JP2016094191A - Steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater built-in type steering wheel at a low cost having favorable temperature-rise performance.SOLUTION: A steering wheel includes a rim part 2 to be held and operated in which the rim part 2 has a core metal 10 and a cover 30 for covering an outer circumference of the core metal 10, an electric heater assembly body is arranged by being embedded in the cover 30, and the electric heater assembly body is configured by fitting an electric heater wire 40 to a support skeleton 20. The support skeleton 20 has a support 21 supported by the core metal 10, and an electric heater wire holding portion 22 separated from the core metal 10 and having a lattice shape in which the electric heater wire holding portion 22 is arranged by being embedded in a resin layer which constitutes the cover 30, an outside cover layer of the cover 30, the electric heater wire holding portion 22 and an inside cover layer of the cover 30 are arranged in this order from a surface of the rim part 2, and the support skeleton 20 is made of resin.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an operation handle, a knob, a grip, such as a grip for operating a vehicle such as an automobile, a motorcycle, a bicycle, and a motor boat, and a member for an interior member, and a heating function. It is.

For example, there are a steering wheel, a shift knob, a door grip, an assist grip, a joystick operation knob, an armrest, and the like as a gripping member and interior member of an automobile.
These gripping members are members that are touched and / or operated by the passengers of the car. Especially in cold regions, the surface temperature decreases due to parking for a long time outdoors, etc. It has been demanded.
The steering wheel is cold, such as in the winter morning, and the driving operation is not comfortable for a while after starting. In EV and the like, there is nothing equivalent to engine cooling water that has become hot water, and the room is heated exclusively using the electric energy of the battery, but if the cruising distance is shortened by using energy for heating There is a problem. As a means for suppressing the temperature increase in the room and making the driver feel warm, there is a temperature increase of the steering wheel. It is said that the warmth of the part touched directly is effective in enhancing the warmth.
As described above, there is a need to apply a steering wheel in which a heater is incorporated in an EV. How to lower the vehicle price is important in spreading EV. Significant cost increases should be avoided for steering wheels that do not incorporate heaters.
Conventional techniques include a rim cored bar that forms a skeleton part of the rim part, a hard cover member provided around at least a portion of the rim cored in the circumferential direction, and a heating element that generates heat when energized. A heater element made of a flexible sheet body, arranged along the outer surface of the cover member, and formed by injection molding around the heater element so as to cover the heater element in a contact state, and has its own outer surface There exists a steering wheel (for example, refer patent document 1) provided with the resin-made coating | coated part which makes a design surface.

Japanese Unexamined Patent Publication No. 2011-73544 (refer to the claims, detailed description of the invention, and FIGS. 1 to 12)

Patent document 1 which is the said prior art has disclosed the steering wheel which attached the heater element to the surface of the hard cover member, and covered with the soft coating | coated part (polyurethane).
However, the inside of the hard cover is made hollow, the end of the cover is closed, and the inflow of the soft material that covers the rim portion (grip portion) other than the cover member is stopped.
Although heat conduction (loss) to the inside can be reduced, if the soft covering is thickened to obtain a tactile sensation, the feeling of warmth transmitted to the driver is reduced. If the density of urethane is increased or decreased in order to increase the warm feeling, it becomes difficult to produce a soft touch. If the hollow part is not completely airtight, the low-viscosity liquid urethane molding material will intrude through the gaps, reducing the heat insulation effect of the hollow part, which may cause the small pieces to become free and cause abnormal noise. The urethane molding material is injected into the mold in anticipation of the cavity volume of the period, but since the urethane molding material leaks into the hollow portion, the urethane molding material is insufficient with respect to the cavity, causing shot variations and so-called short shots, and worsening the yield. Unlike thermoplastic materials, RIM (Injection Reaction Molding) urethane materials are difficult to reuse, and frequent defects can cause industrial waste disposal problems, which are undesirable in terms of environmental impact.
An object of the present invention is to provide a steering wheel with good tactile sensation that has a built-in heater that suppresses the occurrence of defects and enables mass production with high productivity while making the steering wheel incorporating the heater that solves the above problems soft and high tactile sensation. It is an object.

A first aspect of the present invention is a steering wheel as set forth in claim 1, and is as follows.
A rim portion for gripping operation is provided, the rim portion includes a cored bar and a covering part that covers the outer periphery of the cored bar, the electric heating assembly is embedded in the covering part, and the electric heating assembly is attached to the support skeleton. The support skeleton has a support part supported by the cored bar and a heating wire holding part that forms a lattice separated from the cored bar, and the heating line holding part has a covering part. It is arranged embedded in the resin layer to be configured, arranged in the order of the outer covering layer of the covering portion, the heating wire holding portion, and the inner covering layer of the covering portion from the surface of the rim portion, and the support skeleton is a resin. is there.

Since the steering wheel according to the present invention has the configuration as described above, the following effects can be obtained.
(1) In the invention described in claim 1, since the support skeleton is embedded in the covering portion together with the heating wire, the urethane RIM molding can be molded by one shot molding, so that the mass productivity is good. Since the hollow portion is not formed inside, there is no problem of resin material leakage affecting the shot size (effective amount of injected resin), and the yield is good. Since the support skeleton can be deformed along with the deformation when the covering portion is compressed and deformed, a gripping sensation equivalent to a single gripping sensation of the covering portion can be obtained. The heating wire holding part is separated from the cored bar and is directly under the outer coating layer, so that electric heat (heat loss) to the cored bar is suppressed and a warm feeling is easily obtained. Since the heating wire is positioned by the heating wire holding part and the thickness of the outer coating layer is stabilized (there is little variation in mass production), a steering wheel with uniform performance can be stably supplied. Further, if the supporting skeleton is made of resin, it is easy to obtain elastic deformation that can easily follow the compressive deformation of the covering portion, and thermal and electrical insulation between the heating wire and the cored bar becomes easy.

An example of the steering wheel of this invention is shown, (a) is a partial cross-sectional schematic front view, (b) is a schematic front view which shows the cross-section part of (a) in detail. It is the sectional view on the AA line of FIG. It is a schematic perspective view which shows the principal part of the steering wheel of this invention. It is a schematic perspective view which shows the state which attached the heating wire to the support frame | skeleton which is the characteristics of the steering wheel of this invention. It is a principal part schematic perspective view which shows the other Example of the steering wheel of this invention. It is a schematic sectional drawing which shows the state before attaching the support frame | skeleton of the other Example of the steering wheel of this invention to a metal core.

  A rim portion for gripping operation is provided, the rim portion includes a cored bar and a covering part that covers the outer periphery of the cored bar, the electric heating assembly is embedded in the covering part, and the electric heating assembly is attached to the support skeleton. The heating skeleton is attached, and the support skeleton has a supporting portion supported by the cored bar and a heating wire holding unit that forms a lattice separated from the cored bar, and the heating wire holding unit constitutes a covering unit. Embedded in the resin layer, arranged in the order from the surface of the rim portion to the outer covering layer of the covering portion, the heating wire holding portion, and the inner covering layer of the covering portion, and the support skeleton is a resin steering wheel is there.

An embodiment of the steering wheel of the present invention will be described with reference to FIGS.
As can be understood from FIG. 1, the steering wheel of the present embodiment includes a steering wheel 1, a rim portion 2, a spoke portion 3, a center pad 4 indicated by an imaginary line (which incorporates an airbag device), a boss portion 5, and a boss 6. , Cored bar 7 (rim cored bar 10, spoke cored bar 11, bossed cored bar 13), support frame 20 which is a positioning member, and heater wire (heated wire) 40. The cored bar 7 is made of, for example, a magnesium alloy formed by die casting.

  As can be understood from FIGS. 2 and 3, the soft foamed polyurethane constituting the skin of the rim portion 2 is formed by injection reaction molding (RIM), and constitutes the covering portion 30. The support skeleton 20 is obtained by injection molding using a high density polyethylene resin (HDPE).

Further, as can be understood from FIG. 4, the support skeleton 20, which is a feature of the present invention, includes a support portion 21 that holds the rim core metal 10, a horizontal beam 22 that is a heating wire holding unit, and a double mountain shape of the horizontal beam 22. Projection 23, semicircular turn guide 24, locking claw 25, and locking recess 26. The turn guide portion 24 further has a semicircular groove 27. The support skeleton 20 is composed of a member that can be divided into an upper half 20 </ b> U and a lower half 20.
The upper half 20U is in contact with the upper support portion 21U that contacts the upper half of the core metal 10, and the lower half 20L is in contact with the insertion piece 21La inserted into the sickle-shaped recess 10a of the core metal 10 and the pair of corner portions 10b and 10c. A holding portion 21Lb that is positioned so as to be held is provided.
Further, the heater wire (electric heating wire) 40 is a copper alloy wire separately routed to each of the upper half 20U and the lower half 20L. Each half 20U and 20L is drawn so as to meander and is positioned and attached by each projection 23 and turn guide portion 24.
In addition, each terminal of the heater wire 40 is attached by crimping a not-shown giboshi terminal.
Then, the upper and lower halves 20U and 20L to which the heater wires 40 are attached are combined so that the cored bar 10 is sandwiched, and the locking claw 25 and the locking recess 26 are engaged and attached. In this state, a polyurethane molding material is injected by inserting into the RIM mold and foamed to form the covering portion 30. As shown in FIG. 2, the outer side of the virtual line PhL connecting the horizontal rails 22 with a smooth curve is the outer coating layer 30A, and the inner side is the inner coating layer 30B.
The heater circuit is formed in each of the upper and lower halves 20U and 20L. These are connected in parallel or in series as appropriate and connected to a power supply circuit (not shown). The power supply circuit includes a thermostat that prevents overheating of the heater wire 40.
The steering wheel 1 is combined with a lower cover, an airbag module (center pad 4), etc. (not shown).

Here, advantages of the steering wheel using the support skeleton of the present invention will be described.
Normally, the polyurethane reaction liquid is a very low-viscosity liquid in an unreacted state and enters a fine gap, but circulates with bubbles, and if it adheres to the mold surface (cavity surface) etc. It becomes defective and does not become a product. However, the support skeleton 20 facilitates the flow of the internal fluid, facilitating the flow of the polyurethane reaction liquid. Therefore, the yield in mass production is good.
In addition, since the polyethylene skeleton structure is easily bent and deformed, a touch and grip feeling close to those of a single polyurethane can be obtained as the grip of the covering portion 30. As long as the heater device is not energized, there is no difference or uncomfortable feeling that a special heater device is incorporated. In addition, HDPE has a low density and is equivalent to polyurethane and has a slightly higher specific gravity than foamed polyurethane, so there is almost no influence on the operational feeling, that is, no influence on the moment of inertia.
As a result, the heater-equipped steering wheel and the heaterless steering wheel can be freely selected and mounted without any particular change in peripheral components, which is preferable in terms of vehicle option settings.
In addition, since the skeleton structure can be separated from the core metal by a desired distance and the heater wire can be positioned at a very small distance from the surface, exposure of the heater wire is eliminated, optimal surface heating performance and minimum Heat loss (electric heat to the core metal) can be achieved.

5 and 6 show other forms of the skeleton structure. In the previous embodiment, the skeletal structure is composed of two upper and lower parts, but the skeletal structure 50 of this embodiment is connected and integrated by a hinge 50A.
The metal core 10 was a steel pipe, and after bending a straight pipe, the opposite ends were butt welded to form a ring shape. The upper half 50U and the lower half 50L of the metal core 10 are provided with protrusions 50Ua to Uc and 50La to Lc that contact the metal core 10, and contact parts 50Ud and 50Ld at the tip, respectively. Each has a receiving part.
The upper and lower halves 50U and 50L are opened around the hinge 50A as shown in FIG. Since the subsequent molding process is the same as in the previous embodiment, a detailed description is omitted.
In this embodiment, since the skeletal structure 50 is connected by the hinge 50A, the attaching operation of the heater wire 40 is further facilitated, and the heater circuit arranged along the rim portion can be one circuit.

  For the support skeleton 20 and the like, a resin other than HDPE can be selected. That is, a resin material can be selected in consideration of physical properties such as price, moldability, and bending elasticity. For example, it can be selected from polypropylene resin, polyethylene terephthalate (PET) resin, 6 nylon (PA6), and the like. Moreover, materials other than resin can also be selected. A metal material may be used in the same manner as the core metal 7 and shaped with a mold. Specifically, a magnesium alloy, an aluminum alloy, or the like can be used. Since the support skeleton 20 and the like are in contact with the core metal 7 with a small area and the main part is in the vicinity of the surface of the covering portion, the metal support skeleton 20 is heated by the heat of the heating wire, and the heat is planar. To produce a thermal effect more widely. In addition, wood and bamboo can also be used. For example, the support skeleton 20 may be configured by combining warps and cocoons.

  It can be used for the steering wheel of all vehicles.

DESCRIPTION OF SYMBOLS 1 ... Steering wheel 2 ... Rim part 3 ... Spoke part 4 ... Center pad 5 ... Boss part 6 ... Boss 7 ... Core metal 9 ... ... Rib 10 ... Rim core 10a ... Recess 10b ... Corner 10c ... Corner 11 ... Spoke core 13 ... Boss core 20・ ・ ・ Support skeleton 20U ・ ・ ・ ・ Upper half 20L ・ ・ ・ ・ ・ ・ Lower half 21 ・ ・ ・ ・ ・ ・ Support part 21U ・ ・ ・ ・ ・ ・ Upper support part 21La ・ ・ ・ ・ ・ ・ Insertion piece 21Lb ・ ・ ・ ・ ・ ・ Holding part 22 ・...... Horizontal crosspiece 23... Projection 24... Turn guide part 25... Locking claw 26... Locking recess 27 ... Groove 30 ... Covering part 30 A ... Outer coating layer 30B ... Inner coating layer 40 ... Heater wire 50 ... Skeletal structure 5 A ... Hinge 50U ... Upper half 50L ... Lower half 50Ua ... Projection piece 50Ub ... Projection piece 50Uc ... Projection piece 50La ... Projection piece 50Lb ... .... Projection piece 50Lc ... Projection piece 50Ud ... Contact part 50Ld ... Contact part

Claims (1)

A rim portion for gripping operation is provided, the rim portion includes a cored bar and a covering part that covers the outer periphery of the cored bar, the electric heating assembly is embedded in the covering part, and the electric heating assembly is attached to the support skeleton. The heating skeleton is attached, and the support skeleton has a supporting portion supported by the cored bar and a heating wire holding unit that forms a lattice separated from the cored bar, and the heating wire holding unit constitutes a covering unit. Embedded in the resin layer, arranged in the order of the outer covering layer of the covering portion, the heating wire holding portion, and the inner covering layer of the covering portion from the surface of the rim portion, and the support skeleton is a resin And steering wheel.

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