JP2002283983A - On-slope start auxiliary device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-slope start auxiliary device of a vehicle capable of operating an HSA in a gear-in state without changing the gear to neutral after stopping the vehicle and preventing the starting of the vehicle by a creep force without detecting a brake stepping pressure at this time. SOLUTION: This device comprises a, fluid coupling for generating a predetermined creep force in the gear-in a brake force holding valve 61 for holding a brake force at this time in closing the valve and releasing the brake force in opening the valve, a gear-in sensor 46 of a transmission 3, a brake sensor 52, an accelerator sensor 54, a speed sensor 47, and a controlling part 56 for controlling the opening or closing of the brake force holding valve 61. When the brake sensor 52 detects the stepping of a brake pedal 51 and the speed sensor 47 detects the stop of the vehicle, the controlling part 56 allows the closing of the brake force holding valve 61 whether the transmission 3 is in a gear-in state or the neutral state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle having a hill which retains the braking force even when the brake pedal is released and the brake pedal is released, and releases the braking force held at the time of starting. The present invention relates to a start assist device.

[0002]

2. Description of the Related Art Hill Start Ai
d: may be abbreviated as HSA in the following), which makes it easy to start on a slope without using a side brake (parking brake). When applying the HSA to a vehicle having a fluid coupling (including a torque converter) between an engine and a transmission (a vehicle with a so-called torque converter), the brake pedal is released when the brake pedal is depressed and stopped. The brake force is maintained even afterward, and then the brake force held when the accelerator pedal is depressed is released.

[0003] Specifically, a braking force for maintaining a braking force at that time by closing a passage in a fluid pressure passage between a master cylinder operated by a brake pedal and a wheel cylinder operating a wheel brake. When a brake valve is depressed, the vehicle is stopped, and the gear is in neutral as shown in FIG. 5, the brake force holding valve is closed and the brake pedal is released. The brake force is maintained even after being released, and thereafter, as shown in FIG. 6, when the accelerator pedal is depressed in the gear-in state, the brake force holding valve is opened (HSA is released).

[0004]

However, as shown in FIG. 5, only when the gear is stopped in a neutral state, the HS
If A is operated (the braking force holding valve is closed), the HSA cannot be operated unless the shift lever is moved to the neutral position even when the vehicle is stopped in the gear-in state, and the operation becomes complicated. .

[0005] Further, after the vehicle is stopped in a neutral state and the HSA is operated, when the shift lever is moved to shift into the starting stage, the creep force generated by the gear-in is H.
If the braking force is larger than the braking force caused by the activation of the SA, the vehicle starts moving against the driver's intention (the intention that the vehicle should be stopped because the HSA is activated) due to the creep force.

In order to avoid this, as shown in FIG. 7, a step of "brake pressure> P ₁ " is provided after a step of "brake depression?", And the brake pressure in the fluid pressure passage is changed to the starting stage. it is conceivable to allow the operation of only HSA when a predetermined pressure P ₁ or more that can counteract the creep force of but, apparatus and control is complicated.

SUMMARY OF THE INVENTION An object of the present invention, which has been made in view of the above circumstances, is to enable the HSA to be operated in a gear-in state without shifting the gears one by one after the vehicle stops, without detecting the brake depression pressure at that time. It is an object of the present invention to provide a vehicle hill start assistance device that can prevent the vehicle from starting to move due to creep force.

[0008]

In order to achieve the above object, a vehicle hill start assist system according to the present invention is provided between an engine and a transmission and generates a predetermined creep force when the transmission is engaged. A fluid coupling, a braking force holding device interposed in the fluid pressure passage of the brake and holding the braking force at that time by closing the passage, a gear-in sensor for detecting gear-in of the transmission, and detecting depression of a brake pedal. A vehicle hill start assist device having a brake sensor, an accelerator sensor for detecting depression of an accelerator pedal, a vehicle speed sensor for detecting stop of the vehicle, and a control device for controlling operation and release of the braking force holding device. When the brake sensor detects depression of a brake pedal and the vehicle speed sensor detects that the vehicle is stopped, In which the allowable operating power holding device.

According to the present invention, when the control device detects that the brake pedal is depressed and the vehicle stops, the control device permits the operation of the braking force holding device regardless of whether the transmission is in gear or neutral. I do. Here, stopping the vehicle in the gear-in state means that the vehicle is stopped with the foot brake force that exceeds the creep force, and if the foot brake stepping pressure is held by operating the braking force holding device, the creep force is used. The vehicle can be prevented from starting, and there is no need to detect the brake depression pressure. That is, according to the present invention, the HSA can be operated in the gear-in state without shifting the gears to neutral each time after the vehicle stops, and at that time, it is possible to prevent the vehicle from starting due to creep force without detecting the brake depression pressure.

By the way, when the HSA is operated by depressing the brake pedal, gearing in and stopping the vehicle,
The release is done only by depressing the accelerator pedal. In this case, it is impossible to start with creep force by loosening the depression of the brake pedal at the time of gear-in, so that creep start and running, which is an advantage of a vehicle with a torque converter, cannot be performed. In particular, when starting on a downhill, if you can not start only by loosening the brake pedal and you can not start without depressing the accelerator pedal, not only is it contrary to the intention of the driver who is used to driving the conventional vehicle with the conventional torque converter, This results in a sudden start of the vehicle, which is not preferable.

Therefore, according to the present invention, when the vehicle is stopped in the gear-in state and the HSA is operated, the accelerator pedal is depressed as it is (while the gear is in), or once the gear is neutralized and then the foot brake is depressed. HSA is released when the operation is performed. This makes it possible to start the vehicle with creep force by loosening the brake pedal in the gear-in state, and it is possible to avoid the feeling of jumping when starting downhill.

More specifically, the control device may be configured such that the gear-in sensor detects gear-in of the transmission and the accelerator sensor detects depression of an accelerator pedal, or the brake sensor detects depression of a brake pedal and detects the gear-in sensor. , When the gear is detected after the neutral of the transmission is detected, the release of the braking force holding device is permitted.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a block diagram of the vehicle start assist device according to this embodiment. As shown, a transmission 3 is connected to the engine 1 via a clutch mechanism 2. As shown in FIG. 4, the clutch mechanism 2 includes a fluid coupling 4 (a fluid coupling: including a torque converter) and a wet multi-plate clutch 5 (a speed change clutch).

The fluid coupling 4 includes a pump unit 7 connected to the output shaft 6 (crankshaft) of the engine 1, a turbine unit 9 opposed to the pump unit 7 and connected to the clutch input shaft 8,
It has a stator section 10 interposed between the turbine section 9 and the pump section 7 and a lockup section 11 for connecting and disconnecting the pump section 7 and the turbine section 9. The wet multi-plate clutch 5 includes a clutch input shaft 8 and an input shaft 12 of the transmission 3.
The connection is made during the shift operation of the transmission 3 and is made after the shift is completed.

According to the clutch mechanism 2, the engine 1
Is operated and its output shaft 6 (crankshaft) is rotated, and if the lockup portion 11 is disconnected, the clutch input shaft 8 is rotated via the fluid coupling 4 and the lockup portion 11 is connected. In this case, the clutch input shaft 8 rotates integrally with the engine output shaft 6. When the wet multi-plate clutch 5 is disengaged, the rotation of the clutch input shaft 8 is not transmitted to the input shaft 12 of the transmission 3, and when the wet multi-plate clutch 5 is connected, the clutch input shaft 8 The rotation is transmitted to the input shaft 12 of the transmission 3.

The transmission 3 has an input shaft 12, an output shaft 13 arranged coaxially with the input shaft 12, and a sub shaft 14 arranged parallel to these. The input shaft 12 is provided with an input main gear 15. The output shaft 13 has a first-speed main gear 16,
2nd speed main gear 17, 3rd speed main gear 18, 4th speed main gear 19
, And a reverse main gear 20 are pivotally supported, and a 6-speed main gear 21 is fixedly provided. On the countershaft 14,
The input sub gear 22 meshing with the input main gear 15, the first speed sub gear 23 meshing with the first speed main gear 16, the second speed sub gear 24 meshing with the second speed main gear 17, and the third speed main gear 18 meshing. A third speed auxiliary gear 25, a fourth speed auxiliary gear 26 meshing with the fourth speed main gear 19, and a reverse auxiliary gear 28 meshing with the reverse main gear 20 via an idle gear 27, respectively. A 6-speed auxiliary gear 29 that meshes with the 6-speed main gear 21 is pivotally supported.

According to the transmission 3, the sleeve 31 is spline-engaged with the hub 30 fixed to the output shaft 13.
Is spline-engaged with the dog 32 of the reverse main gear 20, the output shaft 13 rotates reversely, and the sleeve 31
Is engaged with the dog 33 of the first speed main gear 16 by spline.
The output shaft 13 rotates at the first speed. And the output shaft 13
When the sleeve 35 spline-engaged with the hub 34 fixed to the spline is meshed with the dog 36 of the second speed main gear 17, the output shaft 13 rotates at the second speed and the sleeve 3
When the gear 5 is spline-engaged with the dog 37 of the third speed main gear 18, the output shaft 13 rotates at a speed equivalent to the third speed.

The hub 38 fixed to the output shaft 13
The sleeve 39, which is spline-engaged with the
When the spline meshes with the dog 40 of No. 9, the output shaft 13
When the sleeve 39 is splined with the dog 41 of the input main gear 15, the output shaft 13 rotates at the fifth speed (direct connection). When the sleeve 43 spline-engaged with the hub 42 fixed to the sub shaft 14 is spline-engaged with the dog 44 of the sixth speed sub gear 29, the output shaft 13 rotates at the sixth speed.

The respective sleeves 31, 35, 39, 43
Is operated by a shift lever 45 shown in FIG. 3 in a cab through a shift fork and a shift rod (not shown). At this time, during operation of each of the sleeves 31 and the like, the wet-type multi-plate clutch 5 is disengaged so that a shift can be performed. It has become. In addition, each sleeve 31, 35, 39, 43 and dog 32, 3
A synchronizing mechanism (not shown) is provided between 3, 3, 37, 40, 41, and 44.

As shown in FIG. 3, in the transmission 3, the gears are neutral (each sleeve 31, 35, 39, 43 is attached to any of the dogs 32, 3) based on the position of the shift rod.
3, 36, 37, 40, 41, and 44 are also provided with a neutral sensor 46 for detecting that the splines are not engaged. This neutral sensor 4
Numeral 6 designates a gear-in sensor 46 for detecting the presence or absence of a gear-in of the transmission 3.

The transmission 3 is provided with a vehicle speed sensor 47, as shown in FIGS. The vehicle speed sensor 47 calculates the vehicle speed based on the rotation speed (rpm) of the output shaft 13 of the transmission 3. Further, as shown in FIG. 3, the engine 1 is provided with an engine sensor 48 for detecting whether or not the engine 1 is operating. The engine sensor 48 detects whether or not the engine 1 is in operation based on an output from an ACG (alternating current generator) driven by a crankshaft via a belt or a gear.

The parking brake (side brake) is provided with a parking brake sensor 49 for detecting whether or not the parking brake is applied. The parking brake sensor 49 includes, for example, a limit switch that is turned on when the parking brake lever 50 is rotated by a predetermined angle.

The brake pedal 51 is provided with a brake sensor 52 for detecting depression of the brake pedal 51. The brake sensor 52 may be, for example, a limit switch that is turned on when the brake pedal 51 is depressed at a predetermined angle, or the internal pressure of a brake fluid pressure passage 60 described later has become equal to or higher than a predetermined pressure (0.5 kg / cm ² or the like). A pressure switch that is turned on at the time may be used. The turning on of the brake sensor 52 is linked with the lighting of the stop lamp.

The accelerator pedal 53 is provided with an accelerator sensor 54 for detecting whether or not the accelerator pedal 53 is at an idle position. Accelerator sensor 54
Is composed of, for example, a limit switch that is turned on when the accelerator pedal 53 is at the idle position, and detects depression of the accelerator pedal 53.

In the driver's cab, an HSA release switch 5 for releasing the operation of the vehicle start assist device (HSA) is provided.
5 are provided. When the HSA release switch 55 is turned on, the HSA does not operate and the same behavior as a normal vehicle not equipped with the HSA comes to be exhibited.

Further, as shown in FIG.
Is provided with an engine rotation sensor 64 for detecting the rotation speed of the engine 1. The engine rotation sensor 64
As shown in FIG. 4, the rotation speed of the pump unit 7 connected to the output shaft 6 (crankshaft) of the engine 1 is detected, and the rotation speed of the engine 1 is detected. The sensors and switches described above are connected to the control unit 56 as shown in FIG.
(Controller).

A master cylinder 57 operated by the brake pedal 51 is connected to the brake pedal 51, and a wheel cylinder 59 for operating the brake is connected to the brake of the wheel (wheel) 58. The master cylinder 57 and the wheel cylinder 59 are connected through a fluid pressure passage 60. In the fluid pressure passage 60,
A braking force holding valve 61 that holds the braking force at that time by closing the passage 60 and releases the braking force by opening the passage 60 is provided to be openable and closable.

The braking force holding valve 61 is opened and closed in response to a command from the control unit 56 as described later. Control unit 56
In the present embodiment, the operation of the HSA, that is, the closing of the braking force holding valve 61 is permitted according to the flow shown in FIG.

First, in step 1, it is determined whether the vehicle speed is 0.5 km / h or less. This determination is for detecting whether or not the vehicle is substantially stopped, and is made based on the output from the vehicle speed sensor 47 shown in FIGS. Vehicle speed
If not below 0.5Km / h, go to the end and the vehicle speed is 0.5Km / h
If so, go to step 2. This is because the operation of the HSA is based on the premise that the vehicle stops.

In step 2, it is determined whether the deceleration immediately before stopping is smaller than a predetermined value. This determination is for detecting whether or not the wheel 58 is locked by the brake, and is performed by differentiating the output from the vehicle speed sensor 47 with time. If the deceleration is not small, that is, if the deceleration is large, the wheel 58 may be locked even if the vehicle speed sensor 47 detects the vehicle speed of 0.5 km / h or less in step 1;
The operation proceeds to the end without operating the SA. If the deceleration is small, the operation proceeds to step 3.

In step 3, it is determined whether the brake pedal 51 has been depressed. This judgment is made by the brake sensor 5
2 (a limit switch provided in the brake pedal 51) and a pressure switch (not shown) provided in the brake fluid pressure passage 60 (set pressure = 0.5 kg / cm ² or the like). If the brake pedal 51 is not depressed, the process proceeds to the end. If the brake pedal 51 is depressed, the process proceeds to step 4. That is, the HSA does not operate unless the brake pedal 51 is depressed.

In step 4, it is determined whether the parking brake is off. This determination is made by the parking brake sensor 49 provided on the parking brake lever 50.
Is made based on the output of If the parking brake is not off, that is, if the parking brake is on, the procedure goes to the end. If the parking brake is off, the procedure goes to step 5. This is because if the parking brake is on, the vehicle can be stopped without operating the HSA.

In step 5, the HSA release switch 55
Is turned off. This determination is made based on the output of the HSA release switch 55 provided in the driver's cab. If the HSA release switch 55 is not off, that is, if it is on, the process goes to the end. If the HSA release switch 55 is off, the process goes to step 27. . It reflects the driver's intention. That is, even if the operating conditions of the HSA are prepared, when the driver turns on the HSA release switch 55 because he does not want to operate the HSA, the HSA does not operate.

In step 6, it is determined whether the engine 1 is operating. This determination is made based on the engine sensor 48 (A
CG output sensor). If the engine 1 is not operating, the process proceeds to the end. If the engine 1 is operating, the process proceeds to step 7. This is because if the engine 1 is stopped, there is no need to prepare for restart after stopping and there is no need to operate the HSA.

In step 7, a failure diagnosis of the present system is performed to determine whether the system is normal. This failure diagnosis is performed by each of the sensors 46, 47, 48, 49, 5 shown in FIG.
Whether or not 2, 54, 55, etc. are normal is detected and performed. If abnormal, the process proceeds to the end, and if normal, the process proceeds to step 8. This is because normal operation is impossible even if the HSA is to be activated when the system is abnormal.

At step 8, it is determined whether the gear is neutral. This determination is made based on the output from the neutral sensor (gear-in sensor) 46 of the transmission 3.
If the gear is neutral, go to step 9 and set the gear N
(Neutral) flag is set and step 10
To operate the HSA (the braking force holding valve 61 is closed). As a result, the braking force generated when the brake pedal 51 is depressed at that time is maintained even after the brake pedal 51 is released, and the stop of the vehicle is maintained.

If it is determined in step 8 that the gear is not neutral, that is, if the gear is in a gear-in state, the process proceeds to step 11.
In step 11, it is determined whether the accelerator pedal 53 is in the idle position. This determination is made based on the output of the accelerator sensor 54. If the accelerator pedal 53 is in the idle position, the routine proceeds to step 10 where the HSA is operated (the braking force holding valve 61 is closed). Thus, if the accelerator pedal 53 is in the idle position even in the gear-in state, the braking force generated by depressing the brake pedal 51 at that time is retained even after the brake pedal 51 is released, and the vehicle stops. Will be retained.

Here, the fact that the vehicle stops in the gear-in state means that the vehicle is stopped by the foot brake force exceeding the creep force, and the foot brake stepping pressure (the pressure in the brake fluid pressure passage 60) is shown in FIG. Braking force holding valve 6 shown
By holding the valve 1 by closing it, it is possible to prevent the vehicle from starting to move due to the creep force, and at this time, it is not necessary to detect the brake depression pressure that exceeds the creep force. That is, according to the present embodiment, the HSA can be operated in the gear-in state without shifting the gear to neutral each time after the vehicle stops,
At this time, the vehicle can be prevented from starting to move due to the creep force without detecting the brake depression pressure.

On the other hand, in step 11, the accelerator pedal 53 is not in the idle position, that is, the accelerator pedal 53
If is depressed, the operation proceeds to the end without activating the HSA. When the accelerator pedal 53 is depressed, it is considered that the driver intends to start, and the HS
This is because A need not be operated.

FIG. 2 shows HSA release conditions (opening conditions of the braking force holding valve 61).

First, at step 21, it is determined whether the parking brake is on. This determination is made based on the output of the parking brake sensor 49. If the parking brake is on, go to step 27,
The HSA is released (the braking force holding valve 61 is opened). This is because if the parking brake is on, the vehicle can be stopped even if the HSA is released. On the other hand, if the parking brake is not on, the process proceeds to step S22.

In step 22, it is determined whether the vehicle speed is equal to or higher than 4.5 km / h. This determination is made based on the output from the vehicle speed sensor 47. If the vehicle speed is equal to or higher than 4.5 km / h, the routine proceeds to step 27, where the HSA is released (the braking force holding valve 61 is opened). If the vehicle speed is equal to or higher than 4.5 km / h, there is no need to generate a braking force by the HSA. On the other hand, if the vehicle speed is lower than 4.5 km / h, the routine proceeds to step 23.

In step 23, the HSA release switch 5
It is determined whether 5 is on. This determination is made based on the output of the HSA release switch 55 provided in the cab.
If the HSA release switch 55 is on, the process proceeds to step 27, where HSA is released (the braking force holding valve 61 is opened). It reflects the driver's intention. On the other hand, if the HSA release switch 55 is off, step 24
Head for.

In step 24, it is determined whether the gear is neutral. This determination is made based on the output from the neutral sensor (gear-in sensor) 46 of the transmission 3. And if the gear is neutral, step 2
Set the gear N flag at 8 and go to the end.
Do not cancel. The fact that the gear is neutral means that the driver does not intend to start the vehicle and the operation of the HSA should be held (the closing of the braking force holding valve 61 should be held).

On the other hand, if the gear is not neutral, that is, if it is in the gear-in state, the routine proceeds to step 25. Step 25
Then, it is determined whether or not the gear N flag is set. And if the gear N flag is not set,
Go to step 29. In step 29, the accelerator sensor 54 determines whether the accelerator pedal 53 is depressed. If the accelerator pedal 53 is depressed for a certain degree or more (for example, 3% or more), step 2 is executed.
7, the HSA is released, otherwise it goes to the end without releasing the HSA.

If it is determined in step 25 that the gear N flag has been set, the process proceeds to step 26. In step 26, it is determined whether the brake pedal 51 is depressed. This determination is made by a brake sensor 52 (a limit switch provided on the brake pedal 51) and a pressure switch (not shown) provided in the brake fluid pressure passage 60 (a set pressure = 0.5 kg / cm ² or the like). If the brake pedal 51 is depressed, step 27
The HSA is released, otherwise step 29
Head for.

In step 29, as described above, it is determined by the accelerator sensor 54 whether the accelerator pedal 53 has been depressed. If the accelerator pedal 53 is depressed for a certain degree or more (for example, 3% or more), the HSA is released to step 27, and otherwise the HSA is released.
To end without releasing.

The reason for adopting the HSA release control will be described.

As shown in FIG. 1, depressing the brake pedal 51 (step 3), gear-in (steps 8, 1)
When the HSA is operated at 1) and at a stop (step 1), the HSA must be released only by depressing the accelerator pedal 53. The reason is that if the HSA is released by depressing the brake pedal 51, the gear-in and the stop are other conditions for releasing the HSA.
This is because the HSA release condition overlaps with the HSA operation condition and causes control interference.

However, if the HSA is released by depressing the accelerator pedal 53, the depressing of the brake pedal 51 at the time of gear-in makes it impossible to start with creep force, which is an advantage of a vehicle with a torque converter. Cannot start / run. In particular, when starting on a downhill, the vehicle cannot be started only by loosening the brake pedal 51 and cannot be started unless the accelerator pedal 53 is depressed, which is contrary to the intention of a driver who is accustomed to driving a conventional vehicle with a torque converter. Instead, the vehicle starts suddenly, which is not preferable.

Therefore, when the vehicle is stopped in the gear-in state shown in FIG. 1 and the HSA is operated (steps 8, 11, 10), as shown in steps 24, 25, and 29 in FIG. Depress the pedal 53 or temporarily operate the gear to neutral as shown in steps 24, 25 and 26, and then
When the gear-in operation is performed while stepping on, the HSA is released. This makes it possible to start with a creep force by loosening the depression of the brake pedal 51 in the gear-in state, and it is also possible to avoid the feeling of jumping when starting downhill.

That is, when the gear-in sensor 46 detects the gear-in of the transmission 3 and the accelerator pedal sensor 54 detects the depression of the accelerator pedal 53 (steps 24, 25, 29, and 27), the control unit 56 shown in FIG. Alternatively, when the brake sensor 52 detects the depression of the brake pedal 51 and the gear-in sensor 46 detects the gear-in after detecting the neutral of the transmission 3 (step 2).
4, 25, 26, 27), the opening of the braking force holding valve 61 is permitted.

In this case, the HSA release condition does not overlap with the HSA operation condition and does not interfere, and creep start / run by loosening the brake pedal 51, which is a merit of the vehicle with the torque converter, becomes possible. That is, according to the present embodiment, it is possible to start with the creep force even if the accelerator pedal 53 or the brake pedal 51 is depressed after the operation of the HSA (after the closing of the braking force holding valve 61). Does not interfere with control.

In this embodiment, a two-shaft manual transmission as shown in FIG. 4 is used for the transmission 3, and the wet multiple disc clutch 5 and the fluid coupling 4 are used for the clutch mechanism 2.
However, the present invention is not limited to this, but instead of the two-axis manual transmission, the transmission 3 employs a planetary gear type automatic transmission, and the clutch mechanism 2 does not include the wet multi-plate clutch 5 and employs a fluid. Only the joint 4 may be employed. In short, the present invention provides a fluid coupling 4
The present invention is concerned with the problem of creep force caused by the use of the transmission 3, and the transmission 3 may be any mechanism (belt type CVT, half toroid CVT, etc.) as long as it has the fluid coupling 4.

[0056]

As described above, the vehicle hill start assist system according to the present invention has the following effects. (1) In a vehicle equipped with a fluid coupling that generates a predetermined creep force at the time of gear-in of the transmission, the HSA can be operated in a gear-in state without shifting the gears one by one after the vehicle stops, and at this time, the brake depression pressure is reduced. It is possible to prevent the vehicle from starting to move due to creep force without detection. (2) After the HSA is actuated (after the braking force holding valve is closed), the vehicle can be started with creep force even if the accelerator pedal is depressed or the brake pedal is depressed. Can be avoided.

[Brief description of the drawings]

FIG. 1 is a flowchart showing operating conditions of a vehicle start assist device (HSA) according to an embodiment of the present invention.

FIG. 2 is a flowchart showing conditions for releasing the HSA.

FIG. 3 is a schematic diagram showing the HSA system.

FIG. 4 is an explanatory diagram showing a transmission and a clutch mechanism of the HSA.

FIG. 5 is a flowchart showing operating conditions of an HSA under development by the inventor.

FIG. 6 is a flowchart showing a HSA release condition under development by the inventor.

FIG. 7 is a flow chart showing operating conditions of another HSA under development by the present inventors.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 engine 3 transmission 4 fluid coupling 46 gear-in sensor (neutral sensor) 47 speed sensor 51 brake pedal 52 brake sensor 53 accelerator pedal 54 accelerator sensor 56 control unit 60 fluid pressure passage 61 braking force holding valve

Claims (2)

[Claims] 1. A fluid coupling interposed between an engine and a transmission for generating a predetermined creep force at the time of gear-in of the transmission. A braking force holding device that holds a braking force, a gear-in sensor that detects gear-in of the transmission, a brake sensor that detects depression of a brake pedal,
A vehicle hill start assistance device comprising: an accelerator sensor for detecting depression of an accelerator pedal; a vehicle speed sensor for detecting vehicle stop; and a control device for controlling activation and release of the braking force holding device. The apparatus according to claim 1, wherein the brake sensor detects depression of a brake pedal and the vehicle speed sensor detects that the vehicle has stopped, and permits the operation of the braking force holding device. 2. The control device according to claim 1, wherein the gear-in sensor detects a gear-in of the transmission and the accelerator sensor detects a depression of an accelerator pedal, or the brake sensor detects a depression of a brake pedal and the gear-in sensor detects the transmission of the transmission. 2. The vehicle slope start assist device according to claim 1, wherein when the gear-in is detected after the neutral is detected, the release of the braking force holding device is permitted.