the protruding piece 20a is recessed. By press-fitting into the groove 11 from the front, the projecting piece 20 a comes into contact with the inner peripheral surface of the concave groove 11 and is fixed. After the operation block 20 is attached to the front case 10, the protective cover 30 is attached from the front. The protective cover 30 is provided with a hole 32 for exposing the rubber key head 8 a of the rubber key 8 and an opening window 31 for exposing the display unit 13. For this reason, the protective cover 30 can prevent a portion other than the rubber key head portion 8a of the operation block 20 from coming into direct contact with the user, and can prevent the operation block 20 from being removed.
[0012]
Hereinafter, the case where a counter is comprised as an example of a control apparatus is demonstrated.
[0013]
A coupling hole 16 is formed in a projecting piece projecting rearward of the front case 10, and the circuit board 40 is coupled to the front case 10 by inserting a protruding portion 40 a of the circuit board 40. In front of the circuit board 40, a display element unit 50 made of, for example, a liquid crystal or a backlight is provided behind the display unit 13. The display element unit 50 is controlled by a control circuit described later, and a count value, a preset value, and the like are digitally displayed on the liquid crystal. A fixed contact 41 is provided on the front surface of the circuit board 40 at a position facing the movable contact at the tip of the rubber key leg portion 8b, and a key switch circuit for setting a preset value or the like according to the operation of the rubber key head portion 8a is formed. ing. Here, when the rubber key head portion 8a is not pressed, the movable contact is separated from the fixed contact 41. When the rubber key head portion 8a is pressed, the support portion 8c is elastically deformed and the rubber key 8 is moved to the front case 10 side. The movable contact and the fixed contact 41 come into contact with each other. That is, both the contacts come and go according to the operation of the rubber key head 8a.
[0014]
The front case 10 is provided with four projecting pieces 14 projecting rearward in addition to the projecting pieces. The coupling hole 15 formed in the projecting piece 14 has, for example, a control piece. An input circuit to which various external input signals are applied, a clock generation circuit for generating a clock pulse of a reference frequency, and a counting means for counting up to a preset value based on the clock pulse input from the clock generation circuit are set by a key switch circuit A control circuit that outputs the preset value and the count value counted by the counting means as an output signal, an output circuit that outputs this to an external device when the count value reaches the preset value, and an external power supply connected to each circuit Projection portions of a circuit board on which components constituting a power supply circuit for supplying a predetermined voltage and the like are mounted are coupled. The front case 10 is joined to the case body so as to cover each circuit board, the display element portion, and the like after the circuit board and the like are joined. Instead of the counting means of the control circuit, for example, a timer can be configured by providing time measuring means for measuring time based on the output of the clock generation circuit.
[0015]
In this reference example, the operation block 20 is securely fixed to the front case 10 by press-fitting the protruding piece 20a of the operation block 20 into the concave groove 11 formed on the front surface of the front case 10, and the rubber key Since the insertion hole through which the leg 8b is inserted can be covered with the operation block 20, the waterproof property can be improved, and the operation block 20 is removed by providing the protective cover 30 on the front surface of the front case 10. Therefore, the waterproofness of the front surface of the front case 10 can be enhanced while ensuring operational stability. Further, since there is no need to provide the operation block holding member 70 as in the conventional example, the number of parts can be reduced as compared with the conventional example.
[0016]
(Working-shaped state)
By the way , in the structure of the first reference example , the operation block 20 may be lifted from the front surface of the front case 10 while the operation of the rubber key head 8 is repeated. Variation will occur.
[0017]
The present embodiment improves this type of problem, and its basic structure is substantially the same as that of Reference Example 1. As shown in FIGS. 3 and 4, the front case 10 is provided on the rear surface of the protective cover 30. A feature is that a protrusion 30 a that contacts the front surface protrudes, and a protrusion 20 b that contacts the rear surface of the protective cover 30 protrudes from the front surface of the operation block 20.
[0018]
In the present embodiment, when the protective cover 30 is attached to the front case 10, the protrusion 30 a contacts the front surface of the front case 10, and the protrusion 20 b contacts the rear surface of the protective cover 30. For this reason , compared with the reference example 1, the operation block 20 can be more reliably fixed to the front surface of the front case 10, and the operation block 20 can be prevented from rising due to repeated operation of the rubber key. The operation is reliable and smooth, and any rubber key head 8a can be operated with substantially the same feel.
[0019]
(Reference Example 2)
The basic structure of this reference example is substantially the same as that of reference example 1 , and as shown in FIGS. 5 and 6, the rubber key 8 has two rubber key legs 8b ₁ and 8b ₂ for one rubber key head 8a. It differs in that it is formed. A protrusion 8d is formed between the rubber key legs 8b ₁ and 8b _{2 on} the rear surface of the rubber key head 8a.
[0020]
In this reference example, the front surface of the rubber key head portion 8a is formed in a protruding curved shape in which an upper portion and a lower portion protrude from the center portion. The front case 10 is formed with a convex portion 19 in contact with the protruding portion 8d at a position ahead of the circuit board 40, and when the upper or lower portion of the rubber key head portion 8a is pushed in the horizontal direction as shown in FIG. As shown in FIG. 8B, the protrusion 8d serves as a rotation fulcrum. At this time, both the rubber key legs 8b ₁ and 8b ₂ move in the front-rear direction along the guide holes through which the rubber key legs 8b ₁ and 8b ₂ are inserted. The circuit board 40, the fixed contact 43 for causing up the setting value at a position opposite to the movable contact provided at the tip of Gomuki legs 8b ₁ provided facing the movable contact provided at the tip of Gomuki leg 8b ₂ by the provision of the fixed contacts 42 to bring down the set value in a position Ri is formed with similar key switch circuits as in reference example 1. Thus, pressing the top of Gomuki head 8a, and movable contact of Gomuki legs 8b ₁ is the fixed contact 43, and press the bottom of Gomuki head 8a, the movable contact of Gomuki leg 8b ₂ is the fixed contact Therefore, a so-called seesaw key that raises or lowers the set value can be realized by operating one rubber key head 8a.
[0021]
In this reference example, as shown in FIG. 8 (b), the protrusion 19 is provided at a position in front of the circuit board 40 in the case, so that the protrusion 8d is formed as shown in FIG. 8 (a). Compared with the one in contact with the circuit board 40, the movement amount b of the rubber key head 8a for obtaining the same stroke L is small (b <a), so the diameter B of the rubber key head 8a exposed in the hole 32 can be increased ( B> A), the operability of the rubber key is improved.
[0022]
Further, by making the cross-sectional shapes of the key leg portions 8b ₁ and 8b ₂ and the movable contact into an elliptical shape having a long lateral diameter, the seesaw operation can be increased in a limited space, and the seesaw operation can be performed. The contact area between the movable contact and the fixed contacts 43 and 42 provided on the circuit board 40 can be increased. In addition, the shape of the insertion holes 12a and 12b provided in the front case 10 is also formed in an oval shape in accordance with the cross-sectional shape of each rubber key leg portion 8b ₁ and 8b ₂ .
[0023]
Further, by making the rubber key leg portion 8b ₂ positioned below longer than the rubber key leg portion 8b ₁ positioned above, when the rubber key head portion 8a is operated as a seesaw, the lower portion of the rubber key head portion 8a is covered with a soft finger pad portion. Even when pressed, the movable contact at the tip of the rubber key leg 8b ₂ can be brought into contact with the fixed contact 42 with certainty.
[0024]
【The invention's effect】
According to the first aspect of the present invention, the rubber key switch is mounted such that the movable contact portion at the tip of the rubber key leg contacts and is separated from the fixed contact portion in the case of the control device in accordance with the operation of the rubber key head provided on the front surface of the operation block A protruding piece projecting rearward is formed on the outer peripheral edge of the operation block, and a recess groove into which the rubber key leg is inserted and a protruding piece of the operation block are press-fitted on the front surface of the case. Since the protective cover that covers the part other than the rubber key head of the operation block is attached to the front surface of the case, press the protruding piece of the operation block into the concave groove formed on the front surface of the case The operation block can be securely fixed to the case, and the operation block can be prevented from being removed by the protective cover. There is an effect that it is Mel possible.
[0025]
Further, the invention of claim 1 is provided with a protrusion that contacts the front surface of the case on the rear surface of the protective cover, and a protrusion that contacts the rear surface of the protective cover on the front surface of the operation block. Since each projecting portion comes into contact with the opposing surface, the operation block can be more securely fixed to the front surface of the case, and the rubber key operation can be reliably and smoothly performed.
[0026]
According to a second aspect of the present invention, in the first aspect of the present invention, the rubber key is composed of a rubber key head, two rubber key legs, and a protrusion protruding at a position between the two rubber key legs. Since a convex portion serving as a rotation fulcrum of the protruding portion is provided at a position in front of the fixed contact portion, a rubber key for obtaining the same stroke as compared with the case where a rotation fulcrum is provided near the fixed contact portion in the case Since the amount of movement of the head is reduced and the diameter of the rubber key head can be increased, the operability of the rubber key is improved.
[0027]
According to a third aspect of the invention, in the first or second aspect of the invention, the control device is a timer or a counter. There is an effect that can be done.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a rear side showing a reference example 1. FIG.
FIG. 2 is a cross-sectional view of the above.
3 is an exploded perspective view showing an exemplary shape condition.
FIG. 4 is a perspective view of the rear side of the protective cover of the above.
5 is an exploded perspective view showing Reference Example 2. FIG.
FIG. 6 is a cross-sectional view of the above.
[Fig. 7] Fig. 7 is a use state diagram of the main part.
FIG. 8 is an operation explanatory diagram of the main part of the above.
FIG. 9 is an exploded perspective view showing a conventional example.
FIG. 10 is a use state diagram of the main part of the above.
[Explanation of symbols]
8 Rubber Key 8a Rubber Key Head 8b Rubber Key Leg 10 Front Case 11 Concave Groove 12 Insertion Hole 13 Display Part 20 Operation Block 20a Projecting Piece 30 Protective Cover 32 Hole

Claims (3)

A rubber key switch mounting structure in which the movable contact part at the tip of the rubber key leg contacts and separates from the fixed contact part in the case of the control device according to the operation of the rubber key head provided on the front of the operation block. A protruding piece protruding rearward is formed on the outer peripheral edge of the block, and an insertion hole through which the rubber key leg portion is inserted and a concave groove into which the protruding piece of the operation block is press-fitted are formed on the front surface of the case. A protective cover that covers the part other than the rubber key head is attached to the front of the case, and a protrusion that contacts the front of the case is provided on the rear surface of the protective cover. A rubber key switch mounting structure, characterized in that a protrusion is provided in contact with the rear surface . The rubber key is composed of a rubber key head, two rubber key legs, and a protrusion protruding at a position between the two rubber key legs, and the rotation of the protrusion at a position ahead of the fixed contact in the case. 2. The rubber key switch mounting structure according to claim 1 , wherein a convex portion serving as a fulcrum is provided . 3. The rubber key switch mounting structure according to claim 1 , wherein the control device is a timer or a counter .

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