JPH10129434A - Slope start controlling device for tractor/trailer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly perform the slope start by installing a release of tractor/ trailer braking operation judging means for outputting a braking operation releasing signal for releasing the operation of the brakes of the tractor and the trailer, when the driving force of an engine is larger than the downward force of the connected vehicles. SOLUTION: The mass of a trailer is calculated by a mass of trailer computing means 56. The downward force of the connected vehicles is calculate by an computing means 57 for the downward force of the connected vehicles. The driving force of an engine is calculated by a driving force computing means 58. When it is judged that the engine driving amount is larger than the downward force of the connected vehicles, by a release of tractor trailer/braking operation judging means 59, the operation of the brakes of the tractor and the trailer is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of hill start control of a connected vehicle in which a tractor and a trailer are connected via a coupler, and in particular, uses a coupling force applied to the coupler by a trailer pushing up. TECHNICAL FIELD The present invention relates to a technical field of a tractor / trailer slope start control device using tractor / trailer brake control for performing coupling force control (hereinafter, also referred to as CFC) for controlling brake pressure.

[0002]

2. Description of the Related Art In a tractor / trailer connection vehicle in which a trailer is connected to a tractor via a coupler, an air brake system is generally employed for both the tractor and the trailer. That is, a brake pressure necessary for braking the tractor and the trailer is formed by the air pressure. This brake pressure is preferably adjusted so that the trailer is decelerated with exactly the same braking acceleration as the tractor.

[0003] Therefore, conventionally, a trailer brake control method in which a braking pressure supplied to a trailer in relation to a braking force of a tractor is adjusted to keep the braking force of the trailer constant at an appropriate value each time. However, Japanese Patent Laid-Open
-310111.

The trailer brake control method disclosed in this publication is a brake control method using the above-mentioned CFC. In this case, the coupling force applied to the coupler by trailer thrust or the like is 0 or a slightly negative value, that is, The trailer braking force is set to be slightly greater than the tractor braking force. The reason for setting the brake force of the trailer in this manner is that if the brake force of the trailer is set smaller than the brake force of the tractor, the trailer pushes up against the tractor during braking of the tractor / trailer, causing a so-called jackknife phenomenon. This is because there is a possibility that the jackknife phenomenon may be prevented, and because it is conventionally better to set the braking force of the trailer to be larger than the braking force of the tractor in driving feeling.

In the trailer brake control method disclosed in this publication, a coupling force sensor is used to measure the coupling force applied to the coupler by the trailer. However, since the coupling force sensor is extremely expensive, it has been relatively difficult to commercialize the aforementioned trailer brake control method.

Therefore, a method of calculating the coupling force without using such a coupling force sensor has been proposed in Japanese Patent Laid-Open No. Hei 6-323931. The coupling force calculation method disclosed in this publication defines the balance of the force in the vertical direction (hereinafter, also referred to as the vertical direction in the description of the present invention) and the force in the front-rear direction in the tractor. The coupling force is calculated from the balance between the vertical force and the longitudinal force. According to this coupling force calculation method, it is possible to know the coupling force at low cost without using an expensive coupling force sensor.

[0007]

However, in the trailer brake control method disclosed in the above two publications, the trailer brake force is set to be larger than the tractor brake force, so that the trailer is not used. It tends to be overbrake when it is a little. When the trailer is overbrake, there is a problem that the trailer may run over the tractor, that is, a so-called trailer swing phenomenon may easily occur.

In the coupling force calculation method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-323931, not only the data of the tractor is necessary for the calculation but also these data are detected values, It is a measured value or a constant.

However, the use frequency of the trailer is generally lower than the use frequency of the tractor, and the life of the trailer is long. For this reason, various types of trailers are connected to the tractor from the old model to the new model, and the combination of the tractor and the trailer is not constant. Further, the loading state of the trailer has various states from an empty state to a full state.
Therefore, the trailer under various conditions is connected to the tractor, and it is desirable that the coupling force calculation also takes into account the data of the trailer so that the brake control of the trailer can be performed more accurately.

Further, as described above, since the trailer under various conditions is connected to the tractor, the braking forces required for the tractor brake and the trailer brake are not constant, and the braking forces differ depending on the conditions of each trailer. In addition, when traveling on a slope, the braking force varies depending on the road gradient. As described above, it is desired that the tractor and the trailer can be more appropriately braked even when the conditions of the trailer and the road surface gradient are different.

On the other hand, when the vehicle is temporarily stopped on a slope, it is necessary to keep depressing the brake pedal and apply the side brake to keep the connected vehicle in the brake operating state. Therefore, there is a problem that the labor of the driver increases. Further, when starting on an uphill, it is necessary to start the connected vehicle by depressing the accelerator pedal of the tractor while releasing the side brake. For this reason, there is a problem that the starting operation is complicated, and it is difficult to start smoothly. In addition, since the starting operation is complicated, there is a problem that the engine speed is unnecessarily increased, the wear of the clutch is unnecessarily increased, and the fuel efficiency is deteriorated.

Incidentally, in order to know the data of the tractor and the trailer, it is necessary to provide various sensors and control devices on the tractor and the trailer. However, installing sensors and control devices on the trailer not only increases the cost, but also makes it extremely economically useless to install them on a trailer that is less frequently used than a tractor. It will be something without. Therefore, it is required that a trailer can be smoothly started on a slope without providing these sensors and control devices.

The present invention has been made in view of such circumstances, and an object of the present invention is to make it possible to easily and smoothly start a slope on a trailer without providing an expensive coupling force sensor or control device on a trailer. Tractors that can be
An object of the present invention is to provide a trailer slope start control device.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention of claim 1 is a brake control device for a tractor and a trailer connected to each other via a coupler, A tractor / trailer slope start control device that controls a tractor / trailer start using a brake control device that controls the operation of the trailer brake by air pressure output from a provided brake valve. An engine driving force transmission state determining means for determining whether or not an engine driving force of an engine mounted on the tractor is transmitted to a drive shaft of the tractor; and determining a change in a vehicle body speed calculated from the wheel speed. Vehicle speed change determining means for performing, road surface gradient calculating means for calculating a road surface gradient based on the change in vehicle speed, A tractor / trailer brake operation determining means for outputting a brake operation signal for operating each brake of the tractor and the trailer trailer when the vehicle is stopped while the surface gradient is equal to or higher than a predetermined value and the engine is driven; Trailer mass calculating means for calculating mass, coupled vehicle descending force computing means for calculating a descending force of a coupled vehicle that attempts to lower a tractor and a trailer based on the road surface gradient and the trailer mass, and a driving force of the engine And a tractor / trailer brake operation release determining means for outputting a brake operation release signal for releasing the operation of each brake of the tractor and the trailer trailer when the lowering force is larger than the descending force of the connected vehicle. .

According to a second aspect of the present invention, the engine driving force transmission state determining means determines transmission of the engine driving force to the drive shaft based on an engine speed and a wheel speed of a tractor. And

[0016]

In the hill start control device according to the first aspect of the present invention, whether or not the driving force of the engine is transmitted to the driving shaft of the driving wheels of the tractor is determined by the engine driving force transmission state determining means. Is determined. The vehicle speed is calculated from the wheel speed. And when the engine driving force is not transmitted to the drive shaft of the tractor,
When the vehicle speed changes in the decreasing direction, it is determined that the tractor and the trailer are traveling uphill, and the road surface gradient of the uphill is calculated. When the vehicle connected to the tractor / trailer temporarily stops while the engine is running on an uphill slope having a road surface gradient equal to or higher than a predetermined value, each brake is automatically applied to the tractor and the trailer, and each brake is activated. Is automatically retained.

Further, the mass of the trailer is calculated. The mass of the trailer is calculated, for example, from the engine speed, the governor angle, the engine driving force F _m estimated from the engine torque map, the vehicle acceleration calculated from the wheel speed, and the known mass of the tractor. Then, using the calculated road surface gradient and the trailer mass, a descending force for lowering the connected vehicle of the tractor / trailer was calculated, and the driving force of the engine became larger than the descending force of the connected vehicle. At this time, the tractor and trailer brakes are released. As a result, the tractor / trailer starts uphill. As described above, when the tractor / trailer stops on an uphill, the tractor and the trailer are automatically braked and held in the brake operating state, and when the vehicle starts moving, the tractor / trailer brake is automatically released. The tractor / trailer can start off smoothly.

In the present invention, the engine driving force transmission state determining means determines whether or not the engine driving force is transmitted to the drive shaft of the tractor based on the engine speed and the wheel speed of the tractor. I do. That is, when the engine driving force is transmitted to the tractor drive shaft, the engine speed and the wheel speed are correlated with each other, but when the engine driving force is not transmitted to the tractor drive shaft, the engine rotation Since the correlation between the number and the wheel speed disappears, the transmission state of the engine driving force to the drive shaft is determined.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a tractor according to the present invention.
It is an air brake circuit diagram on the tractor side of the tractor / trailer air brake system used in each example of the embodiment of the trailer speed control device.

As shown in FIG. 1, an air brake system 1 on the tractor side includes a brake pedal 2 for performing a brake operation and a dual control for supplying and discharging a brake operation instruction pressure for a service brake of a tractor / trailer. A brake valve 3, a main reservoir 4 for storing air at a predetermined pressure, and first to fourth sub reservoirs 5, 6, 7, connected to the main reservoir 4 and storing air from the main reservoir 5 at a predetermined pressure. 8, a compressor 9 for supplying air to the main reservoir 4, and another normal circuit when at least one of the circuits of the first to fourth sub reservoirs 5, 6, 7, 8 fails. And a protection valve 10 for protecting the air pressure of the vehicle and brakes applied to the left and right front wheels by supplying air from the first sub-reservoir 5, respectively. Left and right front wheel power chambers 11, 12 for generating a braking force for kicking the left and right front wheel power chambers 11, 12 by the brake actuation command pressure by the air of the first Saburizaba 5 from the brake valve 3
Front wheel relay valve 13 for controlling air supply and exhaust to and from
Anti-lock (hereinafter also referred to as ABS) modulators 14 and 15 for adjusting air pressures supplied to the left and right front wheel power chambers 11 and 12 to prevent locking of the left and right front wheels, respectively; Left and right rear wheel spring brake actuators 16 and 17 with spring brakes for generating a braking force for applying a brake to the left and right rear wheels by supplying air from the second sub-reservoir 6 to the left and right rear wheels, respectively. A rear-wheel relay valve 18 for controlling the supply and exhaust of air to and from the brake actuators 16 and 17, and a rear-wheel relay valve 18 without the brake valve 3
An electromagnetic proportional valve 19 for supplying a brake operation instruction pressure proportional to an input signal of the second sub-reservoir 6 by air, and a brake operation instruction pressure by the air of the second sub-reservoir 6 from the normal brake valve 3 to a rear wheel relay valve. 18 for controlling the operation of the first switching valve 20 for supplying the brake operation command pressure from the electromagnetic proportional valve 19 to the rear wheel relay valve 18 when necessary. A first electromagnetic switching valve 21 for controlling the supply of pilot pressure by air of the second sub-reservoir 6 to the first switching valve 20
And an ABS modulator 22, which adjusts the air pressure supplied to the left and right rear wheel spring brake actuators 16, 17 to prevent the left and right rear wheels from being locked.
23, and controls the tractor and trailer emergency brakes and parking brakes by controlling the spring brake actuator release command pressures for the spring brakes of the left and right rear wheel spring brakes 16 and 17 and manually controlling the trailer brakes. The right and left rear wheel spring brake actuators 16 and 1 are operated by a hand control valve 24 and a spring brake operation release instruction pressure from the hand control valve 24.
7, a spring brake relay valve 25 for controlling the supply and exhaust of air from the third sub-reservoir 7 to the spring brake of No. 7, and supply and control of air from the third sub-reservoir 7 to the trailer service line A to operate the trailer brake. The air is branched from an air passage 27 between the hand brake valve 26 and the hand brake valve 26 and the third sub reservoir 7, and supplies the air from the third sub reservoir 7 to the trailer service line A to operate the trailer brake. Air passage 28, a second electromagnetic proportional valve 29 disposed in the branch air passage 28 for supplying air pressure proportional to an input signal, and an air pressure output from the second electromagnetic proportional valve 29 when necessary. The second electromagnetic switching valve 30 that supplies the trailer service line A and the air from the hand brake valve 26 Check valve 31 that outputs the larger of the pressure and the air pressure from the second electromagnetic switching valve 30, and the output pressure from the brake valve 3 and the double check valve 31 for the service brake of the trailer. The air having the larger output pressure is selected and supplied to the trailer service line A, and the air from the hand control valve 24 is supplied to the trailer service line A for the parking brake of the trailer.
Supply air from sub reservoir 7 to trailer supply line B
To the passage 33 connecting the first outlet D1 of the brake valve 3 and the first designated pressure port C1 of the trailer control valve 32 to the front wheel relay valve 13 The second trailer control valve 32
A switching valve 34 and a first pressure pickup 35 for detecting the air pressure from the brake valve 3 to detect the brake operation
A second pressure pickup 36 for detecting an air pressure output from the second electromagnetic switching valve 30; a third pressure pickup 37 for detecting an air pressure output from the rear wheel relay valve 18; and first to third pressure pickups 35, 36, 37, front and rear left and right wheel ABS modulators 14, 15, 22, 23, 1st
An electronic control unit (hereinafter also referred to as ECU) 38 to which the first and second electromagnetic proportional valves 19 and 29 and the first and second electromagnetic switching valves 20 and 30 are connected, a tractor-side coupler 39 for the trailer service line A, And a tractor-side coupler 40 for a trailer supply line B.

The trailer control valve 32 selects the larger one of the command pressure of the first command port C1 and the command pressure of the second command port C2, and sets the pressure corresponding to the selected command pressure to the first command port. Output from exit D1.

The air brake system 1 of the tractor includes an ABS system for adjusting the brake pressure of the wheels so that the lock is released when the wheels are locked, and a brake for the drive wheels so that the idle wheels are released when the drive wheels idle. A traction control (hereinafter also referred to as a TRC system) is provided. Therefore, although not shown, a wheel speed sensor for detecting the wheel speed is provided on the wheel of the tractor.

FIG. 2 is an air brake circuit diagram on the trailer side of the tractor / trailer air brake system shown in FIG. As shown in FIG. 2, the trailer-side air brake system 41 includes a trailer reservoir 42 for storing air for a trailer service brake at a predetermined pressure, and air supplied from the trailer reservoir 42 to supply the left and right front wheels. The left and right front wheel power chambers 43 and 44, which generate braking force for applying the brake, and the left and right rear wheel generating brake force for applying the brake to the rear left and right wheels, respectively, by supplying air from the trailer reservoir 42. Trailer service line A from rear wheel power chambers 45 and 46, tractor side brake valve 3
Connected to the trailer relay valve 47 and the tractor-side coupler 39 for the trailer service line A for controlling the supply and exhaust of air to the left and right front and rear wheel power chambers 43, 44, 45 and 46 by the brake operation instruction pressure supplied through Trailer side coupler 4 for trailer service line A
8. Tractor-side coupler 4 for trailer supply line B
A trailer-side coupler 49 for the trailer supply line B connected to the trailer supply line B is provided.

In the tractor / trailer air brake system constructed as described above, when the trailer is connected to the tractor, the trailer-side coupler 48 of the trailer service line A is connected to the tractor-side coupler 39 of the trailer service line A. At the same time, the trailer-side coupler 49 of the trailer supply line B is connected to the tractor-side coupler 40 of the trailer supply line B. When the hand control valve 24 is set to the parking brake release position I, the spring brake operation release instruction pressure is supplied to the spring brake relay valve 25, and the air in the third sub reservoir 7 is released from the spring brake relay valve 25 and the double Check valve 50
Through each spring brake actuator 16,1
7 are supplied to the spring brake release chambers 16a and 17a. Thereby, the spring brake of the tractor is released, and the parking brake is released.

Further, since the trailer parking brake operation release instruction pressure from the hand control valve 24 is supplied to the trailer control valve 32, the trailer control valve 32 is operated by the power chambers 43, 44, 45, 46 for the right, left, front and rear wheels of the trailer. The air inside is exhausted and the parking brake of the trailer is released.

In this state, the tractor / trailer travels,
When the brake pedal 2 is depressed to apply the service brake during the traveling, the brake valve 3 is switched, and the first and second inlets S1 and S2 are connected to the corresponding first and second outlets D1 and D2, respectively. You. This allows
The air of the first sub-reservoir 5 has a first inlet S1 and a first outlet
It is supplied as a brake operation instruction pressure to an instruction pressure port C of the front and rear wheel relay valve 13 through D1. Therefore, the inlet S and the outlet D of the relay valve 13 communicate with each other, and the first sub-reservoir 5 which is supplied to the inlet S of the relay valve 13 is connected.
Is supplied to the left and right front wheel power chambers 11 and 12 through the outlet D and the ABS modulators 14 and 15, and the service brakes of the left and right front wheels of the tractor are applied, respectively.

The air in the second sub-reservoir 6 is output from the second outlet D2 of the brake valve 3. At this time, the air pressure from the second outlet D2 is detected by the first pressure pickup 35, and a brake operation detection signal is sent to the ECU 38. The ECU 38 performs brake control by CFC using a coupling force described later. That is,
The ECU 38 calculates the braking force required for the tractor based on the coupling force,
The first electromagnetic proportional valve 19 is controlled based on the calculation result. In this case, the coupling force corresponds to the axle load of the trailer. As a result, the first electromagnetic proportional valve 19 outputs an air pressure corresponding to the braking force calculated by controlling the air pressure of the second sub reservoir 6. Further E
The CU 38 switches the first electromagnetic switching valve 21 to the position II,
Thereby, the first switching valve 20 is switched. Therefore, the indication pressure port C of the relay valve 18 is connected to the output side of the first electromagnetic proportional valve, and the air of the air pressure output from the first electromagnetic proportional valve 19 is supplied to the indication pressure port C of the relay valve 18.
For this reason, the inlet S and the outlet D of the relay valve 18 communicate with each other, and the air of the second sub-reservoir 6 supplied to the inlet S of the relay valve 18 passes through the outlet D, the ABS modulators 22 and 23, and then flows right and left. Service brake chamber 16b, 1 of wheel spring brake actuator 16,17
7b, and the service brakes of the left and right rear wheels of the tractor are respectively applied. In this case, the left and right rear wheel spring brake actuators 16 and 17 brake the rear wheels of the tractor with a braking force corresponding to the coupling force.

When the first electromagnetic proportional valve 19, the first electromagnetic switching valve 21, or the first pressure pickup 35 fails, air from the second outlet D2 of the brake valve 3 passes through the switching valve 20 and relay valve. Since the pressure is supplied to the designated pressure port C of 18, the service brake of the rear wheel of the tractor can be reliably applied.

On the other hand, the ECU 38 calculates the braking force required for the trailer based on the coupling force, and controls the second proportional solenoid valve 29 based on the calculation result. In this case, the coupling force corresponds to the axle load of the trailer. As a result, the second electromagnetic proportional valve 29 outputs an air pressure according to the braking force calculated by controlling the air pressure of the third sub reservoir 7. Further, the ECU 38 switches the second solenoid-operated directional control valve 30 to the position II, and supplies the air of the air pressure output from the second solenoid-operated proportional valve 29 to
It is supplied to the second indication pressure port C2 of the trailer control valve 32 through the double check valve 31. At this time,
Since the air pressure supplied to the second instruction pressure port C2 of the trailer control valve 32 is introduced into the second switching valve 34, the second switching valve 34 is switched to the second position II and the first switching valve 34 is switched to the first position II. The indication pressure port C1 is communicated with the atmosphere.

Therefore, during normal brake operation, the air pressure at the second designated pressure port C2 becomes larger than that at the first designated pressure port C1, and the trailer control valve 32 sets the air pressure at the second designated pressure port C2, ie, Air having a pressure corresponding to the air pressure according to the axle load of the trailer controlled by the second electromagnetic proportional valve 29 is always supplied to the designated pressure port C of the trailer relay valve 45. As a result, the output pressure of the trailer relay valve 45 always becomes the air pressure according to the axle load of the trailer, and the air of this air pressure is supplied to each power chamber 4 of the trailer.
3, 44, 45, and 46, and the service brakes of the left, right, front, and rear wheels of the trailer are applied.

Therefore, during normal brake operation, the brake of the trailer always has an appropriate braking force according to the loaded weight. Even when the air pressure controlled by the second electromagnetic proportional valve 29 is smaller than the air pressure from the brake valve 3, the trailer control valve 32 generates air having a pressure corresponding to the air pressure controlled by the second electromagnetic proportional valve 29. Since the air is supplied to the trailer relay valve 45, the braking force of the trailer does not become excessively large unlike the conventional air brake system.

In this way, when the normal brake is applied,
The trailer does not under brake or over brake, and the occurrence of the jackknife phenomenon and the swing phenomenon is suppressed. Further, the ECU 38 turns on a stop lamp (not shown) in response to a brake operation signal from the first pressure pickup 35 to display a brake operation to notify a following vehicle.

When the brake pedal 2 is released to release the service brake, each of the outlets D1, D2 of the brake valve 3 is released.
Is shut off from each of the inlets S1 and S2 and connected to the exhaust port E, so that the indication pressure port C of the front wheel relay valve 13 on the tractor side is set.
Is exhausted from the exhaust port E of the brake valve 3. For this reason, the relay valve 13 is deactivated and its outlet D is cut off from the inlet S and connected to the exhaust port E, so that the air supplied to the power chambers 11 and 12 is discharged from the exhaust port E of the relay valve 13. Exhausted from
The service brake on the front wheel of the tractor is released. Also,
Air supplied to the command pressure port C of the rear wheel relay valve 18 on the tractor side is exhausted from the exhaust port E of the brake valve 3. As a result, the relay valve 18 is deactivated and its outlet D is cut off from the inlet S and connected to the exhaust port E, so that the spring brake actuators 16, 1 are connected.
7 is supplied to the exhaust port E of the relay valve 18.
And the service brake on the rear wheel of the tractor is released.

Further, since there is no brake operation signal from the first pressure pickup 35, the ECU 38 switches the second electromagnetic switching valve 30 to the original position I. As a result, the air supplied to the second instruction pressure port C2 of the trailer control valve 32 is exhausted into the atmosphere from the second electromagnetic switching valve 30, so that the air supplied to the trailer service line A is reduced to the trailer control valve. Air is exhausted from the 32 exhaust ports E. Therefore, the trailer relay valve 45
Is shut off from the inlet S and connected to the exhaust port E, so that air supplied to the power chambers 43, 44, 45, and 46 is exhausted from the exhaust port E of the trailer relay valve 47, and The service brake of each wheel is released.

When the ECU 38 detects a lock on the tractor wheel based on a wheel speed signal from a wheel speed sensor (not shown) provided on each wheel of the tractor, the ECU 38 modulates the ABS modulator of the locked wheel. 14,1
The air pressure of the power chambers 11 and 12 or the brake actuators 16 and 17 is adjusted so as to release the wheel lock by controlling 5, 22, and 23. Further, when the ECU 38 detects the idling of the drive wheels of the tractor based on the wheel speed signals from the wheel speed sensors of the drive wheels of the tractor, the ECU 38 operates the first electromagnetic proportional valve 19 and the first electromagnetic switching valve 21 to operate the brake actuator. Air pressure is supplied to the driving wheels 16 and 17, and the driving wheels are braked so that the idling of the driving wheels is eliminated.

In the tractor / trailer air brake system, as shown in FIG. 3, brake ratios Z ₁ , A ₁ , A ₂ , A ₃ , A ₄ of the tractor and trailer axes are used.
The trailer brake is controlled so that Z ₂ , Z ₃ and Z ₄ are the same. These brake ratios Z ₁ , Z ₂ , Z ₃ ,
Z ₄ is defined by those dividing braking force F ₁ of each wheel _{respectively, F 2, F 3, F} 4 with axle load _{W 1, W 2, W 3} , W 4. By making the brake ratios Z ₁ , Z ₂ , Z ₃ , and Z ₄ of each axis the same as described above, it is possible to maximize the adhesive utilization rate of the road surface and to apply the brake regardless of the loaded weight of the trailer. The effect is fixed.

Next, a specific example of a trailer brake control method in which the brake ratios Z ₁ , Z ₂ , Z ₃ , and Z _{4 of the} tractor and trailer axes are the same will be described.

First, as one example, the brake ratio Z ₁ of the tractor front axis A ₁ is set as the target brake ratio, and the brake ratio Z ₂ , Z of the tractor rear axis A ₂ and each of the axes A ₃ , A ₄ of the trailer are set. _3, Z ₄ controls the braking force and the braking force of the trailer of a tractor rear axle a ₂ to be the same as the target braking ratio. In that case, the load of the tractor front axle A ₁ as described above to be constant. The vertical component F _kz of the coupling force F _k is almost applied to the rear axis A ₂ ,
Since the front axle A ₁ load is almost the same as that at the time the tractor motorcycle, as well thus the load of the tractor front axle A ₁ constant, no particular trouble.

The ECU38 is to calculate the coupling force F _k and brake ratio Z will be described later,
These coupling force F _k and brake ratios Z, the brake ratio of the tractor rear axle A ₂ and each axis of the trailer _{A 3, A 4 Z 2,} Z 3, Z 4 is the target brake ratio tractor front axle A ₁ of the braking force of the brake ratio Z ₁ is the same as the above tractor rear axle a ₂ and calculates the braking force of the trailer. Then, the ECU 38 switches the electromagnetic switching valves 21 and 30 and controls the electromagnetic proportional valves 19 and 29 to control the rear shaft brake of the tractor and the brake of the trailer to the respective calculated braking forces. In this case, when the brake ratio of a certain axis is smaller than the target brake ratio, the brake pressure of that axis is increased to increase the braking force, and when the brake ratio is larger than the target brake ratio, Brake control is performed so that the brake pressure is reduced and the braking force is reduced. Thereby, the brake ratio of the axis is corrected so as to be the same as the target brake ratio.

As a second example, the brake ratios Z ₃ and Z ₄ of the semi-trailer are determined by the coupling force ratio F _kx
Use that can be assumed to be approximately equal to / F _kz . That is, in the second example, the coupling force ratio F _kx / F _kz and the brake ratio Z ₂ of the tractor rear shaft A ₂ are the same as the brake ratio Z ₁ of the tractor front shaft A ₁ which is the target brake ratio. braking force of the tractor rear axle a ₂ and controls the braking force of the trailer. In this case, the load of the tractor front axle A ₁ is constant. And
If the brake ratio is different from the target brake ratio,
The same brake control as in the above example is performed, and the brake ratio is corrected so as to be the same as the target brake ratio.

Further, as a third example, the trailer brake force is controlled so that the trailer brake ratios Z ₃ and Z ₄ have a predetermined value set as a target brake ratio. As the specified value, for example, the relationship between the brake pressure _Pm and the brake ratio Z shown in FIG. 9 is used. Also in this example, when the brake ratio is different from the target brake ratio, the correction is made to be the same as in the above-described respective examples.

Further, as a fourth example, the braking force of the trailer is controlled so that the trailer brake ratios Z ₃ and Z ₄ become the brake ratio Z ₁ of the front axis A ₁ of the tractor which is the target brake ratio. Also in this example, when the brake ratio is different from the target brake ratio, the correction is made to be the same as in the above-described respective examples.

Further, as a fifth example, the braking force of the trailer is controlled so that the coupling force ratio F _kx / F _kz becomes a specified value preset as a target brake ratio. As the specified value, for example, the relationship between the brake pressure _Pm and the brake ratio Z shown in FIG. 9 is used. Also in this example, when the brake ratio is different from the target brake ratio, the correction is made to be the same as in the above-described respective examples.

Further, as a sixth example, the brake force of the trailer is controlled such that the coupling force ratio F _kx / F _kz becomes the brake ratio Z ₁ of the front axis A ₁ of the tractor, which is the target brake ratio. Also in this example, when the brake ratio is different from the target brake ratio, the correction is made to be the same as in the above-described respective examples.

By the way, in order to perform the brake control method of the trailer by the CFC, it is necessary to obtain the coupling force F _k , the coupling force ratio F _kx / F _kz and the brake ratio Z. Ring force F _k , coupling force ratio F _kx
A method for determining / F _kz and the brake ratio Z will be described. In this case, as a prerequisite, (1) As shown in FIG. 1, an ABS / TRC is provided in the tractor brake system. Therefore, each wheel of the tractor is provided with a wheel speed sensor, and the vehicle acceleration is reduced. (2) The rear wheel of the tractor is supported by an air suspension, (3) The weight of the tractor alone, the axle load of the tractor, and various data on the dimensions of the tractor are known and constant. There are certain things to set.

First, the coupling force will be described. In the present invention, the coupling force is estimated using the data of the tractor and the trailer without using an expensive coupling force sensor.
The data required to estimate the coupling force are: (a) Data on the tractor: mass , (rear axle load), weight
Coupler position and the axle position on cardiac, (b) data relating to the trailer: mass, coupler position and the axle position relative to the center of gravity, a (c) (vehicle acceleration), of these data, underline data is a known and constant Yes, and the data in parentheses is measurable data. Therefore, it suffices to obtain the data relating to the trailer in (b). In this case, no sensor or control device for obtaining the trailer data is provided on the trailer, and the data of these trailers is also estimated.

Table 1 shows specific data for estimating the coupling force.

[0048]

[Table 1]

FIG. 4 is a diagram for explaining an example of a method for estimating the coupling force.

As shown in FIG. 4, first, the trailer mass M _a
Is estimated. Data required for calculating the trailer mass M _a, the engine driving force (engine torque) F _m, a vehicle acceleration a and the tractor mass M _z. Engine driving force F _m
Can be estimated from the engine speed, governor angle, and engine torque map. Further, the vehicle acceleration a can be obtained from a wheel speed signal from a wheel speed sensor. Then, ECU 8 calculates the equation _{F m = (M z + M} a) from × a trailer mass M _a. Thus, the trailer mass M _a can be estimated, this estimation of the trailer mass M _a is performed for each time of acceleration, is stored in the memory.

Next, the coupler position and the axle position with respect to the center of gravity of the trailer are estimated. Hereinafter, the trailer center of gravity in FIGS. 4 and 5 means the coupler position and the axle position with respect to the center of gravity of the trailer. 4 and 5, the tractor center of gravity position means the coupler position and the axle position with respect to the tractor center of gravity position.

The estimation of each of these positions is performed based on the balance equation of the force in the front-rear direction and the vertical direction and the balance equation of the force moment at the center of gravity.

Firstly, it estimates the coupler position X _ak and the axle position X _a relative longitudinal direction center of gravity of the trailer. Therefore, when the vehicle is stopped first, estimating the tractor rear axle load F ₂ by the air suspension pressures of the tractor. The trailer axle load F ₂ , the estimated trailer mass M _a , the known tractor mass M _z , the known coupler position X _k and the known axle position X ₁ with respect to the center of gravity of the tractor, Of the coupler position X _ak and the axle position X _a with respect to the center of gravity in the front-rear direction.

Next, estimate the coupler position Z _ak and the axle position Z _a relative vertical position of the center of gravity of the trailer. Therefore, when the first acceleration, with estimates the tractor rear axle load F ₂ by the air suspension pressures of the tractor, estimates the vehicle acceleration a by the wheel speed sensor. Then, this tractor rear axle load F _2, the trailer mass M _a and a mass M _z of known tractors, known coupler position Z _k and the known axle position relative to the center of gravity of the tractor Z ₁₂ described above estimated
If, from a vehicle acceleration a described above estimation, it estimates the coupler position Z _ak and the axle position Z _a relative position of the center of gravity of the vertical trailer. Estimation of the coupler position Z _ak and the axle position Z _a relative vertical position of the center of gravity of the trailer is carried out every time the vehicle acceleration, stored in the memory.

Next, to estimate the coupling force F _k of the front and rear direction and the vertical direction at the time of braking. Estimation of the coupling force F _k is so with the estimation result of each data described above is carried out from the balance equation of the moment of force at the balance equation and the center of gravity of the longitudinal and vertical forces. Specifically, the front-rear component F _kx and the vertical component F _kz of the coupling force are calculated using the following equations 1 and 2 (equation 25 described on page 10 of JP-A-6-323931). I do.

[0056]

(Equation 1)

[0057]

(Equation 2)

In this way, the coupling force F _k is estimated by the coupling force estimation method of this example.

FIG. 5 is a diagram for explaining an example of a method of calculating the brake ratio. As shown in FIG. 5, in the brake ratio calculating method of this example, first, a braking force of a tractor and a trailer is calculated at the time of braking. Braking force F _a of the tractor is estimated from the braking pressure detected by the third pressure pickup 37 and the braking force of the trailer braking force F _a of the tractor, vehicle deceleration a, which is estimated by the wheel speed sensors, tractor The mass M _z is calculated from the data of the trailer mass and the coupling force F _{k in} FIG. 4 calculated by an example of the coupling force calculation method.

Next, the front-axis braking force and the rear-axis braking force of the tractor are calculated based on the calculated tractor braking force, coupling force _Fk, and coupler position X _k , with respect to the tractor center of gravity position.
Z _k and the axle position X _1, X _2, respectively calculated from Z _12. The front shaft braking force and the rear shaft braking force of the tractor may be obtained by distributing them at a fixed ratio. Since the braking force distribution ratio of the tractor hardly changes, there is no problem even if the distribution ratio is fixed. Further, the front-axis braking force and the rear-axis braking force of the tractor can be obtained from each output pressure of the brake valve 3.

Next, the trailer shaft load is calculated from the trailer mass obtained in FIG. 4, the coupler position X _ak , Z _ak and the axle position X _a , Z _a with respect to the center of gravity of the trailer. Further, the tractor rear shaft load F _{2 is determined} by the air suspension pressure.
From the rear tractor rear shaft load F ₂ , the tractor mass M _z , the coupling force F _k , and the coupler positions X _k , Z _k and the axle positions X ₁ , X ₂ , Z _{12 with} respect to the tractor center of gravity position. calculates the axial load F _1. Since the vertical component F _kz of the coupling force F _k is almost applied to the rear shaft, the tractor front shaft load F ₁ may be a known constant.

Finally, the tractor braking force, the trailer braking force, the tractor front and rear axle braking forces, the trailer shaft load, and the tractor front and rear axle loads
The brake ratio of each axis of the tractor and trailer is calculated from the formula (braking force / axial load).

By the way, the tractor / trailer slope start control apparatus of the present invention uses a part of the tractor / trailer brake control by the CFC as described above, for example, after the tractor / tractor stops on the uphill, By automatically releasing the brakes of the tractor / trailer when the vehicle starts, the connected vehicles can smoothly start on a slope.

FIGS. 6 to 8 are diagrams showing an example of such a tractor / trailer slope start control device according to an embodiment of the present invention. As shown in FIG. 6, when the vehicle connected to the tractor and the trailer is stopped on an uphill road with a road surface gradient α, a force for descending the slope is applied to the connected vehicle. This force, slope direction component of the weight of the tractor weight (M _z · g) and the trailer (M _a · g), i.e. (M _a + M _z) ·
g · sinα. Therefore, the slope start control device according to the present embodiment is configured such that when a connected vehicle stopped on an uphill with a road surface gradient α starts, the driving force of the engine, which is a force that tries to make the connected vehicle go uphill, causes this downhill. Force to try (M _a +
M _z) · g · until greater than sin .alpha holds remains braked tractor and trailer, when the driving force exceeds the force _{(M a + M z) ·} g · sinα, the tractor and trailer Each brake is released.

As shown in FIG. 7, the hill start control device of this embodiment includes a vehicle speed calculating means 51 provided in the ECU 38 for calculating the vehicle speed, and a vehicle speed determining means 51 for judging whether or not the vehicle speed has changed. Speed reduction determining means 52, engine driving force transmission state determining means 53 for determining whether or not the engine driving force is transmitted to the drive shaft of the drive wheels of the tractor; road surface gradient calculating means 54 for calculating road surface gradient α; , a tractor-trailer brake actuation determining means 55 for determining whether or not operating the brakes of a tractor trailer, trailer mass calculation unit 56 for calculating the mass M _a trailer
If, releasing the operation means 57 of the force tending to lower the articulated vehicle of a tractor trailer in the uphill, the driving force calculating means 58 for calculating a driving force F _m of the engine, the operation of the brake of the tractor trailer And a tractor / trailer brake operation release determining means 59 for determining whether or not to perform the operation.

In the hill start control device of the present embodiment thus configured, hill start control is performed according to the flow shown in FIG. First, in step S1, the engine speed and the governor angle are detected by the engine speed detecting means 60 and the governor angle detecting means 61, respectively. Further, the wheel speed is detected, and the wheel speed is the wheel speed of the tractor detected by the wheel speed sensor 62 attached to the wheel of the tractor. Next, in step S2, it is determined whether the driving force of the engine is transmitted to the drive shaft of the tractor. This determination is made by the engine driving force transmission state determining means 53 based on the detected engine speed and wheel speed. That is, the engine speed and the wheel speed have a correlation with each other when the engine driving force is transmitted to the drive shaft, and have a correlation with each other when the engine driving force is not transmitted to the drive shaft. Since there is no engine speed, the engine driving force transmission state is determined based on the engine speed and the wheel speed. In addition, the clutch switch that detects the disengagement of the clutch and the neutral switch that detects the state of the mission,
It may be determined whether or not the engine driving force is transmitted to the drive shaft.

If it is determined in step S2 that the engine driving force is not transmitted to the drive shaft, step S3
, The vehicle speed is calculated by the vehicle speed calculating means 51 based on the wheel speed. Next, in step S4, it is determined whether the vehicle speed has decreased. The determination of the vehicle speed reduction is made by the vehicle speed reduction determining means 52. When the vehicle speed reduction determining means 52 determines that the vehicle speed has decreased, it detects that the connected vehicle is traveling uphill on an uphill. Next, in step S5, the road surface gradient α is calculated by the road surface gradient calculation means 54. The road surface slope calculating means 54 reduces the vehicle speed (ie, deceleration).
, The road surface gradient α is calculated by the following equation 3.

[0068]

(Equation 3)

Is obtained from

Next, in step S6, it is determined whether the calculated road surface gradient α is equal to or greater than a predetermined value. When it is determined that the road surface gradient α is equal to or greater than the predetermined value, it is determined in step S7 whether the engine is running. If it is determined that the engine is running, it is determined in step S8 whether the vehicle is stopped. These determinations in steps S6 to S8 are made by the tractor / trailer brake operation determining means 55. If it is determined that the vehicle is stopped, the tractor and trailer brakes are operated in step S9. These tractor and trailer brakes are respectively provided with first and second electromagnetic proportional valves 19 and 29, respectively.
And the first and second electromagnetic switching valves 21 and 30 are operated.

Next, the mass M _a trailer is calculated by the trailer mass calculation unit 56 in step S10. Trailer weight calculating unit 56 calculates the mass M _a trailer in the manner shown in Figure 4 above. Next, step S1
The calculation means 57 of the force tending to lower the articulated vehicle at 1, a force for lowering the vehicle combination (M _a +
M _z ) · g · sin α is calculated. Then, step S
Driving force F _m of the engine is calculated in 12. The engine driving force _Fm is calculated by the driving force calculating means 58 based on the engine speed and the governor angle using an engine torque map in the same manner as the method shown in FIG.

Next, in step S13, it is determined whether or not the engine driving force _Fm is greater than the force for lowering the connected vehicle. If it is determined that the engine driving force _Fm is not greater than the force for lowering the connected vehicle,
In step S14, the brakes of the tractor / trailer are maintained in the operating state by holding the first and second electromagnetic proportional valves 19, 29 and the first and second electromagnetic switching valves 21, 30 in the operating state, respectively. Return to start again. When it is determined in step 13 that the engine driving force _Fm is greater than the force for lowering the connected vehicle, the brakes of the tractor / trailer are released in step S15. The brakes of these tractors and trailers are released by deactivating the first and second electromagnetic proportional valves 19 and 29 and the first and second electromagnetic switching valves 21 and 30, respectively.

As described above, according to the tractor / trailer slope start control device of the present embodiment, when the connected vehicle is stopped while the engine is being driven on an uphill with a predetermined road surface gradient or more,
With both automatically brakes applied to the tractor and trailer, the engine driving force F _m is greater than the force which tends to lower the articulated vehicle and tractor and trailer brakes are released together automatically, uphill , The connected vehicle starts smoothly from the stopped state.

Further, since the vehicle body speed, the trailer mass M _a , the road surface gradient α and the force for lowering the connected vehicle are calculated and obtained, various sensors and controls for expensive coupling force sensors and trailers are used. A device is not required, and the slope start control device can be formed at lower cost.

[0075]

As is apparent from the above description, according to the tractor / trailer start control apparatus for a tractor / trailer according to the present invention, the connected vehicle stops while the engine is being driven on an uphill slope having a road surface gradient equal to or more than a predetermined value. Sometimes, both the tractor and the trailer are automatically braked, and when the engine driving force is greater than the force to lower the connected vehicle, both the tractor and the trailer brakes are automatically released. The connected vehicle can be started easily and smoothly on an uphill.

Further, since the starting operation is simplified, unnecessary increase of the engine speed can be prevented, so that wear of the clutch can be suppressed and fuel efficiency can be improved.

Further, since the vehicle speed, the mass of the trailer, the road surface gradient and the force for lowering the connected vehicle are calculated and obtained, various sensors and control devices are not required for expensive coupling force sensors and trailers. Thus, the slope start control device can be formed at lower cost.

[Brief description of the drawings]

FIG. 1 is an air brake circuit diagram on the tractor side of a tractor / trailer air brake system used in an example of an embodiment of a tractor / trailer brake slope start control device according to the present invention.

FIG. 2 is an air brake circuit diagram on the trailer side of the tractor / trailer air brake system shown in FIG.

FIG. 3 is a diagram illustrating a brake ratio and a coupling force in a tractor and a trailer.

FIG. 4 is a diagram illustrating an example of a coupling force estimation method.

FIG. 5 is a diagram illustrating an example of a brake ratio estimating method.

FIG. 6 is a diagram illustrating a descending force for lowering the connected vehicle when the connected vehicle is stopped on an uphill.

FIG. 7 is a diagram illustrating an example of a tractor / trailer slope start control device according to an embodiment of the present invention.

FIG. 8 is a diagram showing a flow used for slope start control in the example shown in FIG. 7;

FIG. 9 is a diagram showing a relationship between a brake pressure and a brake ratio.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1: air brake system on tractor side, 2: brake pedal, 3: dual brake valve, 11, 12: power chamber for left and right front wheels, 13: relay valve for front wheels,
14, 15 ... ABS modulator, 16, 17 ... left and right rear wheel spring brake actuator, 19 ... 1st proportional solenoid valve, 20 ... 1st switching valve, 21 ... 1st solenoid switching valve,
29: second electromagnetic proportional valve, 30: second electromagnetic switching valve, 34 ...
2nd switching valve, 35 ... 1st pressure pickup, 36 ... 2nd
Pressure pick-up, 37 ... third pressure pick-up, 38
... Electronic control unit (ECU), 39 ... Tractor-side coupler for trailer service line A, 40 ... Tractor-side coupler for trailer supply line B, 41 ... Trailer-side air brake system, 43,44 ... Left and right front wheel power chamber, 45, 46 ... power chamber for left and right rear wheels, 47
... Relay valve for trailer, 51 ... Vehicle speed calculation means,
52: body speed reduction determining means, 53: engine driving force transmission state determining means, 54: road surface gradient calculating means, 55: tractor / trailer brake operation determining means, 56: trailer mass calculating means, 57: lower the connected vehicle Calculating means of the force to be used, 58: driving force calculating means, 59: tractor
Trailer brake operation release determination means, 60: engine speed detection means, 61: governor angle detection means, 62: wheel speed sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Oe 1464-4, Moon Ring, Namerikawa-cho, Hiki-gun, Saitama Prefecture Inside JK Truck Truck Brake Systems Co., Ltd. (72) Takashi Kushiyama, Nameki-cho, Hiki-gun, Saitama Prefecture Wheel 1464-4 Jacques Truck Brake Systems Co., Ltd.

Claims (2)

[Claims] 1. A brake control device for a tractor and a trailer connected to each other via a coupler, wherein a brake of the trailer is operated and controlled by an air pressure output from a brake valve provided on the tractor. A tractor / trailer hill start control device that controls the tractor / trailer start on a hill using a brake control device that transmits the engine driving force of the engine mounted on the tractor to the tractor drive shaft Engine driving force transmission state determining means for determining whether or not the vehicle speed has been changed; vehicle body speed change determining means for determining a change in vehicle body speed calculated from the wheel speed; and calculating a road surface gradient based on the change in vehicle body speed. A road surface gradient calculating means, and a vehicle in which the road surface gradient is equal to or more than a predetermined value and the engine is driven. At the time of stop, tractor / trailer brake operation determining means for outputting a brake operation signal for operating each brake of the tractor and trailer / trailer, trailer mass calculating means for calculating the mass of the trailer, and the road surface gradient and the trailer mass. A coupled vehicle descending force calculating means for calculating a descending force of the coupled vehicle for lowering the tractor and the trailer based on the tractor and the trailer trailer when the driving force of the engine is greater than the descending force of the coupled vehicle. A tractor / trailer slope start control device, comprising: a tractor / trailer brake release cancellation determining means for outputting a brake release signal for releasing the operation of each brake. 2. The engine driving force transmission state judging means judges transmission of the engine driving force to the drive shaft based on an engine speed and a wheel speed of a tractor. Tractor / trailer slope start control device.