JPH10119739A - Tractor-trailer speed control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically brake a tailer so as to suppress the speed to the specified speed or less at the time of vehicle speed being increased in large degree during downward slope travel or constant speed travel without providing the trailer with an expensive coupling force sensor and a control device. SOLUTION: On the basis of engine speed and wheel speed detected on the tractor side (S1, S2), if engine driving force is judged to be in the state of not being transmitted to driving shafts of dirigible road wheels (S3) and body speed computed from wheel speed is judged to have changed (S5) it is so judged that a connected vehicle is traveling on a slope. When body speed changes in an increase direction, the connected vehicle is judged to be in downward slope travel, and a road surface gradient is computed from this change of body speed (S6). Using this road surface gradient, the upward thrust force increase portion of a trailer is computed (S8), and when the upward thrust force increase portion of the trailer is the specified value or more, a brake of the trailer is automatically actuated, an alarm is generated, and safety speed is displayed (S10).

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 speed control of a connected vehicle in which a tractor and a trailer are connected via a coupler, and more particularly to a method using a coupling force applied to the coupler by, for example, pushing up a trailer. The present invention relates to the technical field of a tractor / trailer speed control device using tractor / trailer brake control for performing coupling force control (hereinafter, also referred to as CFC) for controlling a 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 coupling force changes depending on the inclination of the road surface, and the coupling force also differs depending on the conditions of each trailer. Especially,
When traveling downhill, the coupling force increases due to the road surface gradient. If the coupling force increases greatly, not only will the traveling of the connected vehicle become unstable, but also the vehicle speed will increase. Therefore, it is desired to automatically apply a brake to the trailer to suppress the speed to a predetermined speed or less. .

Further, when the connected vehicle is traveling at a constant speed (auto cruise), for example, on a downhill, the vehicle speed may gradually increase, and the distance from the preceding vehicle may be reduced. In this case, the engine is usually decelerated by applying the engine brake to the drive wheel of the tractor's rear axle, but when the engine brake is applied to the tractor's rear axle, the side force of the tractor's rear axle decreases. As a result, the stability of the vehicle may be impaired. Therefore, even in such an auto cruise of a vehicle, it is desired that when the vehicle speed increases, the trailer is automatically braked to suppress the speed to a predetermined speed or less.

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 the trailer be automatically braked to suppress the speed to a predetermined speed or less and to issue an alarm in the case described above, without providing these sensors and control devices on the trailer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the vehicle speed during downhill running or constant speed running without providing an expensive coupling force sensor or control device on the trailer. The present invention is to provide a tractor / trailer speed control device capable of automatically applying a brake to a trailer when the vehicle speed greatly increases and suppressing the speed to a predetermined speed or less.

[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 speed control device that controls the speed of the tractor / trailer by controlling the operation of the trailer brake by air pressure output from a provided brake valve,
Engine driving force transmission state determining means for determining whether the driving force of the engine mounted on the tractor is transmitted to the drive shaft of the tractor, and vehicle body speed for determining a change in the vehicle speed calculated from the wheel speed Change determining means, a road slope calculating means for calculating a road slope based on the change in the vehicle body speed, a trailer mass calculating means for calculating the mass of the trailer, and a trailer for a tractor based on the road slope and the trailer mass. A trailer pushing force increasing amount calculating means for calculating the pushing force increasing amount, and a trailer brake actuation determining means for actuating the trailer brake when the trailer pushing force increasing amount is equal to or more than a predetermined value set in advance. It is characterized by having.

According to a second aspect of 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. The feature is to judge.

Further, the invention according to claim 3 further comprises an alarm means which is activated when the amount of increase of the trailing force of the trailer is equal to or more than the predetermined value, and issues an alarm. Tractor / trailer speed controller.

Further, the invention according to claim 4 further comprises a safety speed display means for displaying a preset safety speed when an increase in the pushing force of the trailer is equal to or more than the predetermined value. And

Further, the invention of claim 5 is a brake control device for a tractor and a trailer, which are connected to each other via a coupler, wherein the brake control device is configured to control the air pressure output from a brake valve provided on the tractor. A tractor / trailer speed controller that controls the speed of the tractor / trailer by controlling the operation of the trailer brake determines whether the tractor / trailer is traveling at a predetermined target vehicle speed at a constant speed. Automatic cruise determining means, a vehicle speed calculating means for calculating a vehicle speed from the wheel speed of the tractor, and a brake of the trailer is operated when the vehicle speed calculated by the vehicle speed calculating means is higher than the target vehicle speed. And a trailer brake operation determining means.

Further, the invention according to claim 6 further comprises a driving force calculating means for calculating a driving force of the engine, and an automatic operation for canceling the constant speed running based on the target vehicle speed when the calculated driving force increases. And a cruise canceling means.

[0020]

In the speed control device according to the first aspect of the present invention, it is determined whether or not the engine driving force is transmitted to the drive shaft of the tractor. The vehicle speed is calculated from the wheel speed. When the vehicle speed changes in the increasing direction in a state where the engine driving force is not transmitted to the drive shaft of the tractor, the tractor and the trailer are assumed to be traveling downhill and the road surface gradient of the downhill is calculated. Is done. 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.

Using the calculated road gradient and the mass of the trailer, an increase in the thrust force of the trailer is calculated. When the increase in the thrust force of the trailer exceeds a predetermined value, the trailer is automatically braked. Is applied. This suppresses a gradual increase in the speed of the tractor / trailer during downhill traveling of the tractor / trailer in a state where the engine driving force is not transmitted to the drive shafts of the drive wheels. In this way, the tractor / trailer speed can be automatically prevented from increasing and becoming unstable,
The trailer can run at a safe speed.

Further, in the speed control device according to the second aspect of the present invention, it is determined 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. That is, when the engine driving force is transmitted to the drive shaft of the tractor, the engine speed and the wheel speed are correlated with each other, but when the engine driving force is not transmitted to the drive shaft of the tractor, the engine rotation speed is reduced. Since the number and the wheel speed lose this correlation,
A state where the engine driving force is not transmitted to the drive shaft of the tractor is detected.

Further, in the speed control device according to the third aspect of the present invention, an alarm is issued when the increase in the pushing force of the trailer exceeds a predetermined value. By this warning, the driver can know that the speed of the tractor / trailer may increase due to the increase in the pushing force of the trailer exceeding a predetermined value.

Further, in the speed control device according to the fourth aspect of the present invention, the safety speed stored in advance is displayed when the increase in the pushing force of the trailer exceeds a predetermined value. As the safe speed, an empirical value or the like generally obtained from past experience based on, for example, a trailer mass, a road surface gradient, or the like is used.

Further, in the speed control device according to the present invention, when the tractor / trailer is running at a predetermined target vehicle speed under constant speed driving control, the vehicle speed calculated based on the wheel speed is obtained. When is greater than the target vehicle speed, the trailer is automatically braked.
This suppresses an increase in the speed of the tractor / trailer while the tractor / trailer is traveling at a constant speed. Thus, it is possible to automatically suppress the speed of the tractor / trailer from increasing and becoming unstable, and it is possible to drive the tractor / trailer at a safe speed. In particular, when the vehicle is traveling at a constant speed on a long downhill, the speed of the tractor / trailer is gradually increased without the driver's knowledge to prevent the vehicle from approaching the preceding vehicle too much, and the vehicle stability of the tractor / trailer is reduced. Will be secured.

Further, in the speed control device according to the present invention, when the calculated driving force of the engine increases during the constant speed running control of the tractor / trailer at the target vehicle speed, the constant speed running control is automatically performed. It will be released.

[0027]

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, a tractor-side air brake system 1 includes a brake pedal 2 for performing a brake operation and a dual brake for controlling the supply and discharge of 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 4 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; and a third pressure pickup 37 for detecting an air pressure output from the rear wheel relay valve 18.
Alarm means 51 (shown in FIG. 3) for notifying the abnormality of the tractor / trailer brake by voice display or visual display, and safe speed display means 52 (shown in FIG. 3) for displaying the safe speed when traveling downhill by visual display. Illustrated), first to third pressure pickups 35, 36, and 37, and front and rear left and right wheels AB
S modulators 14, 15, 22, 23, first and second electromagnetic proportional valves 19, 29, first and second electromagnetic switching valves 2
0, 30, alarm means 51, and safe speed display means 52
Are connected, a tractor-side coupler 39 for the trailer service line A, and a tractor-side coupler 40 for the 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 that adjusts the brake pressure of the wheels so that the lock is released when the wheels are locked, and a brake applied to the drive wheels such 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 thus configured, when the trailer is connected to the tractor, the tractor-side coupler 39 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 command 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 left, right, 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 runs,
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 electromagnetic proportional 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 of the second command pressure port C2 becomes higher than that of the first command pressure port C1, and the trailer control valve 32 sets the air pressure of the second command 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, when the normal brake is operated, 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 and 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 actuator 16,
The air supplied to 17 is the exhaust port of relay valve 18
Exhaust from E 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 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, the brake ratio Z ₁ , A ₁ , A ₂ , A ₃ , A ₄ of the tractor and trailer axes
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 brake control method for a trailer 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 axis 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 have coupling force ratios 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 brake force of the trailer is controlled such 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. 6 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 brake force of the trailer is controlled such 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 such 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. 6 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 so 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 such a trailer brake control method by 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 axle position with respect to the center; (b) data on the trailer: mass, coupler position and axle position with respect to the center of gravity, and (c) (vehicle acceleration), of which the underlined data is 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.

[0057]

[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 to estimate the trailer mass M _a. Data required for calculating the trailer mass M _a, the engine driving force (engine torque)
F _m , vehicle acceleration a and tractor mass M _z . Engine drive force F _m is the engine speed, it can be estimated from the 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, the ECU 8 calculates the formula F _m = (M _z + M _a )
× calculates the mass M _a trailer from a. This allows
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 moment of force at the center of gravity. First, to estimate 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.

[0063]

(Equation 1)

[0064]

(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 brake sensor (e.g., the third pick-up 37, etc.) is estimated from the brake pressure detected by the braking force of the trailer braking force F _a of the tractor, the vehicle is estimated by the wheel speed sensor deceleration a, calculated from the tractor mass M _z, trailer mass and the coupling force F _k of the data of Figure 4 calculated in an example of the coupling force calculating 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 F _k, and coupler position X _k ,
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 mass of the trailer 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 are:
The brake ratio of each axis of the tractor and trailer is calculated from the formula (braking force / axial load).

The tractor / trailer speed control apparatus of the present invention uses a part of the tractor / trailer brake control by the CFC as described above to greatly increase the vehicle speed, for example, when traveling downhill or during auto cruise. In this case, the trailer is automatically braked to suppress an increase in speed, thereby ensuring vehicle stability of the connected vehicle.

FIGS. 7 to 9 show a first embodiment of the tractor / trailer speed control apparatus according to the present invention. When connecting a vehicle of the tractor and the trailer is traveling on a downhill road gradient alpha as shown in FIG. 7, the coupling force F _k is to vary the road surface gradient alpha. In that case, the front and rear component F _kx clogging trailer thrust up force of the coupling force F _k is increased by the vehicle longitudinal direction component M _a · g · sinα weight M _a · g of the trailer. Increase in M _a · g · s of the push-up force of the trailer
inα causes the speed of the connected vehicle to gradually increase when going downhill. Therefore, the speed control device of the present embodiment suppresses an increase in the speed of the connected vehicle when going downhill.

As shown in FIG. 8, the speed control device of this embodiment includes a vehicle speed calculating means 53 provided in the ECU 38 for calculating the vehicle speed, a vehicle speed calculating means 53 for judging whether or not the vehicle speed has changed. Change determining means 54, engine driving force transmission state determining means 55 for determining whether the driving force of the engine is transmitted to the drive shaft of the drive wheels of the tractor, road surface gradient calculating means 56 for calculating road surface gradient α, , the trailer mass calculation means 57 for calculating the mass M _a of the trailer, the push-up force increment arithmetic unit 58 of the trailer for calculating a push-up force increment trailer increased by road gradient alpha,
The vehicle is provided with a trailer brake operation determining means 59 for determining whether to operate a trailer brake, an alarm means 51, and a safe speed display means 52.

In the speed control device of the present embodiment thus configured, speed control is performed according to the flow shown in FIG. First, in step S1, the engine speed is detected. This engine speed is detected by the engine speed detecting means 60. Next, the wheel speed is detected in step S2. This wheel speed is the wheel speed of the tractor detected by the wheel speed sensor 61 attached to the wheel of the tractor. Next, in step S3, it is determined whether the engine driving force is transmitted. This determination is made by the engine driving force transmission state determining means 55 based on, for example, the engine speed and the wheel speed. That is, there is a correlation between the engine speed and the wheel speed when the engine driving force is transmitted to the drive shaft of the drive wheel, and the engine drive force is transmitted to the drive shaft of the drive wheel. Since there is no correlation with each other when the state is not performed, the state in which the engine driving force is not transmitted to the drive shaft of the drive wheel is determined based on the engine speed and the wheel speed. The determination as to whether or not the engine driving force is transmitted to the drive shaft of the drive wheels is based on the correlation between the engine speed and the wheel speed, as well as the signal of the neutral switch for detecting the transmission neutral state or the clutch connection state. It can be performed based on a signal of the clutch switch to be detected.

If it is determined in step S3 that the engine driving force has not been transmitted to the driving shaft of the driving wheels, the vehicle speed is calculated by the vehicle speed calculating means 53 based on the wheel speed in step S4. Next, step S5
It is determined whether or not the vehicle speed has changed. This change in the vehicle speed is performed by the vehicle speed change determining means 54. When the vehicle speed change determining means 54 determines that the vehicle speed has changed, it detects that the vehicle is traveling on a slope. That is, the vehicle speed change determining means 54 determines that the connected vehicle is traveling downhill if the vehicle speed increases, and determines that the connected vehicle is traveling uphill if the vehicle speed decreases. Then
In step S6, the road surface gradient α is calculated by the road surface gradient calculation 56. The road surface gradient calculation 56 calculates the road surface gradient α by the following equation 3 based on a change in vehicle body speed (acceleration or deceleration).

[0075]

(Equation 3)

Is obtained from

Next, the mass M _a trailer is calculated by the trailer mass calculation unit 54 in step S7. The trailer mass calculation unit 54 calculates the mass M _a trailer in the manner shown in Figure 4 above. Then, step S
The push-up force increment arithmetic unit 58 of the trailer in 8, with the trailer of the push-up force increment M _a · g · sinα is calculated by the trailer brake actuation determining means 59 at step S9, M _a · The push-up force increment It is determined whether g · sin α is equal to or greater than a predetermined value. Trailer brake operation determining means 5
If the push-up force is determined to be greater than or equal to the predetermined value, the speed is determined to greatly increase, and the second electromagnetic proportional valve 29 and the second electromagnetic switching valve 30 are operated in step S10 to brake the trailer. . Simultaneously, the alarm means 51 is operated to notify the driver, and the safe speed display means 52 displays the safe speed of the connected vehicle on the slope having the road surface gradient α. This safe speed is an empirical value generally obtained from experience based on the trailer mass M _a , the road surface gradient α, and the like, and is input to the ECU 38 in advance.

When it is determined in step S3 that the engine driving force has been transmitted to the drive shaft of the drive wheels, when it is determined in step S5 that the vehicle body speed has not changed, and in step S9, the trailer thrust force is determined. When it is determined that the increment is not more than the predetermined value, the process returns to the start.

In this way, when the connected vehicle travels downhill and the engine driving force is not transmitted to the drive shaft of the drive wheels, the brake is applied to the trailer if the increase in the thrust force of the trailer exceeds a predetermined value. The automatic application suppresses an increase in the speed of the connected vehicle.

According to the speed control device of the first example, when the connected vehicle is traveling on a downhill, the thrust from the trailer is increased by the road surface gradient α, and the vehicle speed of the connected vehicle is increased. Stabilization can be automatically suppressed, and the connected vehicle can run at a safe speed.

Further, since the vehicle body speed, the trailer mass M _a , the road surface gradient α and the trailer thrusting force are calculated and obtained, various sensors and control devices are not required for expensive coupling force sensors and trailers. The control device can be formed at lower cost.

FIGS. 10 and 11 are diagrams showing a second embodiment of the tractor / trailer speed controller according to the present invention. The speed control device of the second example performs constant-speed traveling control at a target speed set by a connected vehicle of a tractor and a trailer, that is, when traveling by auto-cruise,
By making a decision to brake the trailer based on the target vehicle speed set by the driver, if the vehicle speed of the connected vehicle is higher than the target vehicle speed, the brake is applied to the trailer and the vehicle speed of the connected vehicle is reduced. The vehicle speed is controlled to reach the target vehicle speed.

As shown in FIG. 10, the speed control device of this embodiment includes a vehicle speed calculation means 5 provided in the ECU 38.
3, a trailer brake operation determining means 59, an auto cruise determining means 62 for determining whether or not auto cruise is set, a driving force calculating means 63 for calculating the driving force of the engine, and an increase in the driving force of the engine. There is provided a driving force determining means 64 for determining whether or not the driving has been performed, and an automatic cruise releasing means 65 for releasing the automatic cruise.

In the speed control device of the second example configured as described above, speed control is performed according to the flow shown in FIG. First, in step S11, the auto cruise determining means 62 determines whether or not auto cruise is set. If it is determined that the auto cruise is in the set state, the engine speed and the governor angle are detected by the engine speed detecting means 60 and the governor angle detecting means (not shown) in step S12, and the engine torque map is selected. Is done.
Further, the wheel speed is detected by a wheel speed sensor 61.
Next, in step S13, the engine driving force and the actual vehicle speed are calculated. The engine driving force is calculated by the engine driving force calculating means 63 based on the engine speed, the governor angle and the engine torque map in the same manner as described above by the method shown in FIG. The vehicle speed is also calculated by the vehicle speed calculating means 53 on the basis of the wheel speed in the same manner as described above.

Next, in step S14, it is determined whether the actual vehicle speed is higher than the target vehicle speed set by the driver. This judgment is made by the trailer brake operating means 5
9, the trailer brake operating means 59
When it is determined that the actual vehicle speed is higher than the target vehicle speed, it is determined that the constant speed running at the set target speed has not been performed, and the second electromagnetic proportional valve 29 and the second electromagnetic switching valve 30 are operated in step S15. And brake the trailer. As a result, the connected vehicle is decelerated, the vehicle speed approaches the target vehicle speed, and auto cruise is performed according to the target vehicle speed. In this case, the brake pressure of the brake applied to the trailer is controlled by the second proportional solenoid valve 29 in accordance with the speed difference between the actual vehicle speed and the target speed. Incidentally, the brake pressure can be controlled depending on the road surface gradient α or trailer mass M _a.

Next, in step S16, it is determined whether the engine driving force has increased. This judgment is made by the driving force increase judging means 64, and when the driving force increase judging means 64 judges that the driving force does not increase, the auto cruise canceling means 65 holds the auto cruise,
Return to start. Therefore, at this time, the constant speed traveling is maintained as it is. When it is determined in step S16 that the engine driving force has increased, the auto cruise canceling unit 65 determines that the vehicle speed-up operation has been performed, cancels the auto cruise, and then returns to the start. Therefore, at this time, the constant speed traveling is canceled and the speed increasing traveling is performed.

Further, when it is determined in step S11 that the vehicle is not in the auto cruise setting state, and when it is determined in step S14 that the actual vehicle speed is not higher than the target vehicle speed, the process directly returns to the start.

According to the speed control device of the second example, it is possible to surely prevent the connected vehicle from naturally approaching the preceding vehicle when the connected vehicle is traveling downhill by auto cruise on a long downhill. At the same time, vehicle stability can be ensured by suppressing an excessive increase in the vehicle body speed.

Further, since the vehicle body speed and the engine driving force are respectively calculated and obtained, various sensors and control devices are not required for expensive coupling force sensors and trailers as in the first example, and the speed control is performed. The device can be formed at a lower cost.

[0090]

As is apparent from the above description, according to the tractor / trailer speed control device of the first to fourth aspects of the present invention, the tractor / trailer travels downhill and the engine driving force drives the drive shaft of the drive wheels. If the increase in the trailer's push-up force exceeds a predetermined value when the vehicle is traveling without being transmitted to the vehicle, the brake is automatically applied to the trailer, preventing the tractor / trailer speed from increasing. it can. This makes it possible to automatically suppress the instability of the tractor / trailer due to an increase in the thrust force from the trailer due to the road gradient and the increase in the vehicle speed of the tractor / trailer when descending a hill. It can be run at various speeds.

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

In particular, according to the third aspect of the present invention, a warning is issued when the amount of increase in the pushing force of the trailer is equal to or greater than a predetermined value, so that the driver can surely know. According to the fourth aspect, the safe speed in this case is displayed, so that the driver can know the safe speed in this case. Therefore, the driver can more appropriately cope with an increase in the trailing force of the trailer that is equal to or more than the predetermined value.

Further, according to the speed control device of the fifth and sixth aspects of the present invention, if the speed of the tractor / trailer exceeds the target vehicle speed during the constant speed traveling control, the brake is automatically applied to the trailer. Therefore, it is possible to suppress an increase in the speed of the tractor / trailer while the tractor / trailer is traveling at a constant speed. As a result, the tractor / trailer can be automatically prevented from becoming unstable, and the tractor / trailer can run at a safe speed. Especially,
When traveling at a constant speed on a long downhill or the like, the speed of the tractor / trailer gradually increases without the driver's knowledge and it is possible to prevent the vehicle from approaching the preceding vehicle too much, and to secure the vehicle stability of the tractor / trailer.

In particular, according to the invention of claim 6, when the calculated driving force of the engine increases while the tractor / trailer is traveling at a constant speed at the target vehicle speed, the constant speed traveling control is automatically released. become able to.

[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 embodiments of a tractor / trailer brake abnormality alarm device and a brake 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 showing a relationship between a brake pressure and a brake ratio.

FIG. 7 is a diagram illustrating an increase in the pushing force of the trailer when the connected vehicle is traveling on a downhill.

FIG. 8 is a diagram illustrating a first example of an embodiment of a tractor / trailer speed control device according to the present invention.

9 is a diagram showing a flow used for the speed control of the first example shown in FIG.

FIG. 10 is a diagram illustrating a second example of the embodiment of the present invention.

11 is a diagram showing a flow used for the speed control of the second example shown in FIG.

[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, alarm means, 52 ... safe speed display means, 53 ... vehicle speed calculation means, 54 ... vehicle speed change determination means, 55 ... mission neutral state determination means, 56 ... road surface gradient calculation means, 57 ... trailer mass Calculation means, 58 ... calculation means for increasing the trailing force of the trailer, 5
9: trailer brake operation determining means, 60: engine speed detecting means, 61: wheel speed sensor, 62: auto cruise determining means, 63: driving force calculating means, 64: driving force increase determining means, 65: auto cruise canceling means

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

Claims (6)

[Claims] 1. A brake control device for a tractor and a trailer connected to each other via a coupler, wherein the brake of the trailer is operated and controlled by an air pressure output from a brake valve provided on the tractor. In the tractor / trailer speed control device that controls the speed of the tractor / trailer, the engine drive power transmission state that determines whether the drive power of the engine mounted on the tractor is transmitted to the drive shaft of the tractor Determining means, vehicle body speed change determining means for determining a change in vehicle body speed calculated from the wheel speed, road surface gradient calculating means for calculating road surface gradient based on the change in vehicle body speed, and calculating mass of the trailer Trailer mass calculating means, and a trailer for a tractor based on the road surface gradient and the trailer mass. A trailer pushing force increase calculating means for calculating the trailer pushing force increase, and a trailer brake operation determining means for actuating the trailer brake when the trailer pushing force increase is equal to or greater than a predetermined value. Equipped tractor / trailer speed control device. 2. The engine driving force transmission state determining means determines whether 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. The tractor according to claim 1
Trailer speed control. 3. The tractor / trailer speed according to claim 2, further comprising an alarm unit that is activated to generate an alarm when an increase in the pushing force of the trailer is equal to or greater than the predetermined value. Control device. 4. The vehicle according to claim 1, further comprising safety speed display means for displaying a preset safety speed when the amount of increase in the pushing force of said trailer is equal to or greater than said predetermined value. A tractor / trailer speed control device according to any one of the preceding claims. 5. A brake control device for a tractor and a trailer connected to each other via a coupler, wherein the brake control of the trailer is controlled by an air pressure output from a brake valve provided on the tractor. In the tractor / trailer speed control device that controls the speed of the tractor / trailer, an auto cruise determining unit that determines whether the tractor / trailer is traveling at a constant speed at a preset target vehicle speed, A vehicle speed calculating means for calculating a vehicle speed from the wheel speed of the tractor; and a trailer brake operation determining means for operating a trailer brake when the vehicle speed calculated by the vehicle speed calculating device is higher than the target vehicle speed. Tractor characterized by having
Trailer speed control. 6. A driving force calculating means for calculating a driving force of an engine, further comprising: when the calculated driving force increases,
6. The tractor / trailer speed control device according to claim 5, further comprising: an automatic cruise canceling unit that cancels the constant speed running at the target vehicle speed.