JPH0249948B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a steering wheel for an automobile or the like, and particularly to a steering wheel that is heated by providing a heating element on a rim portion held by a driver.

[Conventional technology]

As this kind of steering wheel
The one shown in Japanese Patent No. 183348 is known.

This steering wheel uses a positive temperature coefficient thermistor (ceramic heating element) as the heating element.
This heating element is mounted around a rim core bar (metallic core aggregate), and these are embedded in a synthetic resin covering (synthetic resin skin material).

[Problem that the invention seeks to solve]

In the case of the above-mentioned steering wheel, the heat generating element is attached around the rim core metal, so the heat of the heat generating element is absorbed by the rim core metal, making it difficult for warmth to be transmitted to the surface of the rim, reducing efficiency. Because of this, it is not effective unless the heating element is made larger, and the positive temperature coefficient thermistor itself is more expensive than other heating elements, which is a major cost increase factor. Since it is buried within the covering, there was a problem that it could not be replaced if some kind of failure occurred.

The present invention has been developed in view of these points, and it efficiently transmits the heat of the heating element to the surface of the rim, uses a small positive temperature coefficient thermistor for the heating element, and eliminates the need for replacement in the event of a failure. The purpose is to make it possible.

[Means for solving problems]

In the steering wheel of the present invention, an annular rim portion 3 is connected around a boss portion 1 via spoke portions 2, a fitting recess 11 is formed in a gripped portion of the rim portion 3, and a fitting recess 11 is formed in the gripped portion of the rim portion 3. 11 and a heating element 12 fitted therein, the heating element 12 has one electrode part of a heating element 20 made of a positive temperature coefficient thermistor bonded to the inner side of a heat dissipating current carrying body 19 made of, for example, an aluminum plate. Then, a current carrying body 22 made of, for example, an aluminum plate is bonded to the other electrode portion of this heating element 20, and these heat dissipating current carrying body 19, heating element 20, and current carrying body 2 are connected to each other.
2 is covered with a covering member 24 to form a unit.

[Effect]

The steering wheel of the present invention includes a heating element 2
0 heat is directly transferred to the heat dissipating current carrying body 19 near the surface of the rim portion 3 to efficiently utilize the heat, and the heat dissipating current carrying body 19, the heating element 20, and the current carrying body 22 are covered with the covering body 24 to generate heat. By making the body 12 into a unit and fitting it into the fitting recess 11 of the rim part 3,
This allows the heat generating part to be replaced as a unit.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 3 shows a steering wheel, which is formed by connecting an annular rim part 3 around a boss part 1 via a pair of spoke parts 2.

As shown in FIGS. 1 and 2, the rim portion 3 is constructed by embedding an annular rim core 4 in a synthetic resin covering 5, and surrounding this covering 5 with a natural or The rim core metal 4 is covered with synthetic leather 6, and the rim core metal 4 is welded to the metal boss 8 of the boss part 1 via the spoke core metal 7 of each spoke part 2 shown in FIGS. 3 and 6. are integrally connected.

Fitting recesses 11 are formed on the surface of the covering body 5 at two positions of the rim portion 3 that are gripped by the driver, and a heating element 12 is inserted into the fitting recesses 11 in the rim portion. The outer surface of the heating element 12 is covered with the leather 6.

A pair of locking recesses 14 having undercut-shaped locking side surfaces 13 are formed at the bottom of the fitting recess 11, and an undercut-shaped locking side surface 15 is formed on the inner side of the heating element 12. A pair of locking protrusions 16 are formed, and these locking recesses 1
4 and the locking convex portion 16, the heating element 12 independently engages the fitting concave portion 1 in the state before being covered with the leather 6.
1, which facilitates the work of wrapping and sewing the leather 6.

As shown in FIG. 4, the heating element 12 is formed from both inner ends of a heat dissipating current carrying body 19 which is made of aluminum plate, iron plate, copper plate, brass plate, etc., bent into a trapezoidal shape with an opening at the bottom, and has a heat dissipating effect and a current carrying effect. One electrode portion of a heating element 20 made of a positive temperature coefficient thermistor is adhered to the heating element 20 with a conductive adhesive 21, and each heating element 20 is
A conductive adhesive 23 is applied to the other electrode part of a narrow current carrying body 22 made of a plate material similar to that of the heat dissipating current carrying body 19 , with both ends thereof separated from the heat dissipating current carrying body 19 .
As shown in FIG. 5, the heat dissipating current carrying body 19, each heating element 20, and the current carrying body 22 are made of urethane resin, vinyl chloride resin, or silicone rubber with excellent thermal conductivity. It is covered with a synthetic resin covering 24 to form a unit, and each of the locking protrusions 16 is formed of a part of the covering 24.

A plate-shaped terminal 27 is cut and bent at one end of the heat dissipating current carrying body 19 of the heating element 12, and a plate-shaped terminal 28 is bent and formed at the other end of the current carrying body 22. Each terminal 27, 2
8 protrudes from the inner side of the covering body 24.

Further, a pair of terminals 31 and 32 on the power supply side are provided at the bottom of the fitting recess 11 in correspondence with the terminals 27 and 28 of the heat-dissipating current-carrying body 19 and the current-carrying body 22. As shown in FIG. 6, each of the terminals 31 and 32 is formed into a flat cylindrical shape, and when the heating element 12 is fitted into the fitting recess 11, the heat dissipating current carrying element 12 is inserted into the fitting recess 11.
9 and the terminals 27 and 28 on the current-carrying body 22 side are fitted to connect electrically.

One terminal 31 on the power supply side connected to the terminal 27 of the heat dissipating current carrying body 19 is welded to the rim core metal 4 of the rim portion 3, and this rim core metal 4 is connected to the spoke core metal of the spoke portion 2. Boss part 1 through 7
Since this boss 8 is electrically connected to the negative terminal of the battery, the heat dissipating current carrying body 19
One electrode portion of each heating element 20 is connected to the negative electrode via the heating element 20 .

The other terminal 32 on the power supply side connected to the terminal 28 of the current carrying body 22 is provided on the rim core metal 4 of the rim portion 3 via an insulating case 33, and is connected via a lead wire 34 and a switch 35. It is connected to the slip ring 36 of the boss part 1, and this slip ring 36 is electrically connected to the positive terminal of the battery, so that the other electrode part of each heating element 20 is connected to the positive terminal via the current carrying body 22. It's getting old.
In addition, 37 is a heat-resistant tube that surrounds the lead wire 34 and protects the lead wire 34 from the heat during molding of the covering body 5. It is a heat-resistant tube that surrounds the lead wire 34 and protects the lead wire 34 from the heat generated when the covering body 5 is formed. Keep it fixed at 7.

Therefore, when the switch 35 is turned on, each heating element 20 is energized, each heating element 20 generates heat and each heat dissipating current carrying body 19 is warmed, and when the temperature rises, the resistance of the positive temperature coefficient thermistor used for each heating element 20 increases. increases, the amount of heat generated decreases, and at a predetermined temperature it reaches an equilibrium state and maintains that temperature.

At this time, the heat of each heating element 20 is directly transmitted to the heat dissipating current carrying body 19 near the surface of the rim part 3, so the heat is not easily taken away by the rim core metal 4, and the heat can be used efficiently, so that the heat can be used efficiently. It is possible to use a small positive temperature coefficient thermistor that has a rapid temperature rise, consumes little power, and is inexpensive.

The positive temperature coefficient thermistor used in the heating element 20 is made of barium titanate ceramic material whose resistance value increases rapidly at a desired temperature, so that the temperature rises quickly and the equilibrium state is reached. I'm trying to make it happen.

In addition, since the heat dissipating current carrying body 19, the heating element 20, and the current carrying body 22 are covered with the covering body 24 to form the heat generating body 12 into a unit, which is fitted into the fitting recess 11 of the rim portion 3, in the event of a failure etc. It is possible to replace the heat generating part of the unit immediately, and the assembly work during manufacturing is facilitated. Moreover, when the heat generating element 12 is fitted into the fitting recess 11, each terminal 31, 32 on the power supply side of the fitting recess 11 is connected.
Since the terminals 27 and 28 on the side of the heat dissipating current carrying body 19 and the current carrying body 22 of the heating element 12 fit together and are electrically connected, work such as wire connection is unnecessary, and workability during manufacturing and repair is good. .

In the case where the heating element 12 is not integrated into a unit, that is, the heat dissipating current carrying body 19, the heating element 20, and the current carrying body 22 are not covered with the covering body 24, but are covered with the covering body 5 together with other parts of the rim portion 3. When the covering body 5 is molded, the flow of the synthetic resin of the covering body 5 is blocked by the heat dissipating current carrying body 19, the heating element 20, and the current carrying body 22, so that molding defects in the rim portion are likely to occur. As in the present invention, when only the heat dissipating current carrying body 19, the heating element 20, the current carrying body 22, etc. are separately covered with the covering body 24, there is less occurrence of molding defects, and moreover, silicone material with excellent thermal conductivity is used. Even when an expensive synthetic resin is used for the covering body 24, an inexpensive synthetic resin can be used for the other parts of the covering body 5, which is advantageous in terms of cost.

In this embodiment, the terminals 27 and 28 on the heat dissipating current carrying body 19 and the current carrying body 22 are plate-shaped, and a pair of terminals 31 and 28 on the power supply side are provided at the bottom of the fitting recess 11.
32 is made into a flat cylindrical shape, the relationship between the plate and the tube may be reversed, and as shown in FIG. A pair of flat cylindrical fitting parts 4 are inserted between the two.
A connecting fitting 43 having terminals 1 and 42 may be interposed, or terminals that fit into each other may be omitted and the connection may be made using lead wires or the like.

Further, in this embodiment, the entire circumference of the rim portion 3 is covered with the leather 6 as a cover body, but only the heating element 12 portion may be covered.

〔Effect of the invention〕

As described above, according to the present invention, the heat of the heating element is directly transmitted to the heat dissipating current carrying body near the surface of the rim portion, so that the heat of the heating element can be efficiently utilized. A small and inexpensive characteristic thermistor can be used.

In addition, the heat-dissipating current-carrying body, the heating element, and the current-carrying body are covered with a covering to form the heat-generating body into a unit, and this unitized heat-generating body is fitted into the fitting recess of the rim, so that it can be easily fixed in the event of a failure. The heat generating part can be replaced as a unit, and assembly work during manufacturing is also facilitated.

Then, the heat dissipating current carrying body, the heating element, and the current carrying body,
Since the rim is covered with a covering separately from the rest of the rim, molding defects are less likely to occur, and it is also suitable when using expensive synthetic resin such as silicone rubber with excellent thermal conductivity for the heating element covering. Also, since inexpensive synthetic resin can be used for the covering of the other parts of the rim, it is advantageous in terms of cost.

In addition, if the heating element is provided with a pair of terminals on the side of the heat dissipating current carrying body and the current carrying body, and a pair of terminals on the power supply side are provided in the fitting recess, which are connected to each terminal of the heating element when the heating element is fitted, wiring connections etc. This eliminates the need for additional work, and improves workability during manufacturing and repair.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the steering wheel according to the present invention, FIGS. 1 and 2 are cross-sectional views of its heating element, FIG. 3 is its overall plan view, and FIG. 4 is its FIG. 5 is a perspective view of the internal structure of the heating element, FIG. 6 is a perspective view of the core structure of the heating element, and FIG. 7 is a perspective view of the terminal. It is a perspective view which shows the modification of a part. DESCRIPTION OF SYMBOLS 1... Boss part, 2... Spoke part, 3... Rim part, 11... Fitting recessed part, 12... Heating element, 19...
...heat dissipating current carrying body, 20... heating element, 22... current carrying body, 24... covering body, 27, 28, 31, 32...
...Terminal.

Claims (1)

[Claims] 1. An annular rim portion is connected around the boss portion via spoke portions, a fitting recess is formed in the gripped portion of the rim portion, and a heating element is fitted into the fitting recess. The heating element has one electrode part of a heating element made of a positive temperature coefficient thermistor bonded to the inner side of a heat dissipating current carrying body, and a current carrying body is bonded to the other electrode part of this heating element. A steering wheel characterized in that the heat-dissipating current-carrying body, the heating element, and the current-carrying body are covered with a covering body to form a unit. 2 The unitized heating element has the heat dissipating current carrying body and a pair of terminals on the side of the current carrying body on the inside thereof,
2. The steering wheel according to claim 1, wherein the fitting recess of the rim portion has a pair of terminals on the power supply side that are connected to respective terminals of the heating element when the heating element is fitted.