JPH01301461A - Steering wheel of automobile - Google Patents

Abstract

PURPOSE:To improve the operability of a horn switch and facilitate the production and the assembly of a steering wheel by putting a primary connection terminal and a secondary connection terminal in the position corresponding to that of a supporting member, on the pad. CONSTITUTION:Lead wires 31 and 32 extending from a membrane switch 30 are laid along a core 13 and connected at end to primary connection terminals 50 and 51. Both a lead wire 52 which passes through a communication hole formed in a boss plate 17 and connected to a slip ring and a lead wire 53 which is connected to the boss plate 17 with a screw 29 are laid inside a case 16 and connected at ends to primary connection terminals 54 and 55 mounted as they cover a projection 14. When the pad 11 is engaged and fixed with the case 16, the primary connection terminals 50 and 51, respectively, make electric contact with the secondary connection terminals 54 and 55 placed at the tops of the projections 14.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to improvements in steering wheels for automobiles.

[Prior art]

BACKGROUND ART Conventionally, a horn switch in a car alarm system is configured with a mechanism in which contacts open and close in accordance with the displacement of a pad formed in the center of a steering wheel. The pad is normally biased upward by a spring so that the contact remains open, and when the horn switch is operated, the pad is pushed downward against the biasing force of the spring. ing.

[Problem to be solved by the invention]

However, in recent automobiles, shock absorbing mechanisms, car telephone devices, etc. are often mounted on the pad, and in such cases, the weight of the pad increases, making it difficult to operate the horn. There is a problem that operability deteriorates. Further, since the horn switch is composed of mechanical mechanisms such as springs and contacts, there is also the problem that it takes time to assemble and adjust the pad. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to improve the operability of a horn switch and to facilitate the manufacture and assembly of a steering wheel.

[Means for Solving the Problems] A structure of the invention to solve the above problems is that, in a steering wheel having a urethane pad that serves as an operating member such as a horn switch, a core serving as a reinforcing material for the pad; A thin planar membrane switch is integrally molded near the skin 11 of the pad and conducts with a minute displacement or pressure caused by operation, and a thin planar membrane switch is connected to the membrane switch and is attached to the core along the core. A lead wire disposed up to a side end, a support member on the main body side of the steering wheel for fixing the pad, and a first connection connected to the lead wire and provided at the side end of the core. a second connection terminal provided on the support member, electrically connected to the first connection terminal when the pad is fixed to the support member, and connected to a wiring to the main body side of the steering wheel; It is characterized by comprising:

[Effect]

The membrane switch is built into the surface of the urethane pad and is integrally molded with the pad, making it easy to manufacture the steering wheel and eliminating the need for mechanical assembly and adjustment of the horn switch. Assembly to the wheel is easy. or,
Since it is a thin, flat membrane switch, it can be closed with a light operation. Furthermore, since the membrane switch described above is built into the pad, the wiring method between the membrane switch and the steering wheel body becomes a problem. That is, since the pad is fixed so as to cover the support member on the side of the steering wheel body, the electrical connection must be completed before assembling the pad to the support member. Therefore, work is required to make this electrical connection, but in the present invention, the pad is provided with a second connection terminal at a position corresponding to the first connection terminal and the support member, so that the pad is supported. When the pad is fixed to the member, the two automatically come into electrical contact, and the electrical connection is completed at the same time as the pad is fixed. Therefore, even if the pad has a built-in membrane switch, it can be assembled to the support member extremely easily.

【Example】

The present invention will be described below based on specific examples. FIG. 1 is a sectional view showing a steering wheel 10 according to this embodiment. A steering shaft 18 is disposed inside a column case 26 fixed to the vehicle body, and a serration 19 is formed at the upper end of the steering shaft 18. Also, the boss 2 has serrations formed on its inner surface.
0 meshes with the serration 19, and its boss 20
A boss plate 17 is welded to. The boss plate 17 is fitted onto the steering shaft 18 by a boss 20, and is fixed to the steering shaft 18 by a nut 22 which is screwed into a male screw 21 formed on the upper part of the steering shaft 18. Then, spokes (not shown) connected to the ring 23 extend from the boss plate 17, and when the ring 230 rotates, the boss plate 17
7 rotates, and the steering shaft 1 is rotated through the boss 20.
The rotational force is transmitted to 8. Further, below the boss plate 17, the boss plate 1
7 is disposed on the bottom of the central part, and a resin case 16 as a supporting member is fixed to the boss plate 17 with a screw wire, and a slip ring 24 is disposed on the bottom of the case 16. There is. The slip ring 24 is in sliding contact with a pin 25 fixed to a column case 26, the pin 25 and slip ring 24 constitute a positive voltage wiring system, and the boss plate 17 and steering shaft 18 constitute a ground wiring system. It consists of On the other hand, a pad 11 made of urethane is fitted onto the upper part of the case 16. A core 13 made of hard resin is disposed inside the pad 11, and a membrane switch 30 is disposed on the upper flat surface of the core 13. Such a pad 11 has a core 13 and a membrane switch 3.
The core 13 and the membrane switch 30 are integrally molded by injecting the urethane constituent material into the mold and causing it to react and foam. This pad 11 is fitted with the case 16 on its entire circumference, and in the fitted state, as shown in FIG.
The protrusion 14 formed on the inner surface of the pad 11 is fixed by firmly fitting into the engagement recess 15 formed on the outer surface of the core 13 of the pad 11, so that the two do not easily separate. Further, as shown in FIG. 2, lead wires 31 and 32 extending from the membrane switch 30 extend along the core 13, and their tips are connected to a flat plate provided at the bottom of the engagement recess 15. They are connected to first connection terminals 50 and 51, respectively. In addition, a boss plate 17 is provided on the inner surface of the case 16.
A lead wire 52 connected to the slip ring 24 through a communication hole 28 formed in the boss plate 17 and a screw 29 connected to the boss plate 17
Lead wires 53 are laid, and their ends are respectively connected to second connection terminals 54 and 55 disposed so as to cover the protrusion 14. When the pad 11 is mechanically fitted and fixed by the case 16, the engagement recess 15, and the protrusion 14, the first connection terminal 50.51 at the bottom of the engagement recess 15 is automatically connected to the protrusion. 1
and the second connection terminals 54 and 55 on the top of 4, respectively.
There will be electrical contact. Therefore, at the same time as the pad 11 is assembled to the case 16,
Electrical connections are also completed, making it extremely easy to assemble the pads. That is, the first connection terminal 50.51 and the second
If the connection terminals 54 and 55 are not present, the pad 11 must be fixed to the case 16 after connecting the long lead wire from the membrane switch 30 to the slip ring 24 and the boss plate 17. This work is difficult because the pad 11 is separate from the case 16. However, as described above, since the first connection terminal 50.51 and the second connection terminal 54.55 are provided and also serve as mechanical engagement between the pad 11 and the case 16, Assembly becomes extremely easy. The membrane switch 30 built into the pad 11 is constructed as shown in FIGS. 3 and 4. The printed circuit board 33 is provided with tooth portions 36 and 37 of the horizontal electrode 34 and the comb-shaped electrode 35 arranged alternately along the rV-rV cutting line direction so that the comb-shaped electrode 34 and the comb-shaped electrode 35 mesh with each other. It is formed to be. And the comb-shaped electrode 34.3
A plurality of pressure-sensitive conductive rubber strips 39 are arranged in parallel in a direction perpendicular to the teeth 36 and 37 of 5. Further, a sealing member 38 made of resin is protruded around the entire circumference of the printed circuit board 33, and the upper surface of the sealing member 38 and the pressure-sensitive conductive rubber 3
A thin film 40 is disposed so as to cover the entire top surface of 9. As a result, the inside of the membrane switch 30 is completely sealed from the outside, and the constituent materials of urethane are prevented from entering the inside of the membrane switch 30 when the pad 11 is integrally molded. or,
The pressure-sensitive conductive rubber 39 fills the space parallel to the pressure-sensitive conductive rubber 39, and a fixing member 44 made of resin or rubber, which is slightly thinner than the pressure-sensitive conductive rubber 39, is used to prevent misalignment. being held in place. The fixing members 44 on both side ends are integrally formed with the sealing member 38. When pressure is applied to the pressure-sensitive conductive rubber 39, the resistance of that portion decreases, and the comb-shaped electrode 34 and the comb-shaped electrode 35 become electrically connected. For example, as shown in Figure 'M4, when pressure is applied to part A, the pressure-sensitive conductive rubber 39 at the bottom becomes conductive, forming a current path as shown. Further, although the current flowing through the pressure-sensitive conductive rubber 39 is limited, a transistor 41 is provided in the circuit configuration shown in FIG. 6 for the purpose of current amplification so that a current sufficient to drive the horn relay can flow. ing. That is, transistor 4
1 collector is lead wire 31. First connection terminal 50. Second
Connection terminal 54° Lead wire 52. Slip ring 24. Vehicle battery 43 via bin 25° horn relay 42
The emitter is connected to the lead wire 32, the first connection terminal 51. Second connection terminal 55. Lead wire 53° boss plate 17. It is grounded via the steering shaft 18. A membrane switch 30 is connected between the collector and base of the transistor 41. By using the transistor 41 in this manner, the transistor 41 becomes conductive when the switch is turned on, allowing a sufficient current to flow through the horn relay 42. Such a membrane switch 30 is connected to the outer skin 12 of the pad 11.
The membrane switch 30 is integrally molded and embedded near the membrane switch 30, and by simply pressing down on the skin 12, the membrane switch 30 becomes conductive, improving operability. In the above embodiment, only the upper part of the protrusion 14 may be tapered to facilitate the fitting between the pad 11 and the case 16. Alternatively, the pad 11 and the case 16 may be directly fixed by rivets, screws, etc. without providing the engaging recess 15 and the projection 14. For example, as shown in FIG.
It may be fixed with rivets. At this time, a metal washer-shaped first connection terminal 51 connected to the lead wire 32 is fixed to the outside of the core 13 of the pad 11, and a metal washer-shaped first connection terminal 51 connected to the lead wire 53 is fixed to the corresponding inside of the case 16. The second connection terminal 55 of is fixed. Then, when the pad 11 is fastened to the case 16 with the rivet 56, the electrical connection between the first connection terminal 51 and the second connection terminal 55 is completed. Further, the pad 11 may be fixed as shown in FIG. That is, the pad 11 is fastened to a metal support leg 57 extending in electrical contact with the boss plate 17 using bolts 94 and nuts 95. At this time, a metal washer-shaped first connection terminal 91 connected to the lead wire 32 is arranged on the outer end surface of the core 13 of the pad 11.
The connection terminal 91 is electrically connected to a bolt 94 and, via a nut 95, to a second connection terminal 93 which also serves as a portion for fixing the pad 11 of the support leg 57. In this way, the wiring of the ground system is completed at the same time as the pad 11 is mechanically fixed to the support leg 57. Further, the wiring of the positive potential system is executed by a configuration as shown in FIG. That is, similar to the wiring of the grounding system shown in FIG. It is connected to the second connection terminal 92 via a nut 94 and a nut 95. The support leg 58 is fixed to the boss plate 17 via an insulating packing 96.
8 and the slip ring 24 are connected by a lead wire 52.

【Effect of the invention】

The steering wheel of the present invention includes a membrane switch that is integrally molded and built into the vicinity of the surface of the pad, and a first membrane switch that connects the membrane switch to a lead wire that is disposed along the core and is provided at the side end of the core. The connection terminal is provided at the contact part with the pad of the support member that fixes the pad, and when the pad is fixed to the support member, it is electrically connected to the first connection terminal and connects the wiring to the main body side of the steering wheel. Since there is no need to assemble or adjust the horn switch, manufacturing and assembling the steering wheel is facilitated. In particular, the first connection terminal and the second
Since it has a connection terminal, electrical connection is automatically made when the pad is assembled to the support member, so there is no need to perform electrical wiring during assembly, improving assembly work efficiency. do. Furthermore, since a thin, planar membrane switch is built in near the skin of the pad, the horn operation is easy, the ease of imitation is improved, and failures are reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a steering wheel according to a specific embodiment of the present invention. FIG. 2 is a perspective view showing the connection between the steering wheel pad and the case. 'rfr
Figure J3 is a plan view of the membrane switch, and Figures 4 and 5 are cross-sectional views of the membrane switch. FIG. 6 is a circuit diagram of an alarm device using a membrane switch as a horn switch. FIG. 7, FIG. 8, and FIG. 9 are cross-sectional views showing a method of fixing a steering wheel pad according to another embodiment. 10・°°°Steering wheel 11゛・-Pad 12 Skin 13 Core 16-Case 17°゛°Boss plate 24' Slip ring 30-1゛Membrane switch 33°°°Printed circuit board 34.35-Comb-shaped electrode 38・・-Sealing member 39°°°゛Pressure-sensitive conductive rubber 40゛Film 31, 32. 52.53 Lead wires 50.51, 90. 91 First connection terminal 54
．． 55.92.93 Second connection terminal patent applicant Toyota Gosho Co., Ltd. Representative Patent attorney Shuq Fujitani Hanishi Figure 3 Figure 4 Figure 5 n Figure 6 Fl.

Claims (1)

[Scope of Claims] A steering wheel having a urethane pad that serves as an operating member for a horn switch, etc., includes a core that serves as a reinforcing material for the pad, and a core that is integrally molded near the skin of the pad so that minute displacement due to operation is possible. or a thin planar membrane switch that conducts with minute pressure; a lead wire connected to the membrane switch and disposed along the core to a side end of the core; and a steering wheel for fixing the pad. a support member on the main body side of the wheel; a first connection terminal connected to the lead wire and provided at a side end of the core; and a first connection terminal provided at a contact portion of the support member with the pad, and the pad is connected to the A steering wheel for an automobile, comprising a second connecting terminal that is electrically connected to the first connecting terminal when fixed to a support member and that is connected to a wiring to a main body side of the steering wheel.