JPH10236299A - Braking control device for tractor-trailer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cheap braking control device that can properly control each braking operation of a tractor.trailer according to the changes in trailer conditions. SOLUTION: The brake ratio calculated by a brake ratio memory changing means 69 is memorized in a memory as a target brake ratio, and the braking force of each wheel of a tractor.trailer is controlled so that the brake ratio of each wheel of the tractor.trailer becomes same as the target brake ratio memorized. The brake ratio memorized is held until the number of times of braking operation becomes a specified number of times and is renewed to the brake ratio calculated when the number of times of braking operation becomes a specified number of times. When a trailer mass change judging means 60 detects changes exceeding a specified value in the mass of the trailer, even if the number of times of braking operation is smaller than a specified number of times after the brake ratio is memorized in the memory, the brake ratio memorized is renewed to the brake ratio calculated when trailer mass changes.

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 brake 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 pushing up a trailer or the like. In a tractor / trailer brake control that performs a coupling force control (hereinafter also referred to as CFC) for controlling a brake pressure, a tractor / trailer brake control device for preventing a tractor / trailer jackknife phenomenon and a trailer swing phenomenon. It concerns the technical field.

[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 depending on the conditions of the trailer, the braking force of the trailer may be insufficient. Or excessive. If the braking force of the trailer becomes excessive, the trailer swing phenomenon is likely to occur, and if the braking force of the trailer is insufficient, the jackknife phenomenon tends to occur, and the running of the tractor / trailer becomes unstable. For this reason, it is desirable to control the tractor and trailer brakes as appropriately as possible.

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, there is a demand for more appropriately controlling the tractor and trailer brakes without providing these sensors and control devices on the trailer.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide each brake of a tractor / trailer according to a change in the condition of the trailer without providing various sensors and control devices on the trailer. It is an object of the present invention to provide an inexpensive tractor / trailer brake control device that can be controlled more appropriately.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is a brake control apparatus for controlling respective brakes of a tractor and a trailer connected to each other via a coupler. Controlling the operation of the trailer brake by air pressure output from a brake valve provided on the tractor, and calculating at least the coupling force applied to the tractor by the trailer via the coupler to control the wheel. A tractor / trailer brake control device that performs a brake control so that a brake ratio defined by dividing the power by the axle load of the axle of the wheel becomes a target brake ratio stored in a memory. After the ratio is stored in the memory as the target brake ratio, the number of braking operations is The target brake ratio stored in the memory is held until the predetermined predetermined number of times is reached, and when the number of times of the brake operation reaches the predetermined number of times, the target brake ratio of the memory is calculated by the brake calculated at this time. A target brake ratio changing means for updating to a ratio is provided.

Further, the invention according to claim 2 further comprises a trailer change judging which detects and outputs that the condition of the trailer connected to the tractor has changed significantly as compared with the condition of the trailer connected so far. Means,
When output from the trailer change determining means, the target brake ratio in the memory is updated to the brake ratio calculated when output from the trailer change determining means.

Further, the invention of claim 3 is characterized in that the trailer change judging means is a trailer mass change judging means which outputs when the mass of the trailer changes by a predetermined value or more.

Further, the invention according to a fourth aspect is characterized in that at least a trailer mass calculating means for calculating the mass of the trailer from the data of the tractor is provided.

Further, the invention of claim 5 is characterized in that the trailer change judging means is a trailer center of gravity position change judging means that outputs when the center of gravity of the trailer changes by a predetermined value or more.

Further, the invention according to claim 6 is characterized in that at least a trailer center-of-gravity position calculating means for calculating the trailer center-of-gravity position from the data of the tractor is provided.

Further, the invention of claim 7 is characterized in that it comprises a coupling force calculating means for calculating the coupling force from the data of the tractor.

[0020]

In the tractor / trailer brake control apparatus according to the first aspect of the present invention, the braking force of the wheel calculated first by the target brake ratio changing means is applied to the axle load of the axle of the wheel. Is stored in the memory as a target brake ratio, and the brake ratio of each wheel of the tractor / trailer is set so that the brake ratio of each wheel of the tractor / trailer becomes the stored target brake ratio. The force is controlled. Then, the target brake ratio changing means, once storing the calculated brake ratio in the memory, thereafter, holds the target brake ratio stored in the memory until the number of times of the brake operation reaches a predetermined number of times. Thus, when the number of times of the brake operation reaches the predetermined number without updating again, the target brake ratio in the memory is updated to the brake ratio calculated at this time. Therefore, the influence of the calculation error of the brake ratio due to the measurement error or the calculation error of each value at the time of the brake control by the CFC is eliminated, and the brake control by the more appropriate CFC is performed.

According to the second aspect of the present invention, when the condition of the trailer connected to the tractor greatly changes as compared with the condition of the previously connected trailer, the change in the trailer is determined by the trailer change determining means. Is detected. That is, for example, when there is a change in the type of the trailer connected to the tractor, or a change in the empty vehicle status of the trailer or the loading status of the loaded vehicle, the change in the status of these trailers is detected by the trailer change determination means. . Then, when there is a change in the condition of these trailers, after the previous brake ratio is stored in the memory, even if the number of braking operations is less than the predetermined number, the target brake ratio in the memory is changed to the condition of this trailer. Is immediately updated to the calculated brake ratio when the value changes. Therefore, each braking force of the tractor / trailer has an appropriate value according to a change in the condition of the trailer, and the fear of the jackknife phenomenon and the fear of the trailer swing phenomenon can be eliminated. In this way, even when the condition of the trailer changes greatly, the brake control of the tractor / trailer can be performed more appropriately.

In this case, according to the third aspect of the present invention, the change in the condition of the trailer is determined by detecting the change in the mass of the trailer by the trailer mass change determining means. When the change in the center of gravity of the trailer is detected by the change in the center of gravity of the trailer, the change in the condition of the trailer can be determined. As a change in the condition of the trailer, a change in the mass of the trailer or a change in the position of the center of gravity of the trailer appears remarkably, and the change in the mass of the trailer or the change in the position of the center of gravity of the trailer greatly affects the brake control of the tractor / trailer. By using the change in the mass of the trailer or the change in the position of the center of gravity of the trailer to determine the change in the condition of the trailer, the brake control of the tractor / trailer can be performed more appropriately.

Further, in the invention of claim 4, the mass of the trailer is calculated from the data of the tractor, and in the invention of claim 6, the position of the center of gravity of the trailer is calculated from the data of the tractor, and in the invention of claim 7, , The coupling force is calculated from the tractor data.
This eliminates the need to provide sensors and control devices necessary for brake control on trailers that are used less frequently than tractors, which reduces costs and is extremely economical. You will be able to meet your needs.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a tractor according to the present invention.
FIG. 2 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 brake 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 brake for controlling 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
A first electromagnetic proportional valve 19 for supplying a brake operation instruction pressure proportional to an input signal of the second sub reservoir 6 by air;
Normally, the brake operation instruction pressure by the air of the second sub reservoir 6 from the brake valve 3 is applied to the rear wheel relay valve 1.
A first switching valve 20 which is set to a position I for supplying to the rear wheel relay valve 18 and which is set to a position I for supplying the brake operation command pressure from the first electromagnetic proportional valve 19 to the rear wheel relay valve 18 when necessary. Is normally set to the closed position I, and is set to the position II at which the pilot pressure by the air of the second sub-reservoir 6 is supplied to the first switching valve 20 to control the operation of the first switching valve 20 when necessary. A first electromagnetic switching valve 21 and ABS modulators 22 and 23 for adjusting the air pressure supplied to the left and right rear wheel spring brake actuators 16 and 17 to prevent the left and right rear wheels from being locked, respectively.
The manual supply of the spring brake operation release instruction pressure to the left and right rear wheel spring brake actuators 16 and 17 of the tractor, and the trailer left and right front wheel power chambers 43 and 44 and the left and right rear wheel power chamber 45 described later. , 46, a parking brake releasing position for supplying a parking brake release instruction pressure for each parking brake, and a parking brake for discharging a brake release release pressure for each spring brake of the tractor and each parking brake of the trailer. An operating position II is set, and a position III for setting the tractor to release a spring brake release command pressure for each spring brake and supplying a trailer parking brake release command pressure for each parking brake is set. B The air from the third sub-reservoir 7 to the spring brakes of the left and right rear wheel spring brake actuators 16 and 17 is controlled by the hand control valve 24 for controlling the operation of the parking brake and the parking brake. A spring brake relay valve 25 for controlling the supply and discharge, and a hand brake valve 2 for controlling the supply of air from the third sub reservoir 7 to the trailer service line A to operate the trailer brake.
6, the hand brake valve 26 and the third sub reservoir 7
And a branch air passage 28 for supplying air from the third sub-reservoir 7 to the trailer service line A to operate the trailer brake, and to the branch air passage 28. A second electromagnetic proportional valve 29 for supplying an air pressure proportional to the input signal, and a position I which is normally shut off from the second electromagnetic proportional valve 29 and output from the second electromagnetic proportional valve 29 when necessary. A second solenoid-operated directional control valve 30 set at a position II for supplying air pressure to the trailer service line A, and a larger one of the air pressure from the hand brake valve 26 and the air pressure from the second electromagnetic directional control valve 30 Output double check valve 31
Of 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, the air from the hand control valve 24 is supplied to the trailer service line A for the parking brake of the trailer, and the air from the third sub reservoir 7 is further supplied. A trailer control valve 32 for supplying air to the trailer supply line B, and a front wheel relay of the passage 33 in a passage 33 connecting a first outlet D1 of the brake valve 3 and a first indication pressure port C1 of the trailer control valve 32. The trailer control valve 32 is located on the trailer control valve 32 side from the branch point to the valve 13.
The second switching valve 34 is set at a position I that communicates with the valve, and is set at a position II that shuts off the passage 33 when necessary, and a first pressure pickup 35 that detects air pressure from the brake valve 3 to detect a 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 the air pressure output from the rear wheel relay valve 18, first to third pressure pickups 35, 36, 37, ABS modulators 14, 15, 22, 23 for the front, rear, left and right wheels; The first and second solenoid proportional valves 19,
29, an electronic control unit (hereinafter also referred to as ECU) 38 to which the first and second electromagnetic switching valves 20 and 30 are respectively connected, a tractor-side coupler 39 for a trailer service line A, and a tractor for a trailer supply line B And a side coupler 40.

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

The tractor air brake system 1 includes an ABS system that adjusts the brake pressure of the wheels so that the wheels are unlocked when the wheels are locked, and a brake applied to the drive wheels so that the idles are canceled 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 configured 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.

Also, the trailer parking brake operation release command pressure from the hand control valve 24 is supplied to the third command pressure port C3 of the trailer control valve 32. The air in 43, 44, 45, and 46 is discharged, 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 the first electromagnetic proportional valve 1
9 is connected to the output side, and the air of the air pressure output from the first electromagnetic proportional valve 19 is supplied to the designated 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 16 for wheel spring brake actuators 16 and 17
b, 17b, 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 passes through the 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.

For this reason, at the time of normal brake operation, the air pressure of the second designated pressure port C2 becomes larger than that of the first designated pressure port C1, and the trailer control valve 32 sets the air pressure of 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.

As described above, 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) disposed 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.

[0041] In the air brake system of the tractor trailer in this example, the axes A ₁ of the tractor and the trailer, as shown in FIG. 3, A _2, A _3, brake ratio in _{A 4 Z 1, Z 2,} Z 3, as Z ₄ are the same, and controls the braking of the trailer. 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.

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 trailer axes A ₃ , A ₄ 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 first and second electromagnetic switching valves 21 and 30 and controls the first and second electromagnetic proportional valves 19 and 29,
The rear axle brake and the trailer brake of the tractor are controlled so as to have the calculated respective 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. 11 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 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 brake 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. 11 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 the trailer brake control method using 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. It is possible to measure the wheel speed for calculating the speed, (2) the rear wheel of the tractor is supported by an air suspension,
(3) The data of the weight of the tractor alone, the axle load of the tractor, and the data of each dimension of the tractor are known and constant,
Are set respectively. Note that the ABS / TRC does not necessarily need to be provided in the tractor, but only needs to be provided with a wheel speed sensor for measuring the wheel speed of each wheel of the tractor.

First, the coupling force Fk will be described. In the present invention, the coupling force Fk 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 Fk 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; The data is known and constant, 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.

[0053]

[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. The trailer center of gravity in FIGS. 4, 7, 9, and 10 hereinafter means the coupler position and the axle position with respect to the center of gravity of the trailer. In FIGS. 4 to 7 and 9, the term "center of gravity of the tractor" means the position of the coupler and the axle relative to the position of the center of gravity of the tractor.

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

[0058] 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). .

[0061]

(Equation 1)

[0062]

(Equation 2)

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

FIG. 5 is a diagram for explaining another example of the coupling force estimation method. As shown in FIG. 5, in the coupling force estimation method of this example, first, a coupling force ratio F _kx / F _kz is calculated.

The data necessary for calculating the coupling force ratio F _kx / F _kz includes the braking force F _a , the vehicle acceleration a, the tractor mass M _z , and the coupler position X _k with respect to the tractor center of gravity position,
Z _k and the axle position _{X 1, X 2, Z 12} , and a tractor rear axle load F _2. The braking force _Fa is the third pressure pickup 37
Can be estimated from the brake pressure sensor detected by The vehicle acceleration a can be obtained from the wheel speed sensor in the same manner as described above. Furthermore, the tractor rear axle load F ₂ can be estimated from in the same way as described above the air suspension pressure. Other data are known quantities. Then, the ECU 8 calculates the coupling force ratio F _kx / using the following Expression 3 (Expression 23 described on page 9 of JP-A-6-323931).
Calculate F _kz .

[0066]

(Equation 3)

On the other hand, by subtracting the rear axle load of the tractor alone (when the semitrailer is not connected) from the tractor rear axle load F ₂ , the vertical component F _{kz of the} coupling force F _k is _obtained.
Is calculated. The calculation of the vertical component F _kz of the coupling force F _k is based on the tractor mass M _z , the coupler position X _k , Z _k and the axle position X ₁ , X ₂ , Z with respect to the tractor center of gravity position.
It can also be calculated from ₁₂ .

[0068] Then, the vertical component of the coupling force F _k by the vertical component F _kz last coupling force ratio was calculated F _kx / F _kz coupling force F _k F
Calculate _kx . Thus, the coupling force F _k is estimated by the coupling force estimation method of this example.

FIG. 6 is a diagram for explaining still another example of the coupling force estimation method. As shown in FIG.
In the coupling force estimation method of this example, first, a coupling force ratio F _kx / F _kz is calculated. In that case, in the example of the coupling force estimating method of FIG. 5 described above, although including data tractor rear axle load F _2, not included in the tractor rear axle load F ₂ in the example of this coupling force estimating method , Braking force F _a , vehicle acceleration a, tractor mass M _z , coupler position X _k , Z _k and axle position X ₁ , X ₂ , Z _{12 with} respect to the tractor center of gravity position,
(Equation 21 described on page 9 of JP-A-6-323931) using the coupling force ratio F _kx / F
Calculate _kz .

[0070]

(Equation 4)

Thereafter, the vertical component F _kz and the vertical component F _kx of the coupling force F _k are calculated in the same manner as in the above-described example of the coupling force estimation method shown in FIG. Thus, the coupling force F _k in the coupling force estimation method of this example is estimated.

FIG. 7 is a diagram for explaining an example of a method of calculating the brake ratio. As shown in FIG. 7, the brake ratio calculation method of this example first calculates the braking force of the tractor and the trailer during braking. The braking force F _a tractor calculated from similarly brake pressure in the case shown in FIGS. 5 and 6, the braking force of the trailer, the braking force F _a of this tractor,
The vehicle deceleration a estimated by the wheel speed sensor, the tractor mass M _z , the trailer mass and the coupling force F of FIG. 4 calculated by an example of the coupling force calculation method.
Calculated from _k data.

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

FIG. 8 is a diagram for explaining another example of the method of calculating the brake ratio. As shown in FIG. 8, the braking force of the tractor is calculated from the brake pressure during braking. In this case, the braking force of the tractor is distributed to the front shaft and the rear shaft in the same manner as in the above-described example shown in FIG. 7 to calculate the front shaft braking force and the rear shaft braking force of the tractor. Moreover, to calculate the tractor rear axle load F ₂ from the air suspension pressure. Further, in the case of this embodiment has a tractor front axle load F ₁ and known constant. Then, the brake ratios Z ₁ , Z ₂ of the front and rear shafts of the tractor are respectively determined by the front shaft braking force and the rear shaft braking force of these tractors, the tractor rear shaft load F ₂ , and the tractor front shaft load F _1. calculate.

On the other hand, in the brake ratio calculation method of this example, the coupling force ratio F _kx shown in FIG. 5 or FIG.
/ F _kz is the trailer brake ratio Z ₃ , Z ₄ . In this manner, the tractor and the tractor brake ratios Z ₁ , Z ₂ , Z ₃ ,
Z ₄ is required.

FIG. 9 is a view for explaining still another example of a method of calculating the brake ratio. As shown in FIG. 9, in the brake ratio calculation method of this example, in the brake ratio calculation method of the example shown in FIG. 7, the trailer mass M _a , the coupling force F _k , and the coupler position X _ak , with respect to the trailer center of gravity position. Instead of Z _ak and axle position X _a , Z _a , the coupler position X _ak , Z _ak and axle position X _a , Z _{a with} respect to the trailer mass M _a , the coupling force F _k , and the center of gravity of the trailer determined in FIG. Is used to calculate the trailer braking force, the trailer shaft load, and the tractor front shaft load. The other configuration of the brake ratio calculation method of this example is the same as the brake ratio calculation method of the example shown in FIG. Thus, the tractor and the brake ratio of the tractor are obtained by the brake ratio calculation method of this example.

FIG. 10 is a diagram for explaining still another example of a method of calculating the brake ratio. As shown in FIG. 10, in the brake ratio calculating method of this example, the trailer braking force calculated by the brake ratio calculating method of the example shown in FIG. 7 and the trailer calculated by the brake ratio calculating method of the example shown in FIG. Only the brake ratio of the trailer is calculated based on the shaft load.

By the way, the tractor / trailer brake control device of the present invention is intended to more surely prevent the tractor / trailer jackknife phenomenon and the trailer swing phenomenon in the tractor / trailer brake control by the CFC as described above. The following brake control is performed.

FIG. 12 is a diagram showing an example of a tractor / trailer brake control device according to an embodiment of the present invention.
As shown in FIG. 12, the tractor / trailer brake control device of this example includes an air suspension pressure detecting means 51 for detecting a pressure of an air suspension interposed between a rear shaft of the tractor and a chassis of the tractor; Wheel speed sensor 52 for detecting wheel speed, engine speed detecting means 53 for detecting engine speed, governor angle detecting means 54 for detecting governor angle of the engine (accelerator opening detection for detecting accelerator opening) Means
When, after the tractor to calculate with and a first pressure pickup 35 described above, further provided in the ECU 38, the axial load F ₂ after the tractor based on air suspension pressure from the air suspension pressure detecting means 51 Shaft load calculating means 55, vehicle acceleration / deceleration calculating means 56 for calculating the acceleration / deceleration of the connected vehicle based on the wheel speed from wheel speed sensor 52, and engine speed and governor angle detecting means from engine speed detecting means 53 a driving force calculating means 57 for calculating an engine driving force F _m on the basis of the governor angle from 54, it is determined whether the brake operation is performed based on the output pressure of the brake valve 3 from the first pressure pickup 35 Brake valve pressure determining means 58 and vehicle acceleration a from vehicle acceleration / deceleration calculating means 56 and driving force calculating means 57 The trailer mass calculation means 59 for calculating a trailer mass M _a on the basis of the engine driving force F _m,
Trailer mass calculation means and the trailer mass change determination means 60 for determining whether the trailer mass M _a is changed on the basis of the trailer mass M _a from 59, the tractor rear axle load F ₂ from tractor rear axle load calculating means 55 and trailer gravity position calculating means 61 for calculating a trailer barycentric position based on trailer mass M _a from the trailer mass calculation means 59
A tractor front shaft load calculating means 62 for calculating a tractor front shaft load based on a previously input tractor known weight and a tractor rear shaft load from the tractor rear shaft load calculating means 55; The tractor rear shaft load calculating means 5
Tractor rear axle load F ₂ from 5, the coupling on the basis of the trailer center of gravity of the vehicle acceleration a, the trailer mass M _a and trailer center-of-gravity position calculating means 61 from the trailer mass calculation unit 59 from the vehicle acceleration calculating means 56 coupling force calculating means 6 for calculating the force F _k
3 and the trailer mass M from the trailer mass calculating means 59
_a and a trailer shaft load calculating means 64 for calculating a trailer shaft load based on the trailer center of gravity position from the trailer center of gravity position calculating means 61 and a vehicle deceleration from the vehicle acceleration / deceleration calculating means 56 and a trailer from the trailer mass calculating means 59. mass M _a and trailer braking force calculating means 65 and the tractor braking force calculating means 66 respectively calculates the respective braking force of the trailer and the tractor on the basis of the coupling force F _k from the coupling force calculating means 63, the coupling force calculation coupling force F _k and from the means 63, calculates each respective braking force of the tractor front axle and rear axle on the basis of the trailer and the braking force of the tractor from the trailer braking force calculating means 65 and the tractor braking force calculating means 66 Tractor front and rear axle control A power calculating means 67, and the trailer shaft load from the tractor after the axial load F _2, the tractor front axle load F ₁ from the tractor front axle load calculating means 62, the trailer shaft load calculating means 64 from the tractor rear axle load calculating means 55 , brake ratio based on the trailer and the braking force of the tractor from the trailer braking force calculating means 65 and the tractor braking force calculating means 66 Z _1, Z _2,
The brake ratio calculating means 68 for calculating Z ₃ , Z ₄ , and the brake ratios Z ₁ , Z ₂ ,
Z ₃ and Z ₄ are stored in a memory (not shown) in the ECU 38 and once stored, the brake ratios Z ₁ , Z ₂ , Z ₃ ,
Holding the Z _4, based on the judgment result of the trailer mass M _a from the trailer mass change determination unit 60 is changed, the brake ratio Z ₁ that are stored in memory, Z _2, Z
_3, a Z _4, and a brake ratio memory changing means 69 for storing changes in the memory on the trailer mass M new brake ratio is calculated based on _{a Z 1, Z 2, Z} 3, Z 4 was changed I have.

In the brake control device of the present embodiment thus configured, the brake ratios Z ₁ , Z ₂ , Z ₃ , Z ₄ are calculated at the time of the brake operation during the brake control by the CFC, and the brake ratio memory changing means 69 Stores the calculated brake ratios Z ₁ , Z ₂ , Z ₃ , Z ₄ in the memory as target brake ratios for brake control by CFC. In this case, in order to minimize the influence of the calculation error of the brake ratio due to the measurement error or calculation error of each value, the brake ratio memory changing means 69 sets the brake ratios Z ₁ , Z ₂ , Z ₃ , Z ₄ in the memory. To the new brake ratios Z ₁ , Z ₂ , Z ₃ , calculated for each calculation of the brake ratio.
Z ₄ to without updating each time, to hold the brake ratio stored previously in the memory. Then, the brake ratio memory changing means 69 sets the brake ratio in the memory as a new target brake ratio to the brake ratios Z ₁ , Z ₂ , Z ₃ , Z ₄ calculated at the time of the brake operation after a predetermined number of brake operations. I try to update.

However, unless the target brake ratio in the memory is updated unless the brake operation is performed a predetermined number of times, for example, the type of trailer connected to the tractor changes, or the loading status of a trailer such as a loaded vehicle or an empty vehicle. There also vary greatly mass M _a of the trailer or to change, brake control by the CFC based on the target brake ratio stored previously in the memory will be performed.
For this reason, for example, despite the fact that the mass Ma of the trailer has changed from _a small value to a large value, the mass M of the trailer previously stored in the memory as the target brake ratio
_The brake ratios Z ₁ , Z ₂ ,
If brake control of the tractor / trailer is performed based on Z ₃ and Z ₄ , the braking force of the trailer will be insufficient, and the jackknife phenomenon will tend to occur. Conversely, when the mass Ma of the trailer changes from _a large value to a small value, the braking force of the trailer becomes excessive, and the trailer swing phenomenon tends to occur. Thus, when the mass M _a trailer greatly changes, the brake control of the tractor-trailer is not necessarily being properly performed.

Therefore, the brake control device of this embodiment further stores the brake ratios Z ₁ , Z ₂ , Z ₃ , and Z ₄ in the memory, and then stores the mass of the trailer while the brake operation is not performed a predetermined number of times. when M _a is changed greatly, the braking ratio memory changing means 69, a new target braking the calculated braking ratio when the target brake ratio in the memory, the mass M _a trailer is determined to have changed significantly I try to update it as a ratio. This allows
Brake control device in this example, even when the mass M _a trailer greatly changes, the mass M of the changed trailer
_The brake control is performed by the target brake ratio that responds quickly to _a to avoid the jackknife phenomenon and trailer swing development.

More specifically, this brake control is performed, for example, according to the flow shown in FIG. That is, first, in step S1, the engine speed and the governor angle (or the accelerator opening) are detected by the engine speed detecting means 53 and the governor angle detecting means 54, respectively. The wheel speed is detected by a wheel speed sensor 52, and the wheel speed is the speed of the drive wheels of the tractor. Further, the air suspension pressure is detected by the air suspension pressure detecting means 51. Next, in step S2, the driving force calculating means 57
Engine drive force F _m, based the engine speed and the governor angle (or accelerator opening) to be calculated from the engine torque map which is prepared in advance of the engine mounted on the tractor. Next, in step S3, the vehicle acceleration a is calculated by the vehicle acceleration / deceleration calculating means 56 when the vehicle is accelerating, and in step S4, based on the engine driving force _Fm , the vehicle acceleration a and the known tractor mass _Mz . trailer mass M _a is calculated by the trailer mass calculation unit 59.

[0086] Next, calculation of the current trailer mass M _a in step S5 whether the first time or not after starting the engine is determined. When the calculation of the trailer mass M _a is determined to be the first time, after being stored at step S6 in the memory in the example ECU 38, the shaft after the tractor shaft load F ₂ is after the tractor based on air suspension pressure in step S7 It is calculated by the load calculating means 55. When the calculation of the trailer mass M _a is determined not to be the first time in step S5, the trailer mass M _a that is calculated this time is no longer a memory, the process proceeds to directly to step S7.

[0087] Next, the trailer center of gravity position calculating means 61, based on trailer mass Ma and known tractor mass M _z and the center of gravity of a known tractor and tractor rear axle load M ₂ each time the vehicle is stopped at step S8 The center of gravity of the trailer in the front-rear direction is calculated in step S9.
Vertical position of the center of gravity of the trailer is calculated based on each time of acceleration of the vehicle in the front-rear direction position of the center of gravity of the vehicle acceleration a and the trailer mass Ma and tractor rear axle load M ₂ and the trailer in. Next, in step S10, the output pressure of the brake valve 3 is detected by the first pressure pickup 35, and in step S11, the brake operation is performed by the brake valve pressure determination means 58 based on the output pressure of the brake valve 3. Is determined. The determination as to whether or not the brake operation has been performed is not limited to the detection by the first pressure pickup 35, and it goes without saying that other means such as a pedal switch for detecting depression of the brake pedal 2 may be used. When it is determined that the brake operation is not performed, the mass of the trailer stored in the memory is updated to the current mass of the trailer in step S24, the process proceeds to step S1, and the processes after step S1 are repeated again.

When it is determined that the brake operation has been performed,
In step S12, the vehicle acceleration / deceleration calculating means 56 calculates the vehicle deceleration based on the wheel speed from the wheel speed sensor 52. Next, in step 13, the trailer mass M _{a is} calculated by the coupling force calculating means 63.
And the center of gravity of the trailer in the vertical direction and the rear axle load on the tractor F ₂
And the coupling force F _k based on
Is calculated. Then, the trailer braking force calculating means 65 and the tractor braking force calculating unit 66 in step 14, based on the tractor mass M _z and the trailer mass M _a and the vehicle deceleration and the coupling force F _k, the trailer braking force and the tractor The braking force is calculated respectively. Further, in step S15, the tractor front shaft / rear shaft braking force calculating means 67 calculates the front and rear shafts of the tractor based on the known center of gravity of the tractor, the coupling force _Fk , the trailer braking force, and the tractor braking force. Each braking force is calculated individually, and at step S1
The trailer axis load calculating means 64 at 6, the trailer axle weight is calculated on the basis of the center of gravity of the trailer mass M _a and trailer. Further, in step 17, the tractor front shaft load calculating means 62 calculates the tractor mass _MZ.
Tractor front axle load F ₁ is calculated on the basis of the tractor center-of-gravity position and the tractor rear axle F ₂ and the coupling force F _k and. Then, in step 18, the brake ratio Z ₁ , Z ₂ , Z ₃ , Z ₄ of each axis of the trailer / tractor is calculated by the brake ratio calculating means 68 by the tractor front shaft load F ₁ , the tractor rear shaft load F ₂ and the trailer axial load and trailer and the braking force of the tractor and on the basis of the respective braking force of the front axle and rear axle of the tractor, the brake ratio Z ₁ of each axis of the trailer tractor, Z _2, Z _3, calculates Z ₄ each Is done.

Next, in step 19, it is determined whether or not the brake ratio is stored in the memory. If it is determined that the brake ratio is stored, in step S20, the current brake operation is performed and the previous brake ratio is stored in the memory. After being stored, it is determined whether or not the operation has been performed after a predetermined number of times. When this brake operation is determined to not have been performed after a predetermined number of times, the trailer mass change determining means 60 at step S21, the trailer mass M _a stored in this trailer mass M _a memory It is determined whether the difference is equal to or greater than a predetermined value. If the difference between both the trailer mass M _a is determined to be equal to or greater than the predetermined value, the brake ratio memory changing means 6 in step S22
After canceling the brake ratio stored in the memory by step 9, the brake ratio calculated this time is newly stored in the memory as the target brake ratio in step S23, and the process returns to step 1.

If it is determined in step S19 that the brake ratio is not stored in the memory, the process proceeds to step S23, and the brake ratio calculated this time is stored in the memory as the target brake ratio.
After the trailer mass stored in the memory is updated to the current trailer mass in step S24, the process proceeds to step S1.
Return to If it is determined in step S20 that the current brake operation has been performed after a predetermined number of times, the process proceeds to step S22 to cancel the blurring in the memory. Then, the brake ratio calculated in step S23 is calculated. The target brake ratio is stored in the memory, and the trailer mass stored in the memory is updated to the current trailer mass in step S24, and the process returns to step S1. Further, when the difference between the trailer mass M _a in step S21 in step S21 is determined to be equal to or greater than the predetermined value, the flow returns to step S1 after updating the trailer mass which is stored in the memory in step S24 in this trailer mass .

According to the brake control device of this example, the brake ratio in the memory is determined by the brake ratios Z ₁ , Z calculated at the time of the braking operation after the predetermined number of braking operations.
_{Since 2} , Z ₃ and Z ₄ are updated as new target brake ratios, there is no need to update the brake ratio in the memory each time the brake ratio is calculated. Therefore, the influence of the calculation error of the brake ratio due to the measurement error or the calculation error of each value at the time of the brake control by the CFC can be reliably eliminated, and the more appropriate C
Brake control by FC can be performed.

[0092] Moreover, after storage in the memory of the previous brake ratio, even when the brake operating cycle is less than a predetermined number of times, when changed significantly mass M _a of the trailer, the type of trailer to be connected to for example a tractor as an unusual, as the loading condition of the trailer of a have the product wheel and empty car or the like is changed immediately so as to update the braking ratio calculated when the braking ratio of the memory mass M _a trailer greatly changes since it is, when changes to a large value from the mass M _a smaller value of the trailer (for example, when changed from unladen to the product wheel, etc.), the brake ratio calculated based on the large trailer mass M _a immediate target brake Set as ratio. Therefore, the braking force of the trailer becomes a sufficiently appropriate value, and the possibility of the jackknife phenomenon can be eliminated. Conversely, when the mass Ma of the trailer changes from _a large value to a small value (for example, when changing from a loaded vehicle to an empty vehicle).
The brake ratio calculated based on a small trailer mass M _a is immediately set as the target brake ratio. Therefore, the braking force of the trailer becomes a small appropriate value, and the possibility of the trailer swing phenomenon can be eliminated. Thus, when the mass M _a trailer changes greater, it is possible to perform the brake control of the tractor-trailer to more properly.

FIG. 14 is a view showing another embodiment of the tractor / trailer brake control device according to the embodiment of the present invention. FIG. 15 shows the tractor / trailer brake control performed by the tractor / trailer control device of this embodiment. It is a figure showing a flow. In addition, the same components as those of the brake control device of the above-described example are denoted by the same reference numerals, and the same processes as those of the control flow of the above-described example are denoted by the same step numbers, so that their details are described. Detailed description is omitted.

In the above-described example, by detecting a large change in the mass Ma of the trailer, _a change in the type of the trailer connected to the tractor or a change in the loading state of the trailer is determined, and the number of times of the brake operation reaches the predetermined number. Although the target brake ratio is updated even when it is not present, the brake control device in this example detects a large change in the position of the center of gravity of the trailer, and changes the type of trailer connected to the tractor or changes in the loading condition of the trailer. And the target brake ratio is updated even when the number of times of the brake operation is less than the predetermined number.

That is, as shown in FIG. 14, the brake control device of the present embodiment is provided with a trailer center-of-gravity position change determining means 70 instead of the trailer mass change determining means 60 of the above-described example. Further, in the flow of the brake control of the brake control device of this example, the processes of steps S5, S6, and S21 of the above-described example are omitted, and these steps S5, S6, and S21 are replaced with each other as shown in FIG. Are respectively set in steps S25, S26, S27 and S28 just by changing the mass of the trailer to the position of the center of gravity of the trailer. In this case, the processes in steps S25 and S26 are set between the processes in steps S9 and S10, and the process in step S27 is set between the processes in steps S20 and S22. S2
8 is set at the end. Other configurations and operational effects of the brake control device of the present example are the same as those of the above-described example.

The present invention is not limited to the above-described FIG. 12 and FIG.
Of the brake control device shown in FIG. 4 and FIGS.
It goes without saying that various design changes are possible without being limited to the flow of the brake control shown in FIG.

[0097]

As is apparent from the above description, according to the tractor / trailer brake control device of the present invention, once the calculated brake ratio is stored in the memory, the number of times of the brake operation is set in advance. Until the predetermined number of times is reached, the target brake ratio stored in the memory is not newly updated while being held.When the number of times of the brake operation reaches the predetermined number, the target brake ratio of the memory is calculated at this time. Since the brake ratio is updated, the influence of the calculation error of the brake ratio due to the measurement error or the calculation error of each value at the time of the brake control by the CFC can be eliminated, and the brake control by the CFC is more appropriately performed. be able to.

According to the second aspect of the present invention, when the condition of the trailer changes, even if the number of times of the brake operation is less than the predetermined number of times after the previous brake ratio is stored in the memory, the memory in the memory is stored in the memory. Target brake ratio is immediately updated to the brake ratio calculated when the condition of this trailer changes, so that each braking force of the tractor / trailer is set to an appropriate value according to the change in the condition of the trailer. be able to. Thus, even when the condition of the trailer greatly changes, the risk of the jackknife phenomenon and the risk of the trailer swing phenomenon can be reliably eliminated, and the brake control of the tractor / trailer can be performed more appropriately.

In particular, according to the third aspect of the present invention, a change in the condition of the trailer is determined by detecting a change in the mass of the trailer. According to the fifth aspect of the present invention, the change in the state of the trailer is determined by the trailer. Since the change is detected by detecting the change in the center of gravity, the change in the trailer situation is relatively remarkable, and the change in the mass of the trailer or the change in the position of the center of gravity of the trailer, which has a great effect on the brake control of the tractor / trailer, can be used. Thus, the tractor / trailer brake control can be performed more appropriately.

Further, according to the invention of claim 4, the mass of the trailer is calculated from the data of the tractor, and according to the invention of claim 6, the position of the center of gravity of the trailer is calculated from the data of the tractor. According to the method, the coupling force is calculated from the data of the tractor, so that it is not necessary to provide a sensor or a control device necessary for performing the brake control on a trailer that is less frequently used than the tractor. As a result, the cost can be reduced, the cost can be extremely advantageous, and the demand for market versatility can be sufficiently satisfied.

[Brief description of the drawings]

FIG. 1 is a tractor / trailer brake control device according to an embodiment of the present invention.
It is an air brake circuit diagram of the tractor side of a trailer air brake system.

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 another example of a coupling force estimation method.

FIG. 6 is a diagram showing still another example of the coupling force estimation method.

FIG. 7 is a diagram illustrating an example of a brake ratio estimating method.

FIG. 8 is a diagram showing another example of a brake ratio estimating method.

FIG. 9 is a diagram showing still another example of the brake ratio estimating method.

FIG. 10 is a diagram showing still another example of the brake ratio estimating method.

FIG. 11 is a diagram showing a relationship between a brake pressure and a brake ratio.

FIG. 12 is a diagram illustrating an example of an embodiment of a brake control device for a tractor / trailer according to the present invention.

FIG. 13 is a diagram showing an example of a flow for performing brake control using the brake control device of the example shown in FIG.

FIG. 14 is a diagram illustrating another example of the embodiment of the tractor / trailer brake control device according to the present invention.

15 is a diagram showing an example of a flow for performing brake control using the brake control device of the 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,
19: first electromagnetic proportional valve, 20: first switching valve, 21: first
Electromagnetic switching valve, 29: second electromagnetic proportional valve, 30: second electromagnetic switching valve, 34: second switching valve, 35: first pressure pickup, 38: electronic control unit (ECU), 41: air brake on trailer side System, 43, 44: Power chamber for left and right front wheels, 45, 46: Power chamber for left and right rear wheels, 47: Relay valve for trailer, 51: Air suspension pressure detecting means, 52: Wheel speed sensor, 53 Engine speed Detecting means, 54: governor angle detecting means, 55: tractor rear shaft load detecting means, 56: vehicle acceleration / deceleration calculating means, 57: driving force calculating means, 58: brake valve pressure determining means, 59: trailer mass calculating means, 60 ... Trailer mass change determination means, 61 ... Trailer center-of-gravity position calculation means,
62: Tractor front shaft load detecting means, 63: Coupling force calculating means, 64: Trailer shaft load calculating means, 6
5: Trailer brake force calculating means, 66: Tractor brake force calculating means, 67: Tractor front / rear shaft braking force calculating means, 68: Brake ratio calculating means, 69: Brake ratio memory changing means, 70: Trailer center of gravity position change Judgment means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Oe 1464-4, Moon Ring, Namerikawa-cho, Hiki-gun, Saitama Japan JC Truck Truck Brake Systems Co., Ltd.

Claims (7)

[Claims] 1. A brake control device for controlling respective brakes of a tractor and a trailer connected to each other via a coupler, wherein the brake of the trailer is controlled by an air pressure output from a brake valve provided on the tractor. The brake ratio is calculated using at least a coupling force applied by the trailer to the tractor via the coupler, and defined by dividing the braking force of the wheel by the axle weight of the axle of the wheel. A tractor / trailer brake control device that performs brake control so as to achieve a target brake ratio stored in the memory, wherein after the calculated brake ratio is stored in the memory as the target brake ratio, the number of times of brake operation is Until the predetermined number of times is reached, the target brake stored in the memory is reached. And a target brake ratio changing means for updating the target brake ratio of the memory to the brake ratio calculated at this time when the number of times of the brake operation reaches the predetermined number while maintaining the ratio. Tractor / trailer brake control device. 2. A trailer change judging means for detecting that the condition of the trailer connected to the tractor has changed significantly compared to the condition of the trailer connected so far, and outputting the detected result, 2. The tractor according to claim 1, wherein the target brake ratio in the memory is updated to the brake ratio calculated when output from the trailer change determining unit, also when the output is output from the trailer change determining unit. -Trailer brake control device. 3. The trailer mass change judging means, which outputs when the mass of the trailer changes by a predetermined value or more, is a trailer mass change judging means.
A tractor / trailer brake control device as described. 4. The tractor / trailer brake control device according to claim 3, further comprising at least a trailer mass calculating means for calculating the trailer mass from the tractor data. 5. A trailer center-of-gravity position change judging unit that outputs when the center of gravity of the trailer changes by a predetermined value or more.
Or a brake control device for a tractor / trailer according to 2 above. 6. The tractor / trailer brake control device according to claim 5, further comprising a trailer center-of-gravity position calculating means for calculating the trailer center-of-gravity position from the tractor data. 7. The tractor / trailer brake control device according to claim 1, further comprising a coupling force calculating means for calculating the coupling force from the data of the tractor.