handle

Abstract

To provide a steering wheel in which a coating film-like sensor layer for detecting gripping and a terminal can be stably connected.SOLUTION: In a steering wheel W1, a sensor layer 13 formed of a coating film containing a conductive material is disposed on the front side of a soft coating layer 10 disposed around a metal core, so that gripping during steering can be detected. The sensor layer allows the connection of a terminal 30 of a lead wire 26 electrically continuous with a gripping detection circuit. The terminal is pressed by a screw 37 inserted through insertion holes 16, 11, and 8 of the sensor layer 13, the coating layer 10, and a metal core 6, respectively, thereby being connected to the sensor layer. The screw includes a head part 38 and a screw rod part 39 having a male screw part 40 fastened to a fitting seat 21 provided on a component part of the steering wheel. There is disposed, around the screw rod part, a spring-like member 33 which exerts repulsive force in a direction opposite to a pressing direction so that it is possible to maintain the state of pressure-contact of the terminal pressed by the head part with the sensor layer when the screw is fastened to the fitting seat.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a steering wheel having a sensor layer that can detect a driver's grip at a location where the driver grips the steering wheel when steering the steering wheel. [Background technology]

[0002] Conventionally, in this type of steering wheel, a sensor layer made of a sheet-like conductive material capable of detecting gripping by an increase in electrostatic capacitance is arranged in the gripping portion that is gripped when steering (see, for example, Patent Document 1). The sensor layer is arranged on the surface side of the gripping portion of the steering wheel, and terminals of lead wires extending from a grip detection circuit that detects gripping are riveted in place. The sensor layer is arranged by, for example, adhering to the surface side of the coating layer around the core metal of the gripping portion of the steering wheel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-63761 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the sensor layer for detecting the grip is arranged on the surface of the coating layer around the core metal like a thin coating, even if a terminal is arranged on the surface side of the sensor layer, there is no space on the back side of the sensor layer to expand the diameter of the tip side of the rivet that has been penetrated and riveted the terminal to the sensor layer, so that the coating-like sensor layer and the terminal cannot be smoothly connected. In this case, it is possible to fasten the terminal by penetrating a fastening means such as a rivet or a screw so as to penetrate the coating layer and the core metal with the terminal placed on the front side of the sensor layer. However, even in this case, if the sensor layer is arranged on the front side of the coating layer and the head of the rivet or screw presses the sensor layer against the coating layer during fastening, there is a risk that the part of the sensor layer that contacts the terminal will cause a crack such as a break due to the elastic deformation of the coating layer on the back side of the sensor layer, and the terminal cannot be stably connected to the sensor layer, making it difficult to ensure a stable conductive state between the sensor layer and the terminal. In particular, the coating layer that covers the core wire is usually made of a soft material such as urethane foam, and since the elastic deformation of the coating layer is large, the portion of the sensor layer that comes into contact with the terminal can be broken or otherwise damaged due to the elastic deformation of the coating layer, making it impossible to stably connect the terminal to the sensor layer.

[0005] The present invention is devised to solve the above-mentioned problems, and has an object to provide a handle that can stably connect a coating-like sensor layer for grip detection to a terminal. [Means for solving the problem]

[0006] In the steering wheel according to the present invention, a sensor layer made of a coating film containing a conductive material is disposed on the surface side of a soft coating layer disposed around a core metal so as to be capable of detecting gripping during steering. The sensor layer is a handle for connecting a terminal of a lead wire that is connected to a grip detection circuit for detecting a grip, the terminal is configured to be pressed and connected to the sensor layer by a screw inserted through each insertion hole of the sensor layer, the covering layer, and the core metal, and is configured to have an attachment hole through which the screw is inserted, the screw includes a head portion capable of pressing against a periphery of the mounting hole of the terminal, and a threaded rod portion having a male thread portion protruding from the head portion and capable of passing through the mounting hole and each of the insertion holes, and fastened to a mounting seat provided on a component of the handle, A spring-like member is disposed around the screw rod portion and exerts a repulsive force in a direction opposite to the pressing direction so as to maintain the terminal pressed against the sensor layer by the head when the screw is fastened to the mounting seat.

[0007] In the handle of the present invention, if a terminal is placed on the sensor layer, and a screw is inserted through the mounting hole of the terminal, the sensor layer, the covering layer, and each of the insertion holes of the core, and the terminal is fastened to the mounting seat against the repulsive force of the spring-like member arranged around the screw rod portion with a fastening force within a range in which the terminal does not break the sensor layer, the terminal can be connected to the sensor layer while stably ensuring a conductive state. That is, in this fastened state, the spring-like member acts as a buffer material, and the sensor layer crimps the terminal to a degree that follows the deformation of the soft covering layer and does not break, making it possible to maintain a stable conductive state with the terminal.

[0008] Therefore, in the handle according to the present invention, the coating-like sensor layer for grip detection and the terminals can be stably connected, enabling good grip detection.

[0009] In the handle according to the present invention, it is preferable that the spring member is a wave washer disposed between the terminal and the head of the screw.

[0010] With this configuration, compared to the case where a spring washer with a notch is used, the periphery of the mounting hole of the terminal can be pressed evenly against the sensor layer, further preventing breakage of the sensor layer and connecting the terminal to the sensor layer.

[0011] In the handle according to the present invention, it is preferable that the mounting seat is disposed on a lower cover disposed on the underside of the handle.

[0012] In this configuration, the lower cover disposed on the steering wheel itself can be used to form the mounting seat for fastening the screw, so there is no need to prepare a separate member with a mounting seat. Also, since this screw also functions to attach the lower cover to the core metal of the steering wheel, it is possible to suppress an increase in the number of parts for the mounting screws for the lower cover.

[0013] Furthermore, in the handle according to the present invention, the sensor layer is disposed on substantially the entire outer periphery of the covering layer so as to cover both sides of the covering layer around the core metal, the sensor layer on the back surface side of the mounting seat is pressed toward the mounting seat when the screw is fastened to the mounting seat, via a washer through which the threaded rod portion is inserted and a wave washer, The screw, the mounting seat, the washer, and the wave washer may be configured to be conductive.

[0014] In this configuration, even if the portion of the sensor layer that is in contact with the terminal breaks and the electrical conductivity between the terminal and the sensor layer becomes unstable, the sensor layer on the mounting seat side will be in electrical conductivity with the washer and corrugated washer on the mounting seat side, and further, the mounting seat and the screw itself will be in an electrical conductivity state. As a result, the sensor layer on the mounting seat side and the screw will be in an electrical conductivity state, and since the head of the screw is in contact with the terminal via the corrugated washer, an electrical conductivity can be secured between the sensor layer on the mounting seat side and the terminal, and the grip detection signal of the sensor layer can be smoothly output to the grip detection circuit.

[0015] In the handle according to the present invention, the sensor layer covers the front and back of the coating layer around the core metal, and is configured to include a first sensor layer on the head side of the screw and a second sensor layer on the mounting seat side, which are disposed separately from each other, The second sensor layer is configured to be pressed against the mounting seat side when the screw is fastened to the mounting seat via a second terminal through which the threaded rod portion is inserted and a second wave washer, The second terminal and the second wave washer are configured to be in a non-conductive state with respect to the screw, The second terminal may be connected to a lead wire that is electrically connected to a grip detection circuit that is capable of detecting a grip on the second sensor layer side.

[0016] In such a configuration, a first sensor layer and a second sensor layer which are conductive to the respective grip detection circuits are disposed on the front and back of the coating layer around the core wire, and when gripped, it can detect whether the front side, back side, or both sides of the gripped portion are gripped. For example, simply detecting one of the front and back sides can determine that the gripped portion has simply been touched, or detecting both the front and back sides can determine that the gripped portion is being gripped properly.

[0017] In the handle according to the present invention, the sensor layer is The mold coating agent may be formed from a urethane-based paint containing a conductive material, and may be disposed on the surface side of the coating layer when the coating layer is molded.

[0018] In this configuration, the sensor layer formed as a coating film is a mold coat layer (in-mold coat layer), and the mold coating agent made of a urethane-based paint containing a conductive material is applied in advance to the mold surface of the mold when molding the coating layer, and then the coating layer can be easily formed by simply molding the coating layer. Furthermore, as a comparative example, for example, in a case where the sensor layer is not made into a mold coat layer, but a urethane-based paint containing a conductive material for forming the sensor layer is applied to the outer surface side of the coating layer after molding and then cured to form the sensor layer, a primer is applied to the outer surface of the coating layer after molding, or a labor for drying after applying the urethane-based paint is required, but compared to this case, the handle provided with the sensor layer made of the mold coat layer of the present invention can be easily manufactured because the primer application process and drying process described above are not required. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a schematic plan view showing a handle of one embodiment of the present invention. [Diagram 2] 2 is a schematic cross-sectional view of a gripping portion of the handle of the embodiment, which corresponds to the portion II-II in FIG. 1. [Diagram 3] 1A to 1C are diagrams illustrating a manufacturing process of the handle according to the embodiment. [Figure 4] 4A to 4C are diagrams for explaining the manufacturing process of the handle according to the embodiment, showing the state after FIG. 3. [Diagram 5] 2 is a schematic cross-sectional view of a portion of the handle in the embodiment where a terminal is provided, the portion corresponding to the portion VV in FIG. 1. [Figure 6] 13 is a schematic cross-sectional view of a terminal arrangement portion in a modified example of the embodiment. FIG. [Figure 7] FIG. 11 is a schematic cross-sectional view of a gripping portion of another modified example of the embodiment. [Figure 8] 8 is a schematic partial cross-sectional view of a portion of the handle shown in FIG. 7 where a terminal is provided. [Figure 9] 8 is a schematic cross-sectional view of a portion of the handle shown in FIG. 7 where a terminal is provided. [Figure 10] FIG. 11 is a schematic cross-sectional view of a gripping portion of yet another modified example of the embodiment. [Figure 11] 11A to 11C are diagrams illustrating a manufacturing process of the handle shown in FIG. 10. [Figure 12] 11A to 11C are views for explaining the manufacturing process of the handle shown in FIG. 10 and show the state after FIG. [Figure 13] 11 is a schematic cross-sectional view of a portion of the handle shown in FIG. 10 where a terminal is provided. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An embodiment of the present invention will be described below with reference to the drawings. As shown in Figs. 1 and 2, the steering wheel W1 of the embodiment is configured to include a substantially annular grip portion R1 to be gripped when steering a vehicle (not shown), a boss portion B at the center of the grip portion R1, and spoke portions S (L, R, B) connecting the grip portion R1 and the boss portion B. The spoke portion S includes spoke portions SL, SR extending from the boss portion B to both the left and right sides, and a spoke portion SB extending from the boss portion B to the rear. The steering wheel W1 is also configured to include an airbag device 100, indicated by a two-dot chain line, disposed on the upper side of the boss portion B, a steering wheel main body H1, and a lower cover 20 covering the lower side of the boss portion B.

[0021] The airbag device 100 and the lower cover 20 have substantially the same outer shape when viewed from above, and the airbag device 100 is disposed above the handle body H1, and the lower cover 20 is disposed below the handle body H1. The airbag device 100 is attached to the handle body H1 by engaging a plurality of mounting legs (not shown) with corresponding locking holes 9 of the handle body H1. The lower cover 20 is made of synthetic resin such as polypropylene, and is provided with mounting seats 21 provided with nuts 22 (see FIG. 5) made of metal such as steel for fastening screws 37, 42. The screws 37, 42 penetrating the handle body H1 are fastened to the mounting seats 21, and the handle body H1 is attached to the lower cover. The screws 37 also have the function of connecting the terminals 30 to the sensor layer 13, as described later. The mounting seat 21 of the lower cover 20 is disposed by insert molding using the nut 22 as an insert when the lower cover 20 is molded.

[0022] The handlebar body H1 is configured with a grip portion R1, a boss portion B, and a core metal 3 made of a metal material such as an aluminum alloy that connects the spoke portions S. The core metal 3 is configured with a grip core metal portion 4 disposed in the grip portion R1, a boss core metal portion 5 disposed in the boss portion B, and spoke core metal portions 6 (L, R), 7 disposed in the spoke portions S (L, R, B) so as to connect the grip core metal portion 4 and the boss core metal portion 5. The boss core metal portion 5 has a steel boss 5a disposed thereon that is connected to the steering shaft of the vehicle. The spoke core metal portion 6 is configured with spoke core metal portions 6L, 6R disposed in the left and right spoke portions SL, SR, and two spoke core metal portions 7, 7 disposed in the rear spoke portion SB, branching to the left and right at the boss core metal portion 5 side and connected to the grip core metal portion 4 side.

[0023] A grip detection circuit 25 is disposed in the boss portion B at a portion of the steering wheel main body H1 covered by the airbag device 100. Lead wires 26 extending from a sensor layer 13 described below are connected to the grip detection circuit 25, and when the driver's hand approaches the sensor layer 13 of the grip portion R1 as if gripping the grip portion R1, the capacitance increases, and the grip detection circuit 25 detects the increase and detects the driver's grip.

[0024] 2, the gripping portion R1 is composed of a gripping core bar portion 4 of the core bar 3, a covering layer 10 made of urethane foam formed by molding so as to cover the periphery of the gripping core bar portion 4, a sensor layer 13 disposed on the surface of the covering layer 10, and a protective layer 18 disposed on the surface side of the sensor layer 13. In the areas of the left and right spoke portions SL, SR that are covered by the airbag device 100, the protective layer 18 does not cover the sensor layer 13 in areas away from the gripping core bar portion 4, leaving the sensor layer 13 exposed.

[0025] The sensor layer 13 is formed from a mold coating agent 58 made of a urethane-based paint containing a conductive material (a urethane-based paint mixed with conductive carbon, metal oxide powder, etc. as a conductive filler) (see Figure 3), and is configured as a coating film that is applied to the mold surfaces 51a, 52a of the coating layer 10 during molding, and is disposed on the surface side of the coating layer 10 when the coating layer 10 is molded.

[0026] In this embodiment, the sensor layer 13 is formed from a urethane paint containing conductive carbon.

[0027] In this embodiment, the protective layer 18 is provided as a skin layer made of urethane foam that is provided by molding.

[0028] That is, in the embodiment, the urethane foam is composed of a urethane layer as a covering layer 10 on the gripping core portion 4 side on the back side of the sensor layer 13, and a urethane layer as a protective layer 18 on the front side of the sensor layer 13.

[0029] In this embodiment, the sensor layer 13 is made of a urethane-based paint containing conductive carbon, and the surface of the coating layer 10 is covered in a dark black color, while the protective layer 187 is not black, but is formed using urethane foam containing a light beige pigment to enhance the design.

[0030] In this embodiment, the thickness dimension St1 of the sensor layer 13 is set to 20 μm within a range of approximately 5 to 50 μm, preferably 10 to 30 μm, taking into consideration the conductivity, durability, and feel, and the thickness dimension Ut1 of the urethane layer of the protective layer 18 is set to 2 mm within a range of approximately 1 to 3 mm, taking into consideration the durability, feel, and sensitivity of the sensor layer 13.

[0031] 5, the lead wire 26 is connected to the sensor layer 13 by using a screw 37 that attaches a terminal 30 connected to the tip of the lead wire 26 to a mounting seat 21 disposed on a component of the handle W1. The terminal 30 is an annular conductive metal ring having a mounting hole 31 in the center for inserting the screw 37 therethrough.

[0032] The portion of the steering wheel W1 where the terminal 30 is connected is located away from the area gripped by the driver and is covered by the airbag device 100 or other switches, and is therefore located in a position that cannot be seen by the driver. In the case of this embodiment, the connection portion of the terminal 30 is located in the portion of the covering layer 10 that covers the spoke core portion 6R, which is the portion covered by the airbag device 100.

[0033] The terminal 30 is configured to be connected to the sensor layer 13 by being pressed by a screw 37 which passes through the sensor layer 13, the covering layer 10 and the respective insertion holes 16, 11 and 8 of the core metal (spoke core metal portion) 6L.

[0034] The screw 37 is configured to include a disk-shaped head 38 capable of pressing against the periphery of the mounting hole 31 of the terminal 30, and a threaded rod portion 39 having a male thread portion 40 that protrudes from the head 38 and is fastened to the mounting seat 21. The threaded rod portion 39 can be inserted through the mounting hole 31 of the terminal 30 and the respective insertion holes 16, 11, and 8 of the sensor layer 13, the covering layer 10, and the core (spoke core portion) 6R.

[0035] Furthermore, a spring-like member 33 is disposed around the threaded rod portion 39, which exerts a repulsive force in a direction opposite to the pressing direction so that the terminal 30 pressed by the head 38 can be maintained in a pressed contact state against the sensor layer 13 when the screw 37 is fastened to the mounting seat 21. In the case of this embodiment, the spring-like member 33 is a corrugated washer 34 disposed between the terminal 30 and the head 38 of the screw 37. The corrugated washer 34 is an annular member having an insertion hole 35 through which the threaded rod portion 39 can be inserted, and is made of a conductive metal such as steel, like the mounting seat 21 and the screw 27. In this embodiment, the outer dimension D1 of the corrugated washer 34 is larger than the outer diameter dimension D0 of the head 38 of the screw 37 and smaller than the outer diameter dimension D2 of the terminal 30 (D0 <D1<D2)。

[0036] The outer dimension D2 of the terminal 30 is approximately 2 to 20 mm, and in this embodiment, 10 mm, the outer dimension D1 of the wave washer 34 is approximately 2 to 20 mm, and in this embodiment, 6 mm, and the outer diameter dimension D0 of the head 38 is approximately 2 to 20 mm, and in this embodiment, 5 mm.

[0037] The terminal 30 has a protruding connecting seat 30a for connecting the lead wire 26 thereto.

[0038] The handle body H1 of the embodiment is manufactured through a mold coating agent application step, a first urethane layer forming step as the covering layer 10, and a second urethane layer forming step as the protective layer 18.

[0039] 3A and 3B, in the mold coating agent application step, a urethane-based paint containing a conductive material for forming the sensor layer 13 is applied as mold coating agent 58 to mold surfaces 51a and 52a of split molds 51 and 52 of a mold 50 for forming a first urethane layer as the coating layer 10, by a spray gun 57 as an application device. Note that, before applying the mold coating agent 58, a release agent is applied to the mold surfaces 51a and 52a.

[0040] Next, as shown in Figures 3C and 3D as the process for molding the first urethane layer as the coating layer 10, a molding die 50 consisting of split dies 51 and 52 is clamped, and a urethane material for forming the coating layer 10 as the first urethane layer is injected into the cavity 50a and hardened, producing an intermediate molded product 53 forming the coating layer 10, and the molding die 50 is opened to remove the intermediate molded product 53.

[0041] Next, as a molding process of the second urethane layer as the protective layer 18, as shown in Fig. 4A and 4B, a mold 54 consisting of split molds 55 and 56 for molding the second urethane layer is opened, the intermediate molded product 53 is set, and the mold 54 is closed. As shown in Fig. 4B and 4C, a urethane material for molding the second urethane layer as the protective layer 18 is injected into the cavity 54a and hardened to mold the second urethane layer 18. Before molding, a mold release agent is applied to the mold surfaces 55a and 56a of the split molds 55 and 56. After molding the second urethane layer as the protective layer 18, the mold is opened and removed to obtain a molded product provided with a grip portion R1, i.e., a handle body H1.

[0042] During manufacturing (molding) of the handle body H1, insertion holes 11, 16 for inserting the threaded rod portion 29 are formed in the covering layer 10 and the sensor layer 13 at the location of the insertion hole 8 of the spoke core portion 6R. A through hole for inserting the threaded rod portion of the screw 42 is also formed in the left spoke core portion 6L.

[0043] With the steering wheel main body H1 manufactured in this manner, the screws 37, 42 are fastened to each mounting seat 21 to attach the lower cover 20 to the lower side of the boss portion B, while the boss 5a of the boss portion B is fastened to the steering shaft of the vehicle, and the airbag device 100 is attached to the upper side of the boss portion B, whereby the steering wheel W1 can be assembled and mounted on the vehicle.

[0044] When fastening the screw 37 to the mounting seat 21, the terminal 30 is placed on the periphery of the insertion hole 16 of the sensor layer 13, and further the waved washer 34 is placed thereon, and the threaded rod portion 39 of the screw 37 is inserted through the insertion hole 35 of the waved washer 34, the mounting hole 31 of the terminal 30, the insertion holes 16 and 11 of the sensor layer 13 and coating layer 10, and the insertion hole 8 of the spoke core portion 6R, and the male thread portion 40 of the threaded rod portion 39 is fastened to the mounting seat 21. With this fastening, the sensor layer 13 and the grip detection circuit 25 capable of detecting the driver's grip are connected by the lead wires 26.

[0045] In a steering wheel W1 mounted on a vehicle, when the driver's hand approaches the sensor layer 13 of the grip portion R1 as if gripping the grip portion R1, a specified grip detection circuit 25 detects an increase in capacitance, thereby detecting the driver's grip.

[0046] In the handle W1 of the embodiment, the terminal 30 is placed on the sensor layer 13, and the screw 37 is inserted through the mounting hole 31 of the terminal 30, the sensor layer 13, the covering layer 10, and the respective insertion holes 16, 11, and 8 of the core (spoke core) 6R, and the terminal 30 is fastened to the mounting seat 21 against the repulsive force of the spring-like member 33 disposed around the threaded rod portion 39 and with a fastening force within a range that does not break the sensor layer 13, so that the terminal 30 can be connected to the sensor layer 13 while stably ensuring a conductive state. That is, in this fastened state, the spring-like member 33 serves as a buffer material, and the sensor layer 13 crimps the terminal 30 to a degree that does not break by following the deformation of the soft covering layer 10, making it possible to maintain a stable conductive state with the terminal 30.

[0047] Therefore, in the handle W1 of the embodiment, the coating-like sensor layer 13 for grip detection and the terminals 30 can be stably connected, enabling good grip detection.

[0048] In addition, in the handle W1 of the embodiment, the sensor layer 13 is formed from a mold coating agent 58 made of a urethane-based paint containing a conductive material, and is configured to be disposed on the surface (outer surface) 10a side of the coating layer 10 when the coating layer 10 is molded (see Figures 2 and 3).

[0049] Therefore, in the embodiment, the sensor layer 13 formed as a coating film is the mold coat layer (in-mold coat layer) 15, and the mold coat agent 58 made of a urethane-based paint containing a conductive material is applied in advance to the mold surfaces 51a, 52a of the mold 50 when the coating layer 10 is molded, and then the coating layer 10 provided with the sensor layer 13 can be formed by simply molding the coating layer 10. Furthermore, as a comparative example, for example, in a case where the sensor layer is not made into a mold coat layer, but a urethane-based paint containing a conductive material for forming the sensor layer is applied to the outer surface 10a side of the coating layer 10 after molding and then cured to form the sensor layer, a primer is applied to the outer surface of the coating layer after molding, or a labor for drying after applying the urethane-based paint is required, but compared to this case, the handle W1 provided with the sensor layer 13 made of the mold coat layer of the embodiment can be easily manufactured because the above-mentioned primer application process and drying process are not required.

[0050] Of course, if the above points are not taken into consideration, the sensor layer may not be a mold coat layer, but may be formed by applying a urethane-based paint containing a conductive material for forming the sensor layer to the outer surface side of the molded covering layer and then curing it.

[0051] In the handle W1 of this embodiment, the spring member 33 is a wave washer 34 disposed between the terminal 30 and the head 38 of the screw 37.

[0052] Therefore, in the embodiment, compared to the case of using a spring washer with a notch, the periphery of the mounting hole 31 of the terminal 30 can be evenly pressed against the sensor layer 13, which further prevents the sensor layer 13 from breaking and allows the terminal 30 to be connected to the sensor layer 13.

[0053] Of course, if the above point is not taken into consideration, a spring washer may be used as the spring-like member 33.

[0054] In the handle W1 of the embodiment, the mounting seat 21 is disposed on the lower cover 20 disposed on the lower surface side of the handle W1.

[0055] Therefore, in the embodiment, the mounting seat 21 for fastening the screw 37 can be configured using the lower cover 20 disposed on the handle W1 itself, so there is no need to prepare a member with a mounting seat separate from the lower cover 20. Furthermore, this screw 37, together with the other screw 42, also functions to mount the lower cover 20 to the core 3 (spoke core parts 6, 7) of the handle W1, so an increase in the number of parts for the mounting screws for the lower cover 20 can be suppressed.

[0056] In the embodiment, the mounting seat 21 is formed by utilizing the nut 22, but the lower cover 20 itself may be provided with a female thread corresponding to the male thread portion 40 to provide the mounting seat.

[0057] Furthermore, as a configuration for stabilizing the conductive state between the terminal and the sensor layer, a lower cover 20A may be attached to the handle body H2 of the handle W2 shown in Fig. 6. In this handle W2, the sensor layer 13 is arranged on the entire outer circumferential surface 10a (see Fig. 2) of the covering layer 10 so as to cover the front and back of the covering layer 10 around the core 3 (the grip core 4 and the spoke cores 6L, 6R (see Fig. 1)), and the sensor layer 13S on the back side on the mounting seat 21 side is pressed against the mounting seat 21 side when the screw 37 is fastened to the mounting seat 21, via the washer 44 through which the threaded rod portion 39 is inserted and the waved washer 34S. The screw 37, the mounting seat 21, the washer 44, and the waved washer 34S are configured to have conductivity, similar to the terminal 30 and the waved washer 34(F).

[0058] In such a handle W2, even if the portion of the sensor layer 13 (13F) with which the terminal 30 is in contact breaks and the electrical continuity between the terminal 30 and the sensor layer 13F becomes unstable, the sensor layer 13S on the mounting seat 21 side becomes electrically conductive with the washer 44 and corrugated washer 34S on the mounting seat 21 side, and further, the mounting seat 21 and the screw 37 itself become electrically conductive. As a result, the sensor layer 13S on the mounting seat 21 side and the screw 37 become electrically conductive, and the head 38 of the screw 37 contacts the terminal 30 via the corrugated washer 34F. This ensures electrical continuity between the sensor layer 13S on the mounting seat 21 side and the terminal 30, and makes it possible to smoothly output a grip detection signal of the sensor layer 13 (13F, 13S) to the grip detection circuit 25.

[0059] 7 to 9, the sensor layer may be arranged to distinguish the portion for detecting grip. In this handle W3, the sensor layer 13 covers the front and back of the covering layer 10 around the core 3 (the grip core 4 and the spoke core 6), and is configured with a first sensor layer 14F on the head 38 side of the screw 37 and a second sensor layer 14S on the mounting seat 21 side, which are arranged separately from each other. The second sensor layer 14S is configured to be pressed against the mounting seat 21 side when the screw 37 is fastened to the mounting seat 21, via the second terminal 30S through which the screw rod portion 39 is inserted and the second wave washer 34S. The second terminal 30S and the second wave washer 34S are configured to be in a non-conductive state with the screw 37, and the second terminal 30S connects the lead wire 26S that is conductive to the grip detection circuit 25S that can detect gripping on the second sensor layer 14S side. In this handle W3, the grip part R3 has the first sensor layer 14F arranged on the upper surface side and the second sensor layer 14S arranged on the lower surface side, and the first sensor layer 14F is arranged on the upper surface side and the second sensor layer 14S is arranged on the lower surface side at the spoke parts SL and SR (see FIG. 1). On the first sensor layer 14F side, the first terminal 30F is pressed against the first sensor layer 14F side by the first wave washer 34F pressed by the head 38 of the screw 37. The first terminal 30F connected to the first sensor layer 14F is connected to a lead wire 26F that is electrically connected to a grip detection circuit 25F that is capable of detecting a grip on the first sensor layer 14F side.

[0060] In this handle W3, a first sensor layer 14F and a second sensor layer 14S, which are conductive to respective grip detection circuits 25F, 25S, are arranged on the front and back sides 10b, 10c of the covering layer 10 around the core wire (gripping core wire portion) 4, and when gripped, it can detect whether the front side 10b, the back side 10c, or both sides of the gripping portion are gripped. For example, simply detecting one of the front and back sides can determine that the gripping portion R3 has only been touched, or detecting both the front and back sides can determine that the gripping portion R3 is being gripped properly.

[0061] In order to improve the sensitivity of the sensor layer 13, a shield layer 64 may be disposed around the core bar (gripping core bar portion) 4, as in the case of a handle W4 shown in FIGS.

[0062] As shown in Fig. 10, the grip part R4 of the handle W4 is configured to include a grip core bar part 4 of the core bar 3, a covering layer 60 made of urethane foam arranged by molding so as to cover the periphery of the grip core bar part 4, and a sensor layer 67. As in the embodiment, the sensor layer 67 is formed from a mold coating agent 85 made of a urethane-based paint containing a conductive material (conductive carbon) (see Fig. 12), and is applied to the mold surfaces 78a, 79a of the second urethane layer 62 of the covering layer 60 during molding, and is configured to be arranged on the front surface side of the second urethane layer 62 when the second urethane layer 62 of the covering layer 60 is molded. Furthermore, the sensor layer 67 is arranged while being covered with a protective layer 70 arranged on the front surface side.

[0063] The covering layer 60 made of foamed urethane is configured to include a first urethane layer 61 on the gripping core bar portion 4 side of the core bar 3, a second urethane layer 62 on the back side of the sensor layer 67, and a shielding layer 64 arranged between the first urethane layer 61 and the second urethane layer 62.

[0064] The shield layer 64 is made of a first mold coating agent 84 (see FIG. 11) made of a urethane-based paint containing a conductive material (e.g., conductive carbon). The sensor layer 67 is made of a second mold coating agent 85 (see FIG. 12). That is, the first mold coating agent 84 is applied to the mold surfaces 74a, 75a of the mold 73 for the first urethane layer 61 during molding, and is disposed on the surface side of the first urethane layer 61 during molding of the first urethane layer 61, forming the first mold coating layer 65. The second mold coating agent 85 for forming the sensor layer 67 is applied to the mold surfaces 78a, 79a of the mold 77 for the second urethane layer 62 during molding, and the sensor layer 67, which becomes the second mold coating layer 68, is disposed on the surface side of the second urethane layer 62 during molding of the second urethane layer 62.

[0065] The handle body H4 of the handle W4 is manufactured through a shield mold coating agent application step, a first urethane layer molding step, a sensor mold coating agent application step, a second urethane layer molding step, and a protective layer molding step.

[0066] 11A and 11B, in the shielding mold coating agent application process, a urethane-based paint containing a conductive material for forming the shield layer 64 is applied as a first mold coating agent 84 by a spray gun 81 as an application device to mold surfaces 74a, 75a of split molds 74, 75 of a molding die 73 for forming a first urethane layer 61 as a covering layer 60. Before applying the mold coating agent 84, a release agent is applied to the mold surfaces 74a, 75a.

[0067] Next, as the first urethane layer molding process, as shown in B and C of Figure 11, a molding die 73 consisting of split dies 74, 75 is clamped, a urethane material for forming the first urethane layer 61 is injected into the cavity 73a and hardened, an intermediate molded product 66 is produced by molding the first urethane layer 61, and the molding die 73 is opened to remove the intermediate molded product 66.

[0068] 12A, a urethane-based paint containing a conductive material for forming the sensor layer 67 is applied as a second mold coating agent 85 to mold surfaces 78a, 79a of split molds 78, 79 of a mold 77 for forming the second urethane layer 62 as the covering layer 60 by a spray gun 82 as an application device. Before applying the mold coating agent 85, a release agent is applied to the mold surfaces 78a, 79a.

[0069] 12A and 12B, in the second urethane layer molding step, intermediate molded product 66 is set in mold 77 consisting of split molds 78 and 79 for molding second urethane layer 62, mold 77 is closed, and urethane material for molding second urethane layer 62 is injected into cavity 77a and hardened to form second urethane layer 62. Then, after molding second urethane layer 62, the mold is opened and removed to obtain intermediate molded product 69 before molding protective layer 70 (see C in FIG. 12).

[0070] Thereafter, by forming a protective layer 70 on the intermediate molded product 69, the grip portion R4 of the handle body H4 can be manufactured (see D in FIG. 12).

[0071] When the handle body H4 is molded, an insertion hole 67a in the sensor layer 67 and an insertion hole 64a in the shield layer 64, through which the screw 37 can be inserted, are provided at the location of the insertion hole 8 in the spoke core portion 6L through which the screw 37 is inserted.

[0072] With the steering wheel main body H4 manufactured in this manner, similarly to the steering wheel main body H1, the lower cover 20 is attached to the lower side of the boss portion B, the boss 5a of the boss portion B is fastened to the steering shaft of the vehicle, and the airbag device 100 is attached to the upper side of the boss portion B, whereby the steering wheel W4 can be assembled and mounted on the vehicle.

[0073] The lead wire 87 connected to the shield layer 64 is connected to a predetermined shield circuit connected to the grip detection circuit and is joined to a connecting seat 90a of a terminal 90, and the threaded stem portion 39 of the screw 37 is inserted into a mounting hole 91 of the terminal 90, and the terminal 90 is pressed against the resin portion 23 around the mounting seat 21 with the second wave washer 34S interposed therebetween. The sensor layer 67 is crimped to the terminal 30 by fastening the screw 37 to the mounting seat 21 with the wave washer 34F interposed therebetween. [Explanation of symbols]

[0074] 3...core metal, 6(L,R)...spoke core metal portion, 8...insertion hole, 10...coating layer, 10a...outer circumferential surface, 10b...front side, 10c...rear side, 11...insertion hole (of core metal), 13,67...sensor layer, 13S...(rear side) sensor layer, 14F...first sensor layer, 14S...second sensor layer, 16,67a...insertion hole (of sensor layer), 20...lower cover, 21...mounting seat, 25(F,S)...grip detection circuit, 26(F,S)...lead wire, 30(F ,S)...terminal, 30F...first terminal, 30S...second terminal, 31...mounting hole, 33...spring-like member, 34...wave washer, 34F...first wave washer, 34S...second wave washer, 35...insertion hole (of wave washer), 37...screw, 38...head, 39...threaded rod portion, 40...male threaded portion, 44...washer, H1,H2,H3,H4...handle body, R1,R2,R3,R4...gripping portion, W1,W2,W3,W4...handle.

Claims

1. A sensor layer made of a coating film containing a conductive material is disposed on a surface side of a soft coating layer disposed around a core metal so that the gripping of the steering wheel during steering can be detected. The sensor layer is a handle for connecting a terminal of a lead wire that is connected to a grip detection circuit for detecting a grip, the terminal is configured to be pressed and connected to the sensor layer by a screw inserted through each insertion hole of the sensor layer, the covering layer, and the core metal, and is configured to have an attachment hole through which the screw is inserted, the screw includes a head portion capable of pressing against a periphery of the mounting hole of the terminal, and a threaded rod portion having a male thread portion protruding from the head portion and capable of passing through the mounting hole and each of the insertion holes, and fastened to a mounting seat provided on a component of the handle, A handle characterized in that a spring-like member is arranged around the threaded rod portion to exert a repulsive force in a direction opposite to the pressing direction, so as to maintain the terminal pressed against the sensor layer by the head when the screw is tightened into the mounting seat.

2. 2. The handle of claim 1, wherein said spring-like member is a wave washer disposed between said terminal and said head of said screw.

3. 3. The handle according to claim 1, wherein the mounting seat is disposed on a lower cover disposed on a lower surface side of the handle.

4. The sensor layer is disposed on substantially the entire outer periphery of the coating layer so as to cover the front and back of the coating layer around the core metal, the sensor layer on the back surface side of the mounting seat is pressed toward the mounting seat when the screw is fastened to the mounting seat, via a washer through which the threaded rod portion is inserted and a wave washer, 3. The handle according to claim 2, wherein the screw, the mounting seat, the washer, and the wave washer are made to be conductive.

5. the sensor layer covers the front and back of the coating layer around the core metal, and is configured to include a first sensor layer on the head side of the screw and a second sensor layer on the mounting seat side, the first sensor layer and the second sensor layer being disposed separately from each other, the second sensor layer is pressed against the mounting seat side when the screw is fastened to the mounting seat via a second terminal through which the threaded rod portion is inserted and a second wave washer, The second terminal and the second wave washer are configured to be in a non-conductive state with respect to the screw, 3. The handle according to claim 2, wherein the second terminal is connected to a lead wire that is electrically connected to a grip detection circuit capable of detecting a grip on the second sensor layer side.

6. The sensor layer comprises: The handle described in any one of claims 1 to 5, characterized in that it is formed from a mold coating agent consisting of a urethane-based paint containing a conductive material, and is arranged on the surface side of the coating layer when the coating layer is molded.

Images