JP2016068679A - Temperature control method of steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering wheel in which an entire perimeter of the steering wheel can be heated quickly.SOLUTION: A leather and a decorative member are provided on a surface part of a rim part of a steering wheel. A first heater part 24 for adjusting the temperature of the leather and a second heater part 32 for adjusting the temperature of the decorative member are controlled by an ECU 16. The ECU 16 starts energization only to the first heater part 24 first. When the temperature of the first heater part 24 reaches a targeted first specified temperature, the ECU 16 stops the energization to the first heater part 24 and then starts energization to the second heater part 32. When the temperature of the first heater part 24 becomes lower than a second specified temperature, the ECU restarts the energization to the first heater part 24 and thereafter controls ON/OFF of the energization to the first heater part 24 and the second heater part 32 so that the temperature of the first heater part 24 is kept between the first specified temperature and the second specified temperature.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for controlling a steering wheel having a temperature adjustment function.

  For example, in the case of a steering wheel mounted on a vehicle, when the vehicle is used in a cold region, the interior of the vehicle becomes cold and the temperature of the steering wheel decreases. When the driver gets on the vehicle and starts driving in such a state, the driver is gripped by the cold steering wheel, which makes driving difficult. Thus, it has been proposed to provide a temperature adjustment portion on the steering wheel. For example, Patent Literature 1 describes a steering wheel in which the surface of the rim portion of the steering wheel is covered with a heater portion as a temperature adjustment portion. . Moreover, the rim | limb part of the steering wheel described in patent document 1 is formed from the circular-arc-shaped member which consists of synthetic resins, and the circular-arc-shaped member which consists of wood. Since the thermal conductivity is different between the synthetic resin part and the wood part, a separate heater part is installed for each so as not to feel the temperature difference.

JP 2010-76559 A

  However, the steering wheel described in Patent Document 1 has a problem that the upper limit of the power value that can be supplied to the heater unit is limited, so that the entire steering wheel cannot be quickly warmed.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a steering wheel that can quickly warm the entire circumference of the steering wheel.

In order to solve the above problems, the invention according to claim 1 is directed to a steering wheel in which a first design portion and a second design portion are provided on a surface portion of a rim portion.
A first temperature adjusting unit provided inside the first design part and generating heat to the first design part by energization is provided inside the second design part and generates heat to the second design part by power supply. A first control stage for preferentially raising the temperature from the second temperature control unit for performing
When the temperature of the first temperature adjusting unit reaches the first predetermined temperature, the second temperature adjusting unit maintains the temperature of the first temperature adjusting unit between the predetermined temperature and a second predetermined temperature lower than the predetermined temperature. A second temperature control stage for raising the temperature of
When the temperature of the second temperature adjusting unit reaches the third predetermined temperature, the second temperature adjusting unit maintains the temperature of the first temperature adjusting unit between the predetermined temperature and the second predetermined temperature lower than the predetermined temperature. A third control stage for maintaining the temperature of the part between a third predetermined temperature and a lower fourth predetermined temperature;
The gist is that the power supply amount to the first temperature control unit and the second temperature control unit is controlled to be equal to or less than the maximum power amount in the first to third control stages.

In the first aspect of the temperature control method for the steering wheel, the first temperature provided in the interior of the first design portion as a grip portion that is easy to grip when an occupant gets on the vehicle is provided. Only the first design part can be quickly heated by supplying power to the adjustment part with priority. By heating only the first temperature control unit, when the occupant grips the steering wheel, the first design unit is not felt cold and can be gripped comfortably.
In the second control stage, when the temperature of the first temperature adjusting unit reaches the first predetermined temperature, the temperature of the first temperature adjusting unit is set between the predetermined temperature and a second predetermined temperature lower than the predetermined temperature. The second design portion can be heated by raising the temperature of the second temperature adjusting portion while maintaining it, and the entire circumference of the steering wheel can be effectively heated.
Next, in the third control stage, when the temperature of the second temperature adjusting unit reaches the third predetermined temperature, the temperature of the first temperature adjusting unit is set between the predetermined temperature and a second predetermined temperature lower than the predetermined temperature. Maintaining the temperature of the second temperature adjusting unit between the third predetermined temperature and the fourth predetermined temperature lower than the third predetermined temperature, the temperature of the entire steering wheel can be kept constant, which is inconvenient for the passenger. You can drive comfortably without giving a pleasant feeling.
In the first to third control stages, the power supply amount to the first temperature control unit and the second temperature control unit is controlled to be equal to or less than the maximum power amount, and the power value that can be supplied to the steering wheel is limited. The steering wheel can be heated efficiently with the maximum electric energy.

  According to a second aspect of the present invention, in the steering wheel according to the first aspect, in the first temperature control stage and the second temperature control stage, the maximum amount of electric power is always the first temperature adjusting unit or the second temperature. It is supplied to the control unit

  According to the above control method, since the maximum amount of electric power is always supplied to the first temperature adjusting unit or the second temperature adjusting unit, the steering wheel can be efficiently heated in a short time.

  According to a third aspect of the present invention, in the steering wheel according to the first or second aspect, in the first temperature control stage and the second temperature control stage, the first temperature control unit or the second temperature control unit The maximum amount of power is supplied to only one side.

According to the above control method, since the maximum power amount is supplied only to one of the first temperature adjusting unit or the second temperature adjusting unit, the temperatures of the first temperature adjusting unit and the second temperature adjusting unit are set to be predetermined Can be quickly increased to the value of.

According to a fourth aspect of the present invention, in the steering wheel according to the first to third aspects, a temperature adjusting element that detects a temperature of the first temperature adjusting unit, the first temperature adjusting unit, and the second temperature adjusting unit. Control means for controlling power supply to the unit is provided.

The steering wheel includes a temperature control element and a control unit that controls power supply to the first temperature control unit and the second temperature control unit, thereby supplying power to the first temperature control unit and the second temperature control unit. Can be controlled.

According to a fifth aspect of the present invention, in the second control stage, the time required for the temperature of the first temperature adjusting unit to drop from the first predetermined temperature to the second predetermined temperature is less than a predetermined time. If it is long, the process shifts from the second control stage to the third control stage.

According to the above control method, if the time required for the temperature of the first temperature adjusting unit to fall from the first predetermined temperature to the second predetermined temperature is found, the second control stage is compared with the predetermined time. Therefore, the temperature of the steering wheel can be controlled without detecting the temperature of the second temperature adjusting unit.

According to the present invention, by preferentially starting energization to the first temperature control unit, it is not possible to feel cold when grasped and the entire steering wheel can be effectively warmed.

The schematic front view of the steering wheel in this implementation mobile. (A) is a schematic sectional drawing of the rim | limb part along the AA line, (b) is a schematic partial top view which shows a 1st temperature control part. (A) is a schematic sectional drawing of the rim | limb part along BB line, (b) is a schematic partial top view which shows a 2nd temperature control part. The block diagram which shows the electric constitution of a steering wheel. The flowchart of the control which ECU performs with respect to a 1st temperature control part and a 2nd temperature control part. Correlation diagram of power supply and temperature in the first, second and third control stages

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, a steering wheel 11 provided in a driver's seat of a vehicle has a circular shape when viewed from the front, and a steering shaft 12 connected to a steering wheel is connected to a central portion of the steering wheel 11 so as to be integrally rotatable. Has been. The rim portion 13 constituting the steering wheel 11 is formed in an annular shape around the axis L of the steering shaft 12, and the pad 14 surrounded by the rim portion 13 on the inner peripheral surface of the rim portion 13. Are connected via a plurality of spoke portions 15. An electronic control unit (hereinafter referred to as ECU) 16 is provided inside the pad 14. The rim portion 13 and the spoke portion 15 are provided with a core body 17 forming a skeleton portion of the entire steering wheel 11 therein.

  The rim portion 13 includes a first design portion 20 having a surface portion made of leather 19 and a second design portion 18 having a pair of decorating members 31 having a surface portion decorated. The first design portion 20 and the second design portion 18 are provided symmetrically about the axis L of the steering shaft 12. A portion of the core body 17 corresponding to the rim portion 13 is configured as a rim portion core body 21.

  As shown in FIG. 2A, the first design portion 20 has a circular cross-sectional shape orthogonal to its own axis P. The rim core 21 includes a rim core 22 having a substantially U-shaped cross section, and a filler 23 made of a soft material such as polyurethane foam provided so as to cover the rim core 22. . And in the 1st design part 20, the outer peripheral part 21a of the rim | limb part core 21 is covered with the 1st heater part 24 as a 1st temperature control part. The rim core 21 and the first heater 24 are covered with leather 19.

  The 1st heater part 24 is comprised by the heater wire 26 being sewn into the heat insulation sheet 25 which consists of a nonwoven fabric. As shown in FIG. 2 (b), the heat insulating sheet 25 is formed in a substantially elongated rectangular shape in a state of being flattened. The heater wire 26 continuously extends in a wave shape without overlapping with itself. Both ends of the heater wire 26 are electrically connected to the first heater portion electric wire 28 via the first heater portion terminal portion 27. The first heater terminal portion 27 is provided with a temperature detecting element 29 having a characteristic that the resistance decreases as the temperature increases.

  In the present embodiment, the temperature detection element 29 is constituted by a thermistor, and the detection unit is in contact with the heater wire 26 so that the output changes according to the temperature of the heater wire 26. The temperature actually detected by the temperature detecting element 29 is different from the surface temperature of the leather 19. This is because the internal temperature of the leather 19 and the temperature of the surface of the leather 19 are affected by heat storage and thermal conductivity of the leather 19 until the heat from the heater wire 26 is transferred from the inside of the leather 19 to the surface of the leather 19. This is because and change. A first connector 30 is connected to the first heater section electric wire 28 at the end opposite to the first heater section terminal section 27 side.

  On the other hand, as shown in FIG. 3A, a decoration member 31 is provided on the outer side of the rim core 21 in the second design portion 18. The decorative member 31 includes a synthetic resin base 31a in which a cross section perpendicular to the axis P of the rim core 21 is formed in a substantially arc shape, and a wooden decorative plate 31c attached to the outer surface 31b of the base 31a. It is constituted by. A second heater portion 32 as a second temperature adjusting portion is attached to the inner side surface 31 d of the decorating member 31.

  The 2nd heater part 32 is comprised by the heater wire 34 being sewn on the heat insulation sheet 33 which consists of a nonwoven fabric while it is pinched | interposed by the rim | limb part core 21 and the decorating member 31. FIG. As shown in FIG. 3B, the heat insulating sheet 33 is formed in a substantially elongated rectangular shape in a state where the heat insulating sheet 33 is developed in a planar shape. The heater wire 34 continuously extends in a wavy shape without overlapping with itself. Both ends of the heater wire 34 are electrically connected to the second heater portion electric wire 36 via the second heater portion terminal portion 35. A second connector 38 is connected to the second heater portion electric wire 36 at the end opposite to the second heater portion terminal portion 35 side. The second connector 38 is connected to a second coupler (not shown) provided in the ECU 16.

Next, an electrical configuration for controlling the first heater unit 24 and the second heater unit 32 will be described.
As shown in FIG. 4, the ECU 16 for controlling the actuator provided on the steering wheel 11 is provided with a CPU (Central Processing Unit) 40 and a ROM (Read Only Memory) 41 capable of executing control operations in a predetermined procedure. It has been. The ROM 41 stores a control program for controlling various operations of the actuator.

  A temperature detection element 29 is electrically connected to the ECU 16. The ECU 16 is configured to take an output voltage corresponding to a resistance change of the temperature detection element 29 as a voltage value V. The ECU 16 is configured to grasp the temperature of the leather 19 based on the voltage value V.

  The ECU 16 is electrically connected to the first heater unit 24 and the second heater unit 32. The ECU 16 is configured to be able to output different commands to the first heater unit 24 and the second heater unit 32. The ECU 16 is configured to be able to switch ON and OFF of the first heater unit 24 and the second heater unit 32. When the first heater unit 24 is turned on, the ECU 16 energizes the heater wire 26 with a first supply electric energy and executes energization control for raising the temperature of the leather 19 by Joule heat of the heater wire 26. When the section 24 is turned off, the energization control is terminated and the heater wire 26 is not energized. Further, when the second heater unit 32 is turned on, the ECU 16 performs energization control for energizing the heater wire 26 with the first supply power amount and raising the temperature of the decorating member 31 by Joule heat of the heater wire 26. When the second heater section 32 is turned off, the energization control is terminated and the heater wire 26 is not energized.

  The ROM 41 stores a first specified voltage v1 for turning off the first heater section 24, and a second specified voltage v2 for turning on the first heater section 24 after reaching the first specified voltage v1. Yes. The first specified voltage v1 and the second specified voltage v2 take into account the heat storage and thermal conductivity of the leather 19, and when the voltage value V reaches the first specified voltage v1 and the second specified voltage v2, the surface of the leather 19 The temperature inside the leather 19 when the target temperature is reached is estimated, and the output values of the temperature detecting element 29 corresponding to the estimated temperature are set as the first specified voltage v1 and the second specified voltage v2.

Next, control processing when the ECU 16 performs energization control on the first heater unit 24 and the second heater unit 32 will be described.
When a switch operation for starting the engine is performed and a start command is input to the ECU 16 from an in-vehicle ECU (not shown), the ECU 16 starts controlling the first heater unit 24 and the second heater unit 32 according to the flowchart of FIG. FIG. 6 shows changes in the amount of power supplied to the first heater unit 24 and the second heater unit 32 and changes in temperature after the start of control. First, as a first control stage, the ECU 16 inputs a command to start energization only to the first heater unit 24 in step (hereinafter referred to as S) 1. At that time, the maximum amount of electric power is always supplied as the amount of electric power supplied to the first heater unit 24. Next, when the ECU 16 determines in S2 that the voltage value V is higher than the first specified voltage v1, the process proceeds to S3, the first heater unit 24 is turned off, and then the process proceeds to the second control stage.

  In S4 of the second control stage, the ECU 16 inputs a command to start energization of the second heater unit 32 and turns on the timer to start measuring the elapsed time. Next, when the ECU 16 determines in S5 that the voltage value is lower than the second specified voltage v2, the process proceeds to S6. In S6, the timer is turned off, and it is determined whether the elapsed time t is longer than the predetermined time t0. When the elapsed time t is longer than the predetermined time t0, the process proceeds to S9 described later. When the elapsed time t is shorter than the predetermined time t0, the process proceeds to S7. In S7, the energization to the second heater section 32 is turned off and the energization to the first heater section 24 is started. Next, when the ECU 16 determines in S8 that the voltage value is higher than the second specified voltage v1, the process returns to S4. In the second control stage, one of the heater units is energized so that the amount of power supplied to the first heater unit 24 and the second heater unit 32 is always the maximum power amount.

  When it is determined in S6 that the elapsed time t is longer than the predetermined time t0, the process proceeds to the third control stage, and in S9, energization to the first heater unit 24 is started, and energization to the second heater unit 32 is turned off. To do. Next, when the ECU 16 determines in S10 that the voltage value V is higher than the first specified voltage v1, the process proceeds to S11 to turn off the first heater unit 24 and then start energizing the second heater unit 32. Next, when the ECU 16 determines in S12 that the voltage value is lower than the second specified voltage v2, the process proceeds to S9 again. Thereafter, the ECU keeps the surface temperature of the first design portion 20 and the second design portion 18 between the first predetermined temperature and the second predetermined temperature, and between the third predetermined temperature and the fourth predetermined temperature. However, according to the flow of the third control stage, the energization to the first heater unit 24 and the second heater unit 32 is continuously controlled. The amount of power supplied to the first heater unit 24 and the second heater unit 32 in the third control stage is such that the first design unit 20 and the second design unit 18 stay at a predetermined temperature without energizing the maximum supply power amount. It is controlled to supply power.

  When a stop command is input from the in-vehicle ECU to the ECU 16, the ECU 16 turns off the first heater unit 24 and the second heater unit 32, and stops control of the first heater unit 24 and the second heater unit 32.

Next, the operation of the steering wheel in this embodiment will be described.
When the vehicle is parked under severe cold in winter, the temperature inside the vehicle is lowered and the temperature of the steering wheel 11 including the rim portion 13 is also lowered. When the driver sits in the driver's seat and starts driving in this state, the driver performs a switch operation for starting the engine and a heater switch operation of the steering wheel 11. Then, the energization control for the first heater unit 24 is started by the ECU 16. When energization of the first heater unit is started, Joule heat corresponding to the amount of power supplied is generated from the heater wire 26, and the heat is transferred to the leather 19 to warm the leather 19. Therefore, the 1st design part 20 is warmed immediately and a driver | operator can hold | grip comfortably. After that, when the temperature of the first design portion 20 is warmed, energization to the second heater portion is started, so that the second design portion 18 is also warmed in the same manner as the leather. The surface of 31 reaches the same temperature almost simultaneously. Therefore, even if the driver grips the first design part 20 and the second design part 18 in order to operate the steering hole 11 thereafter, the driver does not feel uncomfortable.

According to this embodiment, the following effects can be obtained.
(1) A first heater portion 24 is provided in the first design portion 20 of the rim portion 13. A second heater portion 32 is provided in the second design portion 18 of the rim portion 13. The ECU 16 is electrically connected to the first heater unit 24 and the second heater unit 32, and is configured to be able to control energization to each of the first heater unit 24 and the second heater unit 32.

  (2) The temperature of the leather 19 is detected by the temperature detection element 29, and the detection result by the temperature detection element 29 is input to the ECU 16. Therefore, since the first heater part 24 and the second heater part 32 can be feedback controlled using the temperature detecting element 29, the temperature of the leather 19 and the decorating member 31 can be adjusted more accurately.

  (3) The first specified voltage v1 for determining whether the first heater section 24 is turned off and the second heater section 32 is turned on is a value that can be considered that the temperature of the leather 19 has reached the target temperature. Is set to The second specified voltage v2 for determining whether to turn the first heater unit 24 on again after it is turned off is set to a value that allows the temperature of the leather 19 to be considered lower than the target temperature. Therefore, the temperature of the leather 19 can be kept in the target temperature range, the temperature of the leather 19 and the temperature of the decoration member 31 can be raised to the same temperature, and the steering wheel 11 can be heated more efficiently. Can do.

In addition, this invention can be embodied in another embodiment shown below.
(A) You may comprise the 1st design part 20 and the 2nd design part 18 of the rim | limb part 13 with the same member. For example, you may comprise the 1st design part 20 and the 2nd design part 18 of the rim | limb part 13 only with the leather 19. FIG.
(B) In the above-described embodiment, the temperature detection element 29 is provided only in the first heater unit 24, but another temperature detection element 29 may be provided also in the second heater unit 32. In that case, since the temperature of the second design portion 18 can be detected by the temperature detecting element 29, the energization to the second heater portion 32 is stopped when the second heater portion 32 reaches the third specified voltage v3. The steering wheel 11 can be heated more efficiently.
(C) In the second control stage in the above embodiment, when the first heater unit 24 falls below the second specified voltage v2, the energization to the second heater unit 32 is turned off and the maximum supply to the first heater unit 24 is performed. However, the first heater unit 24 and the second heater unit 32 may be energized at the same time without turning off the energization of the second heater unit 32. In that case, it is necessary to control so that the sum of the amount of power supplied to the first heater unit 24 and the amount of power supplied to the second heater unit 32 does not exceed the maximum amount of power supplied.
(D) In the above embodiment, the temperature detecting element 29 uses an element whose resistance value increases as the temperature rises, but the same can be applied to an element whose resistance value decreases as the temperature rises.

DESCRIPTION OF SYMBOLS 11: Steering wheel 12: Steering shaft 13: Rim part 14: Pad 15: Spoke part 16: Electronic control unit (ECU) 17: Core 18: 2nd design part 19: Leather 20: 1st design part 21: Rim part Core 22: Rim core 23: Filler 24: First heater 25: Thermal insulation sheet 26: Heater wire 27: First heater terminal 28: First heater cable 29: Temperature detection element 30: 1st connector 31: Decorating member 32: 2nd heater part 33: Thermal insulation sheet 34: Heater wire 35: Terminal part for 2nd heater part 36: Electric wire for 2nd heater part 40: CPU (central processing unit) 41: ROM (Read only memory)

Claims (5)

In the steering wheel in which the first design portion and the second design portion are provided on the surface portion of the rim portion,
A first temperature control unit provided inside the first design part and generating heat for the first design part by energization is provided in the second design part and generates heat for the second design part by energization. A first control stage for preferentially raising the temperature from the second temperature control unit for performing
When the temperature of the first temperature adjusting unit reaches the first predetermined temperature, the second temperature is maintained between the first predetermined temperature and a second predetermined temperature lower than the first predetermined temperature. A second temperature control stage for raising the temperature of the temperature control unit;
When the temperature of the second temperature adjusting unit reaches the third predetermined temperature, the temperature of the first temperature adjusting unit is maintained between the first predetermined temperature and a second predetermined temperature lower than the first predetermined temperature. 2 has a third control stage for maintaining the temperature of the temperature adjusting unit between a third predetermined temperature and a fourth predetermined temperature lower than the third predetermined temperature;
A steering wheel temperature control method, wherein power supply amounts to the first temperature adjustment unit and the second temperature adjustment unit are controlled to be equal to or less than a maximum power amount in the first to third control stages.   The said 1st temperature control stage and the said 2nd temperature control stage WHEREIN: The said maximum electric energy is always supplied to the 1st temperature control part from the 1st temperature control part or the 2nd temperature control part. Steering wheel control method.   The maximum power amount is supplied to only one of the first temperature control unit and the second temperature control unit in the first temperature control stage and the second temperature control stage. Item 3. A steering wheel control method according to Item 2.   The steering wheel includes a temperature adjusting element that detects a temperature of the first temperature adjusting unit, and a control unit that controls power supply to the first temperature adjusting unit and the second temperature adjusting unit. The steering wheel control method according to any one of claims 1 to 3.   In the second control stage, if the time required for the temperature of the first temperature adjusting unit to drop from the first predetermined temperature to the second predetermined temperature is longer than the predetermined time, the second control is performed in the first half. The method of controlling a steering wheel according to claim 1, wherein the process shifts from a stage to a third control stage.

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