JP2008269905A - Steering wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To have a structure capable of surely draining infiltrating water and hardly having the infiltrating water intruded into a switch contact part in case rainwater or the like intrudes into a horn switching device fitted at a center part, in a steering wheel of an agricultural work vehicle. <P>SOLUTION: A concave part 14 for setting a horn switching device 13 is formed at a center main body part 12 of a steering wheel, the horn switching device 13 is structured of a container-shape button sheet 15, a fixed contact 18 fitted on a bottom face of the button sheet 15, a coil spring 17 making a movable contact 19 separate from the fixed contact 18, and a horn button 16 making the movable contact 19 contact with the fixed contact 18 by a pushing operation. Further, a water blocking wall 15c to surround the fixed contact 18 is formed on the bottom face of the button sheet 15, and also, a weep hole each is provided on the bottom face of the button sheet 15 to be an inner side of the water blocking wall 15c and on an outer wall part of the button sheet 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steering wheel such as an agricultural vehicle in which a driver's seat does not have a roof and rainwater or the like may be applied to the steering wheel.

Agricultural work vehicles such as tractors are open without a roof in the driver's seat, so rainwater and the like may get on the steering wheel. Rainwater may be infiltrated in the device, and the horn switch device may break down due to this immersion.

Some conventional steering wheels are provided with a drain hole for draining the water to the outside when it is immersed in the horn switch device as described above.
However, if the water immersed in the horn switch device is not sufficiently drained, the water remains in the horn switch device, which causes corrosion of the switch contacts and switching failure.

Japanese Utility Model Publication No.59-120668

In view of the above situation, the present invention is a steering wheel having a horn switch device in the center, and even when water is submerged in the horn switch device, the inundated water can be surely drained. The object is to make the structure that does not easily reach the switch contact.

  In order to achieve the above object, the present invention provides, as a first invention, a steering wheel having a horn switch device in a central body portion attached to a steering shaft, and a concave shape in which the horn switch device is installed in the central body portion of the steering wheel. And the horn switch device is separated from the fixed contact by a spring force and a button contact having a bottomed shape that is housed in the concave portion, a fixed contact provided on the bottom surface of the button sheet. And a movable contact that is brought into contact with the fixed contact in accordance with the pushing operation of the horn button, and further, a water blocking wall is formed on the bottom surface of the button sheet so as to surround the fixed contact. A drain hole is provided in each of the bottom surface portion of the button sheet and the outer wall portion of the button sheet that is inside the wall. To propose a steering wheel which is characterized.

As a second invention, in the steering wheel of the first invention, the bottom surface of the button seat is provided with a raised trapezoidal part, and a fixed contact is provided on the trapezoidal part. Propose.

As a third invention, in the steering wheel of the first invention, the button seat is provided with a locking claw, and the central main body portion is locked with the locking claw so that the button sheet is placed in the center. A locking hole for fixing to the main body is provided. Further, the locking hole is penetrated from the bottom of the concave portion of the central main body to the back surface, and water flowing out from the drain hole is drained through the locking hole. A characteristic steering wheel is proposed.

According to the first aspect of the invention, the water immersed in the horn switch device from between the horn button and the button sheet is drained from the drain hole provided in the outer wall portion of the button sheet.
In addition, since the contact portion of the fixed contact and the movable contact is in the water blocking wall, the water that has been immersed is cut off by the water blocking wall and does not reach the contact portion.
In addition, even when the flooded water gets over the water barrier and enters the water barrier, the water drainage hole is provided at the bottom of the button sheet that is the inner surface of the water barrier, so the water is drained from the water drain hole. .

According to the second invention, since the raised trapezoidal portion is provided with the fixed contact, even if the flooded water flows near the fixed contact through the water blocking wall or the bottom surface of the button sheet, the water is trapezoidal. Water does not touch the fixed contact.

According to the third aspect of the present invention, the button claw is fixed by locking the locking claw in the locking hole of the central main body portion, so that the water that has flowed out from the drain hole has the locking hole. It passes through the central body and passes through.

Next, embodiments of the present invention will be described with reference to the drawings.
1 is a front view of a steering wheel showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1, and FIG. 3 is an enlarged sectional view taken along line BB in FIG.
In these figures, 11 is a steering wheel handle, 12 is a central body portion of the steering wheel, and 13 is a horn switch device provided in the central body portion 12.

The central body portion 12 of the steering wheel is provided with a circular concave portion 14 dug down in a direction perpendicular to the handle 11, and a horn switch device 13 is installed in the concave portion 14.
The horn switch device 13 is composed of a button sheet 15, a horn button 16, a coil spring 17, a fixed contact 18, and a movable contact 19.

As shown in FIGS. 4 and 5, the button sheet 15 is a bottomed cylindrical container made of a synthetic resin material, and the first drain hole 20 is formed at a three-divided position below the outer wall 15a. Is formed.
Note that one of the three first drain holes 20 is preferably formed so as to be in a lower position (lower side in FIG. 2) when the steering wheel is in a normal state (neutral position). .

Further, the button sheet 15 is provided with a raised trapezoidal portion 15b on the bottom surface, and a fixed contact 18 is projected from the upper surface of the trapezoidal portion 15b.
The fixed contact 18 passes through the trapezoidal portion 15b, and the connector piece 21 is fixed on the back side of the trapezoidal portion 15b.

Further, the bottom surface of the button sheet 15 is integrally formed with a cylindrical water cutoff wall 15c surrounding the trapezoidal portion 15b. The water cutoff wall 15c prevents water flowing to the fixed contact 18 side. Yes.
Moreover, the 2nd drain hole 22 is formed in the bottom face of the button sheet | seat 15 used as the inner side of this water cutoff wall 15c.

On the other hand, on the opening side of the button sheet 15, a flange 15 d following the outer wall 15 a is formed outwardly, and the flange 15 d is joined to the front surface of the central body 12, so that the water entering between the button sheet 15 and the central body 12 Is preventing.

The button sheet 15 formed as described above is provided with three locking pieces 15e extending from the rear half of the button sheet 15, and these locking pieces 15e are inserted into the respective locking holes 12a of the central body portion 12. It is configured to be locked and fixed in the concave portion 14 of the central body portion 12.

On the other hand, the locking hole 12a is composed of three through-holes formed so as to penetrate the back surface of the central main body 12 from the three-divided position of the bottom surface of the concave portion 14 provided in the central main body 12. A locking portion for locking the locking piece 15e is provided inside.
The locking hole 12 a formed in this way drains the water flowing out from the first drain hole 20 and / or the second drain hole 22 to the back side of the central body portion 12.

As can be seen from the perspective view of FIG. 6, the horn button 16 has an engaging portion 16 c extending from the three-way position of the peripheral wall 16 a in the first drain hole 20 provided in the outer wall 15 a of the button sheet 15. The horn button 16 is prevented from coming off and the horn button 16 can be pushed within a range in which the engaging portion 16c moves in the first drain hole 20.

As can be seen from the perspective view of FIG. 7, the movable contact 19 is formed by forming a conductive material in a conical shape. The top of the movable contact 19 is freely contactable with the fixed contact 18, and the circular seat 19a has a connector piece 19b. It is provided integrally.
One end of the connector piece 19b is connected to the other end of the cord 25 fixed to the mounting tube 24 of the central body 12 by a screw 23 to connect the movable contact 19 to the ground.
The cord 25 is wired through a small hole 15f provided on the bottom surface of the button sheet 15.

The mounting tube 24 is made of a conductive material such as a metal, and as shown in FIG. 2, the steering shaft 26 is mounted, and the key 26a of the shaft 26 is fitted into the key groove 24a of the mounting tube 24. After the shaft 26 is inserted into the mounting tube 24 as described above, the set screw 26b is screwed into the screw hole at the tip of the shaft 26 and attached.
Therefore, the movable contact 19 is grounded to the vehicle body via the cord 25, the attachment tube 24, and the steering shaft 26.

The movable contact 19 receives a spring force of a coil spring 17 provided between the bottom surface of the button sheet 15 so as to be in pressure contact with the back surface of the horn button 16.
The conical movable contact 19 provided in this way is configured to contact the fixed contact 18 when any position of the horn button 16 is pressed.
Therefore, as shown in FIGS. 2 and 3, the movable contact 19 is separated from the fixed contact 18 and is switched off in the normal state.
In addition, the height of the cylindrical water blocking wall 15c is set to a height at which the movable contact 19 does not contact, and the coil spring 17 is held by the inner peripheral wall thereof.

Further, the horn button 16 pushed by the coil spring 17 via the movable contact 19 moves backward (moves leftward in FIG. 2) as shown in FIGS. The water drain hole 20 is locked to the hole edge of the water drain hole 20 to prevent it from coming off.

On the other hand, a circular frame-shaped back cover 27 is provided on the rear surface of the central main body 12.
The back cover 27 is shown as a front view in FIG. 8, a rear view in FIG. 9, and a perspective view in FIG.
As can be seen from these drawings, the back cover 27 is a bottomed circular frame-like body in which a circular recess 27b is formed in the middle partition 27a, and is provided with three locking pieces 27c extending from the three-divided position of the middle partition 27a. Are inserted into the respective locking holes 12 b of the central body 12 and locked, and attached to the central body 12.
The locking holes 12b are also three through holes formed so as to penetrate from the bottom surface of the concave portion 14 provided in the central body portion 12 to the back surface of the central body portion 12, and the first drain hole 20 and the above-described The water flowing out from the second drain hole 22 is drained in the same manner as the locking hole 12a.

In addition, the middle partition 27a of the back cover 27 is provided with three third drain holes 28 at a position equally divided by three on the outer wall, and three fourth drain holes 28b straddling the wall surface and bottom surface of the circular recess 27b. A drain hole 29 is provided at a position equally divided into three.
When the steering wheel is in the normal position (neutral position), the three third drain holes 28 provided in this way are positioned at the lower position (lower position in FIG. 2). Similarly, the three water drain holes 29 are also arranged so that one water drain hole 29 is in a lower position when the steering wheel is in a normal position (neutral position). It is preferable to form.

Further, the circular recess 27b of the back cover 27 is formed with a circular hole 27d for passing the mounting tube 24 on the bottom surface thereof, and a contact ring 30 is fixed to the back surface of the circular recess 27b. .
The contact ring 30 is provided with a terminal portion 30 a protruding from the hole portion 27 e of the circular recess 27 b, and the terminal portion 30 a and the connector piece 21 of the fixed contact 18 are connected by a cord 31.
The cord 31 is wired through the through hole 12c of the central body 12.

The contact ring 30 is in contact with a brush contact piece provided in a lever switch device such as a direction indicator.
That is, a switch-on signal due to contact between the fixed contact 18 and the movable contact 19 is sent to the horn circuit through the cord 31, the contact ring 30, and the brush contact piece, and the horn circuit operates the horn in response to the switch-on signal. It is as.

When the horn button 16 is pushed in the normal state shown in FIGS. 2 and 3, the steering wheel configured as described above moves the movable contact 19 toward the fixed contact 18 against the spring force of the coil spring 17. When pressed, the movable contact 19 comes into contact with the fixed contact 18, the switch is turned on, and the horn sounds.
When the pushing operation of the horn button 16 is released, the horn button 16 is moved back to the position shown in FIGS. 2 and 3 by the spring force of the coil spring 17, and the movable contact 19 is separated from the fixed contact 18 and switched off. The horn will mute.

Further, when water such as rainwater enters the button seat 15 through the periphery of the horn button 16, the steering wheel described above flows down the bottom surface of the button seat 15, and the first steering wheel at the lower position is located. It flows out from the drain hole 20.
In other words, since the steering wheel is attached at a certain angle so that the lower part is closer to the upper part of the handle 11, the button seat 15 is inclined to the right. Flows downward on the bottom surface and flows out from the first drain hole 20 at the lower position.

Furthermore, when there is water flowing into the water cutoff wall 15c, the water flows downward around the trapezoidal portion 15b and flows out from the second drain hole 22 at the lower position.
In a normal state where the steering wheel is not rotated, as described above, the water that has flowed downward flows out through the first drain hole 20 and the second drain hole 22 at the lower position. When the steering wheel is rotated, water is discharged radially through the respective drain holes 20 and 22.

The water flowing out from the button sheet 15 flows into the back cover 27 through the locking holes 12 a and 12 b and out to the back side of the central main body 12.
As a result, water flowing downward from the locking hole 12b through the middle partition 27a is discharged to the outside of the steering wheel through the third drain hole 28 at the lower position, and enters the circular recess 27b from the locking hole 12b. If there is water, it is discharged through the fourth drain hole 29 in the lower position.
When the steering wheel is rotated, the water flows radially through the drain holes 28 and 29 as described above.

As described above, each drain hole is disposed so that water that has entered the button sheet 15 is always discharged to the outside.
Further, since the locking holes 12a and 12b formed in the concave portion of the central body portion 12 are used as drain holes as through holes, the water efficiently passes the locking pieces 15e and 27c to the outside. Discharged.

Although one embodiment has been described above, when the fourth drain hole 29 is formed across the wall surface and the bottom surface of the circular recess 27b, water flowing out of the circular recess 27b may touch the contact ring 30.
Since the contact ring 30 is coated with grease, there is no problem even if some water touches it. However, in order to prevent the contact ring 30 from coming into contact with the water, as shown in FIG. The water drain hole 29 can be formed.

  Thus, by forming the 4th drain hole 29 along the wall surface of the circular recessed part 27b, water can be drained with the centrifugal force of rotation by rotating a steering handle.

Further, actually, as shown in FIG. 12, the waterproof rib 32a of the non-rotating housing 32 is inserted into the ring concave groove 27f of the back cover 27, and water adheres between the contact ring 30 and the brush contact piece 33. Waterproof structure to prevent
Reference numeral 34 shown in this figure is a lever switch that is not rotated.

    The present invention can be applied as a vehicle steering wheel including a horn switch device having a drainage function.

It is a front view of a steering wheel showing an embodiment of the present invention. It is an AA line expanded sectional view on FIG. It is the BB line expanded sectional view on FIG. It is a perspective view which shows the button seat of the horn switch apparatus with which the said steering wheel is provided. It is a front view of the button sheet. It is a perspective view which shows the horn button of the said horn switch apparatus. It is a perspective view which shows the movable contact of the said horn switch apparatus. It is a front view of the back cover with which the said horn switch apparatus is equipped. It is a rear view of the back cover. It is a perspective view of the back cover. It is the partial perspective view of the back cover which showed the example of improvement of the drain hole. It is an expanded sectional view similar to FIG. 3 provided with the waterproof structure of the contact ring and brush contact piece with which the said horn switch apparatus is provided.

Explanation of symbols

11 Handle 12 Central body portion 12a, 12b Locking hole 13 Horn switch device 14 Recessed portion 15 Button sheet 15a Outer wall 15b Trapezoidal portion 15c Water blocking wall 15e Locking piece 16 Horn button 16b Engaging piece 16c Engaging portion 18 Fixed contact 19 Movable contact 20 1st drain hole 22 2nd drain hole 27 Back cover 27c Locking piece 28 3rd drain hole 29 4th drain hole 30 Contact ring

Claims (3)

In a steering wheel having a horn switch device in a central body portion attached to a steering shaft,
In the central body part of the steering wheel, a concave part to install the horn switch device is formed,
The horn switch device includes a bottomed button sheet that is housed in the concave portion, a fixed contact provided on the bottom surface of the button sheet, and is separated from the fixed contact by a spring force. A movable contact that is brought into contact with the fixed contact according to the pushing operation of
Furthermore, on the bottom surface of the button sheet, a water blocking wall is formed so as to surround the fixed contact, and each of the bottom surface portion of the button sheet that is inside the water blocking wall and the outer wall portion of the button sheet. A steering wheel characterized in that a water drainage hole is provided in the wheel. The steering wheel according to claim 1,
A steering wheel characterized in that a trapezoidal part formed by raising is provided on the bottom part of the button seat, and a fixed contact is provided on the trapezoidal part. The steering wheel according to claim 1,
The button sheet is provided with a locking claw,
The central main body is provided with a locking hole for locking the button sheet to the central main body by locking the locking claw.
Further, the locking hole is penetrated from the bottom surface of the concave portion of the central body portion to the back surface, and the water flowing out from the drain hole is drained through the locking hole.

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