JP2013113431A - Driving force transmission device - Google Patents

Abstract

An object of the present invention is to achieve a state in which a driving force can be transmitted at a low temperature at which a hydraulic pressure required for engaging a hydraulic clutch cannot be generated.
A hybrid driving force transmission device is interposed in a driving force transmission system from an engine Eng to a driving wheel between a clutch hub shaft 2, a clutch drum shaft 4, and both shafts 2, 4 to supply hydraulic pressure. A normally open type dry multi-plate clutch 7 fastened by In this hybrid driving force transmission device, a part of the members constituting the driving force transmission system is a shape memory spring 84 using a material whose shape characteristics change at low temperatures. Then, a first low temperature driving force transmission mechanism A1 is provided that is capable of transmitting a driving force by changing the shape of the shape memory spring 84 at a low temperature when the hydraulic pressure required for fastening the dry multi-plate clutch 7 cannot be generated.
[Selection] Figure 5

Description

  The present invention relates to a driving force transmission device that is applied to a vehicle drive system and includes a normally open type hydraulic clutch.

  2. Description of the Related Art Conventionally, a hybrid driving force transmission device is known that includes a normally open type hydraulic clutch that transmits engine driving force to a driving wheel by fastening in a driving system from the engine to the driving wheel (for example, a patent) Reference 1).

  On the other hand, there is known an electromagnetic clutch that utilizes the characteristics of metal thermal expansion, assists the fastening force of the friction surface, and prevents the reduction of the friction torque due to temperature change (see, for example, Patent Document 2).

JP-A-8-121203 Japanese Utility Model Publication No. 3-22580

  However, the clutch described in Patent Document 1 is not an electromagnetic clutch but a hydraulic clutch, and the friction torque reduction prevention technology for the electromagnetic clutch described in Patent Document 2 cannot be applied. In the case of an electromagnetic clutch, the configuration change is large and the cost increases.

  However, when the hydraulic clutch is engaged by supplying the clutch hydraulic pressure based on the discharge pressure from the electric pump, the hydraulic clutch cannot be engaged at an extremely low temperature. Because the battery output decreases at extremely low temperatures, the motor output is insufficient, and the viscosity of the hydraulic oil is high, so the motor cannot be raised to the required rotation, and the electric pump that obtains the desired discharge pressure is driven. Because it is not possible.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a driving force transmission device capable of achieving a driving force transmission possible state at a low temperature at which a hydraulic pressure necessary for fastening a hydraulic clutch cannot be generated. And

In order to achieve the above object, according to the present invention, a driving force transmission system from a driving source to driving wheels is interposed between a first driving force transmission shaft, a second driving force transmission shaft, and both driving force transmission shafts. And a normally open type hydraulic clutch that is fastened by hydraulic supply.
In this driving force transmission device, some members constituting the driving force transmission system are temperature-sensitive shape changing members using materials whose shape characteristics change at low temperatures.
A low temperature driving force transmission mechanism is provided in which the driving force can be transmitted by changing the shape of the temperature sensitive shape changing member at a low temperature when the hydraulic pressure required to engage the hydraulic clutch cannot be generated.

As described above, some of the members constituting the driving force transmission system are temperature-sensitive shape changing members using materials whose shape characteristics change at low temperatures. In addition, a low temperature driving force transmission mechanism is provided in which the driving force can be transmitted by changing the shape of the temperature sensitive shape changing member at low temperatures.
For this reason, in the low temperature driving force transmission mechanism, the shape change of the temperature sensitive shape changing member is utilized in the low temperature driving force transmission mechanism so that the driving force can be transmitted even though the hydraulic pressure necessary for fastening the hydraulic clutch cannot be generated at low temperatures. .
As a result, it is possible to achieve a state in which the driving force can be transmitted at a low temperature at which the hydraulic pressure required for fastening the hydraulic clutch cannot be generated.

1 is an overall schematic diagram showing a hybrid driving force transmission device (an example of a driving force transmission device) of Example 1. FIG. It is principal part sectional drawing which shows the structure of the motor & clutch unit in the hybrid driving force transmission apparatus of Example 1. FIG. It is a disassembled perspective view which shows the piston assembly of the dry multi-plate clutch in the hybrid driving force transmission device of Example 1. It is principal part sectional drawing which shows the 1st low temperature driving force transmission mechanism in the normal state which interrupted driving force transmission by open | release of the dry multi-plate clutch in the hybrid driving force transmission apparatus of Example 1. FIG. It is principal part sectional drawing which shows the 1st low temperature driving force transmission mechanism in the low temperature state which enabled driving force transmission by the arm fastening of the dry type multi-plate clutch in the hybrid driving force transmission device of Example 1. It is principal part sectional drawing which shows the 2nd low temperature driving force transmission mechanism in the normal state which interrupted driving force transmission by open | release of the dry multi-plate clutch in the hybrid driving force transmission apparatus of Example 2. FIG. It is principal part sectional drawing which shows the 2nd low temperature driving force transmission mechanism in the low temperature state which enabled the driving force transmission by dish fastening of the dry type multi-plate clutch in the hybrid driving force transmission device of Example 2. FIG. 10 is a cross-sectional view of a main part showing a third low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by separating the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of Embodiment 3; It is sectional drawing which shows the 3rd low temperature driving force transmission mechanism with the hybrid driving force transmission device of Example 3. FIG. FIG. 9 is a cross-sectional view of a main part showing a third low temperature driving force transmission mechanism at an extremely low temperature in which the driving force can be transmitted by pin coupling between the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of the third embodiment. FIG. 10 is a cross-sectional view illustrating a modification of the third low temperature driving force transmission mechanism in the hybrid driving force transmission device according to the third embodiment. FIG. 12 is a cross-sectional view of a main part showing a fourth low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by separating the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of the fourth embodiment. It is a front view which shows the guide plate of the 4th low temperature driving force transmission mechanism with the hybrid driving force transmission device of Example 4. FIG. 10 is a cross-sectional view of a principal part showing a fourth low temperature driving force transmission mechanism at an extremely low temperature in which the driving force can be transmitted between the clutch hub shaft and the clutch drum shaft by friction engagement in the hybrid driving force transmission device of the fourth embodiment. FIG. 10 is a cross-sectional view of a main part showing a fifth low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by separating the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of Example 5. It is sectional drawing which shows the 5th low temperature driving force transmission mechanism in a normal state in the hybrid driving force transmission device of Example 5. FIG. 10 is a cross-sectional view of a principal part showing a fifth low temperature driving force transmission mechanism at a cryogenic temperature in which a driving force can be transmitted by cam engagement between a clutch hub shaft and a clutch drum shaft in a hybrid driving force transmission device according to a fifth embodiment; It is sectional drawing which shows the 5th low temperature driving force transmission mechanism in the hybrid driving force transmission device of Example 5 at the time of cryogenic temperature.

  Hereinafter, the best mode for realizing the driving force transmission device of the present invention will be described based on Examples 1 to 5 shown in the drawings.

First, the configuration will be described.
The configuration of the hybrid driving force transmission device (an example of the driving force transmission device) according to the first embodiment is divided into “entire system configuration”, “motor & clutch unit configuration”, and “first low temperature driving force transmission mechanism configuration”. I will explain.

[Overall system configuration]
FIG. 1 is an overall schematic diagram illustrating a hybrid driving force transmission device according to a first embodiment. The overall system configuration will be described below with reference to FIG.

As shown in FIG. 1, the hybrid driving force transmission device includes an engine Eng, a motor & clutch unit M / C, and a transmission unit T / M. The motor & clutch unit M / C connected to the engine output shaft 1 of the engine Eng includes a clutch hub shaft 2, a clutch hub 3, a clutch drum shaft 4, a transmission input shaft 5, a clutch drum 6, and a dry type. A multi-plate clutch 7, a slave cylinder 8, and a motor / generator 9 are provided.
The slave cylinder 8 that hydraulically controls engagement / release of the dry multi-plate clutch 7 is generally called “CSC” (concentric slave cylinder).

  In the hybrid driving force transmission device, when the normally open multi-plate clutch 7 is released, the motor / generator 9 and the transmission input shaft 5 are connected via the clutch drum 6 and the clutch drum shaft 4. As a result, the “electric vehicle traveling mode” using the motor / generator 9 as a drive source is set. When the dry multi-plate clutch 7 is hydraulically engaged, the engine Eng, the motor / generator 9 and the transmission input shaft 5 are connected via the dry multi-plate clutch 7. As a result, a “hybrid vehicle travel mode” using the engine Eng and the motor / generator 9 as drive sources is set. The engine output shaft 1 and the clutch hub shaft 2 are connected via a damper 21.

  The motor & clutch unit M / C includes a dry multi-plate clutch 7, a slave cylinder 8, and a motor / generator 9. The dry multi-plate clutch 7 is connected to the engine Eng to connect and disconnect the driving force transmitted from the engine Eng. The slave cylinder 8 hydraulically controls engagement / release of the dry multi-plate clutch 7. The motor / generator 9 is disposed at the outer peripheral position of the clutch drum 6 of the dry multi-plate clutch 7 and transmits power to the transmission input shaft 5. The motor & clutch unit M / C is provided with a cylinder housing 81 having a first clutch pressure oil passage 85 to the slave cylinder 8 while maintaining the sealing performance by the O-ring 10.

  The motor / generator 9 is a synchronous AC motor, and includes a rotor support frame 91 provided integrally with the clutch drum 6, and a rotor 92 supported and fixed to the rotor support frame 91 and embedded with permanent magnets. The rotor 92 includes a stator 94 that is disposed via the air gap 93 and is fixed to the cylinder housing 81, and a stator coil 95 that is wound around the stator 94. The cylinder housing 81 is formed with a water jacket 96 for circulating cooling water.

  The transmission unit T / M is connected to the motor and clutch unit M / C and includes a transmission housing 41, a V-belt continuously variable transmission mechanism 42, and an oil pump O / P. The V-belt type continuously variable transmission mechanism 42 is built in the transmission housing 41, obtains a continuously variable transmission ratio by passing a V-belt between two pulleys and changing the belt contact diameter. The oil pump O / P is a hydraulic pressure source that creates the hydraulic pressure to the required part. Guide hydraulic pressure to the required part. The transmission unit T / M is further provided with a forward / reverse switching mechanism 43, an oil tank 44, and an end plate 45. The end plate 45 has a second clutch pressure oil passage 47 (FIG. 2).

  The oil pump O / P drives the pump by transmitting the rotational drive torque of the transmission input shaft 5 via a chain drive mechanism. The chain drive mechanism includes a drive-side sprocket 51 that rotates as the transmission input shaft 5 rotates, a driven-side sprocket 52 that rotates the pump shaft 57, and a chain 53 that spans both the sprockets 51 and 52. Have. The drive-side sprocket 51 is interposed between the transmission input shaft 5 and the end plate 45, and is rotatably supported via a bush 55 with respect to a stator shaft 54 fixed to the transmission housing 41. Then, the rotational input torque from the transmission input shaft 5 is transmitted through the first adapter 56 that is engaged with the transmission input shaft 5 by spline fitting and the driving sprocket 51.

[Configuration of motor & clutch unit]
FIG. 2 is a cross-sectional view of the main part showing the configuration of the motor and clutch unit in the hybrid driving force transmission device of the first embodiment. FIG. 3 is a piston set of a dry multi-plate clutch in the hybrid driving force transmission device of the first embodiment. It is a disassembled perspective view which shows a solid. Hereinafter, the configuration of the motor and clutch unit M / C will be described with reference to FIGS.

  The clutch hub 3 is connected to the engine output shaft 1 of the engine Eng. As shown in FIG. 2, the drive plate 71 of the dry multi-plate clutch 7 is held on the clutch hub 3 by spline connection.

  The clutch drum 6 is connected to the transmission input shaft 5 of the transmission unit T / M. As shown in FIG. 2, a driven plate 72 of the dry multi-plate clutch 7 is held on the clutch drum 6 by spline connection.

  The dry-type multi-plate clutch 7 is interposed between the clutch hub 3 and the clutch drum 6 by alternately arranging a plurality of drive plates 71 and driven plates 72 with friction facings 73 and 73 attached on both sides. Be dressed. That is, when the dry multi-plate clutch 7 is fastened, torque can be transmitted between the clutch hub 3 and the clutch drum 6, and by opening the dry multi-plate clutch 7, between the clutch hub 3 and the clutch drum 6. Shut off torque transmission.

  The slave cylinder 8 is a hydraulic actuator that controls the engagement and release of the dry multi-plate clutch 7, and is disposed at a position between the transmission unit T / M side and the clutch drum 6. As shown in FIG. 2, the slave cylinder 8 has a piston 82 slidably provided in the cylinder hole 80 of the cylinder housing 81 and a clutch pressure formed by the transmission housing unit T / M. A first clutch pressure oil passage 85 that leads and a cylinder oil chamber 86 that communicates with the first clutch pressure oil passage 85 are provided. As shown in FIG. 2, a needle bearing 87, a piston arm 83, a shape memory spring 84, and an arm press-fit plate 88 are interposed between the piston 82 and the dry multi-plate clutch 7.

  The piston arm 83 generates a pressing force of the dry multi-plate clutch 7 by a pressing force from the slave cylinder 8, and is slidably provided in a through hole 61 formed in the clutch drum 6. The shape memory spring 84 is interposed between the piston arm 83 and the clutch drum 6. The needle bearing 87 is interposed between the piston 82 and the piston arm 83, and suppresses the piston 82 from being rotated with the rotation of the piston arm 83. The arm press-fitting plate 88 is provided integrally with the bellows elastic support members 89 and 89, and the inner peripheral portion and the outer peripheral portion of the bellows elastic support members 89 and 89 are press-fitted and fixed to the clutch drum 6. The arm press-fit plate 88 and the bellows elastic support members 89 and 89 block leakage oil from the piston arm 83 from flowing into the dry multi-plate clutch 7. In other words, the arm press-in plate 88 and the bellows elastic support member 89 that are hermetically fixed at the piston arm mounting position of the clutch drum 6 divide the wet space in which the slave cylinder 8 is disposed from the dry space in which the dry multi-plate clutch 7 is disposed. It has a function.

  As shown in FIG. 3, the piston arm 83 is composed of an arm body 83a formed in a ring shape and arm ridges 83b projecting from the arm body 83a at four locations.

  As shown in FIG. 3, the shape memory spring 84 comprises a spring support plate 84a formed in a ring shape and a plurality of coil springs 84b fixed to the spring support plate 84a.

  The arm press-fitting plate 88 is press-fitted and fixed to the arm protrusion 83b of the piston arm 83, as shown in FIG. As shown in FIG. 3, bellows elastic support members 89 and 89 are integrally provided on the inner side and the outer side of the arm press-fitting plate 88.

  As shown in FIG. 2, the leak oil recovery oil passage of the first embodiment includes a first bearing 12, a first seal member 31, a leak oil passage 32, a first recovery oil passage 33, and a second recovery oil passage. 34. In other words, the leak oil from the sliding portion of the piston 82 passes through the first recovery oil passage 33 and the second recovery oil passage 34 sealed by the first seal member 31 and returns to the transmission unit T / M. is there. In addition to this, the leak oil passage 32 in which leak oil from the sliding portion of the piston arm 83 is sealed by a partition elastic member (arm press-fit plate 88, bellows elastic support members 89, 89), and the first seal member 31. This is a circuit that passes through the first recovery oil passage 33 and the second recovery oil passage 34 that are sealed by the above and returns to the transmission unit T / M.

  As shown in FIG. 2, the bearing lubricating oil passage of the first embodiment includes a needle bearing 20, a second seal member 14, a first axial oil passage 19, a second axial oil passage 18, and a lubricating oil passage. 16 and a gap 17. The bearing lubricating oil path includes a bearing lubricant from the transmission unit T / M, a needle bearing 20, a first bearing 12 that rotatably supports the clutch drum 6 with respect to the cylinder housing 81, a piston 82, and a piston arm. The bearing is lubricated by a path that passes through the needle bearing 87 interposed between the two and 83 and returns to the transmission unit T / M.

  As shown in FIG. 2, the second seal member 14 is interposed between the clutch hub 3 and the clutch drum 6. The second seal member 14 seals the bearing lubricant from flowing from the wet space in which the slave cylinder 8 is disposed into the dry space in which the dry multi-plate clutch 7 is disposed.

The configuration of the dry multi-plate clutch 7 will be described in more detail.
The dry multi-plate clutch 7 is a clutch that connects and disconnects transmission of driving force from the engine Eng, and is surrounded by the clutch hub shaft 2, the clutch hub 3, the clutch cover 6, and the front cover 60 as shown in FIG. Arranged in the clutch chamber 64 by a sealed space. As a constituent member of the dry multi-plate clutch 7, a drive plate 71, a driven plate 72, a friction facing 73, and a front cover 60 are provided.

  The drive plate 71 is spline-coupled to the clutch hub 3 and has a vent hole 74 through which the airflow flowing in the axial direction passes through the spline-coupled portion with the clutch hub 3.

  The driven plate 72 is splined to the clutch drum 6 and has a ventilation gap 77 through which the airflow flowing in the axial direction passes through the spline coupling portion with the clutch drum 6.

  The friction facings 73 are provided on both surfaces of the drive plate 71, and the friction surface presses against the plate surface of the driven plate 72 when the clutch is engaged.

  The front cover 60 is integrally fixed to a stationary cylinder housing 81 supported by the first bearing 12 with respect to the clutch drum shaft 4 and covers the motor / generator 9 and the dry multi-plate clutch 7. That is, the front cover 60 is a stationary member that is supported by the second bearing 13 with respect to the clutch hub shaft 2 and sealed by the cover seal 15. Of the internal space formed by covering the front cover 60 and the cylinder housing 81, the space on the clutch rotating shaft CL (= rotor shaft) side is defined as a clutch chamber 64 that accommodates the dry multi-plate clutch 7. The outer space is a motor chamber 65 that houses the motor / generator 9. The clutch chamber 64 and the motor chamber 65 divided by the dust seal member 62 are dry spaces that block oil from entering.

[Configuration of first low temperature driving force transmission mechanism]
FIG. 4 shows the first low-temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by releasing the dry multi-plate clutch in the hybrid driving force transmission device of the first embodiment. FIG. 5 shows a first low temperature driving force transmission mechanism in a low temperature state in which driving force can be transmitted by fastening the arm of the dry multi-plate clutch. Hereinafter, based on FIG.4 and FIG.5, the structure of 1st low temperature driving force transmission mechanism A1 is demonstrated.

  First, the first low temperature driving force transmission mechanism A1 includes a clutch hub shaft 2 (first driving force transmission shaft), a clutch drum shaft, and a driving force transmission system from an engine Eng (driving source) to driving wheels (not shown). 4 (second driving force transmission shaft) and a dry multi-plate clutch 7 (hydraulic clutch). The dry multi-plate clutch 7 is a normally open type clutch that is interposed between the clutch hub shaft 2 and the clutch drum shaft 4 and is fastened by supplying hydraulic pressure.

  The first low temperature driving force transmission mechanism A1 is a shape memory alloy that changes the shape characteristics of a return spring, which is a part of the driving force transmission system that constitutes the clutch fastening structure of the dry multi-plate clutch 7, at low temperatures. A shape memory spring 84 (temperature-sensitive shape changing member) using (an example of a material) is used. Then, at a low temperature at which the hydraulic pressure required to fasten the dry multi-plate clutch 7 cannot be generated, the dry multi-plate clutch 7 is fastened by changing the shape of the shape memory spring 84 so that the driving force can be transmitted (FIG. 5).

  The clutch fastening structure includes a drive plate 71 (clutch plate), a driven plate 72 (clutch plate), and a hydraulically operated piston arm 83 (clutch piston) that fastens both plates 71 and 72.

  The piston arm 83 is divided into an arm main body portion 83a that is in contact with both plates 71 and 72 of the dry multi-plate clutch 7 via an arm press-fit plate 88, and an arm base portion 83b that is in contact with the needle bearing 87 of the slave cylinder 8. Composed. The needle bearing 87 is interposed between the piston 82 of the slave cylinder 8 and the arm base portion 83b.

  The shape memory spring 84 is interposed between the clutch drum 6 and the arm main body 83a, and urges the arm main body 83a toward the clutch release side in the normal state shown in FIG. 4, and in a low temperature state shown in FIG. The clutch release side biasing force to the arm main body 83a is lost. Here, the normal state refers to a state in which a normal return spring function is exhibited in a temperature state other than the low temperature range (FIG. 4). The low temperature state is a temperature state in a low temperature region and returns to a stored spring shape (a spring compression shape in which the biasing force disappears) (FIG. 5).

  Between the arm main body portion 83a and the arm base portion 83b, a spring 21 for biasing the arm main body portion 83a toward the clutch fastening side with respect to the arm base portion 83b is interposed. As shown in FIGS. 4 and 5, the clutch drum 6 at a position in contact with the back surface of the arm base portion 83b is provided with a snap ring 22 that restricts the movement of the arm base portion 83b in the left direction in the figure. .

  As shown in FIG. 5, the first low temperature driving force transmission mechanism A <b> 1 loses the urging force on the open side by changing the shape of the shape memory spring 84 at a low temperature when the hydraulic pressure required to fasten the dry multi-plate clutch 7 cannot be generated. The spring 21 generates a biasing force toward the clutch engagement side.

Next, the operation will be described.
The operation of the hybrid driving force transmission apparatus of the first embodiment will be described separately for “a clutch engaging / disengaging operation in a normal state” and “a clutch engaging operation in a low temperature state”.

[Clutch engagement / release action under normal conditions]
Hereinafter, the clutch engagement / disengagement operation in the normal state in which the dry multi-plate clutch 7 is engaged / released by the slave cylinder 8 will be described with reference to FIGS.

  For example, when starting in a normal state other than the low temperature range, the oil pump O / P is driven to rotate by the motor / generator 9, and the clutch hydraulic pressure of the dry multi-plate clutch 7 can be created using the pump discharge pressure as a source pressure. . Further, the shape memory spring 84 exhibits a normal return spring function such as biasing the arm main body 83a toward the clutch release side. Further, the spring 21 interposed between the arm body 83a and the arm base 83b is compressed as shown in FIG. 4 by the urging force of the shape memory spring 84, so that the three members 83a and 83b are compressed. , 21 are integrated as a piston arm 83.

  Accordingly, when the dry multi-plate clutch 7 is engaged by the slave cylinder 8, the clutch hydraulic pressure produced by the transmission unit T / M passes through the first clutch pressure oil passage 85 formed in the cylinder housing 81 and is then used as the cylinder oil chamber. Supply to 86. As a result, the hydraulic pressure obtained by multiplying the hydraulic pressure and the pressure receiving area acts on the piston 82, and the piston 82 is moved against the urging force of the shape memory spring 84 interposed between the arm main body 83 a and the clutch drum 6. Stroke to the right in FIG. Then, the fastening force due to the difference between the oil pressure and the urging force is transmitted from the piston 82 → the needle bearing 87 → the integrated piston arm 83 → the arm press-fitting plate 88, pressing the drive plate 71 and the driven plate 72, and the dry multi-plate The clutch 7 is engaged.

  On the other hand, when the engaged dry multi-plate clutch 7 is released, the hydraulic oil supplied to the cylinder oil chamber 86 is drained to the transmission unit T / M through the clutch pressure oil passage 85, and then to the piston 82. When the acting oil pressure is reduced, the urging force by the shape memory spring 84 exceeds the oil pressure, and the piston arm 83 and the arm press-fit plate 88 that are integrally coupled are stroked in the left direction in FIG. As a result, the fastening force transmitted to the arm press-fitting plate 88 is released, and the dry multi-plate clutch 7 is released.

[Clutch engagement at low temperature]
In the normal state, the dry multi-plate clutch 7 is engaged on the assumption that clutch oil pressure is created. However, when the hydraulic pressure necessary for engaging the dry multi-plate clutch 7 cannot be generated in a low temperature state, it is necessary to secure the clutch engagement by some method other than hydraulic engagement. Hereinafter, based on FIG. 5, the clutch fastening action in the low temperature state reflecting this will be described.

  For example, when starting in a low temperature state, the motor / generator 9 driven by a battery (not shown) (for example, a lithium ion battery) cannot drive the oil pump O / P with a necessary rotational driving force because the battery voltage does not increase. . Further, the oil viscosity increases at a low temperature, and the pump load increases. Therefore, in a low temperature state, the required clutch hydraulic pressure to the dry multi-plate clutch 7 cannot be generated, and the dry multi-plate clutch 7 cannot be fastened. As a result, the driving force from the engine Eng cannot be transmitted to the driving wheels, and the vehicle waits for the oil viscosity to decrease or the motor output to increase due to engine warm-up despite the driver's intention to start. It will start.

  To solve this problem of driving force transmission in a low-temperature state, for example, “Despite the fact that the capacity of the on-board battery is increased, the motor output is increased, and the battery voltage drops or becomes highly viscous in the low-temperature state, A measure such as “fastening the clutch 7” is necessary. However, in the case of this measure, the scale of change as a vehicle becomes large.

  On the other hand, in Example 1, since it is in a low temperature state, the shape memory spring 84 returns to the spring compression shape in which the urging force that is the memory shape disappears as shown in FIG. For this reason, the spring 21 interposed between the arm main body 83a and the arm base 83b urges the arm main body 83a toward the clutch fastening side with respect to the arm base 83b, and the arm main body 83a is shown in FIG. Stroke to the right. The urging force of the spring 21 is transmitted from the arm main body 83a to the arm press-fitting plate 88, and becomes a fastening force that presses the drive plate 71 and the driven plate 72, and the fastening of the dry multi-plate clutch 7 is ensured.

  Therefore, in the low temperature state, the first low temperature driving force transmission mechanism A1 can transmit the driving force from the engine Eng to the driving wheels via the fastened dry multi-plate clutch 7, The vehicle can be started in response to the driver's intention to start.

  Since the dry multi-plate clutch 7 is fastened by changing the spring reaction force of the shape memory spring 84 in this low temperature state, the dry multi-plate clutch is directly fastened by the shape change of the shape memory alloy itself. It is easier to adjust the clutch fastening force than Further, since the shape memory alloy is used only for the shape memory spring 84, the cost can be reduced.

Next, the effect will be described.
In the hybrid driving force transmission device of the first embodiment, the effects listed below can be obtained.

(1) A driving force transmission system from the driving source (engine Eng) to the driving wheel includes a first driving force transmission shaft (clutch hub shaft 2), a second driving force transmission shaft (clutch drum shaft 4), and both drives. In a drive force transmission device (hybrid drive force transmission device) provided with a normally open type hydraulic clutch (dry multi-plate clutch 7) interposed between force transmission shafts and fastened by hydraulic supply,
A part of the driving force transmission system is a temperature-sensitive shape changing member (shape memory spring 84) using a material whose shape characteristics change at low temperatures,
Low temperature driving force transmission in which the driving force can be transmitted by changing the shape of the temperature sensitive shape changing member (shape memory spring 84) at low temperatures when the hydraulic pressure required for fastening the hydraulic clutch (dry multi-plate clutch 7) cannot be generated. A mechanism (first low temperature driving force transmission mechanism A1) was provided.
For this reason, it is possible to achieve a driving force transmission possible state at a low temperature when the hydraulic pressure required for fastening the hydraulic clutch (dry multi-plate clutch 7) cannot be generated.

(2) The temperature sensitive shape changing member (shape memory spring 84) is a part of the clutch fastening structure of the hydraulic clutch (dry multi-plate clutch 7) (return spring),
The low temperature driving force transmission mechanism (first low temperature driving force transmission mechanism A1) is configured to change the temperature sensitive shape changing member (shape) at a low temperature at which the hydraulic pressure required for engaging the hydraulic clutch (dry multi-plate clutch 7) cannot be generated. The hydraulic clutch (dry multi-plate clutch 7) is fastened by changing the shape of the storage spring 84) to enable a drive force transmission.
For this reason, in addition to the effect of (1) above, the low-temperature driving force transmission mechanism (first low-temperature driving force transmission mechanism A1) secures the engagement of the hydraulic clutch (dry multi-plate clutch 7) that is not hydraulically engaged at low temperatures. Thus, it is possible to achieve a drive force transmission possible state.

(3) The clutch fastening structure includes a clutch plate (drive plate 71, driven plate 72) and a clutch piston (arm body portion 83a, arm base portion 83b) by hydraulic operation for fastening the clutch plate,
The temperature sensitive shape changing member is a shape memory spring 84 that urges the clutch piston (arm body portion 83a) to the clutch release side,
The low temperature driving force transmission mechanism (first low temperature driving force transmission mechanism A1) includes a spring 21 that urges the clutch piston (arm body portion 83a) toward the clutch fastening side, and the hydraulic clutch (dry multi-plate clutch). 7) When the release pressure of the shape memory spring 84 disappears due to the shape change of the shape memory spring 84 at a low temperature where the hydraulic pressure required for the engagement of 7) cannot be generated, the spring 21 generates a biasing force toward the clutch engagement side.
For this reason, in addition to the effect of the above (2), it is easy to adjust the clutch engaging force of the hydraulic clutch (dry multi-plate clutch 7) at low temperatures, and the cost can be kept low.

  The second embodiment is an example in which the second low temperature driving force transmission mechanism A2 focused on the retainer plate of the dry multi-plate clutch is used as the low temperature driving force transmission mechanism.

First, the configuration will be described.
[Configuration of first low temperature driving force transmission mechanism]
FIG. 6 shows a second low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by releasing the dry multi-plate clutch in the hybrid driving force transmission device of the second embodiment. FIG. 7 shows a second low temperature driving force transmission mechanism in a low temperature state in which the driving force can be transmitted by dish fastening of the dry multi-plate clutch. Hereinafter, based on FIG.6 and FIG.7, the structure of 2nd low temperature driving force transmission mechanism A2 is demonstrated.

  The second low-temperature driving force transmission mechanism A2 is a bimetal material whose shape characteristics change at low temperatures for the retainer plate, which is a part of the driving force transmission system that constitutes the clutch fastening structure of the dry multi-plate clutch 7. A bimetal dish 78 (temperature-sensitive shape changing member) using an example of a material is used. Then, at a low temperature at which the hydraulic pressure necessary for fastening the dry multi-plate clutch 7 cannot be generated, the dry multi-plate clutch 7 is fastened by changing the shape of the bimetal dish 78 so that the driving force can be transmitted (FIG. 7).

  The clutch fastening structure includes a drive plate 71 (clutch plate), a driven plate 72 (clutch plate), and a hydraulically operated piston arm 83 (clutch piston) that fastens both plates 71 and 72.

  The bimetal dish 78 receives the reaction force of the fastening force by the piston arm 83 together with the snap ring 79 at a position opposite to the drive plate 71 and the driven plate 72. The bimetal dish 78 is configured by combining a first bimetal plate 78a on the side in contact with both plates 71 and 72 and a second bimetal plate 78b on the side in contact with the snap ring 79. Then, by selecting a material whose shrinkage in the low temperature state is such that the first bimetal plate 78a> the second bimetal plate 78b, the retainer plate function in a flat plate shape is exhibited in the normal state shown in FIG. The bias spring function is exhibited by the disc spring shape in the low temperature state shown.

In the second low temperature driving force transmission mechanism A2, the bimetal dish 78 is shaped from a flat plate shape (FIG. 6) to a disc spring shape (FIG. 7) at a low temperature at which the hydraulic pressure required to fasten the dry multi-plate clutch 7 cannot be generated. To generate a biasing force toward the clutch engagement side.
Note that “the overall system configuration”, “the configuration of the motor and clutch unit”, and other configurations are the same as those in the first embodiment, and thus illustration and description thereof are omitted.

Next, the operation will be described.
[Clutch engagement at low temperature]
In Example 2, when it becomes a low temperature state, the bimetal dish 78 changes shape from the flat plate shape shown in FIG. 6 to the disk spring shape shown in FIG. For this reason, the urging force by the bimetal dish 78 that has been changed to a disc spring shape becomes a fastening force that presses the drive plate 71 and the driven plate 72, and the dry multi-plate clutch 7 is fastened with the piston arm 83 as a reaction force receiver. Secured.

  Therefore, in the low temperature state, the second low temperature driving force transmission mechanism A2 can transmit the driving force from the engine Eng to the driving wheels via the fastened dry multi-plate clutch 7, The vehicle can be started in response to the driver's intention to start.

At this time, when the second low temperature driving force transmission mechanism A2 is applied, the existing retainer plate of the dry multi-plate clutch 7 is simply replaced with the bimetal dish 78, and no change in the other configuration is required. Is achieved.
The “clutch engagement / disengagement action in the normal state” is the same as that in the first embodiment, and thus the description thereof is omitted.

Next, the effect will be described.
In the hybrid driving force transmission device according to the second embodiment, the following effects can be obtained.

(4) The clutch fastening structure includes a clutch plate (drive plate 71, driven plate 72) and a hydraulically operated clutch piston (piston arm 83) for fastening the clutch plate,
The temperature sensitive shape changing member is a bimetal dish 78 that receives the reaction force of the fastening force by the clutch piston (piston arm 83) on the opposite side of the clutch plate (drive plate 71, driven plate 72),
The low temperature driving force transmission mechanism (second low temperature driving force transmission mechanism A2) is configured so that the bimetal dish 78 has a flat plate shape at a low temperature at which the hydraulic pressure required for fastening the hydraulic clutch (dry multi-plate clutch 7) cannot be generated. By changing the shape to a disc spring shape, an urging force to the clutch fastening side is generated.
For this reason, in addition to the effect of (2), it is possible to simplify the low temperature driving force transmission mechanism (second low temperature driving force transmission mechanism A2) for fastening the hydraulic clutch (dry multi-plate clutch 7) at low temperatures. it can.

  The third embodiment is an example in which a driving force can be transmitted by directly connecting a clutch hub shaft and a clutch drum shaft by pin coupling.

First, the configuration will be described.
FIG. 8 shows a third low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by separating the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of the third embodiment. FIG. 9 shows a third low temperature driving force transmission mechanism. FIG. 10 shows a third low-temperature driving force transmission mechanism at an extremely low temperature that enables transmission of driving force by pin coupling between the clutch hub shaft and the clutch drum shaft. Hereinafter, based on FIGS. 8-10, the structure of 3rd low temperature driving force transmission mechanism A3 is demonstrated.

  The third low temperature driving force transmission mechanism A3 is a shape memory alloy that changes the shape characteristics of some members of the driving force transmission system constituting the shaft direct connection structure of the clutch hub shaft 2 and the clutch drum shaft 4 at low temperatures. The shape memory spring 23 (temperature-sensitive shape changing member) using (an example of a material) is used. When the hydraulic pressure necessary for fastening the dry multi-plate clutch 7 cannot be generated, the clutch hub shaft 2 and the clutch drum shaft 4 are directly connected by changing the shape of the shape memory spring 23 to enable transmission of driving force (see FIG. 10).

  The shaft direct coupling structure is fitted in the guide fitting groove 24 provided in the clutch hub shaft 2, the fixed fitting groove 25 provided in the clutch drum shaft 4, and the fixed fitting groove 25 by the axial movement along the guide groove 24. And a guide pin 26 (movable fitting member) that can be mated. The guide pin 26 is urged from both sides by a shape memory spring 23 and a spring 27.

  The shape memory spring 23 biases the guide pin 26 to the biaxial open side in the normal state shown in FIG. 8, and the biaxial open side biasing force to the guide pin 26 disappears in the low temperature state shown in FIG. Here, the normal state refers to a state in which a normal spring function is exhibited in a temperature state other than the low temperature range (FIG. 8). Further, the low temperature state means a state in which the temperature is in a low temperature region and returns to the stored spring shape (spring compression shape in which the urging force is lost) (FIG. 10).

The third low-temperature driving force transmission mechanism A3 includes a spring 27 that urges the guide pin 26 toward the two-axis direct coupling side, and the shape memory spring 23 at low temperatures cannot generate the hydraulic pressure required to fasten the dry multi-plate clutch 7. When the urging force to the biaxial open side disappears due to the shape change, the urging force to the biaxial direct connection side is generated by the spring 27.
Note that “the overall system configuration”, “the configuration of the motor and clutch unit”, and other configurations are the same as those in the first embodiment, and thus illustration and description thereof are omitted.

Next, the operation will be described.
[Biaxial direct action at extremely low temperatures]
First, in the normal state, the urging force of the shape memory spring 23 exceeds the urging force of the spring 27, and the biaxial open state in which the guide pin 26 is pressed against the guide groove 24 is maintained as shown in FIG. The

  On the other hand, for example, at the time of starting in a low temperature state, the shape memory spring 23 returns to the spring compression shape in which the urging force which is a memory shape disappears as shown in FIG. For this reason, the urging force to the two-axis direct connection side by the spring 27 is increased, and the urging force causes the guide pin 26 to move in the axial direction along the guide groove 24 from the position shown in FIG. 8 to the position shown in FIG. . By this axial movement, the guide pin 26 is fitted into the fixed fitting groove 25 provided in the clutch drum shaft 4 and is fitted into the guide groove 24 provided in the clutch hub shaft 2 as shown in FIG. The clutch hub shaft 2 and the clutch drum shaft 4 are directly connected to each other through a guide pin 26 to be mated.

  Therefore, in a low temperature state such as at a very low temperature, the driving force from the engine Eng is transmitted to the driving wheel via the clutch hub shaft 2 and the clutch drum shaft 4 that are directly connected by the third low temperature driving force transmission mechanism A3. The vehicle can be started in response to the driver's intention to start.

In this low temperature state, the shafts of the clutch hub shaft 2 and the clutch drum shaft 4 are locked by pin direct connection without fastening the dry multi-plate clutch 7. For this reason, when the temperature is low, the driving force can be reliably transmitted and a high driving force can be transmitted.
The “clutch engagement / disengagement action in the normal state” is the same as that in the first embodiment, and thus the description thereof is omitted.

Next, the effect will be described.
In the hybrid driving force transmission device according to the third embodiment, the following effects can be obtained.

(5) The temperature sensitive shape changing member (shape memory spring 23) constitutes a shaft direct connection structure of the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission shaft (clutch drum shaft 4). Is a part of the member,
The low-temperature driving force transmission mechanism (third low-temperature driving force transmission mechanism A3) is configured to change the temperature-sensitive shape changing member (shape) at a low temperature at which the hydraulic pressure required for fastening the hydraulic clutch (dry multi-plate clutch 7) cannot be generated. By changing the shape of the storage spring 23), the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission shaft (clutch drum shaft 4) are directly connected to make the state capable of transmitting the driving force.
For this reason, in addition to the effect of (1) above, the low temperature driving force transmission mechanism (third low temperature driving force transmission mechanism A3) is used instead of the hydraulic clutch (dry multi-plate clutch 7) which is not hydraulically engaged at low temperatures. By directly connecting the two driving force transmission shafts (clutch hub shaft 2) and the second driving force transmission shaft (clutch drum shaft 4), it is possible to reliably achieve a driving force transmission state.

(6) The shaft direct connection structure includes a guide groove 24 provided on one of the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission shaft (clutch drum shaft 4), and the other A fixed fitting groove 25 provided on the shaft, and a movable fitting member (guide pin 26) that can be fitted into the fixed fitting groove 25 by axial movement along the guide groove 24,
The temperature sensitive shape changing member is a shape memory spring 23 that urges the movable fitting member (guide pin 26) to the biaxial open side,
The low temperature driving force transmission mechanism (third low temperature driving force transmission mechanism A3) includes a spring 27 that biases the movable fitting member (guide pin 26) toward the two-axis direct connection side, and the hydraulic clutch (dry type At a low temperature at which the hydraulic pressure required to engage the plate clutch 7) cannot be generated, if the urging force to the biaxial opening side is lost due to the shape change of the shape memory spring 23, the urging force to the biaxial direct coupling side is caused by the spring 27. Occur.
For this reason, in addition to the effect of (5) above, the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission can be achieved without engaging the hydraulic clutch (dry multi-plate clutch 7) in the low temperature state. By directly connecting the shaft (clutch drum shaft 4) to the pin, it is possible to transmit a higher driving force than when the hydraulic clutch (dry multi-plate clutch 7) is fastened.

  In the third embodiment, as shown in FIGS. 8 to 10, the example in which the guide pin 26 is used as the movable fitting member has been described. However, as shown in the third low temperature driving force transmission mechanism A3 'according to the modification of the third embodiment in FIG. 11, a dog clutch 28 by meshing connection may be used as the movable fitting member.

  In the fourth embodiment, the clutch hub shaft and the clutch drum shaft are directly coupled by frictional engagement so that the driving force can be transmitted.

First, the configuration will be described.
FIG. 12 shows a fourth low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by separating the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of the fourth embodiment. FIG. 13 shows a guide plate of the fourth low temperature driving force transmission mechanism. FIG. 14 shows a fourth low temperature driving force transmission mechanism at a very low temperature that enables transmission of the driving force by friction engagement between the clutch hub shaft and the clutch drum shaft. Hereinafter, based on FIGS. 12-14, the structure of 4th low temperature driving force transmission mechanism A4 is demonstrated.

  The fourth low temperature driving force transmission mechanism A4 is a shape memory alloy that changes the shape characteristics of some members constituting the shaft direct connection structure of the clutch hub shaft 2 and the clutch drum shaft 4 in the driving force transmission system. The shape memory spring 23 (temperature-sensitive shape changing member) using (an example of a material) is used. When the hydraulic pressure necessary for fastening the dry multi-plate clutch 7 cannot be generated, the clutch hub shaft 2 and the clutch drum shaft 4 are directly connected by changing the shape of the shape memory spring 23 to enable transmission of driving force (see FIG. 14).

  The shaft direct connection structure includes a guide groove 35 provided on the clutch hub shaft 2, a fixed friction plate 36 (fixed friction member) provided on the clutch drum shaft 4, and a fixed friction plate by axial movement along the guide groove 35. And a guide plate 37 (movable fastening member) that can be fastened to 36. The guide plate 37 is urged from both sides by the shape memory spring 23 and the spring 27.

  The shape memory spring 23 biases the guide plate 37 to the biaxial open side in the normal state shown in FIG. 12, and the biaxial open side biasing force to the guide plate 37 disappears in the low temperature state shown in FIG. Here, the normal state refers to a state in which a normal spring function is exhibited in a temperature state other than the low temperature range (FIG. 12). Further, the low temperature state refers to a state in which the temperature is in a low temperature range and returns to the stored spring shape (spring compression shape in which the urging force disappears) (FIG. 14).

The fourth low temperature driving force transmission mechanism A4 includes a spring 27 that urges the guide plate 37 toward the two-axis direct coupling side, and the shape memory spring 23 at low temperatures cannot generate the hydraulic pressure required to fasten the dry multi-plate clutch 7. When the urging force to the biaxial open side disappears due to the shape change, the urging force to the biaxial direct connection side is generated by the spring 27.
Note that “the overall system configuration”, “the configuration of the motor and clutch unit”, and other configurations are the same as those in the first embodiment, and thus illustration and description thereof are omitted.

Next, the operation will be described.
[Biaxial direct action at extremely low temperatures]
First, in the normal state, the urging force of the shape memory spring 23 exceeds the urging force of the spring 27, and the biaxially open state in which the guide plate 37 is pressed against the guide groove 35 is maintained as shown in FIG. The

  On the other hand, for example, at the time of starting in a low temperature state, the shape memory spring 23 returns to the spring compression shape in which the urging force which is a memory shape disappears as shown in FIG. For this reason, the urging force to the two-axis direct connection side by the spring 27 is increased, and the urging force causes the guide plate 37 to move in the axial direction along the guide groove 35 from the position shown in FIG. 12 to the position shown in FIG. . By this axial movement, the guide plate 37 is fastened to the fixed friction plate 36 provided on the clutch drum shaft 4 and is fitted into the guide groove 35 provided on the clutch hub shaft 2 as shown in FIG. Via the guide plate 37, the clutch hub shaft 2 and the clutch drum shaft 4 are directly connected by frictional engagement.

  Accordingly, in a low temperature state such as extremely low temperature, the driving force from the engine Eng is transmitted to the driving wheels via the clutch hub shaft 2 and the clutch drum shaft 4 that are directly connected by the fourth low temperature driving force transmission mechanism A4. The vehicle can be started in response to the driver's intention to start.

In this low temperature state, the clutch hub shaft 2 and the clutch drum shaft 4 are directly connected by frictional engagement without engaging the dry multi-plate clutch 7. For this reason, when the temperature is low, the driving force can be reliably transmitted, and the transmission driving force can be adjusted by the urging force of the spring 27.
The “clutch engagement / disengagement action in the normal state” is the same as that in the first embodiment, and thus the description thereof is omitted.

Next, the effect will be described.
In the hybrid driving force transmission device according to the fourth embodiment, the following effects can be obtained.

(7) The shaft direct connection structure includes a guide groove 35 provided on one of the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission shaft (clutch drum shaft 4), and the other A fixed friction member (fixed friction plate 36) provided on the shaft of the shaft, and a movable fastening member (guide plate 37) that can be fastened to the fixed friction member (fixed friction plate 36) by axial movement along the guide groove 35. Have
The temperature sensitive shape changing member is a shape memory spring 23 that urges the movable fastening member (guide plate 37) to the biaxial open side,
The low temperature driving force transmission mechanism (fourth low temperature driving force transmission mechanism A4) includes a spring 27 that urges the movable fastening member (guide plate 37) toward the two-axis direct connection side, and the hydraulic clutch (dry multi-plate). At low temperatures where the hydraulic pressure required to engage the clutch 7) cannot be generated, if the urging force to the biaxial opening side disappears due to the shape change of the shape memory spring 23, the urging force to the biaxial direct coupling side is generated by the spring 27 To do.
For this reason, in addition to the effect of (5) above, the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission can be achieved without engaging the hydraulic clutch (dry multi-plate clutch 7) in the low temperature state. By directly connecting the shaft (clutch drum shaft 4) by frictional engagement, the transmission driving force can be adjusted by the urging force of the spring 27.

  In the fifth embodiment, the clutch hub shaft and the clutch drum shaft are directly connected by cam engagement so that the driving force can be transmitted.

First, the configuration will be described.
FIG. 15 shows a fifth low temperature driving force transmission mechanism in a normal state in which the driving force transmission is interrupted by separating the clutch hub shaft and the clutch drum shaft in the hybrid driving force transmission device of the fifth embodiment. FIG. 16 shows the fifth low temperature driving force transmission mechanism in the normal state. FIG. 17 shows a fifth low temperature driving force transmission mechanism at an extremely low temperature that enables the driving force to be transmitted by cam engagement between the clutch hub shaft and the clutch drum shaft. FIG. 18 shows a fifth low temperature driving force transmission mechanism at an extremely low temperature. Hereinafter, based on FIGS. 15-18, the structure of 5th low temperature driving force transmission mechanism A5 is demonstrated.

  The fifth low temperature driving force transmission mechanism A5 is a bimetallic material whose shape characteristics change at low temperatures (partial members constituting the shaft direct connection structure of the clutch hub shaft 2 and the clutch drum shaft 4 in the driving force transmission system). A bimetal ring 46 (temperature-sensitive shape changing member) using an example of a material is used. Then, when the hydraulic pressure required for fastening the dry multi-plate clutch 7 cannot be generated, the clutch hub shaft 2 and the clutch drum shaft 4 are directly connected by changing the shape of the bimetal ring 46 so that the driving force can be transmitted (FIG. 17). ).

  The shaft direct connection structure includes a first cam groove 47 provided in the clutch hub shaft 2, a second cam groove 48 provided in the clutch drum shaft 4, and between the first cam groove 47 and the second cam groove 48. And a cam 49 (movable cam member) movable in the radial direction.

  As shown in FIGS. 15 and 16, the bimetal ring 46 has a shape that holds the cam 49 in the storage position of the first cam groove 47 in a normal state. The bimetal ring 46 in the low temperature state extends from the shape (FIGS. 15 and 16) that holds the cam 49 in the storage position of the first cam groove 47 and straddles the first cam groove 47 and the second cam groove 48. The shape is changed to a shape that engages in the direction (FIGS. 17 and 18).

The fifth low temperature driving force transmission mechanism A5 causes the cam 49 to move away from the storage position of the first cam groove 47 by changing the shape of the bimetal ring 46 at a low temperature at which the hydraulic pressure required to engage the dry multi-plate clutch 7 cannot be generated. The first cam groove 47 and the second cam groove 48 are straddled and moved in the radial direction to a position where they are engaged in the circumferential direction.
Note that “the overall system configuration”, “the configuration of the motor and clutch unit”, and other configurations are the same as those in the first embodiment, and thus illustration and description thereof are omitted.

Next, the operation will be described.
[Biaxial direct action at extremely low temperatures]
First, in a normal state, the bimetal ring 46 is shaped to hold the cam 49 in the storage position of the first cam groove 47 (FIGS. 15 and 16).

  On the other hand, for example, when starting at a low temperature, the bimetal ring 46 moves the cam 49 away from the storage position of the first cam groove 47 as shown in FIGS. The shape is changed so as to move in the radial direction to the position where the first cam groove 47 and the second cam groove 48 are engaged in the circumferential direction. For this reason, as shown in FIG. 14, the cam 49 is cam-engaged across the first cam groove 47 and the second cam groove 48, and the clutch hub shaft 2 and the clutch drum shaft 4 are cammed via the cam 49. Directly connected by engagement.

  Accordingly, in a low temperature state such as at a very low temperature, the driving force from the engine Eng is transmitted to the driving wheels via the clutch hub shaft 2 and the clutch drum shaft 4 that are directly connected by the fifth low temperature driving force transmission mechanism A5. The vehicle can be started in response to the driver's intention to start.

In this low temperature state, the clutch hub shaft 2 and the clutch drum shaft 4 are directly connected by cam engagement without engaging the dry multi-plate clutch 7. For this reason, in a low temperature state, the driving force can be reliably transmitted and a high driving force can be transmitted.
The “clutch engagement / disengagement action in the normal state” is the same as that in the first embodiment, and thus the description thereof is omitted.

Next, the effect will be described.
In the hybrid driving force transmission device according to the fifth embodiment, the following effects can be obtained.

(8) The shaft direct connection structure includes a first cam groove 47 provided on one of the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission shaft (clutch drum shaft 4). A second cam groove 48 provided on the other shaft, and a movable cam member (cam 49) movable in the radial direction between the first cam groove 47 and the second cam groove 48,
The temperature sensitive shape changing member is a bimetal ring 46 that holds the movable cam member (cam 49) in a storage position in one of the first cam groove 47 and the second cam groove 48,
The low-temperature driving force transmission mechanism (fifth low-temperature driving force transmission mechanism A5) is formed by changing the shape of the bimetal ring 46 at a low temperature at which the hydraulic pressure required for engaging the hydraulic clutch (dry multi-plate clutch 7) cannot be generated. The movable cam member (cam 49) is moved in the radial direction from the storage position to a position where the movable cam member (cam 49) engages in the circumferential direction across the first cam groove 47 and the second cam groove 48.
For this reason, in addition to the effect of (5) above, the first driving force transmission shaft (clutch hub shaft 2) and the second driving force transmission can be achieved without engaging the hydraulic clutch (dry multi-plate clutch 7) in the low temperature state. By engaging the shaft (clutch drum shaft 4) with a cam, it is possible to transmit a higher driving force than when the hydraulic clutch (dry multi-plate clutch 7) is fastened.

  As mentioned above, although the driving force transmission apparatus of this invention has been demonstrated based on Example 1- Example 5, it is not restricted to these Examples about a concrete structure, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention.

  In Examples 1-5, the example which used the dry-type multi-plate clutch as a hydraulic clutch was shown. However, the hydraulic clutch may be a wet type, a dry type, a multi-plate, a single plate, or the like as long as it is a normally open type hydraulic clutch that is fastened by supplying hydraulic pressure.

  In Examples 1 to 5, the shape memory spring 21 (Example 1), the bimetal dish 78 (Example 2), the shape memory spring 23 (Examples 3 and 4), and the bimetal ring 46 are used as temperature sensitive shape changing members. The example of (Example 5) was shown. However, the temperature-sensitive shape changing member includes members other than those in Examples 1 to 5 as long as some of the members constituting the driving force transmission system are formed using materials whose shape characteristics change at low temperatures. It is.

  In the first and second embodiments, as a low-temperature driving force transmission mechanism, the dry multi-plate clutch 7 is fastened by changing the shape of the temperature-sensitive shape changing member at a low temperature at which the hydraulic pressure required to fasten the dry multi-plate clutch 7 cannot be generated. An example of the first low temperature driving force transmission mechanism A1 and the second low temperature driving force transmission mechanism A2 in which the driving force can be transmitted is shown. However, the low temperature driving force transmission mechanism may be, for example, the first low temperature driving force transmission mechanism A1 and the second low temperature driving force transmission mechanism as long as it is a mechanism that engages the hydraulic clutch by changing the shape of the temperature sensitive shape changing member. It is good also as an example which combines A2 or adds the piston only for a low temperature state.

  In the third, fourth, and fifth embodiments, the clutch hub shaft 2 and the clutch drum are used as a low-temperature driving force transmission mechanism by changing the shape of the temperature-sensitive shape-changing member at low temperatures when the hydraulic pressure required to engage the dry multi-plate clutch 7 cannot be generated. An example of the third low temperature driving force transmission mechanism A3, the fourth low temperature driving force transmission mechanism A4, and the fifth low temperature driving force transmission mechanism A5, in which the driving force can be transmitted by directly connecting the shaft 4, is shown. However, the low temperature driving force transmission mechanism may be a mechanism other than A3 to A5 as long as it is a mechanism that directly connects the clutch hub shaft and the clutch drum shaft by changing the shape of the temperature sensitive shape changing member.

  In the first to fifth embodiments, the application example to the hybrid driving force transmission device in which the engine and the motor / generator are mounted and the dry multi-plate clutch is the travel mode transition clutch is shown. However, the present invention can also be applied to an engine driving force transmission device in which only an engine is mounted as a drive source and a hydraulic clutch is a starting clutch, such as an engine vehicle. Further, the present invention can be applied to a motor driving force transmission device in which only a motor / generator is mounted as a driving source and a hydraulic clutch is a starting clutch, such as an electric vehicle and a fuel cell vehicle.

Eng engine (drive source)
2 Clutch hub shaft (first drive force transmission shaft)
4 Clutch drum shaft (second drive force transmission shaft)
7 Dry multi-plate clutch (hydraulic clutch)
71 Drive plate (clutch plate)
72 Driven plate (clutch plate)
A1 First low temperature driving force transmission mechanism (low temperature driving force transmission mechanism)
83 Piston arm (clutch piston)
83a Arm body
83b Arm base
84 Shape memory spring (Temperature sensitive shape changing member)
21 Spring A2 Second low temperature driving force transmission mechanism (low temperature driving force transmission mechanism)
78 Bimetal dish (temperature-sensitive shape changing material)
A3 Third low temperature driving force transmission mechanism (low temperature driving force transmission mechanism)
23 Shape memory spring (temperature-sensitive shape changing member)
24 Guide groove 25 Fixed fitting groove 26 Guide pin (movable fitting member)
27 Spring A4 Fourth low temperature driving force transmission mechanism (low temperature driving force transmission mechanism)
23 Shape memory spring (temperature-sensitive shape changing member)
27 Spring 35 Guide groove 36 Fixed friction plate (fixed friction member)
37 Guide plate (movable fastening member)
A5 5th low temperature driving force transmission mechanism (low temperature driving force transmission mechanism)
46 Bimetal Ring (Temperature Sensitive Shape Changing Member)
47 First cam groove 48 Second cam groove 49 Cam (movable cam member)

Claims (8)

A normal open type that is interposed between the first driving force transmission shaft, the second driving force transmission shaft, and both driving force transmission shafts in the driving force transmission system from the driving source to the driving wheels, and is fastened by hydraulic pressure supply. A drive force transmission device comprising:
Some of the members constituting the driving force transmission system are temperature sensitive shape changing members using a material whose shape characteristics change at low temperatures,
A driving force transmission device provided with a low temperature driving force transmission mechanism in which the driving force can be transmitted by changing the shape of the temperature sensitive shape changing member at a low temperature when the hydraulic pressure required to engage the hydraulic clutch cannot be generated. . The driving force transmission device according to claim 1,
The temperature sensitive shape changing member is a part of the clutch fastening structure of the hydraulic clutch,
The low-temperature driving force transmission mechanism is configured to be in a state capable of transmitting a driving force by engaging the hydraulic clutch by changing the shape of the temperature-sensitive shape changing member at a low temperature at which the hydraulic pressure required to engage the hydraulic clutch cannot be generated. A driving force transmission device characterized by the above. The driving force transmission device according to claim 2,
The clutch fastening structure includes a clutch plate and a hydraulically actuated clutch piston that fastens the clutch plate,
The temperature-sensitive shape changing member is a shape memory spring that biases the clutch piston toward the clutch release side,
The low-temperature driving force transmission mechanism includes a spring that biases the clutch piston toward the clutch engagement side, and can be attached to the open side by changing the shape of the shape memory spring at a low temperature when the hydraulic pressure required to engage the hydraulic clutch cannot be generated. When the power is lost, the spring generates a biasing force toward the clutch engagement side by the spring. The driving force transmission device according to claim 2,
The clutch fastening structure includes a clutch plate and a hydraulically actuated clutch piston that fastens the clutch plate,
The temperature sensitive shape changing member is a bimetal dish that receives the reaction force of the fastening force by the clutch piston on the opposite side of the clutch plate,
The low-temperature driving force transmission mechanism generates an urging force to the clutch engagement side by changing the shape of the bimetal dish from a flat plate shape to a disc spring shape at a low temperature at which the hydraulic pressure required to engage the hydraulic clutch cannot be generated. A driving force transmission device characterized by that. The driving force transmission device according to claim 1,
The temperature-sensitive shape changing member is a part of a member that forms a shaft direct connection structure of the first driving force transmission shaft and the second driving force transmission shaft,
The low-temperature driving force transmission mechanism moves the first driving force transmission shaft and the second driving force transmission shaft by changing the shape of the temperature-sensitive shape changing member at a low temperature at which the hydraulic pressure required to engage the hydraulic clutch cannot be generated. A driving force transmission device characterized in that the driving force can be transmitted by direct connection. In the driving force transmission device according to claim 5,
The shaft direct connection structure includes a guide groove provided on one of the first driving force transmission shaft and the second driving force transmission shaft, a fixed fitting groove provided on the other shaft, and a guide groove. A movable fitting member that can be fitted into the fixed fitting groove by axial movement along
The temperature sensitive shape changing member is a shape memory spring that urges the movable fitting member toward the biaxial open side,
The low-temperature driving force transmission mechanism includes a spring that urges the movable fitting member toward the two-axis direct coupling side, and at low temperatures when the hydraulic pressure necessary for fastening the hydraulic clutch cannot be generated, by changing the shape of the shape memory spring When the urging force to the biaxial open side disappears, the urging force to the biaxial direct connection side is generated by the spring. In the driving force transmission device according to claim 5,
The shaft direct connection structure extends along a guide groove provided on one of the first driving force transmission shaft and the second driving force transmission shaft, a fixed friction member provided on the other shaft, and the guide groove. A movable fastening member that can be fastened to the fixed friction member by axial movement;
The temperature sensitive shape changing member is a shape memory spring that urges the movable fastening member toward the biaxial open side,
The low-temperature driving force transmission mechanism includes a spring that urges the movable fastening member toward the two-axis direct coupling side. When the hydraulic pressure required for fastening the hydraulic clutch cannot be generated, the shape memory spring changes shape 2 at a low temperature. When the urging force to the shaft opening side disappears, the urging force to the biaxial direct connection side is generated by the spring. In the driving force transmission device according to claim 5,
The shaft direct connection structure includes a first cam groove provided on one of the first driving force transmission shaft and the second driving force transmission shaft, a second cam groove provided on the other shaft, A movable cam member movable in a radial direction between one cam groove and the second cam groove,
The temperature sensitive shape changing member is a bimetal ring that holds the movable cam member at a storage position in one of the first cam groove and the second cam groove,
The low temperature driving force transmission mechanism moves the movable cam member from the storage position to the first cam groove and the first by changing the shape of the bimetal ring at a low temperature at which the hydraulic pressure required to engage the hydraulic clutch cannot be generated. A driving force transmission device characterized by moving in a radial direction to a position engaging in a circumferential direction across two cam grooves.