JP2015105071A - Cooling device of steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively cool a rim part of a vehicle steering wheel.SOLUTION: In a cooling device 1 of a vehicle steering wheel which is provided with a heat pipe 2 disposed along a rim part 11 of a steering wheel 10 in a vehicle, the heat pipe 2 having a bent shape includes a first part 21 disposed so as to extend along the rim part 11, and a second part 22 connected to a cooling part 3 so that heat can be transmitted. When the steering wheel 10 is located at a straight traveling position, a bent part C is disposed on the upper side in the rim part 11, a second part 22 is disposed so as to extend downward from the bent part C, and the cooling part 3 is disposed below the bent part C, whereby a hydraulic fluid 23 inside the heat pipe 2 is stored on the second part 22 side.

Description

  The present invention relates to a cooling device for a steering wheel in which a heat pipe is attached to a rim portion.

  For example, Patent Literature 1 describes a cooling device for a steering wheel that is configured so as not to consume electric power, and includes an annular heat pipe in which a working fluid is sealed. . Further, the heat storage body and the working fluid holding container provided inside the heat pipe are configured to be insulated from the heat pipe wall. For example, when the steering wheel is in the straight traveling position, the heat storage body is arranged at the upper part of the rim part, and the working fluid holding container is arranged at the lower part of the rim part so that the heat pipe is not operated.

  Patent Document 2 describes a steering wheel cooling device in which a heat pipe provided in a rim portion is connected to a heat sink exposed from a spoke portion so as to be able to exchange heat. Further, the heat pipe is connected to the surface portion of the rim portion by a thermoelectric element so as to be able to exchange heat. Further, a fan that blows air toward the steering wheel is provided, and electric power that drives the fan is generated by a thermoelectric element.

  Patent Document 3 describes a cooling device for a steering wheel in which a plurality of heat pipes having different lengths are provided inside the steering wheel, and these are arranged in a double or triple manner in the wheel radial direction.

JP-A-2005-178852 JP 2010-58673 A JP 2008-308123 A

  However, in the vehicle steering wheel cooling apparatus described in each of the above-mentioned patent documents, the temperature of the heat radiating portion is unlikely to be low, and the amount of heat radiated in the condensing portion of the heat pipe is not sufficient. Therefore, there is room for improving the cooling device in order to improve the cooling performance of the steering wheel.

  This invention was made paying attention to said technical subject, and it aims at providing the cooling device of the steering wheel for vehicles which improves the cooling rate in the rim part of a steering wheel, and improves cooling performance. To do.

  In order to solve the above-described problems, the present invention includes a heat pipe enclosing therein a working fluid that changes phase, and the heat pipe is disposed along a rim portion of a steering wheel in a vehicle. A vehicle steering wheel cooling device for transporting heat of the rim portion to cool the rim portion, comprising a cooling portion provided in a steering device including the steering wheel, wherein the heat pipe is bent A bent portion that is formed and disposed on the rim portion, and a first portion and a second portion that are formed in series via the bent portion, and the first portion extends along the rim portion. The second part is connected to the cooling part so as to be able to transfer heat, and a steering angle of the steering wheel causes the vehicle to travel straight ahead. The bent portion is disposed on the upper side of the rim portion, and the second portion is disposed so as to extend downward from the bent portion, and the cooling portion is more than the bent portion. It is arrange | positioned below and it is comprised so that the hydraulic fluid in the said heat pipe may be stored by the said 2nd part side rather than the said bending part.

  According to the present invention, in the above invention, of the longitudinal ends of the heat pipe, an end portion on the second portion side is disposed inside the cooling portion, and a steering angle of the steering wheel is the vehicle. A cooling device for a vehicle steering wheel, wherein the hydraulic fluid stored on the second portion side in a state where the vehicle travels straightly travels is arranged inside the cooling unit. It is.

  The present invention is the above invention, wherein the cooling section includes a coolant composed of a phase change material, and a coolant container that houses the coolant therein, and both end portions in the longitudinal direction of the heat pipe. Among these, the end part by the side of the 2nd portion is arranged in the coolant container, and is constituted so that it may contact the coolant, It is a cooling device of the steering wheel for vehicles characterized by things.

  According to the present invention, in the above invention, two heat pipes are provided, the first part of one of the heat pipes is arranged to extend clockwise from the bent part, and the other heat pipe The cooling device for a vehicle steering wheel, wherein the first portion of the pipe is arranged to extend counterclockwise from the bent portion.

  According to the present invention, when the turning angle of the steering wheel is an angle that causes the vehicle to travel straight, the heat pipe is in an inoperative state by arranging the second portion so as to extend downward from the first portion. It becomes. The cooling unit is kept at a low temperature when the heat pipe is inactive. When the steering wheel is steered, the working fluid flows toward the first portion, evaporates by taking heat from the rim portion. That is, the rim portion is cooled. That is, the cooling performance in the rim portion of the steering wheel can be improved. Therefore, when the heat pipe changes from the non-operating state to the operating state in which heat can be transported, the rim portion gripped by the driver can be quickly cooled.

  According to this invention, in a state where the heat pipe is not operated, the hydraulic fluid stored on the second part side can be kept at a low temperature in the cooling unit. Therefore, when the heat pipe changes from the non-operating state to the operating state, the cooling rate at the rim portion of the steering wheel is improved.

  According to this invention, since the coolant accommodated in the coolant container is composed of the phase change material, the interior of the coolant container can be cooled using latent heat. Therefore, the cooling rate is improved and the cooling performance can be improved. Further, since the coolant generates a large latent heat with a small accommodation amount, the cooling device can be miniaturized.

  According to this invention, since it is comprised so that a rim | limb part may be cooled with two heat pipes, a cooling rate and cooling performance can further be improved. Moreover, the evaporation part of each heat pipe can be arrange | positioned in the location where a driver | operator hold | grips a steering wheel.

1 is an explanatory diagram schematically showing a cooling device for a vehicle steering wheel according to an example of the present invention, and particularly an arrangement of heat pipes when the steering wheel is located at a turning angle at which the vehicle travels straight. It is explanatory drawing which showed the cooling device at the time of turning a steering wheel 100 degree | times clockwise from the steering position shown in FIG. It is explanatory drawing which showed the cooling device at the time of turning a steering wheel 180 degree | times from the steering position shown in FIG.

  The present invention will be specifically described below. FIG. 1 shows a cooling device for a vehicle steering wheel according to an example of the present invention. As shown in FIG. 1, the cooling device 1 cools a steering wheel 10 included in a vehicle steering device, and includes a heat pipe 2 and a cooling unit 3 attached to the steering wheel 10.

  For example, when the vehicle is parked or parked in the sun, the gripping portion of the steering wheel 10 is in a high temperature state by being irradiated with sunlight. The cooling device 1 is configured to cool the gripping portion of the steering wheel 10 by transporting heat of the gripping portion to the cooling portion 3 by the heat pipe 2.

  The steering wheel 10 includes an annular rim portion 11 serving as a gripping portion, a spoke portion 12 that supports the rim portion 11, and a boss portion 13 that is connected to the rim portion 11 via the spoke portion 12. The rim portion 11 is gripped by the driver. The boss 13 is connected to a steering shaft (not shown). In short, the steering wheel 10 constitutes a means for receiving a steering operation (steering) by a vehicle driver in a vehicle steering system.

  When the driver steers the vehicle, when the rim portion 11 is steered, the steering device generates a predetermined turning angle with the boss portion 13 as the center of rotation. A steering wheel (wheel) of a vehicle (not shown) is configured such that a steering angle corresponding to the turning angle is generated, and the steering wheel is directed in the traveling direction intended by the driver.

  The heat pipe 2 is sealed with a working fluid that changes in phase inside a metal hermetic container, and is configured to be able to exchange heat with the steering wheel 10 and the cooling unit 3. As the working fluid, for example, water, alcohol, ammonia water, phase changing material (PCM) or the like is used. In addition, as an example of the phase change material, a material having a melting point of 20 to 40 ° C. can be used. In short, the working fluid is configured to flow as a heat transport medium in the sealed space in the heat pipe 2. Explaining the operation of the heat pipe 2, the hydraulic fluid 23 is vaporized in the evaporating part in the heat pipe 2 by heat input to a part (evaporating part) of the heat pipe 2 from the outside. The working fluid (steam) vaporized in the evaporation part flows through the heat pipe 2 toward the condensation part. And the heat | fever transported by the vapor | steam from the evaporation part to the condensation part is thermally radiated outside the heat pipe 2, and the vapor | steam is condensed and becomes a liquid. Furthermore, the working fluid 23 liquefied in the condensing part is refluxed from the condensing part to the evaporation part. In addition, the illustrated hydraulic fluid 23 schematically shows in which part the hydraulic fluid 23 flows relatively in the sealing device of the heat pipe 2, and in actuality, the level of the illustrated fluid level It does not have to be.

  Specifically, the heat pipe 2 has a hermetically sealed container formed in a bent shape in the longitudinal direction, and is arranged so as to follow the shape of the steering wheel 10. The cooling device 1 of this specific example includes two heat pipes 2A and 2B. Each of the first heat pipe 2A and the second heat pipe 2B includes a bent portion C formed between both end portions 21a and 22a in the longitudinal direction, and a first portion formed on the one end portion 21a side from the bent portion C. 21 and a second portion 22 formed on the side of the other end 22a from the bent portion C. The first portion 21 is disposed along the rim portion 11, and the second portion 22 is disposed along the spoke portion 12. That is, the second portion 22 is arranged so as to extend from the bent portion C toward the boss portion 13. In the heat pipe 2 shown in FIG. 1, in the longitudinal direction, the first portion 21 is formed in an arc shape, the second portion 22 is disposed on the opposite side of the first portion 21 with the bent portion C as a base point, and It is formed in a straight line. Moreover, the internal space of the airtight container of the heat pipe 2 is formed in series. That is, the inside of the first portion 21 and the inside of the second portion 22 communicate with each other via the inside of the bent portion C to form a gas flow path through which gas flows.

  In the cooling device 1 shown in FIG. 1, the first portion 21 of the first heat pipe 2 </ b> A and the first portion 21 of the second heat pipe 2 </ b> B are arranged in the rim portion 11 where the driver is likely to grip. ing. For example, if the position of the reference point P shown in FIG. 1 is regarded as the twelve o'clock position of the watch, generally, the driver grasps the two tens portions L and R of the rim portion 11 of the steering wheel 10 with both hands during driving. Often to do. That is, the first portion 21 of the second heat pipe 2B is disposed at the ten o'clock position L held by the driver's left hand, and the first heat pipe 2A is provided at the sufficient position R held by the driver's right hand. The 1st part 21 of this is arrange | positioned. Further, the second portion 22 of each heat pipe 2A, 2B is disposed below the first portion 21 and the bent portion C. Further, the end 22a of the second portion 22 opposite to the bent portion C is connected to the cooling portion 3 so as to be able to exchange heat.

  The cooling unit 3 has a coolant container 31 attached to the boss 13 of the steering wheel 10. The coolant container 31 has a hollow container structure formed of a metal or a material having heat insulation performance. A coolant 32 is accommodated in the coolant container 31. That is, the coolant container 31 is sealed so that the coolant 32 does not leak outside. The coolant 32 is made of, for example, water, alcohol, ammonia water, phase change material (PCM), or the like. As this phase change material, a material having a melting point of 20 to 40 ° C. can be used.

  Moreover, a through hole is provided in the wall portion of the coolant container 31, and the second portion 22 of the heat pipe 2 is disposed inside the coolant container 31 through the through hole. Further, the second portion 22 is configured to be kept in contact with the coolant 32 inside the coolant container 31. That is, the second portion 22 of the heat pipe 2 is configured to exchange heat with the coolant 32 in the coolant container 31. For example, when the coolant 32 is a liquid such as water, the end 22a of the second portion 22 is disposed so as to be immersed in the liquid. In addition, the liquid level of the coolant 32 shown in the figure schematically shows an example, and in practice, it does not have to be the height of the liquid level shown in the figure.

  Accordingly, a portion of the second portion 22 of the heat pipe 2 opposite to the bent portion C constitutes a condensing part of the heat pipe 2. In short, the second portion 22 side of the heat pipe 2 via the bent portion C becomes the condensing portion. That is, the end 21 a side of the first portion 21 opposite to the bent portion C constitutes the evaporation portion of the heat pipe 2.

  A portion of the second portion 22 of each heat pipe 2A, 2B formed outside the coolant container 31 extends from the boss portion 13 toward the rim portion 11 and reaches the reference point P of the rim portion 11. . In the first heat pipe 2A, at the reference point P, the first portion 21 extends clockwise via the bent portion C. On the other hand, in the second heat pipe 2B, at the reference point P, the first portion 21 extends counterclockwise via the bent portion C.

  Further, the second portion 22 of the heat pipe 2 disposed in the coolant container 31 is insulated from the steering wheel 10 by being in contact with the coolant 32. That is, the heat pipe 2 and the coolant 32 can exchange heat, but the heat pipe 2 in the coolant container 31 is configured not to exchange heat with the steering wheel 10. For example, when the coolant container 31 is formed of a heat insulating material, the coolant 32 in the coolant container 31 is insulated from the steering wheel 10 even if the coolant container 31 is disposed in contact with the boss portion 13. Has been. Thereby, even if the temperature of the steering wheel 10 rises, the temperature of the coolant 32 in the coolant container 31 does not rise accordingly. That is, the coolant 32 can be kept in a low temperature state even when the rim portion 11 of the steering wheel 10 is in a high temperature state. Alternatively, even if the coolant container 31 and the steering wheel 10 are in contact with each other so as to be able to exchange heat, the coolant container 31 may be in contact with a steering shaft (not shown) so as to be able to exchange heat. In this case, the coolant 32 in the coolant container 31 can exchange heat with the steering shaft.

  Next, the operation of the cooling device 1 according to the rotation state of the steering wheel 10 will be described with reference to FIGS. 1 to 3. First, the state of the steering wheel 10 shown in FIG. 1 is a state in which the turning angle of the steering wheel 10 is an angle at which the vehicle travels straight. A one-dot chain line Y shown in FIG. 1 is a reference line that extends in the vertical direction through the center of rotation of the steering wheel 10. When the steering wheel 10 shown in FIG. 1 is in the straight traveling position, the reference point P is disposed at the upper portion of the rim portion 11 and is disposed on the alternate long and short dash line Y. For example, even when the steering wheel 10 is steered and the reference point P is deviated from the alternate long and short dash line Y, when the steered angle is within a predetermined angle range, the vehicle described here is brought into a state of traveling straight ahead. included. Here, the state change of the steering wheel 10 and the cooling device 1 shown in FIGS. 2 to 3 will be described with reference to the state shown in FIG.

  In the cooling device 1 shown in FIG. 1, the interior of the first portion 21 of the heat pipe 2 is in a dry-out state when the vehicle is parked or parked in the sun for a long time. In short, since the second portion 22 is arranged so as to extend downward from the bent portion C toward the boss portion 13, the working liquid 23 does not flow back to the first portion 21 and the heat pipe 2 is not operated. It becomes a state. The working fluid 23 in the heat pipe 2 is stored on the end 22a on the second portion 22 side, that is, on the end 22a side of the heat pipe 2 disposed in the coolant container 31. That is, in the cooling device 1, when the steering wheel 10 is in the straight traveling position, the working fluid 23 does not recirculate from the condensing unit to the evaporating unit. In the state shown in FIG. 1, the rim portion 11 is in a high temperature state due to solar radiation. For example, the temperature of the first portion 21 is 90 ° C., and the inside of the coolant container 31 is 30 ° C.

  In addition, the process in which the first portion 21 of the heat pipe 2 disposed on the rim portion 11 reaches dryout will be described. First, the rim portion 11 is heated by sunlight or the like irradiated on the steering wheel 10. And the 1st part 21 of the heat pipe 2 receives the heat | fever of the rim | limb part 11, and the hydraulic fluid 23 in the 1st part 21 evaporates. Further, the gas vaporized in the first portion 21 flows to the second portion 22 side where the internal pressure is relatively low, and the vapor is condensed in the portion of the second portion 22 that contacts the coolant 32 to become a liquid. .

  Next, the cooling device 1 and the steering wheel 10 in the state shown in FIG. 2 will be described. FIG. 2 shows a state in which the steering wheel 10 is rotated clockwise from the straight traveling position state shown in FIG. In the steering wheel 10 shown in FIG. 2, the reference point P is arranged at a position where the turning angle is 100 degrees from the one-dot chain line Y. In the cooling device 1 shown in FIG. 2, the first heat pipe 2 </ b> A of the heat pipes 2 operates.

  Specifically, in the first heat pipe 2 </ b> A, the first portion 21 is disposed below the second portion 22 and the bent portion C. Therefore, in the first heat pipe 2A, the working fluid 23 flows from the second portion 22 through the bent portion C toward the end portion 21a on the first portion 21 side by gravity. That is, the 1st heat pipe 2A operates and the part in which the 1st portion 21 of the 1st heat pipe 2A is arranged among rim parts 11 is cooled. The vapor evaporated in the first heat pipe 2 </ b> A flows toward the end 22 a on the second portion 22 side, that is, the portion disposed in the coolant container 31.

  On the other hand, in the second heat pipe 2B, the first portion 21 is disposed above the bent portion C. In this state, the hydraulic fluid 23 in the second heat pipe 2B does not recirculate to the end portion 21a side of the first portion 21 and remains around the bent portion C. That is, the second heat pipe 2B is not activated in the state shown in FIG. Accordingly, the portion of the rim portion 11 where the first portion 21 of the second heat pipe 2B is disposed is not cooled.

  Next, the cooling device 1 and the steering wheel 10 in the state shown in FIG. 3 will be described. FIG. 3 shows a state in which the steering wheel 10 is rotated clockwise or counterclockwise from the straight traveling position state shown in FIG. In the steering wheel 10 shown in FIG. 3, the reference point P is arranged at a position where the turning angle is 180 degrees from the one-dot chain line Y. In the cooling device 1 shown in FIG. 3, the first heat pipe 2 </ b> A and the second heat pipe 2 </ b> B of the heat pipe 2 operate.

  Specifically, the bent portion C is disposed below the second portion 22 in each of the heat pipes 2 </ b> A and 2 </ b> B. Therefore, in the second heat pipe 2B, which is inactive in the state shown in FIG. 2, the working fluid 23 flows from the second portion 22 toward the bent portion C by gravity. That is, both the heat pipes 2A and 2B are operated, and the portion of the rim portion 11 where the first portions 21 of both the heat pipes 2A and 2B are arranged is cooled. Then, the vaporized in both the heat pipes 2 </ b> A and 2 </ b> B flows toward the end 22 a side of the second portion 22, that is, the portion disposed in the coolant container 31.

  Further, in the process from the state shown in FIG. 1 to the state shown in FIG. 3, the state shown in FIG. 2 or the state in which the steering wheel 10 is turned counterclockwise is passed. Therefore, a portion of the rim portion 11 where at least one of the first heat pipe 2A and the second heat pipe 2B is arranged is cooled before reaching the state shown in FIG. In the state shown in FIG. 3, the rim portion 11 is cooled by the cooling device 1. For example, the temperature of the first portion 21 is reduced from 90 ° C. to 40 ° C. in the state shown in FIG. The temperature inside increases from 30 ° C. to 40 ° C. in the state shown in FIG.

  As described above, according to the cooling apparatus for a vehicle steering wheel in this specific example, the cooling unit can be kept at a low temperature when the heat pipe is not operated. Further, a first portion that becomes the evaporation portion of the heat pipe is arranged on the rim portion of the steering wheel, and a second portion that becomes the condensation portion of the heat pipe is arranged on the boss portion side of the steering wheel. When the turning angle of the steering wheel is an angle that causes the vehicle to travel straight, the heat pipe is in an inoperative state by arranging the second portion so as to extend below the first portion and the bent portion. It is comprised so that. Therefore, when the heat pipe changes from the non-operating state to the operating state in which heat can be transported, the cooling rate of the rim portion gripped by the driver is improved.

  Furthermore, a large latent heat can be generated with a small amount by using the phase change material as the working fluid stored in the heat pipe and the coolant container. Therefore, the cooling device can be reduced in size, and the installation space for the cooling device in the steering device can be reduced.

  Note that the cooling device for a vehicle steering wheel in the present invention is not limited to the specific example described above, and can be appropriately changed without departing from the object of the present invention.

  For example, the number of heat pipes attached to the steering wheel is not limited to two, and may be configured to include one or a plurality of heat pipes. Further, the shape of the heat pipe may be formed so that a part thereof is bent from the shape along the rim portion to the shape along the spoke portion, and as described above, the first portion is formed in an arc shape and the second portion is formed. The portion is not limited to a straight line. In short, it is only necessary that the second portion is arranged below the bent portion in a state where the steering angle of the steering wheel is within a predetermined angle that causes the vehicle to travel straight ahead.

  Further, the first portion of the heat pipe may be embedded in the core portion of the rim portion, or may be attached to the rim portion surface. In short, it is only necessary that the first portion and the rim portion are configured to come into contact with each other so that heat exchange is possible. Therefore, the first portion may be in contact with the metal member in the rim portion, or may be in contact with the skin member or the cloth member in the rim portion.

  Furthermore, the first portion of the heat pipe may be a shape whose longitudinal direction corresponds to the shape of the rim portion, and may be a curved shape without being limited to the arc shape described above. Similarly, the second portion of the heat pipe may be formed in a substantially linear shape as long as the shape in the longitudinal direction is a shape along the spoke portion.

  DESCRIPTION OF SYMBOLS 1 ... Cooling device, 2 ... Heat pipe, 2A ... 1st heat pipe, 2B ... 2nd heat pipe, 3 ... Cooling part, 10 ... Steering wheel, 11 ... Rim part, 12 ... Spoke part, 13 ... Boss part, 21 ... 1st part (evaporation part), 22 ... 2nd part (condensation part), 23 ... Hydraulic fluid, 31 ... Coolant, 32 ... Coolant container, C ... Bending part, P ... Reference point.

Claims (4)

A heat pipe enclosing therein a working fluid that changes in phase; the heat pipe being disposed along a rim portion of a steering wheel in a vehicle; and transporting heat of the rim portion by the heat pipe In a vehicle steering wheel cooling device for cooling
A cooling unit provided in a steering device including the steering wheel;
The heat pipe is
A bent portion formed by bending and disposed on the rim portion;
A first portion and a second portion formed in series via the bent portion;
The first portion is disposed so as to extend along the rim portion;
The second part is connected to the cooling part so as to be capable of transferring heat,
In a state where the steering angle of the steering wheel is an angle that allows the vehicle to travel straight, the bent portion is disposed on the upper side of the rim portion, and the second portion extends downward from the bent portion. And the cooling part is arranged below the bent part, and the hydraulic fluid in the heat pipe is stored on the second part side of the bent part. A cooling device for a steering wheel for a vehicle. Of the both ends in the longitudinal direction of the heat pipe, the end on the second part side is disposed inside the cooling unit,
The hydraulic fluid stored on the second portion side in a state in which the steering angle of the steering wheel is at an angle that causes the vehicle to travel straight ahead is configured to be disposed inside the cooling unit. The cooling device for a steering wheel for a vehicle according to claim 1. The cooling part is
A coolant composed of a phase change material;
A coolant container containing the coolant inside,
The end portion on the second portion side of both end portions in the longitudinal direction of the heat pipe is disposed in the coolant container and is configured to contact the coolant. The vehicle steering wheel cooling device according to 1 or 2. Two heat pipes are provided,
The first part of one of the heat pipes is arranged to extend clockwise from the bent part,
4. The cooling device for a vehicle steering wheel according to claim 1, wherein the first portion of the other heat pipe is arranged to extend counterclockwise from the bent portion. 5. .

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